DRAFT REPORT
IDENTIFICATION AND CONTROL
OF HYDROCARBON EMISSIONS
FROM RUBBER PROCESSING OPERATIONS
Contract No. 68-02-1411
Task 17
November 23, 1977
by
T. J. Hoogheem, C. T. Chi, G. M. Rinaldi,
R. J. McCormick, and T. W. Hughes
Monsanto Research Corporation
Dayton Laboratory
Dayton, Ohio 45407
Project Officer
Karl Zobel
Chemical and Petroleum Branch
Emission Standards and Engineering Division
Research Triangle Park, N. C. 27711
Prepared for
U. S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Washington, D. C. 20460
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DISCLAIMER
This report was furnished to the Environmental Protection Agency
by Monsanto Research Corporation, Dayton, Ohio, in fulfillment
of Contract No. 68-02-1411, Task 17. The contents of this re-
port are reproduced herein as received from the contractor. The
opinions, findings, and conclusions expressed are those of the
authors and not necessarily those of the Environmental Protection
Agency. Mention of company or product names is not to be con-
sidered as an endorsement by the Environmental Protection Agency-
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DRAFT REPORT
IDENTIFICATION AND CONTROL
OF HYDROCARBON EMISSIONS
FROM RUBBER PROCESSING OPERATIONS
by
T. J. Hoogheem
C. T. Chi
G. M. Rinaldi
R. J. McCormick
T. W. Hughes
Monsanto Research Corporation
Dayton Laboratory
Dayton, Ohio 45407
November 23, 1977
Contract No. 68-02-1411, Task 17
Project Officer
Karl Zobel
Chemical and Petroleum Branch
Emission Standards and Engineering Division
Research Triangle Park, N.C. 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Washington, DC 20460
-------
PREFACE
This work was conducted under contract with the Environ-
mental Protection Agency. The intent of this study was to
develop guidelines for the control of volatile organic com-
pounds from specific sources from the rubber products indus-
tries. The method employed was to seek actual operations
representing the best performance of existing emission control
technology and estimate the effectiveness of these systems.
The information was supplemented by a literature review, plant
visits and wide industrial experience.
111
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ABSTRACT
This report describes a study of nine standard industrial
classified segments of the rubber industry undertaken for the
purpose of identifying and quantifying their hydrocarbon emissions,
The nine segments of the rubber industry studied are:
SIC 2822 Synthetic Rubber
SIC 3011 Tires and Inner Tubes
SIC 3021 Rubber Footwear
SIC 3031 Reclaimed Rubber
SIC 3041 Rubber Hose and Belting
SIC 3069 Fabricated Rubber Goods, N.E.C.
SIC 3293 Seals, Gaskets, and Packing Devices
SIC 3357 Wiredrawing and Insulating
SIC 7534 Tire Retreading
In addition, control alternatives for hydrocarbon emission
reductions are given along with estimated costs of these
alternatives. A prioritization of the emission reduction
potential based on new source performance standards is also
given.
IV
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CONTENTS
Section Page
Preface iii
Abstract iv
Figures ix
Tables xi
1. Introduction 1
2. Industry Definition 3
2.1 Elastomer Industry 7
2.2 Fabricated Rubber Products 9
2.3 Air Emissions Inventory and Total U.S.
Hydrocarbon Burden 10
3. Synthetic Elastomers Industry 13
3.1 Synthetic Elastomers 13
3.1.1 Emulsion Polymerization 14
3.1.2 Solution Polymerization 25
4. Tires and Inner Tubes 34
4.1 Process Description 34
4.1.1 Compounding 35
4.1.2 Tread and Sidewall Forming 36
4.1.3 Tire Cord and Belt Forming 37
4.1.4 Tire Bead Manufacture 38
4.1.5 Inner Liner Production 39
4.1.6 Tire Building 39
4.1.7 Green Tire Spraying 39
4.1.8 Molding and Curing 40
4.1.9 Grinding and Buffing Operations 40
4.1.10 White Sidewall Painting 40
4.2 Inner Tube Manufacture 42
4.3 Emissions 43
4.3.1 Compounding (Banbury Mixing) 45
4.3.2 Milling 46
4.3.3 Fabric Cementing 47
4.3.4 Calendering 4 8
4.3.5 Extrusion 48
4.3.6 Undertread and Tread End Cementing 49
4.3.7 Green Tire Spraying 49
4.3.8 Curing 50
4.3.9 Fugitive Emissions 52
4.3.10 Solvent Storage 52
4.3.11 Tire Building 52
4.3.12 Other Emission Sources 53
5. Rubber Footwear 54
5.1 Process Description 54
5.2 Emissions 57
v
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CONTENTS (continued)
Section Page^
5.2.1 Compounding 57
5.2.2 Rubber Cementing 59
5.2.3 Latex Dipping and Drying 60
5.2.4 Curing 60
5.2.5 Molding 61
5.2.6 Milling and Calendering 62
6. Rubber Reclaiming 63
6.1 Process Description 63
6.1.1 Metal Removal, Size Reduction, and
Fiber Separation 64
6.1.2 Depolymerization 66
6.1.3 Mixing, Refining, Straining, and
Packaging VI
6.2 Emissions 72
6.2.1 Digestion 74
6.2.2 Drying 74
6.2.3 Milling 75
6.2.4 Fugitive 75
7. Rubber Hose and Belting 76
7.1 Process Description 76
7.1.1 Belting-Conveyor or Flat Type 76
7.1.2 Machine-Wrapped Ply Hose 78
7.1.3 Hand-Built Hose 82
7.1.4 Braided Hose 85
7.1.5 Spiralled Hose 88
7.2 Emissions 88
7.2.1 Compounding 88
7.2.2 Fabric Cementing 90
7.2.3 Hose Extrusion 90
7.2.4 Calendering 91
7.2.5 Rubber Cementing Operations 91
7.2.6 Curing 92
7.2.7 Milling 93
8. Fabricated Rubber Goods 94
8.1 Process Description 94
8.1.1 General Molded Products 94
8.1.2 General Extruded Products 94
8.1.3 Coated Materials 95
8.1.4 Latex-Based Dipped Goods 97
8.1.5 Cement-Based Dipped Goods 102
8.1.6 Rubber Goods from Porous Molds 103
8.1.7 Latex Thread 104
8.1.8 Latex Foam 104
VI
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CONTENTS (continued)
Section
8.2 Emissions
8.2.1 Compounding
8.2.2 Molding
8.2.3 Extrusion
8.2.4 Connection of Extruded Rubber Parts
8.2.5 Curing of Rubber Parts
8.2.6 Latex Dipping and Drying
8.2.7 Adhesive Spraying
8.2.8 Milling
8.2.9 Calendering
9. Gaskets, Packing and Sealing Devices
9.1 Process Description
9.1.1 Compression Molding
9.1.2 Transfer Molding
9.1.3 Injection Molding
9.2 Selected Plants
9.2.1 Plant A
9.2.2 Plant B
9.3 Emissions
9.3.1 Compounding
9.3.2 Molding
9.3.3 Adhesive Spraying
9.3.4 Milling
9.3.5 Calendering
10. Nonferrous Wiredrawing and Insulating
10.1 Process Description
10.2 Emissions
10.2.1 Compounding
10.2.2 Milling
10.2.3 Extrusion
10.2.4 Curing
11. Tire Retreading
11.1 Process Description
11.1.1 Receiving and Sorting
11.1.2 Buffing
11.1.3 Cleaning
11.1.4 Measuring
11.1.5 Rubber Cement Spraying
11.1.6 Tread Winding
11.1.7 Curing
11.1.8 Finish Buffing
11.2 Emissions
11.2.1 Rubber Cement Spraying
11.2.2 Curing
11.2.3 Paint and Trim Operations
106
106
108
108
108
109
109
109
109
109
110
110
110
113
113
114
114
115
116
118
118
118
118
118
119
119
120
120
123
123
123
124
124
124
125
125
125
125
125
126
126
126
128
128
128
VII
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CONTENTS (continued)
Section
12. Control Technology
12.1 Solvent and/or Monomer Storage
12.2 Polymerization or Reactor Section
12.3 Solvent Purification
12.4 Butadiene Recovery
12.5 Desolvent Area, Solution Polymerization
12.6 Dewatering and Drying
12.7 Compounding/Banbury Mixing
12.8 Milling
12.9 Extrusion
12.10 Press Curing
12.11 Calendering
12.12 Undertread and Treadend Cementing
12.13 Green Tire Spraying
12.14 Tire Building
12.15 Adhesive Spraying or Cementing
12.16 Molding
12.17 Batch Curing
12.18 Fabric Cementing
12.19 Latex Dipping and Drying
12.20 Continuous Curing (Rotocure)
12.21 Reclaimator Processes
12.22 Paint and Trim Activities
13. NSPS Prioritization
13.1 Introduction
13.2 Model IV
13.3 Input Variables
13.3.1 Industrial Factors
13.3.2 Emission Factors
13.4 Results of Prioritization
References
Appendices
A. Associations Concerned with The Rubber
Processing Industry
B. Partial Plant Listing by Standard Industrial
Classification Code
C. Inspection Manual for Hydrocarbon Emissions
from Rubber Processing
D. Partial Listing of Raw Materials Used in
The Rubber Industry
E. Model IV Computer Program
F. Calculation of Emission Factors for Rubber
Volatilization Emission Sources
G. Average Plant Size for Each Industry
H. Economic Assumptions in Cost Estimates
Page
130
130
132
133
133
137
139
145
153
158
159
161
162
164
169
169
173
174
175
178
181
183
185
186
186
187
191
191
197
211
214
223
229
299
391
397
402
407
409
Vlll
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LIST OF FIGURES
Number Page
3-1 Schematic flow diagram for crumb rubber
production by emulsion polymerization 18
3-2 Schematic flow diagram for latex rubber
production by emulsion polymerization 20
3-3 Schematic flow diagram for crumb rubber
production by solution polymerization 27
4-1 Tire flowsheet 41
6-1 Schematic flow diagram of digester process
for reclaiming rubber 68
6-2 Schematic flow diagram of pan process for
reclaiming rubber 70
6-3 Schematic flow diagram of mechanical process
for reclaiming rubber 73
7-1 Belting flowsheet 79
7-2 Ply hose flowsheet 83
7-3 Braided or spiralled hose flowsheet 87
8-1 Flow diagram for the production of typical
latex-based dipped items 99
8-2 Flow diagram for the production of typical
latex foam items 107
9-1 Schematic flow for manufacture of molded
rubber products 117
10-1 Schematic flow diagram for production of
insulated wire and cable using thermo-
setting polymers (i.e., butyl rubber,
neoprene, nitrile rubbers, silicone rubbers,
styrenebutadiene rubbers) 121
10-2 Schematic flow diagram for production of
insulated wire and cable using thermo-
plastic polymers (i.e., polysulfide rubbers) 122
11-1 Retreading flowsheet 127
13-1 Applicability of NSPS to construction and
modification 190
ix
-------
LIST OF FIGURES (continued)
Number Page
C-l Flow diagram for emulsion crumb rubber
production 302
C-2 Flow diagram for solution crumb rubber
production 303
C-3 Schematic diagram of tire manufacturing
process 315
C-4 Schematic flow diagram for the production
of typical canvas footwear items 318
C-5 Schematic flow diagram of digester process
for reclaiming rubber 327
C-6 Schematic flow diagram of pan process for
reclaiming rubber 328
C-7 Schematic flow diagram of mechanical process
for reclaiming rubber 331
C-8 Belting flowsheet 337
C-9 Ply hose flowsheet 342
C-10 Braided or spiralled hose flowsheet 347
C-ll Flow diagram for the production of typical
latex-based dipped items 354
C-12 Flow diagram for the production of typical
latex foam items 361
C-13 Schematic flow for manufacture of molded
rubber products 379
C-14 Schematic flow diagram for production of
insulated wire and cable using thermosetting
polymers (i.e., butyl rubber, neoprene,
nitrile rubbers, silicone rubbers, styrene-
butadiene rubbers) 372
C-15 Schematic flow diagram for production of
insulated wire and cable using thermoplastic
polymers (i.e., polysulfide rubbers) 379
x
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LIST OF TABLES
Number Page
1 Production of Synthetic Elastomers 8
2 U.S. Consumption of Natural and Synthetic
Rubber 11
3 Estimated Total Hydrocarbon Emissions from
The Rubber Industry 12
4 Emissions Summary of Synthetic Elastomers
Production 21
5 Volatile Organic Emissions from The Manufacture
of Tires and Inner Tubes 44
6 Volatile Organic Emissions from The Manufacture
of Rubber Footwear 58
7 Volatile Organic Emissions from Reclaiming
Operations 74
8 Volatile Organic Emissions from Rubber Hose
and Belting Production 89
9 Volatile Organic Emissions from The Production
of Fabricated Rubber Goods 108
10 Volatile Organic Emissions from The Production
of Rubber Gaskets, Packing, and Sealing Devices 116
11 Volatile Organic Emissions from Nonferrous
Wiredrawing and Insulating 123
12 Volatile Organic Emissions from Tire Retreading 126
13 Incineration Costs for A Typical Butadiene
Recovery Operation 136
14 Carbon Adsorption Costs for A Typical Buta-
diene Recovery Operation 137
15 Incineration Costs for A Typical Desolvent
Operation 140
16 Carbon Adsorption Costs for A Typical
Desolvent Operation 141
XI
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LIST OF TABLES (continued)
Number Page
17 Incineration Costs for A Typical Dewatering
and Drying Operation 146
18 Process Parameters for Banbury Mixers 148
19 Incineration Costs for A Typical Banbury Mixing
Operation in The Tire and Inner Tubes Industry 149
20 Incineration Costs for A Typical Banbury Mixing
Operation in A Rubber Footwear Operation 150
21 Incineration Costs for A Typical Banbury Mixing
Operation in The Rubber Hose and Belting
Industry 151
22 Incineration Costs for A Typical Banbury Mixing
Operation in The Fabricated Rubber Goods Industry
and The Gaskets, Packing, and Sealing Devices
Industry 152
23 Carbon Adsorption Costs for Banbury Mixing 153
24 Process Parameters for Milling Operations 156
25 Incineration Costs for Milling Operations 157
26 Incineration Costs for Typical Undertread
and Treadend Cementing 165
27 Carbon Adsorption Costs for Typical Undertread
and Treadend Cementing Igg
28 Carbon Adsorption Costs for Typical Green Tire
Spraying 167
29 Incineration Costs for Typical Green Tire
Spraying 168
30 Incineration Costs for A Typical Adhesive
Spraying Operation \_T2_
31 Carbon Adsorption Costs for A Typical Adhesive
Spraying Operation -, 7~
32 Incineration Costs for A Typical Batch Curing
Operation ,
J- /o
xxi
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LIST OF TABLES (continued)
Number Page
33 Incineration Costs for A Typical Fabric
Cementing Operation 179
34 Carbon Adsorption Costs for A Typical Fabric
Cementing Operation 180
35 Incineration Costs for A Typical Latex Dipping
and Drying Operation 182
36 Carbon Adsorption Costs for A Typical Latex
Dipping and Drying Operation 183
37 Costs of A Condenser-Scrubber System for A
Typical Reclaimator Process 184
38 Input Variables for Model IV Prioritization
of Rubber Products Industries 192
39 Factors for Derivation of E and E - Synthetic
Rubber n s 199
40 Factors for Derivation of E and E - Tires
and Inner Tubes n s 200
41 Factors for Derivation of E and E - Rubber
Footwear n 201
42 Factors for Derivation of E and E - Reclaimed
Rubber n S 202
43 Factors for Derivation of E and E - Hose and
Belting n S 203
44 Factors for Derivation of E and E - Fabricated
Rubber Products n S 204
45 Factors for Derivation of E and E - Gaskets,
Packing, and Sealing Devices1 s 205
46 Factors for Derivation of E and E - Nonferrous
Wiredrawing and Insulating 206
47 Factors for Derivation of E and E - Tire
Retreading n 207
48 No. of Plants per SIC Utilized in E Calculations 209
5
49 Input and Output Variables for Model IV Prior-
itization of Rubber Products Industries 212
xiii
-------
LIST OF TABLES (continued)
Number Page
B-l A Partial Geographic Distribution of Rubber
Products Plants 230
B-2 SIC 2822: Synthetic Rubber (Vulcanizable
Elastomers) 231
B-3 SIC 3011: Tires and Inner Tubes 235
B-4 SIC 3021: Rubber and Plastics Footwear 241
B-5 SIC 3031: Reclaimed Rubber 242
B-6 SIC 3041: Rubber and Plastics Hose and Belting 243
B-7 SIC 3069: Fabricated Rubber Products N.E.C. 248
B-8 SIC 3293: Gaskets, Pakcing and Sealing Devices 279
B-9 SIC 3357: Nonferrous Wiredrawing and Insulating 287
C-l Emissions and Control - Synthetic Rubber 307
C-2 Emissions and Control - Tires and Inner Tubes 316
C-3 Emissions and Control - Rubber Footwear 321
C-4 Emissions and Control - Reclaimed Rubber 332
C-5 Emissions and Control - Hose and Belting 348
C-6 Emissions and Control - Fabricated Rubber
Products 352
C-7 Emissions and Control - Gaskets, Packing, and
Sealing Devices ' 37-^
C-8 Emissions and Control - Nonferrous Wiredrawing
and Insulating 375
C-9 Emissions and Control - Tire Retreading 380
F-l Materials Emitted During Rubber Vulcanization 404
G-l Average Plant Size for Each Industry 408
H-l Typical Items Included in Investment Cost of
Add-On Control Systems 41
xiv
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LIST OF TABLES (continued)
Number Page
H-2 Typical Items Included in Annual Costs of
Add-On Control Systems 411
H-3 Assumptions Used in Developing Cost Estimates
for Catalytic and Noncatalytic Incinerators 412
H-4 Assumptions Used in Developing Cost Estimates
for Carbon Adsorbers 413
xv
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1. INTRODUCTION
This report describes a study that was undertaken on nine
standard industrial classified industries which collectively
make up the rubber industry- This study involved the identifi-
cation and evaluation of technology for the purpose of control-
ling hydrocarbons resulting from the production of synthetic
rubber and fabrication of rubber goods. The nine industries
are individually addressed in the form of 1) a general process
description with identification of specific emission points,
and 2) identification of both currently installed and industry
available hydrocarbon control technology. In addition, the
nine industries are prioritized on the basis of potential
emission reductions resulting from implementation of new
source performance standards. Appendices include a partial
plant listing for each standard industrial classification
(SIC), a raw materials listing, an inspection manual, a trade
association listing, a copy of the prioritization computer pro-
gram, a discussion on rubber volatile emission factor estimates
(«^**?«*«W'**^''^"^J'-^"V^ '"" " *" ' "" " ' 1'"'1 '~*'"*:'^'"--A^afssr^f*,. _ .(,:,^^S^h-'l^™J**^^'"'>'^''?'i!S!?^ "i"lKIC'J!"1"" ''1*
economic assumptions for cost calculations, and derivations of
average plant sizes.
-------
No hydrocarbon emission points were sampled under this
study- Emission factors are estimates based on a number of
information sources. Sixteen plant visits carried out during
the course of the study provided the largest source of informa-
tion. The visits confirmed a conclusion reached early in the
study; i.e., that very little quantitative emissions data for
hydrocarbons in the rubber industry exist. This fact is con-
firmed when one evaluates emissions data contained in the
National Emissions Data System (NEDS) for the rubber industry.
Most emission sources involving the working of rubber, where no
solvent is involved, have neither been verified nor quantified.
Thus, emission factors listed in this report are estimates based
on extremely limited source testing data, on-site plant visits,
limited data obtained from NEDS, information obtained from state
environmental agencies and trade associations, and contractor
files.
The reader is referred to Tables 39-47 (on pages 199-207)
for a summary of all emission points and factors for each SIC
and Table 49 (page 213) for a summary of the results of the
impact prioritization for the nine rubber industry SIC's.
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2. INDUSTRY DEFINITION
The rubber products industry is defined as those plants
which produce either synthetic rubber (vulcanizable elasto-
mers) or fabricated rubber products from natural and synthetic
rubber. Natural rubber production is not performed in the
United States and will not be covered in this study- The
U.S. Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census, has categorized indus-
trial activity in the United States. The categorization
developed for the various segments of the rubber industry is
used in this study. The Standard Industrial Classification
(SIC) code definition of each of the nine segments covered
is given below.
Synthetic Rubber (Vulcanizable Elastomers) (SIC 2822)
This industry comprises establishments primarily engaged in
the manufacture of synthetic rubber by polymerization or co-
polymerization. An elastomer, for the purpose of this classi-
fication, is a rubberlike material capable of vulcanization,
such as copolymers of butadiene and styrene or butadiene and
-------
acrylonitrile, polybutadienes, chloroprene rubbers, and
isobutylene-isoprene copolymers. Butadiene copolymers contain-
ing less than 50 percent butadiene are classified in industry
2821. Natural chlorinated rubbers and cyclized rubbers are
considered as semifinished products and are classified in
industry 3069. l
Tires and Inner Tubes (SIC 3011)
This industry includes establishments primarily engaged in
manufacturing pneumatic casings, inner tubes, and solid and
cushion tires for all types of vehicles, airplanes, farm
equipment, and children's vehicles; tiring; and camelback
and tire repair and retreading materials.2
Rubber and Plastics Footwear (SIC 3021)
This industry includes establishments primarily engaged in
manufacturing all rubber and plastics footwear, . . . having
rubber or plastic soles vulcanized to the uppers.3 (Processes
specific to the utilization of plastics within the rubber and
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Plastics Materials, Synthetic Rubber, and Man-Made
Fibers, SIC 2822. U.S. Department of Commerce, Social and
Economic Statistics Administration, Bureau of the Census.
Washington, B.C. November 1974. 6 p.
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Tire and Inner Tubes, SIC 3011. U.S. Department of
Commerce, Social and Economic Statistics Administration,
Bureau of the Census. Washington, D.C. March 1974. 7'p.
3Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Rubber and Plastics Footwear, SIC 3021. U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washinaton n c
March 1974. 7 p.
-------
plastics footwear industry were excluded from consideration
in this study.)
Reclaimed Rubber (SIC 3031)
This industry includes establishments primarily engaged in
reclaiming rubber from scrap rubber tires, tubes, and mis-
cellaneous waste rubber articles by processes which result in
devulcanized, depolymerized or regenerated replasticized pro-
ducts and sold for use as a raw material in the manufacture
of rubber goods with or without admixture with crude rubber
or synthetic rubber.4
Rubber and Plastics Hose and Belting (SIC 3041)
This industry includes establishments primarily engaged in
manufacturing rubber and plastics hose and belting, including
garden hose.5 (Processes specific to the utilization of plas-
tics within the rubber and plastics hose and belting industry
were excluded from consideration in this study.)
^Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Reclaimed Rubber, SIC 3031. U.S. Department of
Commerce, Social and Economic Statistics Administration,
Bureau of the Census. Washington, D.C. February 1974. 6 p.
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Rubber and Plastics Hose and Belting, SIC 3041.
U.S. Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
February 1974. 7 p.
-------
Fabricated Rubber Products N.E.C.a (SIC 3069)
This industry includes establishments primarily engaged in
manufacturing industrial and mechanical rubber goods, rubber-
ized fabrics and vulcanized rubber clothing, and miscellaneous
rubber specialities and sundries.6
Gaskets, Packing and Sealing Devices (SIC 3293)
This industry includes establishments primarily engaged in
manufacturing gaskets, gasketing materials, compression pack-
ing, molded packings, oil seals, and mechanical seals. In-
cluded are gaskets, packing and sealing devices made of
leather, rubber, metal, asbestos, and plastics.7
Nonferrous Wiredrawing and Insulating (SIC 3357)
This industry includes establishments primarily engaged in
drawing, drawing and insulating, and insulating wire and cable
of nonferrous metals from purchased wire bars, rods, or wire.8
N.E.C.: Not elsewhere classified.
6Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Fabricated Rubber Products, N.E.C., SIC 3069- U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 9 p.
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Gaskets, Packing, and Sealing Devices, SIC 3293.
U.S. Department of Commerce, Social and Economic Statistics
Adminxstration, Bureau of the Census. Washington, D C
March 1974. 6 p.
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Nonferrous Wiredrawing and Insulating, SIC 3357.
U.S. Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 15 p.
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Tire Retreading and Repair Shops (SIC 7534)
This industry includes establishments primarily engaged in
repairing and retreading automotive tires. Establishments
classified here may either retread customers' tires or retread
tires for sale or exchange to the user or the trade.9
2.1 ELASTOMER INDUSTRY
The elastomer industry produces high polymers with
special, unique properties. Elastomers are considered apart
from other polymeric materials because of these unusual pro-
perties and because they generally do not lend themselves to
plastics uses. By definition, the elastomer activities start
with a monomer, other active chemicals, or with natural elas-
tomeric polymers, and terminate with the formation of a
marketable, rubberlike material.
The major raw materials are active monomer, certain chem-
icals with active end groups, or natural elastomers which are
compounded or modified. Many of the same monomers are used
in the synthetic elastomer industry as are used in plastics
and fibers. Table 1 shows the 1973 production of synthetic
elastomers.10 Natural elastomers were not included because
they are not produced in the United States. Approximately
Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Tire Retreading and Repair Shops, SIC 7534. U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 6 p.
10Current Industry Reports. U.S. Department of Commerce,
Bureau of the Census. Washington, D.C. Series M30A. 1972
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Table 1. PRODUCTION OF SYNTHETIC ELASTOMERS10
Product type
Styrene-butadiene rubber
Butyl rubber
Neoprene
Nitrile rubber
Polybutadiene
Polyisoprene
Ethylene-propylene
Othersf
Totals
1973 Production,
106 kg
1,536.7
159.9
175b
84.3
336.9
118.7
119.9
84b
2,615.4
Percent o±
total
58.8
6.1
6.7
3.2
12.9
4.5
4.6
3.2
100.0
b
d
Includes polybutadiene-styrene-vinylpyridene and
emulsion polymerized polybutadiene.
Estimated value.
i
'Includes stereo butadiene elastomers (solution
polymerized). Excludes emulsion polymerized polybutadiene.
Includes stereo polyisoprene elastomers (solution
polymerized).
Q
Includes solution polymerized ethylene-propylene copolymers
(EPM) and ethylene-propylene terpolymers (EPDM).
Includes polyacrylate, polyalkylene sulfide, chloro-
sulfonated polyethylene, polyisobutylene, fluorocarbon
silicone, and polyurethane elastomers. Polyurethane
foam is excluded because it is a plastic material which
is considered in SIC 2821.
78 percent of the elastomers consumed in the U.S. were synthe-
tic; consumption of natural elastomers amounted to 22 percent.
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The chemical composition of an elastomer depends solely
on the monomers, active chemicals, or natural materials used.
The raw materials, or feedstocks, also determine the type and
properties of the product produced. The properties of the
products are, in turn, usually determined by their end use.
The structure, molecular weight, and various properties are
also determined by the polymerization process, as well as by
the catalysts, shortstops, antioxidants, and other ingredients
used.
2.2 FABRICATED RUBBER PRODUCTS
Consumption of new and reclaimed rubber by the industry
can be reported in three parts: 1) tires and tire products,
including pneumatic and solid tires, inner tubes, retread and
repair materials, flaps, and sundries; 2) other products, in-
cluding footwear, belts, hose, mechanical goods, foam sponge,
and sundries; and 3) wire and cable. This breakdown permits
observation of trends in total new rubber consumption. It
also illustrates the dominant position of tires and tire pro-
ducts which consistently use 62 percent to 66 percent of all
new rubber each year. Wire and cable use a small part of the
total which has remained constant in absolute terms but has
declined from three percent to one percent over the years from
1958 to 1972. The other products consume the remainder (about
-------
one-third) of total new rubber production in manufacturing a
great variety of items.11
The tires and inner tubes industry is thus the major industry
of this source, accounting for 66% of finished product weight
of the entire fabricated rubber products industry. The break-
down of consumption of natural and synthetic rubber by end use
as of 1971 is indicated in Table 2.12
2.3 AIR EMISSIONS INVENTORY AND TOTAL U.S. HYDROCARBON BURDEN
As of January 1977, total hydrocarbon emissions in the
United States, from stationary sources, are estimated to be
1.6 x 1010 kilograms/year.13
Total hydrocarbon emissions resulting from the production
activities carried out by the rubber industry (the nine SIC's
covered in this study) are estimated to be 1.38 x 108 kilograms/
year. This figure represents 0.86 percent of total hydrocarbon
emissions from stationary sources in the United States.
i:iPettigrew, R. F. , and F. H. Roninger. Rubber Reuse and
Solid Waste Management, Solid Waste Management in the
Fabricated Rubber Products Industry, 1968. U.S. Environ-
mental Protection Agency. Washington, D.C. Publication
SW-22C. 1971. 120 p.
12Richardson, J., and M. Herbert. Forecasting in the Rubber
Industry. (Presented at the Joint Meeting of the Chemical
Marketing Research Association and the Commercial Develop-
ment Association. New York. May 1974.)
13Eimutis, E. C., and R. P. Quill. State-by-State Listing of
Criteria Pollutant Emissions. U.S. Environmental Protection
Agency. Research Triangle Park, N.C. EPA-600/2-77-l07b.
July 1977. 146 p.
10
-------
Table 2. U.S. CONSUMPTION OF NATURAL AND
SYNTHETIC RUBBER, 197112
Rubber end use
Tires and related products
Molded goods
Automotive
Other
Foam rubber
Shoe products
Hose, tubing
Rubber footwear
0-rings, packing gaskets
Sponge rubber products
Solvent and latex cement
Belts and belting
Wire and cable
Coated fabrics
Floor and wall coverings
Pressure-sensitive tapes
Industrial rolls
Athletic goods
Military goods
Thread (bare)
Drugs and medical sundries
Toys and balloons
All other
Weight %
of total
66.0
4.6
5.2
3.2
1.9
1.9
1.6
1.5
1.4
1.3
1.1
1.1
1.1
0.8
0.5
0.5
0.5
0.5
0.5
0.4
0.4
4.0
Cumulative %
66.0
70.6
75.8
79.0
80.9
82.8
84.4
85.9
87.3
88.6
89.7
90.8
91.9
92.7
93.2
93.7
94.2
94.7
95.2
95.6
96.0
100.0
The quantity of emissions and percent contribution of
each SIC making up the rubber industry to this total are given
in Table 3. Tire and inner tube manufacture accounts for 62.74
percent of the total hydrocarbon emissions in the rubber indus-
try. Five of the nine SIC's covered - tires, rubber footwear,
fabricated rubber goods, synthetic rubber, and hose and
belting - account for 96.2 percent of the total. These esti-
mates are based on emission factors derived in the following
11
-------
industry descriptions and annual production figures described
in the new source performance standards (NSPS) prioritization
section.
Table 3. ESTIMATED TOTAL HYDROCARBON EMISSIONS
FROM THE RUBBER INDUSTRY
SIC
3011
3021
2822
3041
3069
7534
3031
3293
3357
Product
Tires and inner
tubes
Rubber footwear
Synthetic rubber
Hose and belting
Fabricated rubber
goods
Tire retread
Rubber reclaim
Seals, gaskets and
packing devices
Rubber-coated wire
Total hydrocarbon
emissions ,
10 kg/year
86,400
18,749
10,543
10,422
6,380
2", 94 3
1,266
995
33
Percent of
total industry
62.74
13.61
7.65
7.56
4.64
2.14
0.92
0.72
0.02
Cumulative
percent
62.7
76.35
84.00
91.56
96.2
98.34
99.26
99.98
100.0
12
-------
3. SYNTHETIC ELASTOMERS INDUSTRY
3.1 SYNTHETIC ELASTOMERS
For the purposes of this study, styrene butadiene rubber
(SBR) is the major synthetic rubber of concern since it ac-
counts for 58.8% of U.S. synthetic rubber production. Approxi-
mately 60 percent of the SBR produced is used directly in the
manufacture of tires. The other 40 percent is used mainly in
footwear, hose, belt, and fabricated goods manufacture. It
is estimated that more than 96 percent of all styrene butadiene
rubber produced in this country is consumed in the eight rubber
product SIC's covered in this report.12
Styrene butadiene rubber is produced by two different
processes. The first, emulsion polymerization, accounts for
90 percent of the total SBR production. Solution polymeriza-
tion, the newer of the two, accounts for the other 10 percent
of production.l^
^Development Document for Effluent Limitation Guidelines
and New Source Performance Standards for the Tire and Syn-
thetic Segment of the Rubber Processing Point Source Cate-
gory- U.S. Environmental Protection Agency. Washington,
D.C. EPA-440/l-74/013-a. February 1974. p. 31-35.
13
-------
3.1.1 Emulsion Polymerization
3.1.1.1 Process Description - Emulsion polymerization is
basically the bulk polymerization of monomer droplets suspended
in dilute aqueous solution and stabilized by an emulsifier. In
this process, the polymerization reaction is initiated by free
radicals generated in the water phase. After the emulsifier
forms spherical aggregate or molecules, monomer swells these
molecules, free radicals initiate polymerization, and a new
phase is formed, namely latex particles. Monomer droplets in
the aqueous phase decrease in number and completely disappear
at about 60 percent conversion.
The following synthetic rubbers are commercially produced
using emulsion polymerization: styrene butadiene rubbers
(SBR), acrylonitrile butadiene rubbers (NBR), neoprene, fluoro-
elastomers, and polyacrylates. More than 90 percent of SBR,
the major synthetic rubber, is produced by emulsion polymeri-
zation as either rubber latex or rubber crumb. Processing
techniques for each of these two types of emulsion produced
rubber are discussed below.
Crumb rubber - The materials flow for the continuous pro-
duction of crumb SBR by emulsion polymerization is presented
here as being essentially typical of all emulsion processes.
Some monomers have inhibitors added to prevent premature poly-
merization during shipment and storage. The inhibitor is
removed before polymerization by passing the monomer through
a caustic scrubber in which a 20 percent NaOH solution is
circulated.
14
-------
Soap solution, catalyst, activator, and modifier are
added to the mixture of monomers before polymerization. The
soap solution is used to emulsify the monomers in an aqueous
medium. The ingredients of this solution are generally a rosin
acid soap and a fatty acid soap. The catalyst, usually a hydro-
peroxide or a peroxysulfate, is a free-radical initiator. The
activator facilitates the generation of free radicals more
rapidly and at lower temperatures than thermal decomposition
alone. The modifier adjusts the chain length and molecular
weight distribution of the polymeric rubber during its formation.
Polymerization proceeds stepwise in a series of reactors.
The reactor train can produce either "cold" (4°C to 7°C,-
0 kPa to 200 kPa) or "hot" (50°C, 380 kPa to 520 kPa) SBR.
For "cold" polymerization, the monomer/additives emulsion is
cooled prior to reaction, generally using an ammonia or
methanol refrigerant cooling medium. Each reactor has its own
set of cooling coils (to remove the heat of reaction) and each
is agitated by a mixer. The residence time in each vessel is
approximately 1 hr. Conversion of monomer to rubber is
ordinarily carried out to 60 percent or less. The reaction
mixture is a milky white emulsion called latex.
Shortstop solution is added to the latex exiting the
reactors to terminate polymerization at the desired conversion.
Two common shortstops are sodium dimethyl dithiocarbamate
[(CH3)2NCSSNa] and hydroquinone (1,4-dihydroxybenzene). The
15
-------
"stopped" latex is held in blowdown tanks which serve as flow-
regulating holding tanks.
Economics of synthetic rubber production require recovery
and purification of unreacted monomers which may comprise 10
percent to 40 percent of the rubber latex solution. Butadiene
is first stripped from the latex in a vacuum flash tank at
about 20°C to 30°C. The butadiene vapors are compressed,
condensed, and recycled to the feed area for mixing with fresh
monomer. Excess styrene is steam distilled from the latex
under vacuum, condensed and recycled with fresh styrene.
An antioxidant is added to the stripped latex in a blend
tank to protect the polymer from oxidation. Different batches,
recipes or dilutions of the stabilized latex can now be mixed
in the blend tanks.
The latex is transferred from the blend tank to the
coagulator where dilute sulfuric acid (pH 4.0 to 4.5) and
sodium chloride solution are added. This acid-brine mixture,
called the "coagulation liquor," causes the rubber to precipi-
tate out of the latex. Carbon black and/or extender oils can
be added to the rubber latex during coagulation - carbon black
in an aqueous slurry (^5 weight percent) and oil in an aqueous
emulsion.
The precipitated crumb is separated from the coagulation
liquor on a shaker screen. The screened crumb is washed with
water in a reslurry tank to remove extraneous compounds, par-
ticularly residual coagulation liquor. The crumb rubber slurry
16
-------
is next dewatered using vacuum filtration. Coagulation liquor
blowdown and crumb slurry water overflows are usually passed
through separators called crumb pits to trap the floatable
crumb rubber.
The rinsed, filtered rubber solids are finally dried
with hot air (50°C to 120°C) in a continuous belt or screen
dryer. After drying, the rubber is weighed and pressed into
bales. Normally, bales of synthetic rubber weigh 34 kg and
are wrapped in polyethylene film.15"19
A schematic flow diagram for crumb rubber production is
shown in Figure 3-1.
Latex rubber - Latex rubber production includes the same
processing steps as emulsion crumb production with the exception
of latex coagulation and crumb rinsing, drying and baling.
15Morton, M. Rubber Technology, Second Edition. New York,
Van Nostrand Reinhold Company, 1973. p. 228, 231, 251, 280.
16Horn, D. A., D. R. Tierney, and T. W. Hughes. Source
Assessment: Polychloroprene, State of the Art. EPA Contract
68-02-1874, U.S. Environmental Protection Agency, RTP, N.C.
September 1977. 95 p.
17Elastomer Industry—Industrial Catalog Report. Monsanto
Research Corporation, Dayton, Ohio, EPA Contract 68-02-1320,
Task 17. Unpublished. 42 p.
18Hughes, T. W., T. E. Ctvrtnicek, D. A. Horn, and R. W. Serth.
Source Assessment Document No. 24, Rubber Processing.
Monsanto Research Corporation, Dayton, Ohio, EPA Contract
68-02-1874. Preliminary document submitted to the Environ-
mental Protection Agency for review and comments, August 1975,
152 p.
19Materials and Compounding Ingredients for Rubber and Plas-
tics. Compiled by the Editors of Rubber World. Louisville,
Publishers Printing Co., 1965. 720 p.
17
-------
00
PRODUCT
SHIPMENTS
^VOLATILE ORGANICS
Figure 3-1.
Schematic flow diagram for crumb rubber production
by emulsion polymerization.
-------
Monomer inhibitors are removed by scrubbing with caustic
soda. Soap solution, catalysts and modifiers are added to the
monomer(s) prior to feeding the reactors. The number of reac-
tors used is generally less than that used for emulsion crumb
production. Most latexes are made by the "cold" process with
the polymerization temperature kept at about 4°C to 7°C. After
polymerization, the latex is sent to a blowdown tank for holding,
At this point stabilizers are added.
Latex passes from the storage tanks to a vacuum distilla-
tion column for removal of unreacted butadiene. The unrecovered
butadiene may then be vented to the atmosphere. Excess styrene
is separated from the latex in a steam stripper, condensed,
containerized and sent to disposal.
The stripped latex is passed through a series of screen
filters to remove undesirable large solids. The latex is then
stored in blending tanks for mixing with other ingredients of
the final product such as antioxidants.15~19
A schematic flow diagram for latex rubber production is
presented in Figure 3-2.
3.1.1.2 Emissions - Table 4 is a summary of emissions from
synthetic elastomer production. The emission factors presented
are estimated using data provided during plant visits. The
sources of hydrocarbon emissions in the emulsion polymerization
process can be identified by the general areas within the pro-
cess in which they originate. These areas are 1) the tank farm
pr monomer storage area, 2) the polymerization or reactor area,
19
-------
VACUUM SOURCE
(STEAM JET OR
VACUUM PUMP )
WITHOUT CONDENSER
EJECTOR
( STEAM JET OR
VACUUM PUMP )
WITH CONDENSER
MONOMER AND
STEAM CONDENSATE
UNIHIBITED
LATEX BLENDING
AND BULK
STORAGE
ro
o
LIQUID
WASTE
PRODUCT
SHIPMENTS
VOLATILE ORGANICS
Figure 3-2
Schematic flow diagram for latex rubber production
by emulsion polymerization.
-------
Table 4. EMISSIONS SUMMARY OF SYNTHETIC ELASTOMERS PRODUCTION
Source
Emulsion (90% of tota.1 production)
Styrene storage (breathing)
Solvent storage (fugitive)
Reactor section (fugitive)
Recovery area (fugitive)
Butadiene recovery
Coagulation, dewatering, drying
Solution (10% of total production)
Styrene storage (breathing)
Hexane storage (breathing)
Storage (fugitive)
Purification area (fugitive)
Reactor area (fugitive)
Desolventization (vent)
Desolventization (fugitive)
Dewatering, drying
Emission factor,
g/kg of
rubber produced
0.02
0.07
0.4
0.1
0.6
0.6
0.02
0.5
0.07
0.2
0.61
2.7
0.2
20.2
Percent total
emissions
0.4
1.5
8.9
2.3
13.3
13.3
0.05
1.2
0.25
0.6
1.6
6.6
0.6
49.4
21
-------
3) the monomer recovery area and 4) the dewatering and drying
(finishing) area.
In the tank farm area, the raw monomers, reactor coolants,
antioxidants, extender oils, and miscellaneous plant fuels are
stored. For SBR emulsion polymerization, the monomers are
styrene and butadiene. A representative plant can be expected
to have upwards of 80 tanks in the tank farm ranging in size
from 3.0 x 103 liters to 2.3 x 106 liters. In the case of
styrene storage, the tank sizes range from 7.75 x 105 liters
to 2.3 x 106 liters. These tanks are vented to the atmosphere
to allow for breathing losses in the tanks themselves. For a
2.3 x 106 liter tank, such breathing losses amount to approxi-
mately 20 kilograms per day. Using this emission rate, and a
representative plant's yearly production rate of SBR via emul-
sion polymerization the resultant emission factor is 0.02 grams
per kilogram of synthetic rubber produced.
The storage of butadiene is carried out in pressurized
vessels or in vessels located underground or as was the case
at one visited plant, underwater. Only in the instances where
these vessels are located above ground does the potential for
emission of butadiene exist, such as through pressure relief
valves. Because of the extreme volatility of this monomer,
control technology is currently employed to control these emis-
sions by means of connecting the valves to an emergency flare
system. From the on-site visits, the feeling is that no emis-
sions from the storage of butadiene, itself, exist.
22
-------
As mentioned in addition to the storage of the two basic
monomers, a variety of extender oils, antioxidants, recylced
monomers, and fuels are stored in the tank farm area. Due to
the low volatility of the stored oils, the emission of hydro-
carbons via atmospheric vents is calculated collectively as
less than 0.02 grams per kilogram of SBR produced.
Fugitive emissions from the tank farm area result from
leaks in compressor seals, pump seals, and pipeline valves.
Collectively, fugitive emissions at a representative plant's
tank farm can be estimated to be about 40 kilograms per day.
Again using a representative plant's annual production figures,
the emission factor is 0.07 grams/kilogram of synthetic rubber
produced.
The polymerization area contains the pressurized reaction
vessels. Therefore, no atmospheric losses from the reactors,
themselves, such as through vents are present. However, fugi-
tive losses through primarily leaks in pipeline valves and
seals do exist. At a representative plant, these emissions
can be calculated to be about 95 kilograms per day. Based on
more representative data collected by Houdry20 in a survey of
the industry as a whole, the emission factor for this area is
estimated at 0.40 grams per kilogram of synthetic rubber
produced.
In emulsion polymerization, unreacted styrene and butadi-
ene are recovered, separated, and recycled in the recovery area.
20Pervier, J. S., et al., Survey Reports on Atmospheric Emis-
sions from the Petrochemical Industry, Vols 1-3, EPA 450/3-
730-005-a-c, Office and Air. Quality Planning and Standards,
RPT, N.C., April 1974.
23
-------
Steam stripping is utilized to recover styrene and vacuum dis-
tillation to recover butadiene. In the case of styrene, the
stripper, condenser system is entirely closed and any emissions
can be considered as fugitive in nature. In a representative
plant these emissions can be calculated to be about 45 kilograms
per day. Again utilizing this plant's annual production, the
emission factor can be calculated to be 0.1 grams per kilogram
of rubber produced. After butadiene recovery, the remaining
butadiene is~ sent to an absorber after distillation. In some
plants, less than 1% of the unrecovered butadiene is treated
in an absorber system, which functions only to 1) rid the sys-
tem of excess noncondensibles (air, oxygen, etc.) which may
enter the system during vacuum flashing, gas compression, etc.;
and 2) recover the butadiene present in these gases before
release to the atmosphere or flash system. The absorber, because
it is less than 100 percent efficient releases quantities of
butadiene to the atmosphere. Information obtained from state
permit applications for an assumed representative plant yielded
the following: For a gas flow to the absorber of 80 cubic feet
per minute, 55 percent of the gas by volume can be expected to
be butadiene. This results in a daily flow of 12,500 pounds
(5675 kilograms) of butadiene to the absorber. Assuming that a
normally operating absorber is approximately 97 percent efficient,
over 375 pounds (170 kilograms) of butadiene would be released
to the atmosphere. Assuming that these conditions are repre-
sentative and that the absorber is part of the emulsion process,
24
-------
itself, and not a pollution control process, the emission
factor for this point can be calculated to be 0.6 grams per
kilogram of rubber produced.
The finishing area contains the operations of coagulation,
dewatering, and drying. In the case of latex production which
represents approximately 10 percent of all SBR via emulsion pro-
duction,14 these operations are not necessary. The coagulation
process is carried out in open vessels with an unreacted and
unrecovered monomers (<0.2%) in the emulsion free to evaporate
to the atmosphere. Dewatering is carried out on drum filters
which are also open to the atmosphere. The drying operation is
accomplished in enclosed dryers which are vented to the plant
exterior. These dryers may have many of these such vents (as
many as fifty). For a representative plant, the dryer can be
expected to contain 40 such vents with an equivalent height of
39 feet and equivalent diameter of 15 feet. For an exiting ex-
haust gas flow rate of 127.4 m3/sec (270,000 SCFM) with a tem-
perature of 49°C (120°F), the styrene concentration can be
expected to be approximately 5 ppm. The resultant emission rate
is approximately 500 pounds (227 kilograms) per day. Utilizing
these conditions and assuming 90 percent of the SBR production
via emulsion is crumb, the resultant emission factor is calcu-
lated to be 0.6 grams per kilogram of rubber produced.
3.1.2 Solution Polymerization
3.1.2.1 Process Description - Solution polymerization is the
newer process for the production of synthetic crumb rubber in
25
-------
the United States. Solution polymerization systems permit the
use of stereospecific Ziegler-Natta or alkyllithium catalysts
which allow polymerization of monomers, such as isoprene or buta-
diene, in an appropriate organic solvent so as to obtain the
cis structure characteristic of the natural rubber molecule.
In addition to the stereoelastomers, polybutadiene and
polyisoprene, solution polymerization or a variation thereof
is used frequently to produce butyl rubber, solution styrene-
butadiene rubber, ethylene-propylene rubbers (EPDM), silicone
rubbers, polyurethanes, fluoroelastomers, and epichlorohydrin-
based elastomers. Solution polymerization can be used to
prepare homo-, co-, and terpolymers.
Figure 3-3 is a material flow diagram for the production
of crumb SBR by a solution polymerization system whose process-
ing steps are essentially typical of all such systems.
Monomers as received, containing inhibitors, are first
stripped of these compounds by passage through a caustic soda
(NaOH) scrubber. The monomers are then dried, i.e., freed of
extraneous water, using either fractionating towers or molecular
sieves. Drying is crucial since ionic solution polymerizations
using Ziegler-Natta coordination catalysts are extremely
sensitive to polar compounds, such as water, oxygen, and
certain oxygenated organic species. A few ppm of water is a
necessary and controllable maximum in any of the feed streams
to the polymerization reactor. Similarly, active hydrogen
compounds and certain hydrocarbons (acetylenes, cyclopenta-
diene, cyclopentene) must be excluded.
26
-------
RECYCLE SOLVENT
HEAVY SLOPS
TO INCINERATOR
SHORTSTOP
POLYMER-
IZATION
REACTORS
RUBBER
CEMENT_
CATALYST
RESIDUE
REMOVAL
BOTTOM
DECANT LAYER
STEAM,
SOLVENT AND
MONOMER VAPORS
T
PRODUCT
SHIPMENTS
* VOLATILE ORGANICS
COAGULATION
AND STEAM
STRIPPING
NOTE: EXTENDER OIL AND
CARBON BLACK ARE
NOT ADDED TO
NONEXTENDED RUBBER
TYPES
Figure 3-3.
Schematic flow diagram for crumb rubber production
by solution polymerization.
-------
The purified solvent and monomers are next blended to
form the "mixed feed." This mixture can be further dried to
remove any remaining traces of water using a desiccant column.
The dried mixed feed of solvent plus monomers is now
ready for polymerization, and catalysts can be added to the
mixed feed just prior to polymerization, or they can be fed
directly to the reactor. In some cases, catalyst solutions
may be premixed with a portion of the monomers under vigorous
agitation to enhance activity and to ensure uniform distribution
in the reactor.
The blend of solvent, monomer, and catalyst is polymerized
in a series of vessels. The exothermic heat of reaction is
continuously removed through the use of chilled reactor jackets
or internal cooling coils, the latter employing an ammonia
refrigerant, chilled brine, or glycol solutions. Temperature
control is important to ensure the desired average molecular
weight and distribution. The following three temperatures
represent the only such parameters found in the literature on
solution polymerization.
Rubber
EPDM
Polyisoprene
Butyl
Catalyst
Ziegler type
Ziegler type
Aluminum chloride
Solvent
Hexane
Unknown
Methyl chloride
Polymerization
temperature
'v38°C
%49°C
^96°C
At a rubber solids concentration of 8 percent to 10 per-
cent, the solution viscosity is at a level beyond which further
I
conversion of monomer to polymer is inadvisable. Thus, the
28
-------
mixture exits the reactor train in the form of a rubber cement.
Polymerization is halted by adding to this a shortstop solution.
In this case, a small quantity of a polar material such as
t
water destroys the catalyst. The stabilized cement is pumped
to storage tanks prior to further processing.
Excess residues of coordination catalysts are detrimental
to the aging stability of polymeric rubbers. Therefore, the
undesirable residues are removed as soluble salts in a washing
and decanting operation, sometimes using an alcohol or an
alcohol/water solution.
At this point, other chemicals and ingredients are added.
An antioxidant is added to the viscous rubber solution to pre-
vent deterioration of the polymer. A metered flow of a suitable
oil is also added here if the product is to be "oil-extended."
The oil is usually blended with the cement at some point
between the storage tanks and the steam-stripping operation.
Oil-extending serves to reduce the melt viscosity of the rubber
to that required for compounding in subsequent applications.
Inert fillers, such as clay, whiting, or barytes, are
sometimes added to certain solution-polymerized rubbers to
facilitate handling the rubber mixture. In these cases, re-
inforcing fillers such as carbon black are added, in a process
known as "masterbatching," to improve unsatisfactory properties
of the rubber. Oil-extending and masterbatching are used with
solution styrene butadiene rubber, neoprene, stereoelastomers,
and fluoroelastomers.
29
-------
The rubber cement is pumped from storage to the coagulator
where rubber is precipitated in crumb form with hot water under
violent agitation. Surfactants may be added to control crumb
size and to prevent reagglomeration. In addition to coagula-
tion, this operation accomplishes partial vaporization of
the solvent and the unreacted monomer; these vapors pass
overhead.
In the area collectively known as the desolvent (solvent
recovery) area, the resultant crumb slurry passes to steam
strippers to drive off the remaining solvent and monomer. The
equipment generally consists of either a flash tank or an
agitated kettle stripper. Steam, solvent, and monomer vapors
pass overhead to a condenser and decanter for recovery- The
bottom decant layer, saturated in solvent and monomer, is
discharged. The organicxlayer is sent to a multistage frac-
tionator. Light fractions are removed in the first column and
generally consist of unreacted light monomer (e.g., butadiene).
This is usually reclaimed at the monomer supply plant. The
second column produces purified solvent, a heavy monomer-water
fraction, and other heavy components.
The heavy monomer (e.g., styrene) is condensed, decanted,
and recycled. The bottom water layer is discharged. The puri-
fied solvent is dried before reuse. The extraneous heavy com-
ponents stream is waste which can be either decanted before
disposal or incinerated as a slop oil.
30
-------
The stripped rubber crumb slurry is separated and washed
with water on vibrating screens. Part of the slurry rinse
water is recycled to the coagulator with water or steam makeup.
The remaining portion is discharged as overflow. The screened
rubber is passed through an extruder-dryer for further dewatering
and drying. As the rubber is extruded through a perforated
die plate, the mechanical action of the screw heats the material
in the barrel to about 143°C. Dewatering and drying can also
be accomplished using a rotary filter and a hot-air oven dryer.
The dried rubber, usually in the form of pellets, is pressed
into 34-kg bales and usually wrapped in polyethylene for
storage and shipment. 11+~ T 9
3.1.2.2 Emissions - The sources of emissions in the solution
polymerization process can also be identified by the area in
which they occur. These areas are 1) the tank farm or monomer
and solvent storage area, 2) the solvent purification area,
3) the polymerization or reactor area, 4) the desolvent area
and 5) the finishing area.
In the tank farm area, emissions are as they were de-
scribed for emulsion with the addition of emissions resulting
from the storage of the solvent, in almost all cases, hexane.
A representative plant can have hexane storage facilities rang-
ing in size from 1.1 x 105 to 2.3 x 105 liters. These tanks are
vented to the atmosphere, and thus can be expected to have
emissions due to breathing losses. Plants have measured such
losses and found the vent gas to contain over 50 percent by
31
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volume of hexane. The daily mass emission rate has been deter-
mined to be about 500 Ibs (227 kilograms) per day. Utilizing
these data and an assumed representative plant's annual produc-
tion via solution polymerization, the calculated emission factor
for hexane storage breathing losses is 0.5 grams per kilogram
of rubber produced. The emission factor for styrene storage is
the same as for the emulsion process, 0.02 grams per kilogram.
Fugitive emissions are also the same as in the case of the
emulsion tank farm area, 0.07 grams per kilogram.
In the purification area (solvent and monomer separation),
emissions are present due to leaks in pipeline valves, pump
seals, and compressor seals. Plants have measured such emis-
sions at rates of approximately 200 Ibs (91 kilograms) per day.
Utilizing this figure and an assumed representative plant's
annual production, an emission factor for fugitive emissions
from the purification area can be calculated to be 0.2 grams
per kilogram of rubber.
The reactor area emissions result from strainer changes,
anti-oxidant makeup, etc., and are fugitive in nature. The emis-
sion factor is calculated to be 0.61 grams/kilogram of product.
The desolvent area (solvent recovery) has emissions pri-
marily of hexane resulting from unreacted and unrecovered
hexane, styrene, and butadiene evolving off the crumb rubber
solution. This coagulated solution is held in surge tanks
which are vented to the plant exterior. A representative plant
can be expected to have four such vents with an equivalent gas
32
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flow of 5.7 m3/sec (12,000 SCFM) at a temperature of 69°C
(157°F). The composition of the gas can be expected to contain
greater than 550 ppm by volume of the two monomers and the sol-
vent. The mass emission rate will be 2600 Ibs (1180 kilograms)
per day. Using these data and an assumed representative plant's
annual solution production, an emission factor is calculated
to be 2.7 grams per kilogram of rubber producted. In addition,
fugitive losses in this area can be expected to result in an
emission factor of 0.2 grams per kilogram.
The finishing area has emissions due to the operation of
drying of the crumb. This is the major source of emissions
in synthetic rubber production. The crumb, itself, has been
found to retain substantial quantities of hexane, even after
steam stripping and dewatering. Thus, because hexane is still
held tightly within the crumb as it enters the dryer, emissions
from the dryer, itself, are large in magnitude. The dryers
themselves are oven enclosures with a series of vents or stacks
leading to the plant exterior. An average plant can have over
35 such stacks approximately 15.2 meters (50 feet) tall leading
from the dryers. The equivalent flow rate of the exiting gases
can be expected to be 76.0 m3/s (160,000 SCFM) at a temperature
of 52°C (126°F). The exhaust gas will contain approximately
300 ppm of hexane, styrene, butadiene, and extender oil. Uti-
lizing these conditions, the mass emission rate will be 16,300
Ibs (7400 kilograms) per day. The resultant emission factor is
20.2 grams per kilogram of rubber produced.
33
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4. TIRES AND INNER TUBES
4.1 PROCESS DESCRIPTION
Tires consist of five basic parts: the tread, sidewall,
cord, bead, and inner liner. For economic reasons, passenger-
car tire tread is made from a combination of SBR and 25% to 35%
polybutadiene. 21 However, natural rubber is still used in the
production of larger tires and steel-belted tires.
Polyisoprene and EPDM are also used in appreciable quanti-
ties by tire manufacturers. EPDM is used in the cover strip
and white sidewall portion of the tire.
In the compounding operation, the raw crumb rubber is mixed
with a variety of fillers, extenders, curing agents, accelera-
tors, and antioxidants. A typical compound might contain:22
• 100 parts rubber
• 50 parts fillers and extenders
• 3.5 parts curing and accelerating agents
• 8.0 parts antioxidants and other ingredients
21Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Vol. 17. New York, John Wiley & Sons, Inc., 1968
p. 509-540.
22Shreve, R. N. Chemical Process Industries, Third Edition.
New York, McGraw-Hill, Inc., 1967. 905 p.
34
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Carbon black and oil are by far the most common fillers
and extenders. Sulfur, zinc oxide, and any of several sulfon-
amide accelerators comprise the most popular curing combination.
The basic compounding recipes for each type of rubber are
similar, but natural rubber requires different carbon black
loadings, less softener, more sulfur, and more accelerator.
In addition to these rubber stock precursors, large quan-
tities of rayon, nylon, and polyester cord are consumed in
tire cord and belt manufacture. Sizable amounts of steel wire
are used in the production of tire beads, and smaller quantities
of steel and fiberglass fabric are used in radial tire pro-
duction.
4.1.1 Compounding
Compounding and mixing operations are carried out in
Banbury mixers, T-mix extruders, and roller mills. The Banbury
mixer is a batch-type, internal mixer used to mix fillers,
extenders, reinforcers, pigments, and antioxidants into the raw
rubber to form a nonreactive stock. These ingredients must be
added in a certain order because some mix better with rubber
than others. The usual order of mixing is: (1) accelerators,
(2) reinforcers, (3) antioxidants, and (4) fillers. Banbury
mixers are not suitable for the addition of sulfur or other
curing agents because their high operating temperatures cause
premature vulcanization.
After mixing, the nonreactive compound is discharged by
gravity from the Banbury to a battery of roll mills. Here,
35
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the curing agents plus small quantities of the other ingredi-
ents are added and mixed in to form the reactive stock. This
compound is sheeted out for immediate use.
Alternatively, the discharge from the Banbury may be
pelletized and stored. This allows automatic weighing and mix-
ing in the preparation of reactive stock at some later time.
Once sheeted out, the rubber stock is tacky and must be
coated with anti-tack solution or powder prior to storage.
These materials effectively prevent sticking once the rubber
has been processed.
4.1.2 Tread and Sidewall Forming
Rubber stock from the compounding section is fed manually
to a warmup roller mill where it is heated and further mixed.
The heat is provided by the conversion of mechanical energy,
and temperature control is provided by cooling water in the
rolls. From the warmup mill, the heated stock goes to a strip-
feed mill for final mixing. This mill is also cooled to control
the temperature of the stock. The rubber is peeled off the
front roller of the mill in a thin strip and fed continuously
to a single head dual extruder.
At the extruder, two types of rubber stocks from two dif-
ferent strip mills are joined together at the head to form the
tread and two black sidewalls. This tread-sidewall combination
trimmed to the proper width leaves the extruder as a continuous
strip while still hot and tacky.
After extrusion, a cushioning layer is attached to the
underside of the tread. The tread-sidewall ribbon is then
36
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labelled, cemented and cut to the proper length. The trimmings
are manually or automatically transferred back to the proper
strip-feed mill and reprocessed. The finished tread is then
sent to the building area.
4.1.3 Tire Cord and Belt Forming
Tire cords and belts are constructed from woven synthetic
fabrics such as rayon, nylon, and polyester. Upon arrival
from the textile mill, the fabric is unrolled and spliced onto
the tail of the previous roll. Splicing is done adhesively, or
is carried out by high-speed sewing machines. This continuous
sheet of fabric is then fed under controlled tension to a latex
dip or cement dip tank.
After dipping, the fabric is fed past a series of vacuum
suction lines or rotating beater bars to remove excess dip.
Still under tension, the fabric rises through a drying and
baking oven to remove all but the last traces of solvent.
At the present time, more and more latex dip operations
are being transferred from the individual tire plant to textile
mills. The reasons for this trend are:
• Small operations require large capital expenditures.
• Latex dipping's fast operation oversupplies the plant.
• Shipping costs for dipped and undipped fabric are the same.
• One facility handles maintenance and housekeeping problems,
SSteel wire and fiberglass are also used in radial tires
37
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Plants which specialize in tire cord and belt pretreat-
ment are classified under SIC 2296, Tire Cord and Fabric, and
were not considered in this study.
After pretreatment, the fabric is passed through a fric-
tion calendering machine where it is impregnated with rubber.
Both sides of the cord plies are coated at once on the four-
roll calenders most commonly used. Three-roll calenders can
only coat one side of the fabric at a time, increasing the
time requirement for the frictioning operation.
When the calendering operations are completed, the rubber-
ized fabric is cooled by large water- or refrigerant-cooled
drums and the tension is released. The fabric is then rolled,
in a liner and transferred to another area, or cut.
The rubber stock used in the frictioning operation is
worked up on a series of warmup mills and strip-feed mills
in the same manner as the tread and sidewall stocks.
4.1.4 Tire Bead Manufacture
The tire beads are formed by extruding rubber onto a
series of copper-plated steel wires, which are subsequently
wrapped and cut. Actually, several strands of rubber-covered
wire are passed through the die of the extruder simultaneously,
then rolled together to make a bead.
The bead is wrapped with a rubberized, square-woven fabric,
then rewrapped. The edges of this second layer of wrapping
extend upward into the sidewall where they are anchored once
the tire is built.
38
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The rubber stock used to coat the wires is worked up in
the same manner as the tread, sidewall, and frictioning stocks.
4.1.5 Inner Liner Production
The inner liner is formed by calendering or extruding
rubber stock in a manner similar to the tread forming or fabric
frictioning operations. The rubber compound used in this process
is worked up in the manner previously described.
4.1.6 Tire Building
Each tire is built up as a cylinder on a collapsible,
round, rotating drum slightly larger than the tire itself.3
First, the inner liner is applied to the drum, followed by the
layers of cord. One layer of cord ties the beads together in
one direction, the next layer on the other direction. The beads
are attached to the tire by folding over the ends of the cord
fabric, and the belt fabric is laid onto the cord. The tread
is then placed over the cord and belt and wrapped around the
beads. The drum is collapsed, and the green tire is removed.
Rubber cement is used in most tire building operations to tack-
ify the various tire components before assembly.
4.1.7 Green Tire Spraying
Before molding and curing, the green tire is sprayed with
release agents both inside and out. These release agents help
to remove air from the tire during molding and to prevent the
tire from sticking to the mold after curing. Both water- and
solvent-based sprays are used.
Radial tires are built in the doughnut shape of the final
product.
39
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4.1.8 Molding and Curing
Passenger tires are molded and cured in an automatic press,
An inflatable rubber bladder bag is inflated inside the tire,
causing it to take its characteristic shape. As the bladder
inflates, the mold is closed over the shaped tire. Steam heat
is applied through the mold on the outside of the tire and
through the bladder bag on the inside of the tire. After a
timed, temperature-controlled cure, the bladder is deflated by
a vacuum, and the tire is removed. Vulcanization usually takes
20 to 60 minutes at 100°C to 200°C.18 During curing, the excess
rubber and trapped air escape through vent holes in the mold.
Following its removal from the mold, the tire is inflated
with air, and left to cool in the atmosphere.
4.1.9 Grinding and Buffing Operations
After a tire is cooled, the excess rubber which escaped
through the weepholes is ground off. If the tire is to be a
whitewall, additional grinding is performed to remove the black
protective strip. Final buffing and grinding is then done to
balance the tire for good highway performance.
4.1.10 White Sidewall Painting
This is the final operation prior to inspection and ship-
ping. It is usually carried out in spray booths using water-
based paints.
A flow schematic is shown in Figure 4-1.
Radial tires are sometimes cured with hot water rather than
steam.
40
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RUBBER
SPLICING
*v 1
LATEX
DIPPING
1
EX CESS DIP
REMOVAL
^ 1
DRYING
L.
k ADDITIVES
t
>
COMPOUNDING
( BANBURY MIXER )
*
ROLL MILL
1
^v..
s*
s*
ANTI - TACK
TREATMENT
*
s*
WARMUPMILL
i
s*
STRIP -FEED
MILL
r i - -
*V = "LENDER
t
COOLING
CUTTING
SPLICING
CORD INN
AND BIT LIN
ER
ER
?
EXTRUDER EXTRUDER
CUSH
LA
ATTAC
COC
CU
LAB
X 1
ONING CEMENTING
HMENT jl
WRAF
[TING
ELL ING
S*
CEMENTING
\
PING
ING
TREAD AND BEAD
SIDEWALL
BUILDING
*
GREEN TIRE
SPRAYING
I
MOLDING
CURING
^b
— <*
^VOLATILE ORGANICS
Figure 4-1. Tire flowsheet,
41
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4.2 INNER TUBE MANUFACTURE14
Inner tube manufacture is very similar to tire manufacture
in that the process consists of the following steps:
1. Preparation or compounding of the raw materials.
2. The extrusion of these compounded materials to form
a tube.
3. The building, molding, and curing of the rubber to
form the final product.
The basic machinery used in the compounding operation is
similar to that used in tire manufacture; namely, Banbury
mixers and roller mills. One minor distinction of inner tube
manufacture is the high usage of butyl rubbers. In addition,
a soap rather than a soapstone solution is sometimes used.
The process by which the tube is formed is similar to the
extrusion of the tread. The compounded rubber is fed to an
extruder via a warm-up mill. Here the rubber is extruded into
a continuous cylinder.
Once extruded, the tube must be cut to length and the ends
spliced together. A valve must also be attached. Once formed,
the tube must be molded or cured. Again, this operation is
very similar to that of tire manufacture. After curing, the
tube is inspected for defects, packaged and sent to warehousing
and shipping.
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4.3 EMISSIONS23"28
Table 5 is a summary of emissions from the manufacture of
tires and inner tubes. Emission points resulting from the pro-
duction of tires are numerous. In the course of this study,
only some quantification of these points was found. Thus, in
identifying emission points for this industry, some will be
addressed as potential hydrocarbon emission points due to lack
of source testing data. For the purpose of this report, any
23Rappaport, S. M. The Identification of Effluents from Rubber
Vulcanization. In: Proceedings of Conference on Environ-
mental Aspects of Chemical Use in Rubber Processing Opera-
tions (March 12-14, 1975, Akron, Ohio). U.S. Environmental
Protection Agency. Washington, D.C. EPA-560/1-75-002
(PB 244 172). July 1975. p. 185-216.
24Kenson, R. E., P. W. Kalika, and S. Cha. Odor Sources in
Rubber Processes and Their Control. In: Proceedings of
Conference on Environmental Aspects of Chemical Use in
Rubber Processing Operations (March 12-14, 1975, Akron, Ohio).
U.S. Environmental Protection Agency. Washington, D.C.
EPA-560/1-75-002 (PB 244 172). July 1975. p. 17-36.
25Guide for Compiling a Comprehensive Emission Inventory
(Revised). U.S. Environmental Protection Agency- Research
Triangle Park, N.C. Publication No. APTD-1135. March 1973.
209 p.
26Assessment of Industrial Hazardous Waste Practices—Rubber
and Plastics Industry. (Prepared by Foster D. Snell, Inc.,
Florham Park, New Jersey, under EPA Contract 68-01-3194, for
presentation to the Environmental Committee of the Rubber
Manufacturers Association, Cleveland, Ohio, October 22, 1975.)
27Van Lierops, B., and P- W. Kalika. Measurement of Hydrocar-
bon Emissions and Process Ventilation Requirements at a Tire
Plant. (Presented at the 68th Annual Meeting of the Air Pol-
lution Control Association. Boston. June 15-20, 1975.) 23 p.
28Kalika, P. W. Hydrocarbon Emissions - Classification, Regu-
lation, Measurement, and Control. (Presented at the 3rd
Environmental Conference of The Rubber Manufacturers Associ-
ation. Chicago, Illinois. October 29-30, 1973.) 18 pp.
43
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Table 5. VOLATILE ORGANIC EMISSIONS FROM THE
MANUFACTURE OF TIRES AND INNER TUBES
Emission source
Green tire spraying
Fabric cementing
Tire building
Undertread cementing
Tread end cementing
Curing
Compounding
Milling
Calendering
Extrusion
Solvent storage
TOTALS
Emission factor
g/kg of rubber
product
19.7
5b
3.6
1.25°
0.25
0.22
0.1
0.05
0.046
0.01
0.01
30.23
a
Emission type
Solvent
Solvent
Solvent
Solvent
Solvent
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Solvent
Percent
65.2
16.5
11.9
4.1
0.8
0.7
0.3
0.2
0.1
0.04
0.04
99.88
Cumulative
percent
65.2
81.7
93.6
97.7
98.5
99.2
99.5
99.7
99.8
99.84
99.88
99. 889
Solvent emissions account for 98.5% of volatile organic emissions. Rubber
volatiles account for 1.5% of volatile organic emissions.
b
Fabric cementing is assumed to be utilized in 50% of the final product
weight.
Undertreated cementing is assumed to be utilized in 50% of the final prod-
uct weight.
d
Tread-end cementing is assumed to be utilized in production of 20% of the
final product weight.
a
"Calendering is assumed to be utilized in the production of 80% of the final
product weight.
Extrusion is assumed to be utilized in the production of 20% of the final
product weight.
^Totals do not equal 100% due to rounding errors.
44
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process involving the working of rubber where a temperature
of 72°C is exceeded,23 is considered a potential hydrocarbon
emission point. Above 72°C, the potential for release of
hydrocarbons from the rubber material, itself, is assumed to
exist. This assumption is based on the temperature hydrocarbon
release equation developed by Rappaport23 and is discussed in
Appendix F.
4.3.1 Compounding (Banbury Mixing)
The Banbury mixer, through mechanical release of heat to
the rubber stock, itself, generates heat. Normal operating
temperatures in the mixer are between 100°C and 125°C. The
potential for formation of volatile organics off the rubber
stock, thus exists.
Emissions data for mixing are scarce. Available data con-
sists of several stack measurements with emissions reported on
a pounds/hour basis. The values of the measurements vary by a
factor of 2. It is not possible to statistically calculate an
emission factor from this data and accurately characterize the
emissions.
Banbury mixers can vary in size from as small as 2.5 kilo-
grams rubber capacity to 320 kilograms rubber capacity. In
addition, the actual hydrocarbon concentration in the exit gas
could theoretically be reduced by the presence of particulate
in the gas stream. This particulate, mostly carbon black,
could conceivably be adsorbing the hydrocarbons. Thus, even
proposed temperature-volatilization correlations cannot be
45
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verified for this emission source. The engineering estimate
with available data for an emission factor is 0.1 g/kilogram
of rubber stock. It should be emphasized that this factor must
be verified by additional source testing of mixing emissions in
the future. The estimate takes into account the relative magni-
tude of this source's emissions to other sources, temperatures
generated in the process and the nature of the rubber stock at
this stage of the tire manufacturing operation. Additional dis-
cussion of the estimation of this factor is presented in Appen-
dix F.
4.3.2 Milling
Again, through mechanical working of the rubber, heat is
produced in the milling of rubber. The temperature of the stock
as it leaves the mill (commonly called the dump temperature) is
from 70°C to 80°C. As for emissions from compounding, emissions
data are lacking for this source.
Batch capacities for mills vary from 1 kilogram to 135 kil-
ograms. The milling process is not continuous and thus an esti-
mate of an emission factor based on stack hourly measurements
would not be correct. Available data is, however, reported on
a pounds per hour basis. The hydrocarbon quantities measured
vary by a factor of fifteen. The problem of calculating an
emission factor for this source includes two additional consid-
erations. First, at the temperatures involved, any volatile
organics formed can be expected to condense as the exit gases
cool. In addition, background hydrocarbon concentrations
46
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around the mill, but due to other sources, such as a nearby
tread cementer, can make measurements of hydrocarbons from
milling unrepresentative. Considering all these variables, an
emission factor for milling is estimated to be 0.05 g/kilogram
of stock processed. Again, this is an engineering estimate,
based on the limited available data, temperatures involved, and
this source's emission magnitude in relation to other emission
sources. Additional data are obviously needed to verify or im-
prove on the estimated emission factor. Additional background
on the estimate of this factor is presented in Appendix F.
4.3.3 Fabric Cementing
Some tire manufacturer's cement dip or latex dip the
fabric before calendering of the rubber and fabric. After
application, the solvent in the cement is free to evaporate.
The use of this operation, as mentioned, is not practiced in
all tire manufacturing facilities, but at least one facility
is known to practice this step. Available emissions data are
scarce, and measured values, on a pounds/hour basis vary by a
factor of greater than ten. This data itself, again cannot be
used to calculate an emission factor. As before, additional
source testing data is needed to verify any emission factor
that is estimated. Based on limited solvent consumption data
and several independent estimates of emissions, the estimate
for an emission factor from fabric cementing is 10 g/kilogram
of stock.
47
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4.3.4 Calendering
Heat to maintain the plasticity of the rubber stock as it
is bonded to the fabric or steel mesh is furnished by steam-
heated rolls. Temperatures of between 70°C to 80°C are reached
during the operation. No data are available on emissions from
this source. However, based on temperature alone, the emissions
from calendering should have the same relative character and
magnitude as emissions from milling. On this basis alone, an
emission factor for calendering is estimated to be 0.05 g/kilo-
gram of rubber stock. Source testing is again warranted to
verify or improve on this estimate. Additional background into
the estimation of this factor is presented in Appendix F.
4.3.5 Extrusion
As before, heat is generated in this process. The size of
the extruded product determines the amount of heat and thus the
amount of hydrocarbons released. As the size of the product
increases, so does the quantity of hydrocarbons released. Tread
and sidewall extrusion are two examples of these large extruded
products.
No emissions data are available for extrusion operations.
Temperatures involved vary with the size of rubber stock extru-
ded. The exact range of temperature is not known, however, the
range of from 70°C to 90°C characteristic of milling and calen-
dering should apply to extrusion as well. Using this tempera-
ture basis, an emission factor for extruding can be estimated
to be 0.05 g/kilogram of stock. A representative range to
48
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allow for the variation in temperature is estimated at from
0.01 to 0.1 g/kilogram rubber. An example of an extruding
operation in tire manufacture where the emissions will be lower
than the established factor is that for the extrusion of inner
tubes.
4.3.6 Undertread and Tread End Cementing
This operation uses a solvent-based cement to tackify the
tread before it is sent to the tire building operation. The
choice of solvent varies, but one source was observed to use a
naphtha-based solvent. The solvent evaporates rapidly after
being applied. The emission factor for undertread cementing is
calculated to be 2.5 g/kilogram of rubber, based on information
available from two literature sources27'28 and plant supplied
data for this operation.
A range of from 2.0 to 3.0 g/kilogram of stock can be ex-
pected from various operations. The two reference sources27?28
report an emission factor in terms of pounds per square foot of
tread. The emission factor given was 0.083 kg/m2 of tread.
4.3.7 Green Tire Spraying
The green tire spraying operation is accomplished at a
spray booth. Because retention time is extremely short in the
booth, the solvent used in the spray is evaporated to the gener-
al room atmosphere. Data quantifying this emission point were
found from both literature sources and plant visits. Emissions
from green tire spraying are estimated to be 215 g/tire based
on data available from two literature sources27'28/ solvent
49
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consumption data for this emission source, and assuming complete
evaporation after 5 minutes.
A tire is assumed here to contain 10.9 kilograms of rubber
stock. Therefore, an emission factor for green tire spraying
based on g/kilogram of rubber stock can be calculated to be
19.7 g/kilogram of rubber. This factor assumes that all the
solvent applied evaporates before curing. Variations in emis-
sion factors for this operation can be expected to exist from
plant to plant and by the type of solvent used. No data are
available to present such a range.
4.3.8 Curing
Curing of the unvulcanized, green tire is an operation
involving application of heat and pressure over some time
interval. The exact combination of these variables is of course
different for and confidential to each manufacturer. However,
temperatures should exceed 150°C in all cases and thus hydro-
carbon emissions result. Due to the diverse nature of the
emission (multiple presses in a large area of the plant),
actual emissions will vary from press to press.
Emissions data are scarce for curing operations. Rappaport,
in his doctoral thesis, heated 50 gram samples of tread stock
for 20 ( + 2) minutes in a nitrogen-filled chamber at temperatures
from 160°C to 200°C and determined weight loss gravimetrically.
The maximum weight loss found was 2.73 g/kg. The average weight
loss was 2.23 g/kg over the entire temperature range. In sub-
sequent tests by the supplier of the rubber stock, the moisture
50
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loss (includes water absorbed in the stock and water synthesized
by vulcanization reactions) was measured. The stock supplier
found that water produced by curing operations could amount to
about 2.5 g/kg of the organic material in the stock, itself.
Realizing the potential inaccuracies inherent to utilizing
these limited data to characterize emissions from the diverse
and chemically complicated process of vulcanization, an emis-
sion factor was calculated. The maximum weight-loss reported
by Rappaport was 2.73 g/kg. Assuming that 1) all water produced
during vulcanization is vaporized, and 2) the 2.5 g/kg of mois-
ture is the maximum amount produced, the ratio of maximum water
weight loss to maximum total weight loss can be calculated to
be approximately 90% (91.4%). Again assuming that on the aver-
age 90% of total weight loss during curing is water loss, the
remaining 10% is assumed to be volatile organics. Again, using
Rappaport"s average weight loss of 2.23 g/kg, the emission
factor is calculated to be:
(0.1) (2.23) = 0.223 g/kg of rubber stock
In investigating the value of this factor, four calcula-
tions were performed to determine a possible range. The calcu-
lations are presented in Appendix F. The calculations show the
emission factor to possibly vary from .024 g/kg to 2.38 g/kg.
Since the emission factor is only valid to within a factor of
10, source testing is needed.
51
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4.3.9 Fugitive Emissions
Leaks from pump seals and valves used to transport sol-
vents in the plant will result in the release of hydrocarbons.
No emission data on fugitive emissions in tire manufacture were
found, and no emission factor is estimated.
4.3.10 Solvent Storage
Most tire plants have facilities to store and mix their
own solvents and/or cements. Because this mixing is done some-
times in open vessels and in some cases by hand, emissions of
hydrocarbons result. These operations are carried out on a
batch basis with the quantity of emissions varying accordingly
with time. Available data do not permit an absolute estimate
of this source, but an emission factor of less than 0.01 g/kg
of rubber is estimated to exist due to these solvent/cement
handling and mixing activities.
4.3.11 Tire Building
In tire building operations, rubber solvent is utilized to
tackify the various rubber components before fabrication onto
the drum. The amount of solvent utilized per tire varies con-
siderably due to individual tire builder preference. In the
instances where solvent is not used, the rubber has maintained
its tackiness due to the instantaneous use of the component
after fabrication. Utilizing plant tire building solvent con-
sumption data from several tire plants, the emission factor is
calculated to be 3.6 g/kg of rubber.
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4.3.12 Other Emission Sources
Other sources of hydrocarbon emission include bead dipping
and touch-up spraying. No data are available to allow for esti-
mation of an emission factor for these sources.
53
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5. RUBBER FOOTWEAR29
5.1 PROCESS DESCRIPTION
The process description presented here pertains to the
production of canvas footwear, which constitutes the major
product type within the Rubber and Plastics Footwear Industry,
SIC 3021.
Canvas shoes are the product of a number of processing
operations, including: compounding of rubber stocks, molding
of the soles, cutting and fabricating of canvas parts, extru-
sion of other rubber components, construction of the final
product from all these items, and curing of the final product.
The various rubber stocks received at a canvas footwear
plant are compounded with other processing chemicals in Banbury
mixers or roll mills and then sheeted out. The compounded,
sheeted stock is next cooled. Water spraying, immersion in a
cooling water tank or cooling by conduction through stainless
2Development Document for Proposed Effluent Limitations
Guidelines and New Source Performance Standards for the
Fabricated and Reclaimed Rubber Segment of the Rubber Proc-
essing Point Source Category. U.S. Environmental Protec-
tion Agency. Washington, D.C. EPA-440/1-7-030. August
1974. 213 p.
54
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steel belts are the preferred techniques. After cooling, the
sheeted rubber is dipped in an anti-tack solution to prevent
sticking during storage.
A canvas shoe is built from four major components: soles,
inner soles, canvas uppers, and foxing. Each of these pieces
is made separately by different processes before being brought
together in the shoe-building operation.
The soles are either cut from uncured rubber sheets or,
more generally, formed using injection, compression, or trans-
fer molding techniques. The technology employed depends on
the final product. Compression molding is now more common but
requires more manual labor and produces more molding waste
than automated injection techniques. The molded soles are
deflashed, usually in a buffing machine. A coat of latex
adhesive is applied to the soles before they are dried in an
oven.
Production of the inner soles begins with the preparation
of flat, cellular rubber sheets by extruding or calendering a
special rubber stock. The extruded sheet can be continuously
cured by passing through heated presses. Blowing agents, such
as sodium bicarbonate (NaHCOs) or azodicarbonamide/ \\ \\ \
\H2NCN=NCNH2/,
which are mixed into the rubber stock during compounding, de-
compose and release gases which blow the extruded sheet into
cellular sponge. The inner soles are die-cut from the cellu-
lar sheet. The blowing agents are emitted to the atmosphere
during mixing.
55
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Canvas uppers for footwear are made from two- or three-
ply fabric. The canvas material is received at a plant as
single sheets. These individual plies are coated with latex
or solvent, pulled together, and passed over a steam-heated
drum. The sheets are stacked and then cut to the proper
dimensions using a die and a press. The different canvas com-
ponents making up the footwear uppers are stitched together
on sewing machines.
The foxing, or edging, which protects the joint between
the sole and the canvas uppers, is extruded as a long strip
from rubber stock.
The shoe is fabricated from its four basic components on
a form called a last. The canvas upper is cemented at its
edges and placed over the last. The inner sole is attached to
the bottom of the last. The bottom of the inner sole and canvas
combination is dipped in a latex-adhesive solution which will
serve to hold the entire shoe together. Next, the outer sole,
the foxing, and the toe and heel pieces are attached to the
shoe.
The finished shoes are inspected and placed on racks in
an air-heated autoclave for curing under 30 psi to 40 psi total
pressure. Anhydrous ammonia is injected into the autoclave
to complete the cure, the amount required ranging from 0.9 kg
to 4.5 kg of NH3 for every thousand pairs of shoes cured. The
curing cycle lasts about 1 hr, at the end of which the ammonia-
air mixture is vented to the atmosphere.
56
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Some shoes are cured without ammonia. This is done when
the product's tackiness is not very important or when the com-
pounding recipe can be modified to eliminate the tackiness
often associated with conventional air curing. Steam is not
used for curing because it would stain the canvas parts of the
shoe in many cases.
Curing is not necessary in some new methods of shoe pro-
duction. In this process, observed at one of the visited
plants, all shoe components are pieced together by rubber
cement which is manually applied to the components. The com-
pleted shoe is then dried by forced air to drive off the
cement carrying solvent to complete the process. This new
process, although small in capacity compared to the conven-
tional production technique, can be expected to produce sub-
stantially more emissions per shoe due to the increased use
of rubber cement in the process.
5.2 EMISSIONS
Table 6 is a summary of volatile organic emissions from
rubber footwear. Data used to estimate solvent emissions are
taken from information supplied during plant visits. Rubber
volatile estimates are based on assumptions presented in
Appendix F.
5.2.1 Compounding
As mentioned previously, operating temperatures resulting
from Banbury mixing present the potential for hydrocarbon emis-
sions. Temperatures were found to be lower for compounding
done in rubber foot wear plants than for compounding done in
57
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Table 6. VOLATILE ORGANIC EMISSIONS FROM THE
MANUFACTURE OF RUBBER FOOTWEAR
Emission source
Rubber cementing
Molding
Curing
Latex dipping
and drying
Compounding
Milling
Calendering
TOTALS
Emission factor
g/kilogram rubber
95
.nb
.08°
.ld
.1
.05
.05
95.49
a
Emission type
Solvent
Rubber volatiles
Rubber volatiles
Solvent
Rubber volatiles
Rubber volatiles
Rubber volatiles
Percent
99.5
.12
.08
.1
.1
.15
.15
100.1
Cumulative
percent
99.5
99.62
99.7
99.8
99.9
100.05
100.10
100. ie
Solvent emissions account for 99.6% of volatile organic emissions. Rubber
volatiles account for 0.4%.
Molding is assumed to be utilized in 50% of the final product weight.
Curing is assumed to be utilized in 50% of the final product wieght.
d
Latex dipping is assumed to be utilized in 20% of the final product
weight.
e
Totals do not add to 100% due to rounding errors.
tire manufacture. The reason for this is unknown, but presum-
ably it is due to a difference in raw materials. For instance,
the difference may be due to higher percentages of natural
rubber used in rubber footwear. The emission factor for com-
pounding done in rubber footwear manufacture is calculated to
be 0.1 g/kg of rubber, based on the compounding emission factor
for tire production. Though the actual operating temperature
58
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are lower, no data are available to calculate an actual emission
factor compounding in footwear manufacture.
5.2.2 Rubber Cementing
Rubber cementing in footwear production is both large in
emission quantity and numerous in emission points. The emis-
sion factors for all these points have been estimated collec-
tively as one factor due to the lack of specific data on
emission quantities for each emission point. The collective
emission factor represents the following specific emission
points:
1) Spreading - An operation quite similar to fabric
cementing, in which the cement is applied and the
product is heated in an oven. No quantification of
this point was found.
2) Combining - An operation similar to calendering,
except that two sheets of fabric are forced together.
Some plants use water-based cements in this opera-
tion, others use solvent.
3) Basket sole cementing - The sole is coated with
cement and inspected for coverage.
4) Molded outsole cementing - Automatically coated
outsoles are produced, and the sole edges are sprayed
with cement by spray guns, in a booth. The area is
usually vented to the plant exterior.
5) Sole lining - Cement is applied before the sole is
applied to the shoe.
59
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6) Miscellaneous cementing operations - Upper cementing,
lacquer application, etc.
Since data were not available to estimate an emission
factor on each such operation based on either source testing
data or solvent consumption data for each process, solvent
usage for an assumed representative footwear plant was obtained
for an annual basis. Using plant production figures and assum-
ing that no solvent leaves with the finished product and is
thus emitted, an emission factor for all cementing activities
was arrived at. The resultant emission factor for these six
identified emission points collectively was calculated to be
95 g/kg of rubber stock.
5.2.3 Latex Dipping and Drying
After the various components have been attached together,
the shoe or boot is partially or entirely dipped in latex and
dried, either by air or oven. The emission factor for this
operation is calculated to be 0.5 g/kg of rubber. This factor
is based on plant information such as latex usage and assuming
all solvent contained in the latex is emitted. In this opera-
tion, some plants do not, however, use solvent in their latex.
5.2.4 Curing
The shoe or boot is cured in a batch process similar to
that used for hose and belt batch curing. The curing vessel
is vented to the plant exterior.
No data are available for batch curing of rubber footwear.
Using Rappaport's findings for volatilization of rubber stock
60
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during vulcanization and allowing for water loss, an emission
factor of 0.22 g/kg of rubber was assumed. In batch curing the
materials are cured under pressure in a confined vessel. Any
volatile organics formed cannot be released to the atmosphere
until after curing is completed. Because these volatile
organics are not vented until curing is completed, it can be
assumed that a portion of the volatiles will condense before
venting occurs. Assuming 25% to 30% condense before venting
and that the conditions assumed for tire curing apply except
for the condensing, an emission factor for batch curing can
be estimated to be:
(.72) (.22) = .158
= .16 g/kg of rubber
These assumptions and the estimated emission factor can
only be verified or improved on by actual test measurements
of batch curing operations. There is no such data available
at this time.
5.2.5 Molding
All types of molding are used in the industry. Due to
the temperatures involved, hydrocarbon emissions are possible.
No quantification was found during plant visits. Based on
previous calculations for tire curing, the emission factor for
molding is estimated to be .22 g/kg of rubber, based on the
assumption that emission from molding are similar to emissions
from tire curing.
61
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5.2.6 Milling and Calendering
Footwear plants usually work the compounded rubber into
the size and shape necessary for downstream operations. Emis-
sions from these operations are as reported for tire manufac-
turing. Respectively, these factors are 0.05 g/kg of rubber
for calendering operations and 0.05 g/kg of rubber for milling
activities.
62
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6. RUBBER RECLAIMING
6.1 PROCESS DESCRIPTION
J. M. Ball originally defined reclaimed rubber, in the
first edition of Rubber Technology, as "the product resulting
from the treatment of vulcanized scrap rubber tires, tubes and
miscellaneous waste rubber articles by the application of heat
and chemical agents, whereby a substantial 'devulcanization1
or regeneration of the rubber compound to its original plastic
state is effected, thus permitting the product to be processed,
compounded, and vulcanized. Reclaiming is essentially depoly-
merization; the combined sulfur is not removed. The product is
sold for use as a raw material in the manufacture of rubber
goods, with or without admixture with crude rubber or synthetic
rubber."30 The United States Department of Commerce has
adopted this definition in the report on Reclaimed Rubber for
the 1972 Census of Manufactures.
There are currently three different process technologies
used by the rubber reclaiming industry in the United States:
30Brothers, J. E. Reclaimed Rubber. In: Rubber Technology,
Second Edition, Morton, M. (Ed.). New York, Van Nostrand
Reinhold Co., 1973. p. 496-514.
63
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the digester process, the pan (or heater) process, and the
mechanical process. The most common reclaiming technique is
the digester process, which has almost replaced the pan proc-
ess, the oldest of the three. The mechanical process is the
least practiced. All three processes use similar methods of
rubber scrap separation and size reduction. The differences
show up in the depolymerization and final processing.
6.1.1 Metal Removal, Size Reduction, and Fiber Separation
Scrap rubber received at a reclaiming plant is first
sorted to remove steel-belted or studded tires, which can be
either sent to special processing facilities or discarded as
waste. Brass and steel valve stems and valve seats are manu-
ally removed from the remaining tires. The bead wire, which
serves to secure the tire to the wheel rim, may also be cut
out of the tire at this time.
Next, the scrap rubber is size reduced using either
crackers or hammer mills. The cracker is a two-roll machine,
having working roll lengths of 76 cm to 107 cm and diameters
of 46 cm to 81 cm.11 Each roll is axially corrugated, and the
two rotate in opposite directions at different speeds. As the
rubber is dropped into the cracker, the slower roll corruga-
tions momentarily "hold" the waste while the faster roll
corrugations shear, slice, crush, and abrade the waste. This
process is repeated until all the material passes through a
screen of some predetermined mesh size. Some reclaimers
64
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undertake further size reduction down to less than 10 mesh
using secondary and tertiary crackers.
A hammer mill is essentially a high-speed rotating drum
which hammers the scrap rubber with pivoting "T" or "I" bars
or with knives mounted on the drum's periphery. There may be
stationary knives located on the frame within which the drum
revolves, with or without a perforated plate or screen that
retains the scrap until it is sufficiently size reduced to
pass through. The machine containing drum knives may have a
special feeding device to control the input of the rubber waste.
Wastes containing reinforcing fiber materials, such as
cotton, rayon, nylon, polyesters, fiberglass, and metal, require
either mechanical fiber separation or chemical fiber degrada-
tion. The ground rubber-and-fiber mixture is first separated
into streams of different particle size by a screener. These
streams are conveyed to separation tables which effectively
separate loose fiber from clean rubber by vibration and air
flotation. This is a continuous operation with recycle and
with free scrap being added at all times.
The fiber and rubber-fiber portions are next fed into
hammer mills for hammering or scalping. After the material
has been sufficiently size reduced to pass through a peripheral
screen, it is fed to sifters or beaters. In these machines,
loose rubber particles separate from the fiber and pass through
a retaining screen, while the fiber is conveyed for recycle,
either to the screener or to another set of hammer mills.
65
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The final operation of the fiber separation process is
baling the waste fiber. This baled fiber is made up of small
strands, less than 3.8 cm long, and contains a small amount of
entrapped rubber.11 This fiber is discarded unless there is
a market for its reuse.
Fiber-separated rubber is next subjected to fine grinding.
Crackers, similar to those used for primary size reduction,
grind the rubber to 30- mesh or smaller. Hammer mills can be
used for fine grinding but are not as efficient as crackers.
The finely ground rubber is then screened. Particles that pass
through the screens are ready for depolymerization, while the
remaining material is recycled for further size reduction.
6.1.2 Depolymerization
Digester process - Digestion is a wet process using rubber
scrap that has been ground to thicknesses between 0.63 cm and
0.95 cm.30 The fine, fiber-free rubber particles are mixed
with water and reclaiming agents and fed to a jacketed auto-
clave. These digesters can accommodate about 2,300 kg to
2,700 kg of scrap, water, and chemicals in each reclaim batch.30
The digester is agitated by a series of paddles on a shaft
which is continuously driven at a slow speed to maintain the
charge in motion for uniform heat penetration. The digestion
liquor is heated by the injection of steam, at pressures
generally around 1.38 MPa (200 psi) for a residence time of
8 to 12 hours.30 Another reference indicates a residence time
of 5 to 24 hours at a digester temperature of 188°C to 207°C.29
66
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Reclaiming agents are fed to the digester with the scrap rubber
to accelerate depolymerization and to impart desirable pro-
cessing properties to the rubber. Rubber scrap which has not
been mechanically defibered requires chemical degradation during
digestion. Therefore, defibering agents and plasticizing oils
are added to complete the charge.
When the digestion is complete, the resultant slurry is
blown down under internal pressure into a blowdown tank. From
here, the rubber slurry is pumped to a holding tank where
additional water is added for dilution and washing. After agi-
tation, the mixture is discharged onto vibrating screens where
a series of spray nozzles wash the rubber free from the diges-
tion liquor and hydrolyzed fiber. The washed scrap is then
passed through a dewatering press. A small amount of residual
moisture is necessary to prevent excessive buildup of heat
during subsequent refining. A flow schematic is shown in
Figure 6-1.31
Reclaiming agents that are used in the digester process
include petroleum- and coal-tar-based oils and resins as well
as various chemical softeners such as di- and trialkylphenol
sulfides and disulfides, mercaptans and amine compounds. Pre-
ferred amines include aliphatic long-chain (Cio~Ci^) amines
and primary amines. Reclaiming agents generally function by
31Ananth, K. P-, T. Weast, D. Bendersky, and L. J. Shannon.
Waste Material Trace Pollutant Study. Midwest Research
Institute, Kansas City, Mo., under EPA Contract 68-02-1324,
Task 10. May 1974. p. 96-106.
67
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RUBBER SCRAP
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
FIBER SEPARATION
FURTHER SIZE
REDUCTION
SCREENING
WATER
CHEMICALS-
AND OILS
DIGESTIVE
DEPOLYMERIZATION
SLOWDOWN
OIL
RECYCLE
FILLERS
AND LIQUIDS'
DRYING
MIXING
REFINING
STRAINING
^VOLATILE ORGANICS
REUSE OR
'DISPOSAL
RECLAIMED
RUBBER
Figure 6-1. Schematic flow diagram of digester process
for reclaiming rubber.31
68
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catalyzing the oxidative breakdown of polymer chains and sulfur
crosslinks. It should be noted that natural rubber can be
reclaimed in the absence of reclaiming chemicals.
Sodium hydroxide (NaOH) or calcium chloride (CaCl2) and
zinc chloride (ZnCl2) are used as defibering agents in the
digester process. The presence of synthetic rubber, such as
SBR, necessitates the use of metallic chlorides instead of
sodium hydroxide since the latter produces a thermosetting
effect with SBR.
Pan (or heater) process - Fiber-separated, fine-ground
scrap is reduced to an even smaller particle size by grinding
on steel rolls. The rubber is next blended with reclaiming
oils in an open mixer and then placed in stacked shallow
pans. The depth of treated scrap in these pans may be 15 cm
to 20 cm.30 The stacked pans are placed on a carriage that
can be wheeled into a large horizontal heater, which is a
single-shell pressure vessel.
In this method of depolymerization, live steam at 1.38 MPa
(200 psi) to 1.55 MPa (225 psi) is introduced to the heater to
directly contact the rubber scrap.30 Another reference states
that depolymerization is carried out at 185°C [saturated steam
pressure ^1.12 MPa (163 psi)] for 2 to 18 hours.29 After this
treatment, the heater is opened, and the reclaimed scrap is
unloaded and cooled. No drying is required because the small
amount of water remaining will assist in refining. A flow
schematic is shown in Figure 6-2.
69
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RECLAIMING OILS
FILLERS
AND LIQUIDS'
FIBER - FREE
RUBBER SCRAP
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
SCREENING
MIXING
AUTOCLAVE
DEPOLYMERIZATION
MIXING
REFINING
STRAINING
••A-
SLABBING/
BALING
RECLAIMED
RUBBER
^VOLATILE ORGANICS
Figure 6-2. Schematic flow diagram of pan
process for reclaiming rubber.31
70
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Mechanical process - Unlike the other two processes,
mechanical reclaiming is continuous. Fiber-separated, fine-
ground rubber scrap is fed into a high-temperature, high-shear
machine. The machine is a horizontal cylinder in which a screw
forces material along the chamber wall in the presence of
reclaiming agents and depolymerization catalysts. Tempera-
tures generated are in the range of 204°c to 260°C with time
requirements between 1 and 4 minutes.31 The discharged re-
claimed rubber needs no drying.
6.1.3 Mixing, Refining, Straining, and Packaging
Reinforcing materials such as clay, carbon black, and
softeners are most commonly mixed into the rubber using a
horizontal ribbon mixer. This is an enclosed rectangular box
with a rounded bottom in which mixing is accomplished by a
horizontally driven continuous ribbon, paddles, or a combina-
tion of the two. The mixed rubber and filler compounds are
next intimately blended in a Banbury internal mixer. It
usually takes between 1 and 3 minutes to blend the material in
a single batch. Since extruders permit continuous processing,
more reclaimers are converting to that method of blending.
The reclaim next undergoes preliminary refining on a
short two-roll mill called a breaker refiner. The smooth
rolls are of different diameters and rotate at different speeds
so that there is a high friction ratio which tends to form the
stock into a smooth clean sheet, approximately 0.3 mm thick.
The temperature of the rolls is controlled by water cooling.
71
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The sheet is dropped into a screw conveyor which carries
the reclaim to a strainer. The strainer is a heavy-duty extrud-
er which contains a wire screen (10- to 40-mesh openings) held
between two perforated steel plates in the head of the machine.
Straining removes such foreign materials as glass, metal, wood,
or sand from the rubber. After straining, the rubber goes on
to a second refiner called a finisher, which is the same type
of machine as the breaker. The final thickness of the clean
reclaim is between 0.05 mm and 0.25 mm.11
Each reclaimer may complete his operations by sending his
product to the customer in the form of slabs, stacked on pal-
lets, or in bales. Slabs are made by allowing the thin sheet
of reclaim to wrap around a windup roll until the proper thick-
ness is obtained. The wrapped layers are then cut off the roll,
forming a solid slab of a certain length, width, and weight.
Each slab, weighing approximately 14 kg to 16 kg, is dusted
with talc to prevent sticking.30 After quality control approval,
the slabs are piled on pallets until the total wieght is 680 kg
to 910 kg, ready for shipment.30 As an alternative to the slab
process, the reclaim sheet can be air conveyed to a baler,
where the rubber is compacted to form a bale of controlled
weight. The bales are dusted, bagged, stacked on pallets,
tested, and shipped. A flow schematic is shown in Figure 6-3.
6.2 EMISSIONS
Table 7 shows a summary of volatile organic emissions from
rubber reclaiming operations. Data used to estimate the emis-
sion factor are from information supplied during plant visits.
72
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FIBER-FILE
RUBBER SCRAP
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
SCREENING
HIGH-TEMPERATURE,
HIGH SHEAR
DEPOLYMERIZATION
MIXING
REFINING
STRAINING
•&VOLATILE ORGANICS
SLABBING /
BALING
RECLAIMED
RUBBER
Figure 6-3. Schematic flow diagram of mechanical
process for reclaiming rubber.31
73
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Table 7. VOLATILE ORGANIC EMISSIONS FROM
RECLAIMING OPERATIONS
Emission source
Depolymerization
Emission factor
g/kg of rubber
30
Emission type
Solvent and
rubber volatiles
Percent
100
Cumulative
percent
100
6.2.1 Digestion
The reclamatory operation is the primary emission point
of hydrocarbons in rubber reclaiming. The pan, digestion, or
mechanical process emits mainly vapors and mists resulting
from the addition of aliphatic and aromatic oils and solvents
during digestion, or reclaiming. Based on data obtained from
state permit applications for an assumed representative rubber
reclaiming plant, the emission factor is calculated to be
30 g/kg of product. The calculation is made collectively for
all processes since source testing data for specific operations
are not available. It is recognized that the emission factor
will vary with each type of process.
6.2.2 Drying
After digestion, the reclaim is quenched with water or
allowed to cool down naturally by confined air (pressure vessel)
before further processing. If the reclaim is left to cool in
the open atmosphere, without a water quench, hydrocarbon emis-
sions will exist. However, in a representative plant, no open
air drying without quench is assumed to exist. No emission
factor is calculated for drying.
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6.2.3 Milling
After drying, the reclaim is put onto various mills so
that the rubber can be sheeted out. Because of residual mois-
ture remaining after quench or due to the nature of the reclam-
atory process itself, insufficient heat (maximum observed 35°C)
is generated to effect any hydrocarbon emissions. No emission
factor for milling is calculated.
6.2.4 Fugitive
Residual solvent and oil contained in the reclaim contin-
uously evolves off the reclaim, resulting in the odor associ-
ated with most reclaiming plants. For a representative plant,
the emission factor is calculated to be less than 0.1 g/kg.
Control of such fugitive emissions is not possible as the odor
is characteristic of the product produced and not due to poor
housekeeping, leaky pumps or faulty valves.
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7. RUBBER HOSE AND BELTING
7.1 PROCESS DESCRIPTION
7.1.1 Belting-Conveyor or Flat Type
Rubber belting usually consists of a multiple-ply, rub-
berized-fabric carcass sandwiched between two layers of rubber
sheeting. SBR, natural rubber, and reclaimed rubber are used
in the most common types of belting. Neoprene, nitrile rubber,
aerylate rubber, polysulfide, polyurethane, fluoroelastomers,
or epichlorohydrin may be used in belting which requires a
high degree of oil-resistance.21 Due to its particular prop-
erties, reclaimed rubber is used only as an extender for the
more expensive polymers.
Depending upon the choice of raw crumb, a wide variety of
loading pigments, accelerators, plasticizers, antioxidants,
and vulcanizing agents are incorporated into the stock during
mixing.
Compounding - Compounding and mixing are usually carried
out in Banbury mixers, although compounding mills may be used
in some facilities. After mixing, the rubber stock is sheeted
out on a sheeting mill and dipped in a soapstone slurry to
76
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reduce its tack. The rubber leaves the rolling mill in a
ribbon several feet wide and approximately 1 inch thick.26
Both the frictioning and sheeting stocks are worked on
warmup mills prior to subsequent forming operations.
Forming operations - The hot sheeting stock passes from
the warmup mill through an extruder-calender machine where its
dimensions are fixed. Wire reinforcement may be extruded with
the rubber stock during this operation to increase the strength
of the belting. After calendering, the sheet rubber is cooled
in a water spray tank, dried via passage over hot air vents,
and rolled up for storage.
The frictioning compound passes from the warmup mill to
a friction calender where it is impregnated into the fabric
used to build the carcass of the belt. This fabric, usually
rayon or nylon, is pretreated by dipping in latex and/or cement
(50% solvent) and drying to a moisture content of less than
one percent. Drying is carried out immediately prior to
frictioning by passing the dipped fabric over steam-heated
cylinders or platens kept at 115°C, 32 or in other types of
ovens.
Building - The rubberized, single-ply fabric leaving
the calender is used to build belt carcasses of multiple-ply
thickness. A variety of techniques are employed in this oper-
ation, depending on the specifications of the final product.
32Stern, H. J. Rubber: Natural and Synthetic. London,
MacLaren & Sons, Ltd., 1954. 491 p.
77
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Once built, the carcass is sandwiched between two layers of
rubber sheeting by a calendering operation.
Curing - Belt vulcanization is performed in presses, roto-
cures, or hot-air curing ovens- A rotocure employs a combina-
tion of steam, cooling water, and electric heaters to continuously
vulcanize the belting as it passes around the curing drum. Press
curing is effected by two heated belts which hold the belting
between them under pressure, turn, and drag the belting through
the press. Unlike the rotocure, the press curing technique is
a batch operation. Vulcanization requires about 30 minutes at
140°C.32
After curing, the belting is inspected, cut to length, and
stored before shipment.
A flow schematic is shown in Figure 7-1.
7.1.2 Machine-Wrapped Ply Hose
Materials - Machine-wrapped ply hose consists of three
components: the tube (lining), the reinforcement, and the
outer cover. The reinforcement is constructed from rubber-
impregnated fabric, while the tube and cover are made entirely
from rubber.
Natural rubber and a wide variety of synthetic polymers
are used, including SBR, butyl rubber, EPDM, Hypalon, neoprene,
nitrile rubber, polyisoprene, acrylate rubbers, polysulfides,
polyurethanes, fluoroelastomers, and epichlorohydrin.l8'2l' 33
33Hawley, G. G. The Condensed Chemical Dictionary, Eighth
Edition. New York, Van Nostrand Reinhold Co., 1971. 971 p,
78
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COOLING
(WATER SPRAY TANK)
ANTI-TACK
TREATMENT
DRYING
; AIR VENTS:
CALENDERING
CURING
( PRESS, ROTOCURE,
HOT-AIR OVEN)
INSPECTION
CUTTING TO LENGTH
STORAGE
J
Figure 7-1. Belting flowsheet.
79
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Reclaimed rubber is sometimes used in conjunction with one of
the more expensive polymers.
Any number of fillers, softeners, accelerators, activators
antioxidants, pigments, and vulcanizing agents may be combined
with the raw crumb. The recipe is varied to fit the service
requirements of the final product.
Compounding - The rubber stock is usually compounded and
mixed in a Banbury mixer and sheeted out on a roll mill in a
ribbon several feet wide and less than 1/2 inch thick.21 This
rubber sheet is subsequently dipped in a soapstone, clay, mica,
or similar slurry and hung up to dry for further processing.
Tube formation - After drying, the stock is continuously
extruded to form a seamless rubber tube of the desired diam-
eter and wall thickness. As it leaves the extruder, the tube
is cooled in an open tank by direct contact with cooling water,
dipped in a tank of anti-tack agent such as a zinc stearate
solution, and coiled up for storage. Soapstone solution is
not used in this dipping operation because its anti-tack prop-
erties are undesirably permanent.
Reinforcement preparation - The fabric used for reinforce-
ment is received from textile mills in large rolls and impreg-
nated with rubber on both sides by friction calendering. The
frictioned fabric is then cut on a bias and joined together
by natural tackiness of the material or cemented together with
overlapped seams to form a long strip just wide enough to
80
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provide the required number of plies plus an overlap when
wrapped around the tube.
Outer cover formation - The hose cover is formed by
calendering a thin sheet of rubber stock to the required
thickness and cutting it to the width necessary for a slight
overlap on wrapping.
Mandrel insertion - From storage, the formed tube is taken
to the building area where it is temporarily enlarged via air
pressure and mounted on a rigid mandrel. Lubricants are
injected into the tube to prevent it from sticking to itself
or to the mandrel.
Building - The actual hose building is carried out on a
special purpose "making machine" which consists of three long
steel rolls. Two of the rolls are fixed parallel to each other
in the same horizontal plane, while the top roll is mounted on
lever arms so it can be raised and lowered. One or more of
the rolls are power driven.
When the forming operations are completed, the mandrel-
supported tube is placed in the trough formed by the two
bottom rolls of the making machine. One lengthwise edge of
the cut fabric is adhered to the tube and the top roll is
brought down into contact with it. The pressure exerted by
the top roll causes the tube and mandrel to rotate as the
bottom rolls rotate, so the fabric is drawn into the machine
and wrapped around the tube. The pressure from the top roll
serves the dual purpose of compacting the carcass as it is
81
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formed. This same procedure is repeated with the cover to
complete the building operation. Cement and solvent tackifi-
ers may be used to enhance adhesion in this building process.
Vulcanization - The uncured hose is transferred from the
building area to the curing area where it is loaded into an
open steam autoclave for vulcanization at some predetermined
temperature and pressure. The necessary pressure is maintained
by cotton or nylon wraps.
When vulcanization is complete, the autoclave is vented,
the hose is removed and cooled, and the cloth wrap is stripped
away. The hose is then removed from the mandrel with compressed
air or water and hydraulically tested before final storage and
shipment. Machine-wrapped ply hose is commonly produced and
shipped in lengths of about 50 m with internal diameters
ranging from 5 mm to 75 mm.29
A flow schematic is shown in Figure 7-2.
7.1.3 Hand-Built Hose
Materials - Ply hose is built by hand if it is too large
in diameter or too long to fit on the three-roll making machine,
or if it requires special ends, metal reinforcement, or spe-
cially layered fabric reinforcement. The raw rubber compound-
ing ingredients used are the same as those used in the produc-
tion of machine-wrapped ply hose.
Forming operations - For hose with internal diameters
less than 100 mm, the tube is extruded and mounted on the man-
drel as before.29 For larger hose, the tube is formed by
wrapping calendered stock around the mandrel with a slightly
82
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COOLING
WRAP REMOVAL
MANDREL REMOVAL
TESTING
STORAGE
EQUIPMENT
^VOLATILE ORGANICS
Figure 7-2. Ply hose flowsheet.
83
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overlapping seam. The steel mandrel is mounted on a series
of double roller stands with one end held in the jaws of a
power-driven chuck used to rotate it during the building
operation.
The fabric is frictioned and cut as before, and the cover
stock is calendered to the desired thickness.
Building - In the making process, the pretreated fabric
is applied to the mandrel-supported tube by hand. It is rolled
down progressively as the mandrel is turned. The cover stock
is applied in a similar manner.
Wire reinforcement is used in many types of hand-built
hose: to prevent collapse in suction hose, to prevent kinking
in pressure hose curved in small radius loops, and to add
strength in high-pressure hose. The wire in suction hose is
usually placed underneath the main fabric plies for rib sup-
port against external pressure. In pressure hose, the wire is
placed over the fabric reinforcement for hoop strength against
high internal pressure. For a combination of these reinforce-
ment properties the wire is placed midway in the fabric plies.
Wire reinforcement is usually in the form of a closely
spaced helix opposing radial stress but adding little strength
in the axial direction. If axial strength is also required, the
hose is constructed with two or more even numbers of wire
layers. Each layer consists of many strands of solid round
wire or cable spiralled around the hose, forming an angle
greater than 45° with its axis. The direction of the spiral
is reversed with each layer for balanced strength.
84
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In the actual making process, the wire is applied by hand
or by a simple machine using a power-driven chuck to rotate the
mandrel and hose.
All other manufacturing steps are very similar to those
used in the production of machine-wrapped ply hose.
7.1.4 Braided Hose
Materials - Braided hose refers to the type of construction
and method of manufacture in which strands of reinforcement are
interlaced as well as spiralled around the tube. Thus, the
reinforcement consists of yarn or wire rather than sheeted
fabric. The raw rubber and compounding ingredients used are
essentially the same as those used to make ply hose.
Tube formation - Processing usually begins with the ex-
trusion of unsupported tubing, providing that the rubber stock
is firm enough in the raw state to resist excessive deformation
and stretching. When the tubing is too thin, too soft, or when
the internal diameter must be kept within a narrow range, it
must be extruded onto a flexible rubber or plastic mandrel.
The mandrel is at least as long as the tubing itself, and may
have a wire core to prevent stretching. Once formed, the tube
is temporarily stored on a circular tray or reel.
Building - From storage the tube is taken to the braider
where the reinforcement is applied. The tube is drawn through
the center of the machine while the braid is forming on its
surface. Braid formation is carried out by yarn or wire
carriers weaving in and out on a circular track. The angle
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of braiding is adjusted by changing the surface speed of the
overhead takeoff drum or capstan. When braiding is completed,
the hose passes through a crosshead extruder where a seamless
rubber outer cover is applied.
Vulcanization - A substantial portion of all braided hose
is vulcanized by the lead sheath process. The lead casing used
in this operation is formed by means of a lead press or extruder.
A lead press deforms solid lead into a continuous sheath; a
lead extruder works with molten lead. In either case, the
lead sheath is formed around the green hose as it passes through
the press or extruder.
If the lead-sheathed hose is nonsupported, it is filled
with water under pressure, wound on reels, and loaded into an
open steam pressure vessel. The internal water pressure is
maintained throughout the curing cycle to force the hose
against the lead casing. After curing, the water is drained
from the hose and the lead casing is stripped away for recycle.
If the hose is supported, the lead sheath itself applies
some initial pressure by squeezing it against the flexible
mandrel. However, most of the internal pressure necessary
for a solid, homogenous product is supplied by the expansion
of the hose during the high-temperature vulcanization. At
the end of the curing period, the lead sheath is removed by
mechanically slitting and pulling away from the cured hose.
The mandrel is removed by means of a high-pressure hydraulic
system. A flow schematic is shown in Figure 7-3.
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BRAIDER OR
SPIRALLING MACHINE
COVER EXTRUSION
LEAD EXTRUDER
OR PRESS
VOLATILE ORGANICS
VULCANIZATION
SHEATH REMOVAL
MANDREL REMOVAL
TESTING
STORAGE
SHIPMENT
Figure 7-3. Braided or spiralled hose flowsheet.
87
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7.1.5 Spiralled Hose
In spiralled hose, all the strands in a given layer are
aligned in one direction parallel to each other. At least
two layers of reinforcement aligned in opposite directions are
thus required for balanced strength.
Spiralled hose reacts to internal pressure in the same
way that braided hose does, and can be produced at a much
faster rate due to the relative simplicity of the spiralling
machines. However, spiralled hose is not manufactured in as
broad a size range as braided hose.29
A flow schematic is shown in Figure 7-3.
7.2 EMISSIONS
Table 8 is a summary of the volatile organic emissions
from rubber hose and belting production. Solvent data supplied
during plant visits was used to calculate solvent emission
factors. Rubber volatile assumptions are given in Appendix F.
In rubber hose and belt manufacture a great diversity of
sizes and shapes of product is produced. As mentioned in
describing the various processes involved, a large number of
operations are employed which result in the emission of
hydrocarbons.
7.2.1 Compounding
As mentioned previously, operating temperatures present
the opportunity for hydrocarbon emissions. Based on the
assumptions set forth for compounding activities in the tire
industry, the emission factor for Banbury mixing is calculated
88
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Table 8. VOLATILE ORGANIC EMISSIONS FROM RUBBER
HOSE AND BELTING PRODUCTION
Emission source
Fabric cementing
Rubber cementing
Curing
Compounding
Milling
Calendering
Extrusion
TOTALS
Emission factor
g/kg of rubber
12. 5b
6.0
.16
.01
.05
.05
.02°
18.83
a
Emission type
Solvent
Solvent
Rubber vo la tiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
—
Percent
66.38
31.86
0.85
0.5
0.25
0.25
0.01
100.1
Cumulative
percent
66.38
98.24
99.09
99.59
99.84
100.09
100.1
100.1
Solvent emissions account for 98.24% of volatile organic emissions.
Rubber volatiles account for 1.96%.
Fabric cementing is assumed to be utilized in 50% of the final product
weight.
Extrusion of hose is assumed to be utilized in 50% of the final product
weight.
d
Totals do not equal 100% due to rounding errors.
to be 0.1 g/kg of product produced. For some of the newer and
smaller plants in the hose and belting industry, it was found
that these newer plants are using precompounded rubber stock
and thus cannot be expected to have this particular emission
point. However, in the locations where compounding of this
stock is being carried out, the associated emission will still
exist.
89
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7.2.2 Fabric Cementing
As mentioned, the fabric and/or cord is coated with latex
and/or rubber cement either by dipping or spreading. In both
cases, the coated cord/fabric is either air-dried or oven-
dried. Emissions are vented to the atmosphere in the case of
oven drying or simply dispersed to the plant atmosphere in the
case of air drying. For one representative hose and belting
plant, source testing data were obtained for an oven drying,
cord cementing operation. The vented exhaust gas was found to
contain 3,650 ppm as CH^ of volatile organics. For another
representative plant, source testing data were also obtained
for a fabric cementer. Utilizing plant production information
and solvent consumption data, an emission factor for fabric
cementing operations is calculated to be 25 g/kg of product
produced. It should be noted that in some hose plants, the
need for fabric cementing does not exist and the fabric,
itself, is unnecessary. In addition, some fabric cementing
is done after curing of the hose, and thus after construc-
tion of the hose, itself. In this case, the cementing is done
on a cured rubber/fabric combination versus fabric alone. This
practice is known to exist in the industry.
7.2.3 Hose Extrusion
Some types of hose are constructed by extrusion over a
mandrel. Extrusion temperatures vary depending on the wall
thickness of the hose being produced, with the higher tempera-
tures being associated with the larger wall thickness. Based
90
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on the fact that operating temperatures reach greater than 72°
for only 20% of the extruding operations and the fact that
extruders for 20 mm diameter hose reach temperatures of only
30°C, an emission factor is estimated to be 0.04 g/kg of prod-
uct produced.
7.2.4 Calendering
In this industry, various calendering operations are
used, especially in belt manufacture. Operating temperatures
again approach or exceed 72°C. Based on the calculations
utilized for calendering operations in the tire industry, an
emission factor is estimated to be 0.05 g/kg of product.
7.2.5 Rubber Cementing Operations
Especially in small belt and large hose building opera-
tions, quantities of solvent-based rubber cement are used.
When building the belt by hand, cement is added to each succes-
sive layer of rubber for tackifying purposes. The same applies
to large hose building. The amount of cement actually applied
depends strictly on the builder's preference. Utilizing sol-
vent consumption data obtained from an assumed representative
plant, the emission factor for all such manual cementing activ-
ities is calculated to be 6 g/kg of product produced. A repre-
sentative average range is estimated to be 5 g/kg to 8 g/kg of
product. However, for certain individual product types (large
hose) this figure can reach 100 g/kg of product, based on data
found in this industry -
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7.2.6 Curing
Because of the great variation in types of product pro-
duced in this industry and types of curing operation involved,
the emission factor for curing is presented as a range in
value. In large belt manufacture, curing is continuous over
electrically heated rollers (rotocure).
Data obtained for one rotocure operation showed that for
a product weight flow of 286 kg per hour, the exhaust gas flow
of 323 mVmin at 32°C had a hydrocarbon concentration of 14 ppm,
or a mass flow of 172 g per hour. Utilizing these data, an
emission factor for rotocuring operations is calculated to be
0.6 g/kg of product. This emission factor would apply for
large belt manufacture. For small belt curing, done in conven-
tional presses, an emission factor based on tire industry press
curing data has been calculated to be 22 g/kg. In most hose
and small belting manufacture, curing is a batch process in a
closed vessel, either vented to the plant atmosphere or vented
outside the plant completely. For batch curing operations,
using footwear vulcanization calculations, an emission factor
of .16 g/kg of product is estimated.
The majority of curing operations (>50%) in hose and
belting manufacture utilize batch curing. This study calcu-
lates the emission factor as .16 g/kg of product, realizing
that the actual value will vary with the type of hose or belt
produced.
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7.2.7 Milling
As previously discussed in Section 4.3.2, the emission factor
for milling operations is calculated to be 0.05 g/kg of product
produced.
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8 . FABRICATED RUBBER GOODS
8.1 PROCESS DESCRIPTION
8.1.1 General Molded Products
This category includes items such as battery parts, rub-
ber rolls, rubber heels and soles, water bottles, fountain
syringes, nipples, pacifiers, rubber bands, finger cots,
erasers, brushes, combs, mouth pieces, and a wide variety of
mechanical goods.
Rubber molding typically consists of the following
operations:
• Compounding of the rubber stock
• Preparation of the mold preforms or blanks
• Molding
• Deflashing
8.1.2 General Extruded Products
General extruded products include rods, tubes, strips,
channels, mats and matting, floor and wall covering, and stair
treads.
Compounding - The rubber stock is compounded from the
basic ingredients on a compounding mill or in a Banbury mixer.
A wide variety of raw rubbers and compounding ingredients is
94
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used, the choice of which depends on the service requirements
of the product. After mixing, the compound is sheeted out on
a sheeting mill and dipped in a soapstone slurry.
Extrusion - After compounding, the rubber stock passes
through a warmup mill and then through an extruder where it is
continuously formed into the shape of the final product. This
green product is cooled in a cooling tank prior to vulcaniza-
tion and, in some cases, dipped in a soapstone slurry for
temporary storage.
Vulcanization - In the vulcanizing process, extruded
articles are placed in pans which are set on a truck and rolled
into a large steam chamber or heater. Varnish or lacquer may
be applied before vulcanization to produce a smooth, glossy
finish.
Rubber articles that would sag or flatten under their own
weight before they could completely set up must be supported
during vulcanization. In most cases, such articles are embedded
in talc or powdered soapstone. However, rubber tubing is placed
on a mandrel and wrapped with fabric to insure proper curing.
Vulcanization usually requires about 30 minutes at 140°C to
150°C.19
8.1.3 Coated Materials
Rubber-coated materials generally consist of woven or
nonwoven fabrics impregnated with a rubber compound. Synthetic
rubber materials such as acrylic rubber, butadiene-aerylo-
nitrile, butadiene-styrene, chloroprene, chloro-sulfonated
95
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polyethylene, fluorinated polymeric compositions, polyisobuty-
lene, polysulfide, and silicone polymers are used to impart
physical properties, such as water and solvent resistance,
surface-release characteristics, abrasion resistance, and good
aging. Typical uses for rubber-coated textiles include rain-
coats, balloon bags, diaphragms, inflatable life rafts, pon-
toons, friction tape, and tarpaulins.
Compounding - Before the coating process, the rubber
stock is compounded by mixing a variety of extenders, pigments,
accelerators, and antioxidants with the raw crumb. The fabric
to be coated is usually pretreated at a separate facility, but
may be dipped in latex at the coating plant itself.
Coating - Rubber coating is performed by three- or four-
roll calenders. The three-roll calender applies the coat to
one side of the fabric, while four-roll calenders coat both
sides of the fabric simultaneously. The top roll of the three-
roll calender and the bottom and offset rolls of the four-roll
calender are run at different speeds than the center roll to
friction the rubber into the fabric in a uniform manner.
Vulcanization - Rubber-coated fabrics are cured at elevated
temperatures for periods of time ranging from ten minutes to
several hours. For long cures, the ovens may be as much as
30 feet high and hundreds of feet long. For shorter curing
cycles, the ovens are usually from 6 to 8 feet in height and
8 to 20 feet in length.29 Regardless of size, the curing
oven must have a uniform temperature distribution to obtain
96
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uniform product quality. After curing, the coated fabric is
cooled and rolled up for storage.
Building - Products such as rainwear, rafts, and pontoons
are built using dies or jigs to cut the coated material and
rubber cemented to join the various sections. This building
operation may or may not take place in the coating plant.
8.1.4 Latex-Based Dipped Goods
The largest volume latex-based dipped goods are household
gloves, surgical gloves, prophylactics, and balloons. The
very thin-walled goods are produced by a straight-dip method;
thicker walled items are made by coagulation dipping.
Compounding - Regardless of which dipping technique is
employed, the rubber latex and compounding ingredients must
first be brought into solution or dispersion form. Solution
is used when all of the ingredients are water soluble.
Frequently, however, the ingredients are not water soluble,
and it is necessary to emulsify the liquid ingredients and
disperse the solid materials in water.
Dispersions are prepared from coarse slurries of powder
and water containing small quantities of dispersing agents and
stabilizers. Typical dispersing agents are sodium 2-naphthylene
sulfonate with formaldehyde and an alkyl metal salt of sulfon-
ated lignin. These materials are usually employed in concen-
trations of less than one percent by weight.19 Emission of
these agents through evaporation can be expected.
97
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Physically, the dispersions are prepared with grinding
equipment such as colloid mills, ball and pebble mills, ultra-
sonic mills, and attrition mills. Colloid mills, which break
aggregates but which do not change particle size, are used for
clay, precipitated whiting, zinc oxide, and other such mate-
rials. The other types of mills mentioned are used to prepare
dispersions of sulfur, antioxidants, and accelerators which
require both aggregate and particle-size reduction.
Emulsions are prepared by exposing a coarse, aqueous
suspension of ingredients to intense shearing in a colloid
mill, an ultrasonic mill, or a homogenizer. A homogenizer is
a machine that forces the emulsion through a fine orifice
under high pressure.
In itself, the preparation of the latex compound is a
very simple operation consisting of weighing and mixing the
proper amounts of various solutions, emulsions, and dispersions.
This is done in a large tank with a mechanical agitator.
A flow schematic is shown in Figure 8-1.
Coagulation dipping - The coagulation solution is usually
a mixture of coagulants and organic solvents, such as ethanol
and acetone. Typical coagulants are calcium nitrate, calcium
chloride, and zinc nitrate. A surfactant is sometimes added
to the mixture to ensure good "wetting" of the forms, and
release agents are added in cases where the form has a compli-
cated shape and removal of the dipped goods is difficult. Talc,
clay, and diatomaceous earth are commonly used release agents.
98
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FORM
DRYING
(/i
s
&
o
COAGULANT LA
DIP ~*"
SPILLS
LEAKS
WASHDOWN
1
WASTEWATER
LATEX
STORAGE COM
li-COOLING
SPILLS "*- WATER
LEAKS .
WASHDOWN
I
WASTEWATER
COMPOUNDING
INGREDIENTS
SPILLS
LEAKS
WASHDOWN
1
WASTEWATER
CLEANING AGENT
AND RINSE WATER
FORM CLEAN FORM RETURN VIA CLEANING OPERATION
AND RINSE "
SPENT CLEAN ING
AND RINSE WATER
R'NSE jf COOLING RELEASE AGENT 1
WATER WASTEWATER WATER
RINSE
WATER
1
TEX DIP PRELIMINARY PRODUCT ° rR.Y' f? Vr™ COOLING PRODUCTS FORM PRODUCT DRYING
TANK DRYING OVEN """ RINSE "*" "4,0,^- TANK STRIPPING RINSE "" DUSTING
STAMPING PAfKARING
1
SPILLS SPENT ™ COOLING WATER o
LEAKS RINSE WATER 2S OVERFLOW g
WASHDOWN 1 ^ - i "
| WASTEWATER || WASTEWATER ^
WASTEWATER " ^
1 ' '
SPENT
RINSE WATER
WASTEWATER
IATFX STERILIZATION fc STERILIZATION
POUNDING TANK RINSE
' U^; COOLING
,-p..,,. WATER SPENT
LEAKS RINSE WATER
WASHDOWN |
| WASTEWATER
WASTEWATER
* VOLATILE ORGAN ICS
Figure 8-1. Flow diagram for the production of typical latex-based dipped items.29
-------
The actual dipping operation is carried out with glazed porce-
lain or polished metal forms transported through the various
processing units by a closed-loop conveyor. These forms are
dried and heated to 100°C to 120°C with subsequent emission of
volatiles in a conditioning oven prior to dipping in the
coagulation bath.29
After coating with coagulants, the forms are dipped in
the rubber latex compound. The coagulant film on the surface
of the form causes the rubber emulsion to "break." The latex
solids coalesce to produce a film of rubber that covers and
adheres to the form. These coated forms are passed through a
preliminary drying oven with subsequent emission of volatiles
so that the film does not disintegrate and wash away in the
subsequent washing step.
In the washing operation, the soluble constituents of the
rubber film are leached out and rinsed away in a water bath
maintained at 60°C to 71°C.29 Important constituents of the
leachate are the emulsifiers used in the original production
of the latex and metal ions from the coagulant mixture.
The washed forms are sent through a drying oven. In some
applications, such as rubber gloves manufacture, the goods are
not only dried, but they are heated sufficiently to roll the
rubber coating downward on itself to form a reinforced cuff
bead. Usually, the rubber goods are stamped with proprietary
brands and other information, such as size, in a stamping unit
after the drying process.
100
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The rubber products are cured in an oven at temperatures
ranging from 65°C to 95°C.19'29 After curing, the items are
cooled in a water cooling tank and mechanically stripped from
the forms, usually with the aid of a lubricating detergent.
The detergent is subsequently washed from the goods in a rinse
tank. The final manufacturing operation consists of drying
the goods, dusting them inside and outside with talc to pre-
vent sticking, and packaging.
In cases where sterilized products are required, such as
surgical gloves, the goods are immersed in a chlorine dip
tank. The free chlorine concentration in this tank is typ-
ically 1,000 mg/1. After disinfection, the goods are dipped
in a 7.5°C to 80°C water bath to remove residual chlorine.
These two operations generally occur between the postcure
cooling tank and the final drying and packaging operation.29
About once a week, it is necessary to clean the forms in
a bath containing a cleaning agent. If porcelain forms are
used, this cleaning agent is usually chromic acid (mixture of
potassium dichromate, sulfuric acid, and water). Once cleaned
the forms are passed through a rinse tank equipped with a
fresh water makeup and overflow to blow down the accumulation
of cleaning agent.
Straight dipping - The straight-dip method is the simplest
of the latex dipping operations. The forms are dipped directly
in the latex and removed slowly. After dipping, the form is
slowly rotated while the film is drying to ensure a uniform
101
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thickness. The films are dried at room temperature or in warm
air at 50°C to 60°C.29
Thicker articles can be made by a multiple-dipping pro-
cess with intermittent drying. Latex deposits vary from
0.005 to 0.10 inch per dip, depending on the viscosity of the
latex compound.29
8.1.5 Cement-Based Dipped Goods
Various products are formed by cement dipping, most
notably protective gloves worn by electrical workers. The
following discussion focuses on this glove manufacturing
process.
Compounding - The solid gum rubber for the cement recipe
is compounded in small Banbury mixers or compounding mills.
The gumstock additives include antioxidants, curing agents,
and pigments.
After mixing, the stock is milled into small particles
to facilitate its dissolution in the solvent. These rubber
particles are separated by weight into predetermined quantities
and placed in storage bins.
Rubber cement preparation - The rubber cement is prepared
in blend tanks using fixed amounts of rubber stock and solvent.
The solvent is usually aliphatic, e.g., hexane, or a blend of
petroleum spirits.
The blended cement is pumped to storage tanks prior to
the dipping operation. Several cements of different colors
and physical properties are prepared and stored simultaneously.
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Dipping - The gloves are formed by dipping glazed porcelain
forms into the rubber cement. The dipping is carried out auto-
matically and repeated until the desired thickness is reached.
In between dips, the gloves are allowed to drip dry, with
subsequent emission of volatiles to the plant atmosphere. The
temperature and humidity of the air in the drying room are con-
trolled to ensure good drying conditions.
When dipping and drying operations are completed, the
gloves are stamped with size and brand information and the
cuff bead is formed by rolling the existing cuff back on itself.
Curing - Vulcanization is carried out in an open steam
autoclave. The temperature and length of the cure depend on
the type of glove being worked and the properties of the rubber
used in its formation.
At the end of the curing cycle the gloves are removed
from the vulcanizer and partially air cooled. Prior to final
cooling they are dipped in a soapstone slurry. The slurry
dries, leaving a powder on the gloves, which is then stripped
from the form, dusted with talc in a rotating drum, and sent
to the inspection area.
Periodically, the forms require cleaning. This opera-
tion is carried out with a scouring slurry followed by rinsing
in water.
8.1.6 Rubber Goods From Porous Molds
Dolls, squeeze toys, and other rubber sundries are pro-
duced by the porous mold technique.
103
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The molds used in this process are made from plaster of
Paris or unglazed procelain with pore sizes smaller than the
smallest rubber particles. Latex, compounded in the manner
previously described, is poured through a funnel-shaped opening
into the mold where it is allowed to dwell until a deposit of
the desired thickness has developed on the mold wall. The
mold is then emptied of excess compound and placed in an oven
to dry at 60°C.29 The interior surfaces of the rubber article
are dusted with talc to prevent sticking when it is removed
from the mold. Once it is removed, the article may be returned
to the 60°C oven for 30 minutes.
8.1.7 Latex Thread
Latex thread is produced by extruding the latex compound
through fine orifices into a coagulant bath where it is gelled.
The thread is then toughened, washed, dried, and cured.
Dilute acetic acid is commonly used as the coagulant.
8.1.8 Latex Foam
The latex used in foam manufacture may consist of natural
rubber, SBR, or a combination of the two. Before processing,
this latex is compounded with a variety of ingredients as
described in the latex dipping procedure.
The foams produced are generally in slab or molded form
in the density range of 64 to 128 kg/m3 (4 to 8 lb/ft3).29
They are used to manufacture automotive seating, mattresses,
pillows, carpeting, scatter mats, upholstery, and many other
products.
104
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Dunlop process - In the Dunlop process, the foam is pro-
duced by mechanically whipping the latex to a froth. This can
be done on a batch basis, but the Oakes continuous mixer is
the standard piece of equipment for this operation.
Once frothed, the latex must be coagulated to give a
stable foam. This coagulation, or gelation, is effected by
adding sodium silicofluoride and zinc oxide to the mix. These
gelling agents remain dormant long enough to allow the froth
to be poured into molds. When stable latexes are used,
secondary gelling agents may be required to induce coagulation.
Cationic soaps, other salts, and amines are commonly used for
this purpose.
As soon as the gelling agents are added, the foam is
poured into steam-heated molds and cured, with subsequent emis-
sion of volatiles. The product is removed when the curing
cycle is completed and washed with water to remove those
ingredients in the latex recipe which are not permanently held
in the foam matrix. The foam is then dried in a hot-air dryer
and inspected prior to storage and shipment.
Talalay process - In the Talalay process, the froth is
produced by chemical rather than mechanical means. Hydrogen
peroxide and enzymatic catalysts are mixed into the latex, and
the mixture is placed into a mold. The enzyme decomposes the
peroxide, thus liberating oxygen, which causes the latex mix
to foam up and fill the mold. This foam is rapidly chilled,
and carbon dioxide is introduced to effect gelation. The
105
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gelled foam is handled in a manner similar to that used in the
Dunlop process.
A flow schematic is shown in Figure 8-2.
Foam backing - For supported, flat-stock foam, a different
type of gelation agent is used in place of the sodium silico-
fluoride formula used in latex foam. Either ammonium acetate
or ammonium sulfate is employed in combination with zinc oxide.
The froth is prepared with an Oakes mixer, the gelling
agent is added, and the foam is applied to the fabric by direct
spreading. The gelling is carried out at elevated tempera-
tures, usually with the aid of infrared lamps.
To prevent uneven shrinkage, the fabric is carried through
the high-temperature zone and drying ovens on tenters.
8.2 EMISSIONS
Table 9 is a summary of the volatile organic emissions
from the production of fabricated rubber goods. Emission
factors for solvent use are estimated from data supplied from
a plant visit. Rubber volatile emission factors are estimated
as presented in Appendix F.
8.2.1 Compounding
As previously described in Section 4.3.1, the emission
factor is calculated to be 0.1 g/kg of product.
In some cases, the foam is spread on a belt which transfers
it to the fabric.
106
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LATEX
STORAGE
CONDENSER
•-* . rnoi iwr
, , WATER
CONDENSATE
WASTEWATER
CONDENSER
*
WATER
VAPOR y*
FREEZE
AGGLOMERATION
LATEX
CONCENTRATION
BY
EVAPORATION
S
CONCENTRATED INTERMEDIATE
LATFX U
LA W STORAGE
CARBON I
DIOXIDEGAS SPILLS
WASHDOWN
.
WASTEWATER
COMPOUNDING AND
CURING AGENTS
s*
GROUN
LATEX CUR INC
*" COMPOUNDING *
X
5
25
fee
1
O
UJ
Z
i
SPILLS
WASHDOWN
1
WASTEWATER
-
) BALL MILL
GRINDING OF
COMPOUNDING
AGENTS
ti
s*
! "-"-COOLING
WATER
SPILLS
LEAKS
FOAM PRODUCT
STORAGE AND
SHIPMENT
FOAM
DRYING
W
/**
CLEAN
FOAM
ATER
fOI
RINS
STE
i
\M
ING
PS
RINS'E WATER
| COUNTER-
CURRENT
FO
RINS
STE
W
ING
PS
|
FOAM
PRODUCT
o
O_
o
o
FOAM CURING
PRESSES
WASHDOWN
CARBON
"DIOXIDEGAS
^VOLATILE ORGANICS
RINSE
WASTEWATER
SPILLS
WASHDOWN
WASTEWATER
Figure 8-2. Flow diagram for the production of typical latex foam items.29
-------
Table 9. VOLATILE ORGANIC EMISSIONS FROM THE PRODUCTION
OF FABRICATED RUBBER GOODS
Emission source
Bonding of parts
Adhesive spraying
Latex dipping
Molding
Compounding
Curing
Milling
Calendering
Extrusion
TOTALS
Emission factor,
g/kg of rubber
2.0
118 b
0.13b
0.11°
0.1
0.08°
0.05
0.025C
0.015
4.31
a
Emission type
Solvent
Solvent
Solvent
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Percent
46.4
41.76
3.0
2.6
2.3
1.8
1.2
0.6
0.3
d
99.96
Cumulative
percent
46.4
88.16
91.16
93.76
96.06
97.86
99.06
99.66
99.96
99.96
Solvent emissions account for 91.16% of volatile organic emissions.
Rubber volatiles account for 8.8%.
Assumed to be utilized in 25% of the final product weight.
Q
Assumed to be utilized in 50% of the final product weight.
Totals do not add to 100% due to rounding errors.
8.2.2 Molding
As previously described in Section 5.2.5, the emission
factor for molding operations is calculated to be 0.22 g/kg
of product.
8.2.3 Extrusion
As previously described in Section 4.3.5, the emission
factor is calculated to be 0.03 g/kg of product.
8.2.4 Connection of Extruded Rubber Parts
Rubber cement is applied to bond various rubber parts
together. Utilizing solvent consumption data for these opera-
tions and annual production rates for an assumed representative
plant, an emission factor is calculated to be 2.0 g/kg of
product produced.
108
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8.2.5 Curing of Rubber Parts
Usually done in a batch operation, curing of fabricated
rubber goods is very similar to batch curing of other rubber
products such as small hose. Utilizing the assumptions
presented for other batch curing emissions presented in
Section 5.2.4, the emission factor is calculated to be 0.16 g/kg
of product produced.
8.2.6 Latex Dipping and Drying
As previously described in Section 5.2.3, the emission
factor is calculated to be 0.5 g/kg of product.
8.2.7 Adhesive Spraying
As in other cement applications, spraying is done to
tackify the various rubber parts. The operation usually takes
place in a booth. Utilizing solvent consumption data for
this operation for an assumed representative plant, the emis-
sion factor is calculated to be 1.8 g/kg of product.
8.2.8 Milling
As previously described in Section 4.3.2, the emission
factor for milling activities is calculated to be 0.05 g/kg of
product.
8.2.9 Calendering
As previously described in Section 4.3.4, the emission
factor for calendering operations is calculated to be 0.05 g/kg
of product produced.
109
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9. GASKETS, PACKING AND SEALING DEVICES
9.1 PROCESS DESCRIPTION
The principal method of manufacturing gaskets, packing
and sealing devices is molding. This process description29
will consist mainly of general explanations of the three com-
mon molding techniques - compression, transfer, and injection.
The selection of a particular method depends on the rubber
stock used in the production economics. All three molding
techniques are commonly practiced at a single plant location.
Information specific to SIC 3293, as obtained from two selected
plants,29 will follow the general discussion.
Larger molding facilities, or those using special recipes
or nonstorable stocks, compound their own rubber stock from
basic ingredients. Compounding is performed in either a Ban-
bury mixer or a compounding mill. In some plants, airborne
particulates generated during compounding are controlled by
wet scrubbing equipment.
9.1.1 Compression Molding
After compounding, the rubber stock is processed on a
warmup mill and formed to the approximate shape required for
molding by either calendering or extrusion. The formed
110
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rubber is cooled, often in an open tank, and then dipped in
an anti-tack agent, generally a zinc stearate solution or its
equivalent. Soapstone slurry is not used because of its
adverse effects on the quality of the subsequent molding
operation.
The preforms are prepared from the calendered or extruded
rubber stock by cutting, slicing, or stamping. Cutting may be
performed by hand or by machine. Slicing is usually carried
out on a meat slicing machine or guillotine. Although the
exact shape of the preform is not critical, it must contain
sufficient rubber to fill the mold.
The preforms are placed into the open mold, usually by
hand. Sometimes, this is preceded by application of release
agents (powder or liquid) on the mold surfaces. The mold is
closed and held, normally by hydraulic oil pressure, during
the curing cycle. The molds are generally heated by steam
flowing through channels in the mold plates. Some older sys-
tems are electrically heated.
When the molding cycle is complete, the items are removed
and sent on to the deflashing operation. The rubber overflow,
or flash, must be removed from each piece before shipping.
Usually, deflashing is accomplished using a grinding wheel or
press-operated dies. In cases where the rubber is not freeze
resistant, the molded articles are tumbled in dry ice (solid
carbon dioxide) using machines similar to cement mixers. The
thin rubber flash becomes brittle and breaks off during tumbling
111
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while the larger main body of the part is not cooled as much
and remains flexible.
Although not strictly a part of rubber processing, the
manufacture of metal-bonded items, which consist of a molded
rubber component attached to metal, is often undertaken in the
same plant as the molding operation. Grease on the metal
parts, picked up during their production or applied later for
storage and shipping purposes, must first be removed. Degreas-
ing may be performed in a rotating drum wherein the metal part
is contacted with a suitable solvent, such as trichloroethylene
(CHC1=CC12)•
The metal surface to which rubber is to be molded must be
further prepared to provide satisfactory adhesion. In a few
cases, the metal part is pickled with acid. More often, the
bonding surface is sand blasted for roughening and then coated
with rubber cement. This last operation is done by hand for
small items, whereas larger metal surfaces are sprayed with
cement. The prepared metal part and its mating rubber com-
ponent are then placed in the mold cavity and processed in the
same way as an all-rubber product. Deflashing is done by hand
or with a grinding wheel.
In some molding plants, molded items of poor quality are
recycled to reclaim the metal component. The reject rubber is
ground and buffed from the metal, which is then sand blasted
clean. Grinding and buffing create airborne particulates,
which are controlled by wet scrubbers.
112
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9.1.2 Transfer Molding
Rubber for transfer molding is compounded in the same
way as that for compression molding. The rubber stock blanks,
to be fed into the mold's transfer pot, take the form of
slabs as they are cut from extruded or sheeted rubber stock.
The weight of the blanks is brought within a specified tolerance
by trimming. Underweight blanks and trimmings are recycled
to the sheet-out mill.
The transfer cavity, into which a rubber blank is placed,
is fitted with a ram or piston. The applied force plus the
heat from the mold cause the rubber to be softened and flow
into the molding cavity, curing simultaneously. Transfer
molds are normally heated by steam and operated by hydraulic
oil systems. The molded item is deflashed by one of the
methods described for compression-molded items.
Articles containing metal inserts are usually manufactured
by transfer molding, preparation of the metal component fol-
lowing that described for compression-molded products.
9.1.3 Injection Molding
Injection molding, the newest technique, is basically
the same as transfer molding except that the rubber stock is
injected into the mold cavities. There are three types of
injection-molding machines: one uses a ram to force the soft
rubber through runners into the cavities; another uses a
screw; the third uses a reciprocating screw, a combination of
the first two. As the rubber flows through small passages
113
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under high pressure, the temperature increases and the com-
pound is cured.
The molds are often mounted on a revolving turret which
permits cyclic operation. To make injection molding profit-
able, very short cycle times are required, generally ranging
from 45 seconds to 90 seconds.29 This necessitates curing
temperatures of approximately 204°C.29 Deflashing can be
carried out by any of the techniques used for compression-
and transfer-molded products.
9.2 SELECTED PLANTS
Information on these plants is available from the open
literature.2 9
9.2.1 Plant A
This plant manufactures oil seals, o-rings, rubber-to-
metal molded items, and miscellaneous molded rubber products,
using compression and transfer molding. Its average daily
rubber consumption is 340 kg.29
The plant's flow sheet contains the following apparatus
described in the discussion of compression molding:
• Warmup mill
• Extruder
• Guillotine (for cutting)
• Modified meat slicer (for slicing)
• Hydraulic mold presses
• Steam-heated molds
114
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Two operating parameters are given. The mold presses
operate at 13.8 MPa (2,000 psi).29 Steam used for heating
the molds is at 177°C and 862 kPa (125 psi).29
Molded items are deflashed in a "wheelabrator" machine,
which freezes the item with liquid nitrogen and then blasts it
with steel shot that is 0.18 mm to 0.30 mm in diameter.29 The
rubber fines and shot are separated, and the fines and dust
are collected in a bag collector.
Metal parts for composite products are degreased using
perchloroethylene (Cl2C=CCl2) vapor. The bonding surface is
then sand blasted and finally painted with a bonding agent such
as rubber cement.
9.2.2 Plant B
This plant produces rubber pipe seals, weather stripping,
and rubber-to-metal molded items. The daily rubber consump-
tion is 10,100 kg.29
Compounding is done using a Banbury mill. Rubber stock,
batched off in sheets, is protected against sticking during
storage by dipping it in soapstone.
Pipe seals, weather stripping, and molding plugs are
formed using short- or long-barrelled extruders. The former
require warmup and strip-feed mills, whereas the latter do
not. The extruded pieces are cooled, dipped, cut, and placed
in pans for autoclave curing. The rubber articles are then
cured with steam at 690 kPa (100 psi).29
115
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The ends of pipe seal rubber are cemented together in an
electric press to form large, o-ring-type pipe seals. When
bonding rubber to metal, the metal part is degreased, using
trichloroethylene in a closed system, and then sprayed with an
adhesive. The rubber is transfer molded to the metal part.
A flow schematic is shown in Figure 9-1.
9.3 EMISSIONS
Table 10 is a summary of the volatile organic emissions
from the production of rubber gaskets, packing and sealing
devices. Solvent data supplied during a plant visit are used
to estimate solvent emissions. Rubber volatile emission fac-
tors are estimated as presented in Appendix F.
Table 10. VOLATILE ORGANIC EMISSIONS FROM THE PRODUCTION OF
RUBBER GASKETS, PACKING, AND SEALING DEVICES
Source
Adhesive spraying
Molding
Compounding
Milling
Calendering
TOTALS
Emission factor
g/kg of rubber
3.6
0.22
0.1
0.05
0.05
4.02
a
Emission type
Solvent
Rubber volatiles
Rubber volatiles
Rubber volatiles
Rubber volatiles
Percent
89.5
5.5
2.5
1.2
1.2
99. 9b
Cumulative
percent
89.5
95.0
97.5
98.7
99.9
99. 9b
Solvent emissions account for 89.5% of volatile organic emissions.
Totals do not add to 100% due to rounding errors.
116
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y
MOLDED
PRODUCT
PRODJJCT
SHIPMENTS
PARTICULATES
(ORGANIC)
^VOLATILE ORGANICS
Figure 9-1. Schematic flow for manufacture of molded rubber products.29
-------
9.3.1 Compounding
As previously described in Section 4.3.1, the emission
factor for compounding operations is calculated to be 0.1 g/kg.
9.3.2 Molding
As previously described in Section 5.2.5, the emission
factor for molding is calculated to be 0.22 g/kg of product.
9.3.3 Adhesive Spraying
As in other fabricated rubber industries, spraying of
cement is done to tackify the rubber/metal parts before as-
sembly molding. Utilizing solvent consumption data for this
operation from an assumed representative plant, an emission
factor if calculated to be 3.6 g/kg of product produced,
assuming no solvent leaves as part of the finished product.
9.3.4 Milling
As previously described in Section 4.3.2, the emission
factor for milling operations is calculated to be 0.05 g/kg of
product.
9.3.5 Calendering
As previously described in Section 4.3.4, the emission
factor for calendering operations is calculated to be 0.05 g/kg.
118
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10. NONFERROUS WIREDRAWING AND INSULATING
10.1 PROCESS DESCRIPTION
Extrusion is the preferred method of applying a rubber
compound to wire or cable for the purposes of insulating and/or
protective covering. When using a suitably modified extruder,
plastics as well as rubber may be employed as insulation.
A wire to be covered is passed through a right-angle or
side-delivery head. In this operation, the wire is fed through
the head in a direction perpendicular to the axis of the extru-
der screw. The head is designed so that the rubber compound
is deflected 90° and completely surrounds the wire.
The covered cable is pulled through the machine by a
variable-speed hauloff. A satisfactorily uniform coating is
ensured by regulation of the drawing speed.
Continuous vulcanization of insulated wire is accomplished
by extrusion directly into a suitable curing device. This is
usually just a tube fixed to the nozzle of the extruder and
filled with steam at pressures from 1.38 MPa to 1.72 MPa
(13.6 atm to 17.0 atm).l9 Such tubes may be 30.5 meters to
61 meters (100 feet to 200 feet) in length.19 Residence time
for the insulated wire is approximately 15 seconds.19 Glands
119
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through which the cable exits the tube prevent leakage of steam,
Large cables are usually processed in vertical units, but hori-
zontal or cantenary-shaped tubes are also available.
The exterior of insulated wire or cable must be protected
against mechanical and sometimes chemical deterioration. The
type of protective covering applied will depend on the ultimate
end use of the cable. Small wires are covered with a braid,
normally of cotton but possibly of rayon or fine metallic wire.
Another means of protection, tough rubber sheathing (TRS), can
be applied to the insulated wire using an extruder with a side-
delivery head as described previously. The sheathing may con-
sist of neoprene (polychloroprene) or another oil-resistant
rubber. Lastly, some insulated wires and cables may be covered
by an extruded lead sheath explained earlier as a means of
support during vulcanization?^
Two representative flow schematics are shown in Figures
10-1 and 10-2.
10.2 EMISSIONS
Table 11 is a summary of the volatile organic emissions
from nonferrous wiredrawing and insulating.
10.2.1 Compounding
As previously described in Section 4.3.1, the emission
factor for such operations is 0.1 g/kg of product. During
this study, it was found that greater than 70 percent of
3ttMcPherson, A. T., and A. Klemin. Engineering Uses of Rubber.
New York, Reinhold Publishing Corp., 1956. p. 265-269.
120
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JACKETING
EXTRUSION
INSULATOR
CONTINUOUS
VULCAN IZER
JACKETING
* VOLATILE ORGANICS
Figure 10-1. Schematic flow diagram for production of insulated wire and
cable using thermosetting polymers (i.e., butyl rubber, neoprene,
nitrile rubbers, silicone rubbers, styrene-butadiene rubbers).
-------
SYNTHETIC
RUBBERS,
CHEMICALS
COMPOUNDING,
MIXING,
MILLING
^VOLATILE ORGANICS
RUBBER
STOCK
———•*»
GRANULATING
RUBBER STOCK
RUBBER STOCK
JACKETING
EXTRUSION
INSULATING
V
TAPE
CALENDERING
V
PRODUCT
SHIPMENTS
Figure 10-2. Schematic flow diagram for production of insulated wire and cable
using thermoplastic polymers (i.e., polysulfide rubbers).
-------
Table 11. VOLATILE ORGANIC EMISSIONS FROM NONFERROUS
WIREDRAWING AND INSULATING
Source
Extrusion
Curing
TOTAL
Emission factor,
g/kg rubber
produced
0.04
0.6
0.64
Emission type,
solvent evaporation/
rubber volatilization
Rubber volatilization
Rubber volatilization
Percent
total
emission
6.3
93.7
Percent total emissions rubber volatilization derived: 100%
wiredrawing plants buy rubber stock already compounded, and in
these plants, no such emissions will exist.
10.2.2 Milling
As mentioned in compounding, with greater than 70 percent
of the plants buying precompounded stock, the rubber is bought
in strips requiring no further milling activities. The strips
can be fed directly to the extruder.
10.2.3 Extrusion
The wire is coated by drawing through an extrusion device.
As no source testing data were located to allow an emission
factor for wiredrawing extruders, the value of 0.04 g/kg
used for other extruding operations is assumed.
10.2.4 Curing
As previously described for continuous curing operations
in Section 7.2.6, the emission factor is calculated at 0.6 g/kg
of product.
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11. TIRE RETREADING
11.1 PROCESS DESCRIPTION
The tire retreading process consists of a series of
eight unit operations through which worn tires are rendered
serviceable and fit for resale. With the exception of studded
snow tires, nearly every tire size and design is utilized by
the industry. The majority of retreaders receive their tires
from scrap dealers, but turn-ins are also a popular source of
supply.
Raw camelback is nearly always purchased from an outside
supplier. Very few retreaders compound their own stock.
11.1.1 Receiving and Sorting
On arrival, the tires are first inspected to determine
whether or not the casing and carcass are in good condition.
There should be no cuts or visible deterioration of the
reinforcing fabric. Hidden ply separations, the major cause
of tire failure, are detected by injecting air into the tire
shoulders. Since trapped air itself may cause ply separation,
the tire is vented in the bead area so the air can escape
during molding or on highway flexing.
124
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Tires unfit for retreading are usually passed on to the
reclaiming industry.
11.1.2 Buffing
After sorting, the tires are sent to the buffing area
where the remaining tread is ground off with a grinding wheel.
The basic objective in this operation is to develop proper
dimensions of the buffed casing to provide an exact fit for
the retread.
11.1.3 Cleaning
The surface of each newly buffed tire is rendered dust
free with a stiff wire brush.
11.1.4 Measuring
The clean tire is measured in order to select the correct
curing rim and to assure a tight fit in the matrix. Tires can
grow up to seven percent of their original width from road
use, so both the width and wall thickness must be measured.11
11.1.5 Rubber Cement Spraying
Once measured, the tires are taken to the spray area
where they are coated with vulcanizable rubber cement.
11.1.6 Tread Winding
When the surface of the tire is coated with cement,
strips of tread rubber are wound circumferentially around it
and cut to length.
Some retreaders "program" the tread on. In this opera-
tion, the machinist selects a profile to build and the machine
automatically wraps the thin strand of tread until the exact
125
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contour is obtained. The tread-winding process typically
requires about 4.53 kg (10 Ib) of camelback per passenger-car
tire and 15.85 kg (35 Ib) per truck tire.29
11.1.7 Curing
Each tire goes into a mold for curing at some specified
temperature for some predetermined length of time. Most curing
molds are steam heated, but some older ones are electrical.
In newer plants, precured tread is used. Tires built under
the precure system are placed in an autoclave to be vulcanized
to the buffed casing -
11.1.8 Finish Buffing
After curing, the rubber flash is buffed off and the
finished product is inspected and shipped.
A flow schematic is shown in Figure 11-1.
11.2 EMISSIONS
Table 12 is a summary of the volatile organic emissions
from tire retreading. Solvent emission factors are based on
data supplied during plant visits. Rubber volatile emission
factors are estimated as presented in Appendix F.
Table 12. VOLATILE ORGANIC EMISSIONS FROM TIRE RETREADING
Emission source
Painting and trimming
Cement spraying
Curing
TOTALS
Emission factor,
g/kg of rubber
3.2
2.75
0.09
6.04
Emission typea
Solvent
Solvent
Rubber volatiles
Percent
53
45.5
1.5
100
Cumulative
percent
53.0
98.5
100
Solvent emissions account for 98.5% of volatile organic emissions.
Rubber volatiles account for 1.5%.
126
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RECEIVING
AND SORTING
BUFFING
CLEANING
MEASURING
RUBBER
CEMENT
SPRAYING
TREAD
WINDING
CURING
BUFFING
INSPECTION
MID SHIPPING,
•fr VOLATILE ORGANICS
Figure 11-1. Retreading flowsheet.
127
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11.2.1 Rubber Cement Spraying
Usually in a spray booth, the tire to be retreaded is
sprayed with a cement immediately before the new tread is
applied. Utilizing solvent consumption data for this operation
supplied by an assumed representative plant, the emission factor
is calculated to be 2.75 g/kg of rubber. A representative range
is estimated to be 1.8 to 5.4 g/kg of rubber. In addition, de-
pending on how the new tread is applied, the tread itself may
be coated with cement. No quantification of this point was
found; however, this method of applying new tread is thought
to be rapidly disappearing. The major process of programming
the tread on involves no application of cement to the tread
itself.
11.2.2 Curing
Because only the new tread is "green," or unvulcanized,
emissions due to curing are substantially less in retreading
than in new tire curing. The emission factor for curing is
calculated to be 0.09 g/kg of rubber, based on the assumption
that 40 percent of the retread tire is "green" and that the
same curing conditions utilized in new tire curing are used
in retread curing.
11.2.3 Paint and Trim Operations
The retread tire, after curing, may be coated or cleaned
to give the tire a more aesthetically pleasing look. The
cleaning or coating solution used may be either water based,
solvent based, or both. The emission factor for this point
128
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is calculated to be 3.2 g/kg, based on solvent consumption
data for this operation supplied by an assumed representative
plant. An expected range in this factor is estimated to be
from 2.5 to 7.4 g/kg of rubber.
129
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12. CONTROL TECHNOLOGY35"55
12.1 SOLVENT AND/OR MONOMER STORAGE
12.1.1 Industries to Which the Control is Applicable
Synthetic Rubber Production
12.1.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Styrene storage Floating covers 80
Hexane storage Adsorption 80
Butadiene storage Emergency flare 70
Fugitive sources Housekeeping 50-80
12.1.3 General Description
Floating covers are considered state of the art control for
storage tanks. Regulations currently are in effect demanding
such control. The use of such covers is widespread in the
petrochemicals industry. This method of control is estimated
to result in an 80 percent reduction in emissions.
Adsorption is also considered state of the art control for
storage tanks. With the emission confined to a vent, the prob-
lem of obtaining a high collection efficiency is alleviated. In
addition, any recovered monomer and/or solvent would have the
potential to be reused and thus could be considered a savings
35-55See section 14, References, for full citations of these
references.
130
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against which to weigh initial capital and everyday operating
expenses. Again, this type of control is known to exist in the
petrochemicals industry. Eighty percent reduction is estimated.
In the case of butadiene storage, the volatility and
exposure potential of the monomer has warranted the use of
emergency flare systems to control any releases of butadiene.
A representative plant will have installed such equipment and
can expect the emission reduction to be 70 percent due to incom-
plete combustion of the gas. Flaring is thus also considered
state of the art control for storage tanks.
As noted previously, fugitive emissions from the monomer/
solvent storage area result from leaks in compressor seals,
pump seals, and pipeline valves. The largest emission source
of the three is indicated to be pipeline valves. Housekeeping
such as daily inspection and immediate repair of pumps and
valves should result in reducing these emissions 50 to 80 per-
cent. An inspection schedule such as visual inspections every
6 hours and repair within 2 hours or regular head space hydro-
carbon measurements around all pumps and valves with immediate
repair of areas exceeding a designated concentration is con-
sidered practical control.
12.1.4 Cost of Control
Cost of the add-on floating cover was estimated for an
existing fixed cover storage tank with a capacity of 75,700
liters (20,000 gal). The incremental capital cost for the
installation of an interval floating cover is approximately
$18,000. The annualized operating cost is $3,600 including
131
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maintenance, depreciation, property tax, insurance, and
interest charge on capital. This operating cost does not
include the savings due to the reduction of emission loss of
chemical to the atmosphere. If the original loss is greater
than 17,032 liters (4,500 gal)/yr from the 75,700 liter (20,000
gal) tank (which is very likely, depending on the condition of
the storage tank), and assuming that the market value of the
chemical is $0.26/liter ($1.00/gal), 80 percent reduction in
loss due to installation of the floating cover will result in
a net saving.
The capital cost for a smokeless tip flare system that can
be used to control emissions both from the storage tank farm and
from the butadiene recovery scrubber vent is about $25,000. The
operating cost for the flare system is approximately $8,000/yr,
including cost of process water and fuel needed to produce steam
for the smokeless tip.
12.2 POLYMERIZATION OR REACTOR SECTION
12.2.1 Industries to Which the Control is Applicable
Synthetic Rubber Production
12.2.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Reactor (fugitive) Housekeeping 50-80
12.2.3 General Description
In both solution and emulsion polymerization, fugitive
emissions from compressor seal, pump seal, and pipeline valve
132
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leaks exist. in emulsion, the emissions are styrene and buta-
diene. In solution, the emissions also include hexane. No
emission from the reactor itself exists due to the polymeriza-
tion reaction occurring in covered, pressurized vessels. This
was observed at visited plants. Better housekeeping through
daily inspections should result in 50-80 percent reduction in
fugitive emissions, as mentioned in Section 12.1.3.
12.3 SOLVENT PURIFICATION
12.3.1 Industries to Which Control is Applicable
Synthetic Rubber Production
12.3.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Solvent purification Housekeeping 50-80
(fugitive)
12.3.3 General Description
In solution polymerization, unreacted monomer/solvent is
recovered, separated, and reused. Emissions from leaks in
compressors, valves, and pumps again exist. These fugitive
emissions, as mentioned earlier, could be reduced by increased
inspection and monitoring.
12.4 BUTADIENE RECOVERY
12.4.1 Industries to Which Control is Applicable
Synthetic Rubber Production
12.4.2 Summary of Available Control Technology
133
-------
Control system Percent
Affected facility or strategy reduction
Butadiene recovery Adsorption, 90
incineration,
or flare 90
Fugitive Housekeeping 50-80
12.4.3 General Description
In emulsion polymerization, vacuum distillation is used
to recover unreacted butadiene. This butadiene is sent either
to an adsorber or absorber (scrubber) to collect the monomer,
usually followed by condensation and decantation. For the pur-
poses of this report, the absorber or adsorber is considered
part of the process, and not a pollution control device. For a
representative plant, the absorber efficiency can be expected
to be 96-97 percent. Even after absorption, the exiting gas
will, in some cases, contain a high enough concentration to
exceed the point source limitation of 18.2 kg/day. This
situation is even more true in the case of latex production.
In a representative plant, the emission, after absorption,
is sent to an emergency flare system. Reduction is estimated
at 70 percent due to incomplete combustion of the emission.
Adsorption is also feasible because 1) data indicate that the
gas flow rate is low (80-100 scfm) and 2) the butadiene con-
centration of the exit gas is high (2-3 percent by volume).
Again, a potential savings in additional recovered buta-
diene would exist if this control option was implemented. Based
on normal carbon adsorption removal efficiencies, reduction is
estimated at 90 percent.
134
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Thermal incineration is also technically feasible although
it requires additional fuel and does not allow for recovery of
the butadiene. Based on normal removal efficiencies common to
thermal incineration, reduction is estimated at 90 percent.
Fugitive emissions also exist in this area. Better house-
keeping will result in a reduction of emission from 50 to 80
percent, as mentioned previously.
12.4.4 Cost of Control
Using the emission factor presented in Section 3 for the
butadiene recovery absorber vent and assuming a hydrocarbon con-
centration of 3.5 volume percent in the vent gas, the flow rate
of this gas stream was estimated to be 0.03 m3/s (60 scfm) for
a plant with an annual production of 120,000 metric tons of
emulsion SBR. For control of this emission source by incinera-
tion or by carbon adsorption, dilution of the vent gas to a
concentration below 25% LEL is necessary. The total gas stream
to be treated thus becomes 0.25 m3/s (500 scfm).
The costs of incineration and carbon adsorption systems
for the diluted stream are presented in Tables 13 and 14,
respectively. The items calculated included capital cost,
annualized cost, and cost effectiveness (in terms of $/ton of
hydrocarbons removed). For the incinerator, the fuel require-
ments are also given. Due to the small gas flow rate, primary
and secondary heat recovery do not provide much of a reduction
in cost effectiveness for incineration. The economic assump-
tions used in cost calculations are discussed in Appendix G.
The economics of using a flare system for control of this
135
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Table 13. INCINERATION COSTS FOR A TYPICAL BUTADIENE
RECOVERY OPERATION
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
57,000
56,000
83,000
64,000
100,000
72,000
Annualized
operating
cost,
$/yr
18,000
15,000
17,000
14,000
15,000b
13,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
280
230
260
220
230b
200b
Fuel
requirement,
mVyr
fuel oil
74
17
48
11
26b
6b
co
q
Gas flow rate of 0.25 irr/s (500 scfm) , temperature of 21°C (70°F) , hydrocarbon concentration
of 25% LEL.
Assumes heat is recovered and used.
-------
Table 14. CARBON ADSORPTION COSTS FOR A TYPICAL
BUTADIENE RECOVERY OPERATION3
Adsorption device
Capital
cost,
$
Annualized
operating
cost,
$/yr
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
Case with no credit for
recovered solvent 50,000
Case with recovered solvent
credited at fuel value 50,000
21,000
16,000
320
250
SGas flow rate of 0.25 m3/s (500 scfm), temperature of 21°c (70°F),
hydrocarbon concentration of 25% LEL.
source, together with emissions from the storage tank farm,
have been
have been discussed in Section 12.1.4.
12.5 DESOLVENT AREA, SOLUTION POLYMERIZATION
12.5.1 Industries to Which Control is Applicable
Synthetic Rubber Production
12.5.2 Summary of Available Control Technology
Affected facility
Solvent recovery
Desolvent area
Control system Percent
or strategy reduction
Steam stripping 50
efficiency increase
Collection/ 90
incineration
Carbon adsorption 90
Housekeeping 50-80
Fugitive
12.5.3 General Description
After leaving the reactor area, the slurry is coagulated
and the unrecovered butadiene, styrene, and hexane steam strip-
ped, separated and recycled for future use. The crumb slurry
is then sent to surge tanks until the operations of dewatering
137
-------
and drying can commence. Because of the strong affinity of the
crumb for hexane, substantial quantities of unreacted hexane
remain in the crumb after steam stripping.
To control this release of hexane both in the desolvent
area and subsequent downstream operations, the use of increased
stripping capacity will aid in recovering more hexane and
reducing subsequent emissions. One plant is known to be cur-
rently designing for such a stripping capacity increase. They
estimate a reduction of 50 percent in emissions. This control
alternative will be discussed further in the following section
on dewatering and drying.
Another control alternative is incineration. Because the
surge tanks are vented, collection of the emission would pose
little difficulty. A reduction of the emissions from the surge
tank of 90 percent is estimated assuming that common removal
efficiencies utilizing incineration can be expected.
In addition, emissions from the surge tank could also be
recovered using carbon adsorption. A reduction of 90 percent is
assumed achievable if removal efficiencies common to carbon
adsorption can be expected.
In addition, fugitive emissions can be controlled by 50-80
percent if more stringent housekeeping is practiced, as pre-
viously discussed.
12.5.4 Cost of Control
To increase steam stripping efficiency, redesign of the desol-
vent facility will be necessary. The steam rate applied and
138
-------
the capacity of the condenser will have to be increased. In-
formation is not sufficient to make an estimate on the cost of
this process modification.
The cost of incineration and carbon adsorption systems for
control of this source were estimated based on a gas flow rate
of 5 m3/s (11,000 scfm), gas temperature of 21°C (70°F), and
a hydrocarbon concentration at 560 ppm based on hexane. These
parameters are typical of a solution SBR plant with a produc-
tion rate of 120,000 metric tons/yr. Results of the cost
estimates are presented in Tables 15 and 16 for incineration
and carbon adsorption, respectively.
12.6 DEWATERING AND DRYING
12.6.1 Industries to Which Control is Applicable
Synthetic Rubber Production
12.6.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Dewatering and drying (emulsion) Incineration 90
Dewatering and drying (solution) Steam stripping 50
Incineration 90
Use as boiler
combustion air 40
12.6.3 General Description
After steam stripping, coagulation, and screening, crumb
rubber produced in emulsion polymerization is vacuum dewatered
and dried. Unreacted styrene is emitted to the plant atmosphere
from the crumb during dewatering and drying.
The dryer, enclosed and vented, has concentrations of
exhausted styrene of less than 10 ppm. Incineration of this
139
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Table 15. INCINERATION COSTS FOR A TYPICAL
DESOLVENT OPERATION3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
117,000
112,000
137,000
130,000
169,000
158,000
Annualized
operating
cost,
$/yr
180,000
110,000
130,000
80,000
100,000b
75,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
620
380
440
270
340b
260b
Fuel
requirement ,
rnVyr
fuel oil
2,900
1,600
1,900
1,000
l,000b
560b
q
Gas flow rate of 5 m°/s (11,000 scfm) , temperature of 21°C (70°F) , hydrocarbon concentration of
560 ppm based on hexane.
Assumes heat is recovered and utilized.
-------
Table 16. CARBON ADSORPTION COSTS FOR A TYPICAL
DESOLVENT OPERATION9
Adsorption device
Capital
cost,
$
Annualized
operating
cost,
$/yr
Cost
effectiveness,
$/ton of
hydrocarbons
removed
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
250,000
250,000
250,000
90,000
80,000
50,000
300
270
170
3Gas flow rate of 5 m3/s (11,000 scfm), temperature of 21°C (70°F),
hydrocarbon concentration of 560 ppm based on hexane.
exhaust will reduce the emission by 90 percent although sub-
stantial quantities of fuel will be necessary.
In the case of solution crumb dewatering and drying, the
emission situation is substantially more severe. Emissions are
mainly unreacted hexane. The dewatering step is entirely the
same as in emulsion, with the same ventilation/collection
difficulties. However, the concentration of hydrocarbons is
greatly increased over that in emulsion. In the dryer itself,
concentrations average close to 300 ppm with vents in the first
part of the dryer averaging greater than 2,000 ppm primarily of
hexane.
12.6.4 Control Alternatives
As mentioned previously, members of this industry have
investigated solutions for the control of this emission point.
A brief discussion of the alternatives available is given below.
141
-------
Six control alternatives have been investigated:
• Process change
• Solvent change
• Improved stripping process
• Fume incineration
• Use as boiler combustion air
• Carbon adsorption
For the carbon alternative, other alternatives such as
high energy regeneration have also been considered. Among
these were solvent washing, vacuum regeneration, and high
temperature regeneration. None of these attains complete
reactivation of the carbon. They also have other disadvantages
such as high energy requirements and the fact that the nature
of the processes is technically unverified.
After review of the six approaches studied, industry
representatives have offered the following conclusions:
• Process Change - This involves substituting emulsion
polymerization for solution polymerization. This was not
deemed technically viable due to the major rebuilding required
and the unsatisfactory characteristics of the final rubber
product and the substantially poorer wastewater characteristics
that would result.
• Solvent Change - Substitution of another solvent such
as pentane was evaluated but deemed unviable due to uncertain-
ties in processing feasibility (SBR solubility in pentane) and
because pentane's increased volatility would lead to increased
142
-------
emissions. Furthermore, pentane's reactivity gives little
improvement over that of hexane.
• Improved Stripping Process - As mentioned earlier, one
company has evaluated the desolventization process and how its
emissions might be reduced. This evaluation concluded that
emissions leaving the desolvent area could be reduced by
increasing the efficiency of steam stripping. By reducing emi
sions here, the quantity of hexane liberated by dewatering and
drying is correspondingly reduced. Increasing efficiency pri-
marily requires increased steam usage and condensing capacity.
The company estimates a possible reduction of 50 percent.
• Fume Incineration - Three approaches were considered:
afterburning, thermal incineration, and catalytic incineration
Collection of the emissions, as pointed out for the emulsion
process, was immediately recognized as difficult and thus col-
lection efficiency is considered to be less than 100 percent.
The multitude of vents would necessitate many afterburners.
For the purposes of this study, incineration is technically
feasible with a reduction potential of 85 percent to 90 per-
cent. This assumes a 90 percent collection efficiency and
95 percent control efficiency.
• Use As Boiler Combustion Air - This alternative showed
that only 44 percent of the hexane-laden air could be utilized
Technically, the alternative is viable; however, the percent
reduction is lower than that for other options.
143
-------
. carbon Adsorption - This alternative had been deemed
feasible and one company proceeded to pilot test two carbon
units on the drying operation. Initial tests showed that
collection efficiencies were low and that the carbon bed was
being fouled by a low molecular weight extender oil incorporated
in the polymer. Thus, an attempt was made to modify the
pilot program to overcome this fouling problem. The solution
process could not be changed to eliminate the fouling contami-
nant. The oil mist was less than 0.5 ym in diameter and gas
pretreatment processes to remove both gaseous and particulate
pollutants were examined. For gaseous pretreatment, con-
densation proved unsuccessful due to the low concentrations
involved. Absorption simply increases the amount of hydro-
carbon since any solvent used to absorb the oil would likewise
have to be removed. Incineration was disgarded for reasons pre-
viously discussed. The conclusion was that any pretreatment,
unless 100 percent efficient, would only delay the fouling
problem.
In conclusion, the company has decided on modified strip-
ping, which offers an estimated 50 percent reduction. This con-
clusion is based on both economical and technical considera-
tions. This study also considers incineration a technically
viable alternative with the cost of such discussed in the
proceeding section.
Also concerning carbon adsorption, if the oil mist could
be eliminated by removing the extender oil from the process
144
-------
altogether, the option of adsorption might then be technically
viable. This major process change resulting in a changed
final product composition would be possible if extender oils
could be added during compounding in subsequent rubber fabri-
cation activities. This proposed process change would allow
for carbon adsorption to reduce emissions in the 90 percent
range. Because this emission point is the largest of all
points in the industry, the viability of such a process change
needs serious consideration. Use of carbon adsorption (90 per-
cent) versus steam stripping capacity increases (50 percent)
will result in considerable additional reduction in plant
emissions.
12.6.5 Cost of Control
The cost of incineration for this source was estimated for
a solution SBR plant with a production rate of 120,000 metric
tons/yr. The parameters used in the cost calculations include
gas flow rate of 80 m3/s (160,000 scfm), a temperature of 150°C
(300°F), and a hydrocarbon concentration of 300 ppm (based on
C6). Due to the large volume of waste gas to be incinerated,
four incinerators, each handling 20 m3/s, are needed. Results
of this cost estimate are given in Table 17 for both direct
thermal and catalytic incineration. Fuel requirements are
also presented.
12.7 COMPOUNDING/BANBURY MIXING
12.7.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Footwear
Rubber Hose and Belting
145
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Table 17. INCINERATION COSTS FOR A TYPICAL DEWATERING
AND DRYING OPERATION3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
650,000
980,000
888,000
1,200,000
1,000,000
1,400,000
Annualized
operating
cost,
$/yr
2,100,000
1,000,000
1,400,000
920,000
i,ioo,ooob
800,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
960
460
640
420
soob
310b
Fuel
requirement,
m3/yr
fuel oil
35,000
18,000
23,000
12,000
i2,ooob
6,300b
3 a
Gas flow rate of 80 mVs (160,000 scfm), temperature of 150°C (300°F), hydrocarbon concentration
of 300 ppm based on Cg•
Assumes heat is recovered and utilized.
-------
Fabricated Rubber Goods
Gaskets, Packing, and Sealing Devices
12.7.2 Summary of Available Control Technology
Control System Percent
Affected facility or strategy reduction
Banbury mixing Incineration 90
Carbon adsorp-
tion 90
12.7.3 General Description
Although some plants (less than 10 percent) buy precom-
pounded rubber stock, most still have at least one mixer per
plant. Most all mixers (greater than 90 percent) presently
have some type of a particulate control installed. This may be
in the form of a baghouse or scrubber, to name two. The control
of hydrocarbons from this source has not been noted in the lit-
erature, and control will thus be technology forcing in concept.
Control of hydrocarbons is currently possible, however, as the
facilities utilizing scrubbing could be removing hydrocarbons
in conjunction with the particulate. The percent reduction
possible is not known to have been measured.
From a technical standpoint, the control of this emission
point by carbon adsorption is also feasible. The potential
for fouling of the bed should be eliminated due to the present
use of particulate removal equipment. Incineration would also
be feasible as the exhaust gas, although low in hydrocarbon
concentration, has sufficient heat to alleviate at least a por-
tion of the supplemental fuel requirements. Both of these con-
trol options are estimated to be 90 percent efficient as col-
lection will be close to optimum efficiency due to the exhaust
gas being already confined to a vent or stack.
147
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12.7.4 Cost of Control
The cost of control for Banbury mixing varies from industry
to industry because of the variation in quantities of rubber com-
pounds processed by this operation. Based on the average plant
size defined in Appendix H for each industry, the number of
Banbury mixers, operating time, and gas stream flow rate were
estimated and are given in Table 18. These process parameters
were used for cost calculation purposes only. Actual para-
meters for individual plant, may vary from these average
values. The concentration of volatile organic materials in the
gas stream to be treated was estimated at 10 ppm (based on
from a material balance. A temperature of 21°C (70°F) was
assumed for the exhaust gas.
Table 18. PROCESS PARAMETERS FOR BANBURY MIXERS
Industry
Tire and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber
goods
Gaskets, packing, and
sealing devices
Number of
Banbury mixers
2
1
1
1
1
Operating
time,
hr/yr
6,000
1,600
4,000
1,000
1,000
Exhaust gas
flow rate,
m3/s
15
7.5
7.5
7.5
7.5
Exhaust gas temperature: 21°C
Volatile organic compound concentration: 10 ppm based on
The capital and operating costs for control of this source by
incineration and carbon adsorption are presented in Tables 19
through 23 for rubber processing industries which involve
148
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Table 19. INCINERATION COSTS FOR A TYPICAL BANBURY MIXING OPERATION
IN THE TIRE AND INNER TUBES INDUSTRY9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
150,000
210,000
190,000
240,000
230,000
280,000
Annualized
operating
cost,
$/yr
500,000
250,000
350,000
230,000
280,000b
210,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
280,000
140,000
190,000
130,000
160,000b
120,000b
Fuel
requirement,
m3/yr
fuel oil
5,100
8,600
3,300
5,600
1,800
3,000
Based on process parameters presented in Table 18.
Assumes heat is recovered and utilized.
-------
Table 20. INCINERATION COSTS FOR A TYPICAL BANBURY MIXING OPERATION
IN A RUBBER FOOTWEAR OPERATION9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
125,000
138,000
150,000
160,000
185,000
190,000
Annualized
operating
cost,
$/yr
90,000
60,000
80,000
50,000
70,000b
50,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
370,000
250,000
330,000
200,000
290,000b
200,000b
Fuel
requirement ,
m3/yr
fuel oil
1,100
680
720
440
390b
240b
Based on process parameters defined in Table 18,
Assumes heat is recovered and utilized.
-------
Table 21. INCINERATION COSTS FOR A TYPICAL BANBURY MIXING OPERATION
IN THE RUBBER HOSE AND BELTING INDUSTRY3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
125,000
138,000
150,000
160,000
185,000
190,000
Annual! zed
operating
cost,
$/yr
180,000
100,000
130,000
90,000
110,000b
85,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
200,000
110,000
140,000
100,000
120,000b
94,000b
Fuel
requirement,
m3/yr
fuel oil
2,800
1,700
1,800
1,100
980b
600b
Based on process parameters defined in Table 18.
Assumes heat is recovered and utilized.
-------
Table 22. INCINERATION COSTS FOR A TYPICAL BANBURY MIXING OPERATION IN THE FABRICATED RUBBER GOODS
INDUSTRY AND THE GASKETS, PACKING, AND SEALING DEVICES INDUSTRY9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
125,000
138,000
150,000
160,000
185,000
190,000
Annualized
operating
cost,
$/yr
70,000
45,000
55,000
40,000
50,000b
35,000b
Cost
effectiveness,
$/ton of
hydrocarbons
removed
460,000
290,000
360,000
260,000
330,000b
230,000b
Fuel
requirement,
m3/yr
fuel oil
710
430
460
280
250b
150b
b
Based on process parameters presented in Table 18.
Assumes heat is recovered and utilized.
-------
Table 23. CARBON ADSORPTION COSTS FOR BANBURY MIXING3
Industry
Case with no credit for
recovered organics
Tires and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber goods
Gaskets, packing, and
sealing devices
Case with recovered
organics credited at
fuel value
Tires and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber goods
Gaskets, packing, and
sealing devices
Capital
cost,
$
$
380,000
280,000
280,000
280,000
280,000
380,000
280,000
280,000
280,000
280,000
Annualized
operating
cost,
$/yr
143,000
40,000
77,000
25,000
25,000
140,000
39,000
76,000
25,000
25,000
Cost
effectiveness ,
$/ton of
organics
removed
79,000
160,000
130,000
160,000
160,000
78,000
160,000
130,000
160,000
160,000
Based on process parameters defined in Table 18.
Banbury mixing. The control cost per unit weight of organics
removed is very high due to the low concentration of organic
materials in the exhaust gas.
12.8 MILLING
12.8.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Footwear
Rubber Hose and Belting
Fabricated Rubber Goods
Gaskets, Packing, and Sealing Devices
153
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12.8.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Mills, wary-up mills Incineration 60
12.8.3 General Description
A mill may be used to warm up rubber stock or simply to
sheet out the stock, etc. Because the emission is open in
nature, the collection efficiency of any proposed control
alternative will be low (less than 75 percent). Plants were
observed where several mills contained controlled exhaust ven-
tilation but in general, mill emissions are free to disperse
into the plant atmosphere. Because of the number of mills and
their diverse location in a typical tire plant, the use of a
central control location being fed by the exhausts from several
mills is not feasible. The exhaust ventilation manifold work
necessary would be enormous. Thus, control will have to be on
a specific mill basis. The control of the larger mills will
give the best reduction in hydrocarbon emissions from milling
operations, in general. Incineration is the only technically
viable control as adsorption will demand gas pretreatment to
remove any particulate and mists. Using the excepted removal
efficiency of 70 percent, the maximum reduction of these emis-
sions is 60-65 percent. No such control of milling operation
emissions is known to exist in any of the SIC's covered in
this study, and thus the control concept presented will be
technically forcing.
154
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12.8.4 Cost of Control
The control cost for a milling operation was estimated
for each industry involving this operation based on the proc-
ess parameters presented in Table 24 for average size plants
(see Appendix H). Since present ventilation practices in
rubber processing plants do not allow effective collection of
exhaust gases for hydrocarbon control purposes, cost estimates
were also made for the case where redesign of the ventilation
system will increase the organic concentration from 2 ppm to
20 ppm based on CH4.
Results of cost calculations for incineration are given in
Table 25. Catalytic incineration is not included since the
exhaust gas contains heavy oil mists and solid particles which
will foul the catalysts. This situation is different from the
case with Banbury mixing where bag filters are usually used to
remove the liquid and solid aerosols. Also, secondary heat
recovery is not considered because it is doubtful that a rubber
processing plant can utilize the large amount of heat recovered.
It can be seen from Table 25 that the control cost per
unit weight of organics removed and fuel consumption are
extremely high without redesign of the ventilation system.
Even with redesign to reduce the exhaust gas flow by a factor
of ten, the control cost is still substantial. It should be
noted also that the cost for the latter case does not include
that of redesign and reconstruction of a new ventilation system.
155
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Tables 24. PROCESS PARAMETERS FOR MILLING OPERATIONS
Industry
Tires and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber
goods
Gaskets, packing, and
sealing devices
Number
of
mills
15
2
5
2
2
Operating
time
hr/yr
6,000
6,000
6,000
3,800
3,800
Flow rate, m3/s
Before
redesign
38
5
13
5
5
After b
redesign
3.8
0.5
1.3
0.5
0.5
Number of
control units
Before
redesign
2
1
1
1
1
After ,
redesign
1
1
1
1
1
Ul
Exhaust temperature: 21°C (70°F)
aVolatile organic compound concentration: 2 ppm based on
Volatile organic compound concentration: 20 ppm based on
-------
Table 25. INCINERATION COSTS FOR MILLING OPERATIONSa
Industry
No heat recovery
(thermal incineration)
Tires and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber goods
Gaskets, Packing, and seals
Primary heat recovery
(thermal incineration)
Tires and inner tubes
Rubber footwear
Hose and belting
Fabricated rubber goods
Gaskets, packing, and seals
Capital cost, 10 3$
Before
redesign
490
115
140
105
105
590
140
180
125
125
After
redesign
110
83
90
80
80
130
110
115
110
110
Annualized
operating cost,
103$/yr
Before
redesign
1,300
180
420
130
130
900
130
290
95
95
After
redesign
130
50
70
30
30
110
40
60
30
30
Cost effectiveness
106$/metric ton of
hydrocarbons removed
Before
redesign
2.2
2.2
2.2
2.5
2.5
1.5
1.6
1.5
1.9
1.9
After
redesign
0.22
0.62
0.36
0.59
0.59
0.18
0.49
0.31
0.59
0.59
Fuel requirement
103m3/yr fuel oil
Before
redesign
21
2.9
7.1
1.8
1.8
13
1.7
4.3
1.1
1.1
After
redesign
2.1
0.29
0.71
0.18
0.18
1.3
0.17
0.43
0.11
0.11
Based on process parameters given in Table 24.
-------
12.9 EXTRUSION
12.9.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Hose and Belting
Fabricated Rubber Goods
Nonferrous Wiredrawing and Insulating
12.9.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Extruders Process change
(vented extruders) 80
12.9.3 General Description
The amount of heat generated, and thus hydrocarbons emitted
from extruding operations will depend on the quantity of rubber
being processed. In general, the larger the quantity of rubber
extruded per unit time, the higher the heat generation and thus
hydrocarbon emissions. This emission point is also not confined
to a vent. No confined exhaust ventilation of this operation
was observed or reported in the literature. As with milling,
the emission is believed low in concentration and only partially
collectable.
One viable control involves a change to vented extruders.56
Used extensively in polyvinyl chloride processing, vented ex-
truders allow for more efficient collection of the emissions,
before leaving the extruder itself. In combination with a con-
denser, the emissions could be effectively collected and re-
moved from the plant atmosphere. Assuming that 20 percent of
the emissions result from volatilization off the rubber after
56Penn, W. S., PVC Technology, London, England, Applied
Science Publishers, Limited, 3rd Edition, 1971, pp. 285-287,
158
-------
leaving the extruder (80 percent collectable in the extruder),
the reduction potential is estimated at 80 percent. No such
control of extruding operations is known to exist in the rubber
industry, and thus this control concept will also be technology
forcing,. Due to the nature of tire extruding, development of
vented extruders for the tire industry will probably be needed.
Current vented extruders are not directly adaptable to tire
industry extruding operations.
12.10 PRESS CURING
12.10.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Hose and Belting
Tire Retreading
12.10.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Press curing Incineration 60
12.10.3 General Description
Temperatures can range from 100°C to 200°C for tire curing
operations. Hydrocarbon emissions result from these heats and
may occur either through volatilization of species in the stock
or by formation of new species by chemical reactions. In the
case of tire curing, the emission has been shown to be a result
of volatilization rather than chemical reaction.23 Tires are
cured in presses. The number of presses in a given plant is
usually about 100, if not more. They are located over a large
open area which is ventilated or exhausted by large plant fans.
159
-------
In examining control, this fact is of paramount importance as
it affects collection efficiency greatly.
Collection options are 1) to collect or enclose the
ventilation of each individual press or 2) to contain the
emission and air flow of the entire press area to a confined
ventilation enclosure. From this study, the latter is more
feasible. Even with this proposed ventilation controlled
enclosure, only 70 percent of the emission is estimated to be
collectable. As the tire is pulled from the press, emissions
will escape not only from the press area enclosure but with
the tire itself. From this ventilation enclosure, emissions
can be sent to a thermal incineration device. Incineration is
estimated to be 90 percent efficient. Thus total reduction
efficiency is estimated to be 60 percent.
No control of curing emissions has been observed or re-
ported, and thus this concept will also be technology forcing.
12.10.4 Cost of Control
For an average size plant in the tire and inner tube
industry producing 20,000 metric tons/yr of product, the ex-
haust gas stream from curing presses has a flow rate of about
100 m3/s (200,000 scfm). From a material balance, the organics
concentration in this stream is 3.3 ppm based on CH4. To
incinerate this large gas stream, four incinerators will be
needed. Since the present ventilation systems do not allow
for effective collection of volatile organics for subsequent
emission control, redesign of the ventilation system is neces-
sary to increase the efficiency of the control system.
160
-------
The cost of controlling this source will be similar to
that for a milling operation. The extremely high control cost
per unit weight of organics removed and fuel requirements
also apply here. Readers are referred to Section 12.8.4 for
a discussion on this matter.
For an average size tire retreading shop (processing
450 metric tons/yr), the exhaust gas flow rate for curing
presses is about 2.3 m3/s (4,500 scfm). The concentration of
volatile organics in this stream is about 1.4 ppm. The cost
effectiveness is using incineration for control of this source
is similar to the situation in the tire and inner tube
industry.
12.11 CALENDERING
12.11.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Footwear
Rubber Hose and Belting
Fabricated Rubber Products
Gaskets, Packing, and Sealing Devices
12.11.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Calendering Incineration 55
12.11.3 General Description
Calendering is an operation common to all rubber manu-
facturing plants. Used to bond fabric or steel mesh to a
rubber sheet or between two rubber sheets, the calendering
operation is another source where due to heat generation, the
potential exists for emission of hydrocarbons. A large piece
161
-------
of equipment, the exhaust ventilation of a calender is usually
not enclosed, although some exhaust control is known to exist
at some plants. Based on the assumption that 1) hooding is
only 60% efficient in collection and 2) the incineration de-
vice, requiring substantial fuel, will be 90 percent efficient,
this emission point is controllable only to 55 percent. No such
control is known to exist in the applicable industries at this
time, and thus this concept will also be technology forcing.
12.11.4 Cost of Control
The process parameters for calendering in industries
involving this operation are the same as those for Banbury
mixing in number of units, operating time, exhaust flow rate,
and gas temperature. The concentration of organics in the
exhaust gas from a calendering operation is about 5 ppm based
on CH^. The cost of controlling this source by incineration
and the fuel requirements are similar to those discussed in
Section 12.8.4 for a milling operation.
12.12 UNDERTREAD AND TREADEND CEMENTING
12.12.1 Industries to Which Control is Applicable
Tires and Inner Tubes
12.12.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Undertread cementer/ Carbon adsorption 90
Treadend cementer Incineration 90
12.12.3 General Description
The operation here is simply a tackifying step used in
tire manufacture where the tread is dipped in rubber cement.
162
-------
This operation is one of the few emission points where hydro-
carbon control is presently installed. The control system
consists of a ventilation enclosure, which is designed to
capture evaporated solvent from the cementing tank and the
coated tread, and a dual-unit carbon adsorber. This technology
has been observed to have an overall collection efficiency of
about 94 percent. The design features of the exhaust ventila-
tion system include 1) adequate dilution of the volatile
vapors, 2) sufficient residence time of tread on the enclosed
conveyor to ensure capture of solvent during drying, and 3)
operator accessibility to areas within the hood, especially
during tread die changes (startup) and periods of scheduled
maintenance. The total exhaust ventilation flow is routed to
the dual adsorber before being vented to the atmosphere. The
carbon unit itself consists of two carbon beds operated on an
alternating cycle of adsorbing and steam stripping.
Approximately 1,340 kg/day of solvent are evaporated from
the cementer. Of this, approximately 1,206 kg/day are col-
lected and sent to the adsorber. Ninety-five percent of the
collected solvent is recovered by the steam stripping, con-
densation, and decantation steps. The recovered solvent is
reused within the plant both in undertread and other cementing
operations. This control technology is 90 percent efficient.
The use of incineration is also feasible. It is estimated I
to result in a reduction of the emission of 90 percent.
163
-------
The use of collection/incineration has also been
evaluated by the industry. The carbon adsorption option was
chosen due to more favorable economics. This is discussed in
the following section.
12.12.4 Cost of Control
The control cost for this emission source was estimated
based on a gas flow rate of 3.5 m3/s (7,000 scfm), gas tem-
perature of 21°C (70°F), and solvent concentration of 100 ppm
based on C6. Results are presented in Tables 26 and 27 for
incineration and carbon adsorption, respectively.
12.13 GREEN TIRE SPRAYING
12.13.1 Industries to Which Control is Applicable
Tires and Inner Tubes
12.13.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Green tire spraying Use of water-based sprays 90
Carbon adsorption 80
Incineration 80
12.13.3 General Description
Control of hydrocarbon emissions from green tire spraying
by substitution of water-based sprays for solvent-based sprays
has been observed and is considered state-of-the-art control
technology. This applies to both the inside and outside of
green tires.
The spraying operation itself is accomplished in a spray
booth. Green tires are removed from a storage rack and placed
164
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Table 26. INCINERATION COSTS FOR TYPICAL UNDERTREAD
AND TREADEND CEMENTING3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
110,000
108,000
130,000
110,000
150,000
130,000
Annualized
operating
cost,
$/yr
130,000
80,000
100,000
60,000
85,000b
55,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
4,800
3,000
3,700
2,200
3,100
2,000
Fuel
requirement ,
m3/yr
fuel oil
290
170
190
110
100
60
Ul
Based on gas flow rate of 3.5 m3/s (7,000 scfm), gas temperature of 21°C (70°F), and organics
concentration of 100 ppm based on CQ.
Assumes that heat is recovered and utilized.
-------
Table 27. CARBON ADSORPTION COSTS FOR TYPICAL
UNDERTREAD AND TREADEND CEMENTING3
Adsorption device
Capital
cost,
$
Annualized
operating
cost,
$/yr
Cost
effectiveness,
$/ton of
hydrocarbons
removed
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
190,000
190,000
190,000
62,000
60,, 000
55,000
2,300
2,200
2,000
Based on gas flow rate of 3.5 m3/s (7,000 scfm), gas temperature of 21°c
(70°F) , and organics concentration of'100 ppm based on C6.
in the spray booth where the spraying function is automati-
cally accomplished. The tire is then removed and placed on
another rack. Retention time in the booth is less than
5 seconds. Subsequent evaporation is to general room exhaust.
Thus, vapor collection in the booth itself is assumed to be 80
percent or less, including overspray of the tire. If other
than a water-based spray is substituted, the collection
efficiency of the vapors would have to be increased by in-
stalling enclosed drying tunnels or by increasing the retention
time of the tires in the booth. Using increased collection
and either carbon adsorption or incineration, this emission
point is estimated to be 80 percent controllable.
However, as mentioned, the elimination of the emission by
90 percent through substitution of a water-based spray is
166
-------
feasible. The inside spray, primarily needed as a release
agent during curing, is currently known to be water based
(10 percent residual solvent) in several plants. The outside
spray is needed also as a release agent; in addition, it helps
produce an aesthetically pleasing finished product. Although
more difficult to switch to, water-based outside sprays have
also been observed and reported in industry.
Thus, this emission point is considered 90 percent con-
trollable by the substitution of water-based for solvent-based
sprays in both inside and outside green tire applications.
12.13.4 Cost of Control
The cost calculation for this emission source was based
on a gas flow rate of 5 m3/s (10,000 scfm, two spray booths),
gas temperature of 21°C (70°F), and solvent concentration of
1,000 ppm based on C6. Tables 28 and 29 give the results for
incineration and carbon adsorption, respectively.
Table 28. CARBON ADSORPTION COSTS FOR TYPICAL
GREEN TIRE SPRAYING3
Adsorption device
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
Capital
cost,
$
250,000
250,000
250,000
Annualized
operating
cost,
$/yr
90,000
80,000
50,000
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
250
220
140
aBased on gas flow rate of 5 m3/s (10,000 scfm) temperature of 21°C (70°F),
organics concentration of 1,000 ppm based on C6.
167
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Table 29. INCINERATION COSTS FOR TYPICAL
GREEN TIRE SPRAYING3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
115,000
130,000
140,000
160,000
160,000
185,000
Annualized
operating
cost,
$/yr
140,000
110,000
130,000
80,000
ioo,ooob
70,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
390
310
370
220
280b
200b
Fuel
requirement ,
m3/yr
fuel oil
2,400
1,250
1,600
810
840b
440b
oo
Based on flow rate of 5 m3/s (10,000 scfm), temperature of 21°C (70°F), solvent concentration of
1,000 ppm based on C6.
Assumes heat is recovered and utilized.
-------
The switch from solvent-based to water-based low solvent
sprays will not require significant capital investment (as
compared with that of the add-on control). The difference in
operating cost will result from raw material cost.
12.14 TIRE BUILDING
12.14.1 Industries to Which Control is Applicable
Tire and Inner Tubes
12.14.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Tire Building Scheduling change 50
12.14.3 General Description
In this operation, solvent is used to tackify the rubber
components before assembly. If the rubber components are used
as soon as they are constructed, the components will still be
tacky and will not require solvent. By improved scheduling of
component arrival to the builder, it is estimated that half of
the present solvent use could be eliminated. The improved
scheduling could include immediate use of component parts, as
made, during the peak operating shift, or partial solvent
elimination for tackifying certain parts. In addition, builder
preferences for solvent usage could be minimized.
12.15 ADHESIVE SPRAYING OR CEMENTING
12.15.1 Industries to Which Control is Applicable
Rubber Footwear
Fabricated Rubber Goods
Gaskets, Packing, and Sealing Devices
Tire Retreading
169
-------
12.15.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Spray booths Collection/incineration 90
Collection/adsorption 90
Manual applications None Unknown
12.15.3 General Description
Adhesive spraying is usually carried out in spray booths
which are vented to the atmosphere. However, solvent evapora-
tion continues to occur after the sprayed part leaves the
booth. In order to achieve collection efficiencies of greater
than 90 percent, either 1) the residence time of the part in
the booth must be increased or 2) additional ventilation en-
closure must be provided around the part after it leaves the
booth.
The control of the vapors, assuming 95 percent collection
efficiency, based on increasing the residence time, can be
obtained by either incineration or carbon adsorption. Each of
these controls is considered 90 percent efficient. It must be
noted that at present no control of adhesive spraying by either
of these control systems has been reported. In addition,
especially in footwear production, a large number of such
booths exist.
The largest percentage of adhesive applications are
manual in nature. The worker, as in footwear production, may
use the solvent for tackifying a rubber inner sole before it
is placed on the outer sole. In essence, the use of cement
is dispersed widely over a plant manufacturing area, the
quantity used depending not only on the specific application
170
-------
but on the worker's individual preference. The application
may be by a knife, a brush, a roller, or even by hand.
Control of individual applications is not feasible. The
potential for locating all such applications in a general con-
fined area also is not feasible. The application points are
just too spread out in the plant.
In some cases, the substitution of water-based (low sol-
vent) for solvent-based cements has been reported. In some
specific applications, this option is viable. However, the
vast majority of cementing cannot be changed to water-based
cements, and thus this reduction method is not considered to
result in any reduction in emissions.
Any identification of control for these manual applica-
tions must be plant specific in nature. Each plant will have
different numbers of such emission points and different quanti-
ties of emissions resulting from these cementing operations.
12.15.4 Cost of Control
The cost of control for this source was estimated based
on a gas flow rate of 0.5 m3/s (1,000 scfm), gas temperature of
21.1°C (70°F), and hydrocarbon concentration at 25 percent of
LEL (3,000 ppm based on C5). Annual operation time was assumed
to be 3,000 hours. The low gas flow rate and shorter operation
time are characteristics of the source. Results of cost calcu-
lations are shown in Tables 30 and 31 for incineration and car-
bon adsorption, respectively. Note the increase in control cost
with the increasing degree of heat recovery in incineration.
171
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Table 30. INCINERATION COSTS FOR A TYPICAL
ADHESIVE SPRAYING OPERATION9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat
recovery
Thermal
Catalytic
Capital
cost,
$
82,000
80,000
110,000
85,000
125,000
90,000
Annualized
operating
cost,
$/yr
18,000
18,000
21,000
22,000
29,000b
25,000b
Cost
effectiveness,
$/ton of
hydrocarbons
removed
205
205
235
245
330b
290b
Process rate of 0.5 m3/s (1,000 scfm), temperature of 21.1°C (70°F),
operation at 25 percent LEL.
Assumes heat is recovered and used.
Table 31. CARBON ADSORPTION COSTS FOR A TYPICAL
ADHESIVE SPRAYING OPERATION3
Adsorption device
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
Capital
cost,
$
70,000
70,000
70,000
Annualized
operating
cost,
$/yr
25,000
19,000
11,000
Cost
effectiveness,
$/ton of
hydrocarbons
removed
285
220
95
a q
Process rate of 0.5 mi/s (1,000 scfm), temperature of 21.1°C (70°F).
operation at 25 percent LEL.
172
-------
This is due to both the small unit size and the low operating
hours. Considerable fuel is consumed in the frequent startups
and shutdowns, especially when a heat recovery unit is present,
In addition, the incremental investment for heat recovery de-
vices cannot be recovered because of the short time of their
usage.
12.16 MOLDING
12.16.1 Industries to Which Control is Applicable
Rubber Footwear
Fabricated Rubber Goods
Gaskets, Packing, and Sealing Devices
12.16.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Molding area Collection/incineration 60
12.16.3 General Description
Hydrocarbon emissions exist here due to the temperatures
generated in the process. An operation similar to curing,
molding sometimes takes the place of curing altogether.
Rappaport1s23 equation predicts emissions from this operation
due to temperatures involved and subsequent volatilization of
organics.
The control depends heavily on collection efficiency. In
a representative plant, the entire molding area exhaust is
collected and vented to the atmosphere. It is estimated that
the maximum collection efficiency possible for this operation
is 70 percent. Control of the vapors by incineration is feas-
ible with a reduction of 90 percent possible. Overall reduc-
tion potential is thus approximately 60 percent.
173
-------
It must be noted that no control of this emission point
has been observed or reported. A further point must be made
here. Because most plants have chosen to increase ventilation
in molding areas to meet work environment health requirements,
the resultant air flow containing the hydrocarbons is substan-
tially larger and thus the concentration more dilute. This
fact makes the control of the emission not only more techni-
cally difficult but considerably more expensive. In protecting
the health of the worker, the reduction of the emission,
itself, is made more difficult.
12.16.4 Cost of Control
The cost of control for this source is similar to that
for press curing discussed in Section 12.10.4.
12.17 BATCH CURING
12.17.1 Industries to Which Control is Applicable
Rubber Footwear
Rubber Hose and Belting
Fabricated Rubber Products
12.17.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Batch curing Incineration 60
12.17.3 General Description
In batch curing, the operation is closed and pressurized.
The quantity of hydrocarbons produced is less than in press
curing because the steam used in batch curing condenses as the
curing vessel is depressurized, thus also condensing a portion
of the hydrocarbons.
174
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In this batch process, the vessel is vented to the
atmosphere. Thus, the problem of collection is reduced some-
what on a capital cost basis. However, the collection effici-
ency is estimated at 70 percent, again because emissions are
still evolving from the product upon removal. Incineration
is again a technically feasible control alternative with an
efficiency of 90 percent. Overall reduction is again estimated
at 60 percent. Again, this is proposed control. No control
of batch curing operations was observed or reported. This
control concept is thus technology forcing. Quantification of
the emission point is necessary before the feasibility of this
concept can be verified. This quantification will have to be
done on a site-by-site basis as the great variation in curing
temperatures will affect the quantity of hydrocarbons emitted.
12.17.4 Cost of Control
The cost of control for this source was estimated based
on gas flow rate of 0.5 m3/s (1,000 scfm), gas temperature of
21°C (70°F), and organics concentration of 150 ppm based on
CHif. These parameters are typical for an average size footwear
plant producing 6,500 metric tons of product/yr. The results
of the cost estimates for incineration are presented in Table
32.
12.18 FABRIC CEMENTING
12.18.1 Industries to Which Control is Applicable
Tires and Inner Tubes
Rubber Hose and Belting
175
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Table 32. INCINERATION COSTS FOR A TYPICAL
BATCH CURING OPERATION9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
80,000
50,000
110,000
60,000
120,000
70,000
Annualized
operating
cost,
$/yr
50,000
40,000
40,000
25,000
35,000b
20,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
80,000
64,000
64,000
40,000
56,000b
32,000b
Fuel
requirement,
m3/yr
fuel oil
280
170
180
110
100b
60b
-J
en
Based on gas flow rate of 0.5 m3/s (1,000 scfm) , gas temperature of 21°C (70°F) , organics
concentration of 150 ppm based on
Assumes heat is recovered and utilized.
-------
12.18.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Fabric cementer Incinerator 90
Carbon adsorption 85
12.18.3 General Description
In fabric cementing, a rubber coating is imparted to a
textile substrate with a knife of roller spreader. After the
cement is applied, the fabric is oven-dried to drive off the
carrier solvent. The oven itself is vented to the atmosphere.
Thus when considering control, collection of the solvent vapors
can be assumed to be quite high.
Control of this emission point is known to exist in the
industry. One representative plant, in producing small-
diametered braided hose, uses thermal incineration to reduce
by 95 percent hydrocarbon vapors resulting from hose-cementing
operations. The incinerator operates at 760°C (1400°F) and
has heat recovery to the oven itself. In another representa-
tive plant, solvent vapors from a cord cementer drying oven
are vented to a catalytic incinerator. The incinerator
operates at about 260°C (500°F) and is approximately 90 percent
efficient. An inlet concentration of approximately 3,650 ppm
as CH^ is reduced to approximately 385 ppm as CH4. This system
is state-of-the-art technology. The emission point is 90 per-
cent controllable by incineration.
In addition, carbon adsorption has been reported to be
installed on various fabric cementers in the rubber industry.
Reduction was reported to be 85 percent, with losses mainly
attributable to solvent handling and less than 100 percent
177
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collection efficiency. This control option is state-of-the-
art technology with a reduction of 85 percent achievable.42
12.18.4 Cost of Control
The cost calculations for control of this source were
based on a gas flow rate of 1.5 m3/s (3,000 scfm), temperature
of 21°C (70°F), and solvent concentration of 1,000 ppm based
on C6. These process parameters are typical for average size
plants in the tire and inner tube industry and in the hose and
belting industry. The results of cost estimates for incinera-
tion and carbon adsorption are given in Tables 33 and 34,
respectively.
12.19 LATEX DIPPING AND DRYING
12.19.1 Industries to Which Control is Applicable
Rubber Footwear
Fabricated Rubber Goods
12.19.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Dip tank and dryer Water-based latex
substitution 90
Carbon adsorption 85
Incineration 85
12.19.3 General Description
In rubber product production, the stock is dipped before
curing and oven or air drying takes place. In a representative
plant, these dipping operations are collected and exhausted to
the plant exterior. As with adhesive spray booths, the collec-
tion efficiency of the exhaust enclosure can be increased by
increasing the residence time of the dipped stock in the
178
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Table 33. INCINERATION COSTS FOR A TYPICAL
FABRIC CEMENTING OPERATION3
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
95,000
95,000
115,000
110,000
135,000
125,000
Annualized
operating
cost,
$/yr
65,000
60,000
50,000
45,000
so,ooob
45,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
720
670
560
500
560b
500b
Fuel
requirement ,
m3/yr
fuel oil
860
510
560
330
300b
180b
V£>
Based on gas flow rate of 1.5 m3/s (3,000 scfm) , temperature of 21°C (70°F) , and organics
concentration of 1,000 ppm based on
Assumes heat is recovered and utilized.
-------
Table 34. CARBON ADSORPTION COSTS FOR A TYPICAL
FABRIC CEMENTING OPERATION3
Adsorption device
Capital
cost,
$
Annualized
operating
cost,
$/yr
Cost
effectiveness,
$/ton of
hydrocarbons
removed
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
150,000
150,000
150,000
33,000
32,000
25,000
370
360
280
Based on gas flow rate of 1.5 m3/s (3,000 scfm), temperature of 21°c
(70°F), and organics concentration of 1,000 ppm based on CH^.
enclosure. Incineration or carbon adsorption assuming a 95
percent collection and 90 percent removal efficiency will con-
trol this emission point by 85 percent.
In some footwear dipping operations, the base has been
able to be changed from solvent to water (residual solvent,
<10%). It is unknown how many of such latex solutions have
this potential but in the cases where such substitution can
be made, the emissions will be reduced 90 percent. The con-
trol by incineration and adsorption of latex dipping is not
known to exist in the footwear and fabricated goods industry at
this time and control will thus be technology forcing.
12.19.4 Cost of Control
The control cost for this source was calculated based on a
gas flow rate of 0.5 m3/s (1,000 scfm), gas temperature of 21°C
180
-------
(70°F) and organics concentration of 40 ppm based on CHI+. The
results of cost estimates are summarized in Tables 35 and 36
for incineration and carbon adsorption, respectively.
12.20 CONTINUOUS CURING (ROTOCURE)
12.20.1 Industries to Which Control is Applicable
Rubber Hose and Belting
Nonferrous Wiredrawing and Insulating
12.20.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Continuous (rotocure) Incineration 60
curing
12.20.3 General Description
Continuous curing or rotocuring is used in large belt
vulcanization. The emissions are hooded and vented to the
atmosphere. The collection/incineration alternative is again
technically feasible with an overall reduction of 60 percent.
However, source testing verification is again warranted so
that a concentration can be determined to verify or disprove
the feasibility of this control alternative.
12.20.4 Cost of Control
A typical rotocure operation has an exhaust gas with a
flow rate of 7.5 m3/s (15,000 scfm), a temperature of 65°C
(150°F), and an organics concentration of 10 ppm based on CH4.
The cost to control this source by incineration is similar to
that for Banbury mixer as discussed in Section 12.7.4.
181
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Table 35. INCINERATION COSTS FOR A TYPICAL LATEX
DIPPING AND DRYING OPERATION9
Incineration device
No heat recovery
Thermal
Catalytic
Primary heat recovery
Thermal
Catalytic
Primary and secondary heat recovery
Thermal
Catalytic
Capital
cost,
$
80,000
50,000
110,000
60,000
120,000
70,000
Annualized
operating
cost,
$/yr
50,000
40,000
40,000
25,000
35,000b
20,000b
Cost
effectiveness ,
$/ton of
hydrocarbons
removed
220,000
170,000
170,000
110,000
150,000b
87,000b
Fuel
requirement,
m /yr
fuel oil
290
170
190
110
100b
00
3Based on gas flow rate of 0.5 m3/s (1,000 scfm) , temperature of 21°C (70°F) , organic
concentration of 40 ppm based on
Assumes heat is recovered and utilized.
-------
Table 36. CARBON ADSORPTION COSTS FOR A TYPICAL
LATEX DIPPING AND DRYING OPERATION9
Adsorption device
Capital
cost,
$
Annualized
operating
cost,
$/yr
Cost
effectiveness,
$/ton of
hydrocarbons
removed
Case with no credit for
recovered solvent
Case with recovered solvent
credited at fuel value
Case with solvent credited
at market value
65,000
65,000
65,000
25,000
24,000
23,000
110,000
105,000
100,000
9 q
Based on flow rate of 0.5 mVs (1,000 scfm) . temperature of 21°C (70°F) ,
organics concentration of 40 ppm based on CH^.
12.21 RECLAIMATOR PROCESSES
12.21.1 Industries to Which Control is Applicable
Rubber Reclaiming
12.21.2 Summary of Available Control Technology
Affected facility
Reclaimator
Control system
or strategy
Percent
reduction
Adsorption 90
12.21.3 General Description
As mentioned previously, there are several devulcanization
processes. All involve emissions of oily mists, solvent vapors,
and hydrocarbon vapors from the reclaimed stock itself. The
emissions are vented to the atmosphere by a stack and are con-
sidered essentially 100 percent collectable.
Absorption or water scrubbing is considered state-of-
the-art technology. This control was observed at an assumed
183
-------
representative plant. information collected indicated that
control is 90 percent efficient. This control results in a
water pollution problem, however, and the observed control has
associated wastewater treatment equipment installed. Oil is
recovered in this operation and reused in the reclaiming
operation.
In some plants, batch pan devulcanization vessels are
used, mainly for reclaiming inner tubes. Each vessel is
depressurized over a period of several hours, and any emission
is assumed to condense in the vessel itself.
12.21.4 Cost of Control
The capital cost and annualized operating cost for a con-
senser-scrubber system are given in Table 37. These costs are
based on a gas flow rate of 0.8 m3/s (1,500 scfm) and gas
temperature of 93.3°C (200°F). Information is not sufficient
to calculate the control cost based on $/ton of hydrocarbons
removed.
Table 37. COSTS OF A CONDENSER-SCRUBBER SYSTEM
FOR A TYPICAL RECLAIMATOR PROCESS3
Costs $/Year
Capital cost $175,000
Annualized operating cost
Fuels/electricity 16,900
Labor 10,900
Replacement parts 2,400
Depreciation 14,000
Interest on capital 14,000
Taxes and insurance 3,500
Building overhead 3,500
Byproduct recovery (credit) -8,400
TOTAL $ 56,800
aGas flow rate of 0.8 m3/s (1,500 scfm)
and temperature of 93.3°C (200°F).
184
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12.22 PAINT AND TRIM ACTIVITIES
12.22.1 Industries to Which Control is Applicable
Tire Retreading
12.22.2 Summary of Available Control Technology
Control system Percent
Affected facility or strategy reduction
Painting of retreaded tires Water-based sprays 90
or paints
12.22.3 General Description
In this operation, the retreaded tire is painted to give
it a more aesthetically pleasing appearance. For representa-
tive plants, use of both a solvent-based spray, and a water-
based detergent wash, applied manually, is known to exist.
The washing method is considered state-of-the-art control as
some argument exists against the need for a painting step al-
together. Using a water-based detergent wash (<10% residual
solvent), this emission point is 90 percent controllable. The
painting step can be effectively eliminated.
12.22.4 Cost of Control
The switch from solvent-based paint to detergent wash
does not require capital investment, nor any significant change
in operating cost.
185
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13. NSPS PRIORITIZATION
13.1 INTRODUCTION
Section 3 of the Clean Air Act charges the Administrator
of the Environmental Protection Agency with the responsibility
of establishing Federal standards of performance for new sta-
tionary sources which may significantly contribute to air
pollution. These new source performance standards (NSPS) will
reflect the degree of emission limitation achievable through
application of the best demonstrated control technologies, con-
sidering cost. Due to limited manpower and funding, it is
not feasible to set standards for all sources simultaneously.
Therefore, an overall strategy is needed to delineate the pri-
orities by which such standards should be set. This strategy
focuses attention on those sources for which implementation
of NSPS would have the greatest impact on reducing the quan-
tity of atmospheric emissions. Estimates of the projected dif-
ferential in emissions with and without anticipated NSPS are
to serve as the basis for determining these standard-setting
priorities.
The purpose of this section is to present the results of
a study to develop such estimates of emission reduction for
186
-------
the nine rubber processing industries. These emission reduc-
tion calculations have been performed using a generalized pri-
ority rating system developed by EPA and known as Model IV.
13.2 MODEL IV
Model IV was developed by EPA to be used by the Emission
Standards and Engineering Division of the Office of Air Quality
Planning and Standards for assessing numerous industries for
the purpose of establishing priorities for setting NSPS. The
model mathematically expresses the differential in atmospheric
emissions that can be expected at some future time with and
without implementation of NSPS.
The potential for emission reduction, T , for a specified
period is expressed as:
Tr = Ts - Tn
where T = Total emissions in the last year of the period
s
under baseline year control regulations.
T = Total emissions in the last year of the period if
n
the NSPS is implemented in the baseline year and continued to
be effective through the time period.
The following terms are used in the development of
formulas for calculating the values of T and T :
o a
A = baseline year production capacity (production
»
units/yr)
B = production capacity from construction and modifica-
tion to replace obsolete facilities during the time
period (production units)
187
-------
C = production capacity from construction and modifica-
tion to increase output above baseline year capacity
during the time period (production units)
P, = construction and modification rate to replace
b
obsolete capacity (decimal fraction/yr)
P = construction and modification rate to increase
c
industry capacity (decimal fraction/yr)
E = allowable emission factor under existing regulations
s
(mass/unit capacity)
E = emission factor with no control (mass/unit capacity)
E = allowable emission factor under NSPS (mass/unit
capacity)
k = normal fractional utilization rate of existing
capacity, assumed constant during time interval
T = total emissions in the last year of the period
assuming no control
T = total emissions in baseline year under baseline
el
year regulations
The new source performance standard is applicable to con-
trol of emissions from the portion of the plant capacities
resulting from construction and modification to replace obso-
lete capacities (i.e., B) and to increase output above base-
line capacity (i.e., C). Other plant capacities (i.e., A - B)
will be regulated by existing regulations. This relationship
188
-------
is schematically shown in Figure 13-1.57 With the above
revelation, it can be calculated using the following formula:
T = E k(A - B) + E k(B + C)
s s s
= E k(A + C) (2)
S
Similarly, T can be obtained by:
T = E k(A - B) + E k(B + C) (3)
n s n
Therefore, the potential for emission reduction can be
determined as follows:
T = T - T
r s n
= k(B + C) (E - E ) (4)
s n
In addition, the following values can be calculated:
T = E kA (5)
as
TU = Euk(A - B) + EUMB + c)
= E k(A + C) (6)
Supposing i is the number of years in the period, values
of B and C are determined as follows:
(a) If simple growth rate is assumed,
B = AiPb (7)
C = A (8)
57Hopper, T. G., and W. A. Marrone. Impact of New Source
Performance Standards on 1985 National Emissions from Sta-
tionary Sources, Vol. I., U.S. Environmental Protection
Agency. Research Triangle Park, N.C. EPA Contract
68-02-1382, Task 3. October 24, 1975. 170 p.
189
-------
o
-------
(b) If compound growth rate is assumed,
B = A[(l + Pb)1 - 1]
C = A[(l + Pc)1 - 1] (10)
In this study, 1975 was selected as the baseline year be-
cause of the availability of production data for that year and
the abnormal operation of the rubber industry in 1976 due to a
prolonged worker strike; 1985 was selected as the last year of
the time period so that results of this study can be compared
directly with those of other studies57 for other industries.
For the purposes of this study. A, P, , P , k, E , E , and
DC S U.
E are defined as input variables. T , T , T , T , B, and C
n a u s n
are referred to as intermediate variables.
13.3 INPUT VARIABLES
Values of the input variables for each of the nine rubber
processing industries are summarized in Table 38. The deriva-
tion of these values is described in detail in the following
subsections. For the purposes of this study, the input vari-
ables are separated into two groups: k, A, P, , and P are
defined as industrial factors, whereas E , E , and E are
us n
regarded as emission factors.
13.3.1 Industrial Factors
13.3.1.1 Fractional Utilization, k - This variable represents
the fraction of total existing capacity which is brought into
191
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Table 38. INPUT VARIABLES FOR MODEL IV PRIORITIZATION OP RUBBER PRODUCTS INDUSTRIES
SIC
code
2822
3011
3021
3031
3041
3069
3293
3357
7534
Source name
Synthetic rubber
Tires and inner
tubes
Rubber footwear
Reclaimed rubber
Rubber hose and
belting
Fabricated rubber
products, N.E.C.
Gaskets, packing, and
sealing devices
Nonferrous wiredrawing
and insulating
Tire retreading and
repair shops
k
0.89
0.89
0.70
0.75
0.89
0.89
0.89
0.89
0.85
A, units/yr
2.18 x 109
kg rubber produced
2.9 x 109
kg rubber
3.0 x 108
kg rubber
1.10 x 108
kg rubber produced
4.49 x 108
kg product
1.12 x 109
kg product
1.8 x 108
kg product
5.73 x 107
kg rubber consumed
5.59 x 108
kg rubber
Pc
+0.032
simple
+0.040
simple
-0.006
simple
-0.046
simple
+0.038
simple
+0.048
simple
+0.054
simple
+0.000
simple
+0.002
simple
Pb
0.045
simple
0.045
simple
0.000
simple
0.000
simple
0.045
simple
0.045
simple
0.045
simple
0.000
simple
0.000
simple
Emission factor
units
g/kg rubber produced
g/kg rubber produced
g/kg rubber produced
g/kg rubber produced
g/kg product
g/kg product
g/kg product
g/kg rubber consumed
g/kg rubber retreaded
E
u
4.1
30.23
95.49
30
18.83
4.31
4.02
0.64
6.04
E
s
1.01
7.75
61. 29
4.5
8.28
4.31
3.82
0. 64
6. 04
E
n
0.77
6.06
60. 92
3.0
7.36
2.75
0.50
0.25
0. 64
-------
service to produce a given output. It is applied to the
capacity-based values of A, B, and C to determine the impact
on emissions resulting from actual production.
The k factor for the rubber industry as a whole was de-
termined from the average utilization factor reported in the
Survey of Current Business for the period 1965 - 1973.58 This
average value is 0.89 and was used for all rubber processing
industries except for Rubber Footwear, Reclaimed Rubber, and
Tire Retreading. The value for Rubber Footwear was obtained
from contact with a representative at the Rubber Manufacturers
Association. The value for Reclaimed Rubber was derived from
data contained in an EPA report11 and information received
from a representative of the Rubber Reclaiming Association.
The value for Tire Retreading was obtained from Reference 11.
13.3.1.2 Production Capacity, A - This variable is defined as
industrial production capacity in the baseline year, 1975.
It is used to derive the values of new (C) or replaced capacity
(B) in 1985 (Equations 7 to 10) and to define existing capacity
in 1985 which is not subject to NSPS (A - B).
In this study, due to the unavailability of capacity
figures, the capacity of each industry was derived from pro-
duction data by using the fractional utilization factor, k.
The 1975 production data for Synthetic Rubber, Tires and Inner
58Survey of Current Business. U.S. Department of Commerce,
Bureau of Economic Analysis, Washington, B.C. 5_6(7) , 1976.
193
-------
Tubes, and Reclaimed Rubber were obtained from Reference 58.
For tire production and tire retreading, the production was
multiplied by 10.9 kg of rubber stock per tire to get a produc-
tion figure in kilograms of rubber stock/year. Values for
Rubber Footwear, Rubber Hose and Belting, and Fabricated
Rubber Products were extrapolated from graphs contained in
Reference 11. Values for the Gaskets, Packing, and Sealing
Devices industry and the Nonferrous Wiredrawing and Insulating
industry were extrapolated from data reported in the 1972
Census of Manufacturers.59 The tire production value for the
Tire Retreading industry was obtained from personal contact
with a representative of the Tire Retreading Institute.
Units for capacity were selected to be consistent with
those used by the specific industry and to be compatible with
emission factors. The amount of product output was used to
quantify the capacity in all but one industry. This industry
is Nonferrous Wiredrawing and Insulating in which products in-
clude metal wires that do not contribute to emissions. There-
fore, the amount of rubber consumed was used for capacity in
this case.
13.3.1.3 Fractional Increase Rate in Industrial Capacity, P -
This variable is defined as the average anticipated growth
rate per year in industrial capacity during the period 1975 to
591972 Census of Manufacturers, Industry Series. U.S. Depart-
ment of Commerce, Bureau of the Census. Washington, D.C.
1974.
194
-------
1985. It is applied to production capacity (A) to determine
C. It is this value of C to which NSPS can be applied.
P values for Rubber Footwear, Rubber Hose and Belting,
\*r
Fabricated Rubber Products, and Tire Retreading were obtained
from analysis of graphs contained in Reference 11 for the
period 1965 - 1975. For Reclaimed Rubber, the value was de-
rived from data contained in References 11 and 58 and industry
opinion. For the Gaskets, Packing, and Sealing Devices indus-
try, it was calculated from the increase in value of total
product shipments from 1967 to 1972, corrected by the change
in price of synthetic rubber for the same period.59 The value
for synthetic rubber was an extrapolation of 1955 - 1974 produc-
tion data.58 The value for tires and inner tubes was estimated
based on a combination of information from References 57, 60,
and 61. A value of 0.0 was assumed for growth of the Nonferrous
Wiredrawing and Insulating industry because of the increasing
use of plastics, rather than rubber, in this industry.
In all cases, simple growth rate was assumed because
linear curve fitting of the historical production data gave a
correlation coefficient closer to 1, as compared with that of
exponential curve fitting. This indicates that the simple
rate rather than the compound rate, can better describe the
growth of the rubber processing industries.
600utlook 1976. Rubber World. 173(4):23. January 1976.
6Rubber Consumption to Increase. Rubber World. 172 (2) ;83
May 1975.
195
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It should be noted that all figures used to estimate P
were production, not capacity data. This is because the corres-
ponding capacity figures were not available. The use of
production data for this purpose gives the next best estimate.
Since the historical growth pattern was simple in nature,
the value of P was calculated by the following equation:
c
Production in year "x" - Production in year "y"
c ~ (x - y) • Production in 1975 ( 1J
In the calculation, as shown above, it was necessary to
relate the growth to the baseline year, 1975.
13.3.1.4 Fractional Replacement Rate of Obsolete Production
Capacity, P, - This variable is defined as the average rate
per year at which obsolete production capacity is replaced
during the period 1975 to 1985. It is expressed as a fraction
and is applied to A to determine B. It is this value of B to
which NSPS can be applied. Also, the quantity (A - B) defines
the existing production capacity in 1985 to which only state
regulations are applicable.
In this study, the P, values were obtained by using equip-
ment lifetime based on depreciation guidelines published by
the Internal Revenue Service.62 The allowance permitted by
the IRS is an economic factor used for tax collection purposes
and generally depreciates equipment and facilities over a
shorter term than their actual useful life. As suggested by
Reference 57, typical equipment and facilities within each
6ttAsset Depreciation Guidelines. Internal Revenue Service,
Washington, D.C. Publication No. 534. 1976.
196
-------
industry were assumed to have a useful life equal to twice
that allowed by the IRS. Therefore, the following formula was
used to calculate P, ;
b
Pb = 1 (12)
2 • (Asset Guideline Period)
As can be seen from Table 38, Rubber Footwear, Reclaimed
Rubber, Nonferrous Wiredrawing and Insulating, and Tire Retread-
ing all have a P, value of zero. This results from the assump-
i "
tion that industries with zero, negative, or very small growth
rates will not replace obsolete capacities with new capacities.
This is likely especially when the present utilization factor
is small (see Table 38 for k values of the industries having
a P, value of zero) .
b
13.3.2 Emission Factors
13.3.2.1 Uncontrolled Emission Factor, E - This variable
represents the emission factor for volatile hydrocarbons under
a condition of no control. It is used to calculate TU/ the
uncontrolled total emissions from an industry in 1985, the
value to which T and T may be compared to determine the
s n
nationwide impact on emissions of regulations in general. EU
is also employed to develop E , the NSPS controlled emission
factor, and E , the emission factor representing control to
S
the extent required by state regulations.
E for each industry was developed by using information
obtained from plant visits and literature sources, and by
engineering estimates. Details of the derivations have been
197
-------
described in Sections 3 to 11 and will not be repeated here.
Values of EU for each industry are given in Table 38.
13.3.2.2 NSPS Controlled Emission Factor, E - This variable
represents the emission factor under the condition of best
control applied to new sources. It is used to determine TR/ the
emissions of volatile hydrocarbons that would exist in 1985 if
NSPS were applied in 1975. When T is subtracted from T , the
n s
quantitative value of emission reduction, T , is determined.
The factors considered in the determination of E included
the best control technology that can be applied to new sources,
for each emission source in a representative plant, and the
control efficiency that can be obtained. The control efficiency
was then applied to the uncontrolled emissions from each emission
source to arrive at the NSPS emissions. The summation of the
NSPS emissions for each emission source then gave the E for the
n
industry, expressed in the same unit as that of E .
The best control technology and control efficiency were
determined from the literature, government reports, and plant
visits. The discussion of these two factors for each SIC is
presented in Section 12 of this report. Tables 39 through
47 give the En and the factors for its derivation for the nine
rubber processing industries. Also shown in these tables are
factors for the derivation of E , the regulated emission factor
o
which is described in Section 13.3.2.3.
198
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Table 39. FACTORS FOR DERIVATION OP E AND E - SYNTHETIC RUBBER
vo
Emission
source
Styrene storage
(breathing)
Solvent storage
(fugitive)
Reactor section
(fugitive)
Recovery area
(fugitive)
Butadiene recovery
Coagulation, dewatering
drying
Styrene storage
(breathing)
Hexane storage
(breathing)
Storage (fugitive)
Purification area
(fugitive)
Reactor area
(fugitive)
Desolventization
(surge vent)
Desolventization
(fugitive)
Dewatering, drying
Uncontrolled
emissions,
g/kg
Emu
0.02
0.07
0. 4
0.1
0.6
0.6
Sol
0.02
0.5
0.07
0.2
0.61
2.7
0.2
20.2
Factors for derivation of E
technique
Ision polymerizatic
Floating roof
Housekeeping
Housekeeping
Housekeeping
Incineration
Incineration
ution polymerizatic
Floating roof
Floating roof
Housekeeping
Housekeeping
Housekeeping
Improved steam
stripping
Housekeeping
Incineration
Control
efficiency
n (90 percen
80%
50-80%
50-80%
50-80%
90%
90%
n (10 percen
80%
80%
50-80%
50-80%
50-80%
50%
50-80%
90%
NSPS
emissions ,
g/kg
t of total
0.004
0.035
0.2
0.05
0.06
0.06
t of total
0.004
0.1
0.035
0.1
0.30
1.4
0.1
2.0
Factors for derivation of E
Average
uncontrol led
emission rate,
Ib/day
production capa
4
14
78
20
118
118
production capa
4
98
14
39
119
530
39
3,945
Permissible
emission rate,
Ib/day
city)
40
40
40
40
18a
18a
city)
40
40
40
40
40
260b
40
5923
Emission
reduction
reguired
0
0
49%
0
85%a
85%a
0
59%
0
0
66%
50%b
0
85%a
Regulated
emissions ,
g/kg
0.02
0.07
0.2
0.1
0.09
0.09
0.02
0.2
0.04
0.2
0.12
1.4
0.2
3.03
COMPOSITE TOTAL:
E = 4.1*
E, = 0.77
aThe regulation of 85 percent reduction is applied.
50 percent control represents maximum reduction feasible.
E = 0.9 (1.79) + 0.1 (24.5)
U = 1.61 + 2.45
= 4.1
E =1.01
-------
Table 40. FACTORS FOR DERIVATION OF E AND E - TIRES AND INNER TUBES
n s
Factors for derivation of E
n
Uncontrolled
emissions, Best control
Emission source
Compounding
Milling
Calendering
Fabric cementing
Tire building
Extrusion
NJ Undertread cementing
0
0
Treadend cementing
Green tire spraying
Curing
Solvent storage
TOTAL : E
g/kg
0.1
0
0
5
.3
0
1
0
19
0
0
= 30
.05
.04a
b
.6
.oid
.25e
.25f
.7
.22
.01
.23
Factors for derivation of E0
Average
NSPS uncontrolled
Control emissions, emission rate,
technique efficiency 9~/kg
Incineration
Incineration
Incineration
Ventilation and
incineration
Scheduling change
Process change
Carbon adsorption
or incineration
Carbon adsorption
or incineration
Water base spraying
Ventilation and
incineration
—
90% 0.01
60% 0.02
55% 0.02
60% 2
50% 1.8
80% 0.01
90% 0.12
90% 0.025
90% 1.97
60% 0.09
0.01
E = 6.06
n
Ib/day
10
5
4
500
370
1
125
25
1,970
22
1
Permissible
emission rate,
Ib/day
15
15
15
c
200
40
15
40
40
2959
15
40
Emission Regulated
reduction emissions,
required 9/kg
0
0
0
C
60%
50%b
0
68%
0
85%9
32%C
0
0.1
0.05
0.04
2
1.8
0.01
0.4
0.25
2.95
0.15
0.01
Es = 7.75
Calendering is assumed to be utilized in the production of tires in 80 percent of the final product weight.
Fabric cementing is assumed to be utilized in the production of tires in 50 percent of the final product weight.
°60 percent control represents maximum reduction feasible.
Extrusion is assumed to be utilized in the production of tires in 20 percent of the final product weight.
£Undertread cementing is assumed to be utilized in the production of tires in 50 percent of the final product weight.
Treadend cementing is assumed to be utilized in the production of tires in 10 percent of the final product weight.
gThe regulation of 85 percent reduction is applied.
-------
Table 41. FACTORS FOR DERIVATION OF E AND E - RUBBER FOOTWEAR
n s
Emission
source
Compounding
Milling
Calendering
Rubber Cementing
Latex dipping and drying
Molding
Curing
Uncontrolled
emissions,
g/kg
0.1
0.05
0.05
95
o.ic
o.iid
O.OS6
Factors for derivation of E
Best control
technique
Incineration
Incineration
Incineration
Incineration
Process change
Ventilation and
incineration
Ventilation and
incineration
Control
efficiency
90%
60%
55%
36%a
90%
60%
60%
NSPS
emissions,
g/kg
0.01
0.02
0.02
60.8
0.01
0.04
0.03
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
6
3
3
5,240
6
6
4.4
Permissible
emission rate,
Ib/day
15 '
15
15
3,350b
15
15
15
Emission
reduction
reg_uired
0
0
0
36%b
0
0
0
Regulated
emissions ,
g/kg
0.1
0.05
0.05
60.8
0.1
0.11
0.08
TOTAL: E = 95.49 E = 60.92 E = 61.29
40 percent of rubber cementing that is performed in a spray booth can be controlled by 90 percent. The other 60 percent of cementing
is done in open space and is not controllable.
N)
O
These represent the maximum reduction feasible.
°Latex dipping is assumed to be utilized in 20 percent of the final product weight.
Molding is assumed to be utilized in 50 percent of the final product weight.
6Curing is assumed to be utilized in 50 percent of the final product weight.
-------
Table 42. FACTORS FOR DERIVATION OF E AND E - RECLAIMED RUBBER
n s
Emission
source
Depolymerization
Uncontrolled
emissions,
g/kg
30
Factors for derivation of E
Best control
technique
Condenser and
scrubber
Control
efficiency
90%
NSPS
emissions,
g/kg
3.0
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
1790
Permissible
emission rate,
Ib/day
270a
Emission
reduction
required
85%a
Regulated
emissions ,
g/kg
4.5
O
NJ
TOTAL:
a
E = 30
u
E = 3.0
n
"The regulation of 85 percent reduction is applied.
E = 4.5
s
-------
Table 43. FACTORS FOR DERIVATION OF E AND E - HOSE AND BELTING
n s
Emission
source
Compounding
Milling
Calendering
Extrusion-Hose
Fabric cementing
Rubber cementing
Curing
Uncontrolled
emissions,
g/kg
0.1
0.05
0.05
0.02a
12. 5b
6.0
0.16
Factors for derivation of E
Best control
technique
Incineration
Incineration
Incineration
Process change
Incineration
-
Ventilation and
incineration
Control
efficiency
90%
60%
55%
80%
90%
-
60%
NSPS
emissions,
gAg
0.01
0.02
0.02
0.004
1.25
6.0
0.06
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
3
1.5
1.5
0.6
390
186
5
Permissible
emis s ion rate ,
Ib/day
15
15
15
15
58C
40
0
Emission
reduction
required
0
0
0
0
85%°
0
0
Regulated
emissions,
g/kg
0.1
0.05
0.05
0.02
1.9
6.0
0.16
O
co
TOTAL:
a
18.83
E = 7.36
n
Extrusion of hose is assumed to be utilized in 50 percent of the final product weight.
Fabric cementing is assumed to be utilized in 50 percent of the final product weight.
"The regulation of 85 percent reduction is applied.
-------
Table 44. FACTORS FOR DERIVATION OF E AND E - FABRICATED RUBBER PRODUCTS
n s
Emission
source
Compounding
Milling
Calendering
Extrusion
Bonding of parts
Latex dipping
Adhesive spraying
Curing
Molding
Uncontrolled
emissions,
gAg
0.1
0.05
0.025a
0.0153
2.0
0.13b
1.8
0.08a
o.iia
Factors for derivation of E
Best control
technique
Incineration
Incineration
Incineration
Process change
-
Process change
Ventilation and
incineration
Ventilation and
incineration
Ventilation and
incineration
Control
efficiency
90%
60%
55%
80%
-
90%
70%
60%
60%
NSPS
emissions,
g/kg
0.01
0.02
0.01
0.003
2.0
0.01
0.54
0.03
0.04
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
1
0.5
0.2
0.15
17
1
15
0.7
0.9
Permissible
emission rate,
Ib/day
15
15
15
15
40
15
40
15
15
Emission
reduction
required
0
0
0
0
0
0
0
0
0
Regulated
emissions,
gAg
0.1
0.05
0.025
0.015
2.0
0.13
1.8
0.08
0.11
TOTAL:
E = 4.31
u
E = 2.75
n
Assumed to be utilized in 50 percent of the final product weight.
Assumed to be utilized in 25 percent of the final product weight.
E = 4.31
s
-------
Table 45. FACTORS FOR DERIVATION OF E AND E - GASKETS, PACKING, AND SEALING DEVICES
n s
Emission
source
Compounding
Milling
Calendering
Molding
Adhesive
spraying
Uncontrolled
emissions,
g/kg
0.1
0.05
0.05
0.22
3.6
Factors for derivation of E
Best control
technique
Incineration
Incineration
Incineration
Ventilation and
incineration
Incineration
Control
efficiency
90%
60%
55%
60%
90%
NSPS
emissions,
g/kg
0.01
0.02
0.02
0.09
0.36
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
1.5
0.5
0.5
2.6
42
Permissible
emission rate,
Ib/day
15
15
15
15
40
Emission
reduction
required
0
0
0
0
6%
Regulated
emissions,
g/kg
0.1
0.05
0.05
0.22
3.4
NJ
O
Ul
TOTAL:
4.02
E = 0.5
n
E =3.82
s
-------
Table 46. FACTORS FOR DERIVATION OF E AND E - NONFERROUS WIREDRAWING AND INSULATING
n s
Emission
source
Extrusion
Curing
Uncontrolled
emissions,
gAg
0.04
0.6
Factors for derivation of E
Best control
technique
Process change
Incineration
Control
efficiency
80%
60%
NSPS
emissions,
g/kg
0.008
0.24
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
0.9
14
Permissible
emission rate,
Ib/day
15
15
Emission
reduction
required
0
0
Regulated
emissions,
gAg
0.04
0.6
to
o
TOTAL:
=0.64
E =0.25
n
E = 0.64
s
-------
Table 47. FACTORS FOR DERIVATION OF E AND E - TIRE RETREADING
n s
Emission
source
Cement spraying
Curing
Painting and trimming
Uncontrolled
emissions,
g/kg
2.75
0.09
3.2
Factors for derivation of E
Best control
technique
Incineration
Ventilation and
incineration
Process change
(detergent
wash)
Control
efficiency
90%
60%
90%
NSPS
emissions,
g/kg
0.275
0.04
0.32
Factors for derivation of E
Average
uncontrolled
emission rate,
Ib/day
7.2
0.2
8.3
Permissible
emission rate,
Ib/day
40
15
40
Emission
reduction
required
0
0
0
Regulated
emissions,
g/kg
2.75
0.09
3.2
to
o
-J
TOTAL:
= 6.04
E = 0.635
n
6.04
-------
13.3.2.3 State Regulated Emission Factor, E^ - This variable
is the emission factor which represents the 1975 level of hydro-
carbon emission control required by state and local regulations.
It is used to determine T , emissions in 1985 under baseline year
o
regulations. When T is substracted from T , the quantitative
impact of NSPS on emissions is calculated.
State and local regulations for hydrocarbon emissions are
generally related to the nature of the emission source. There
are separate regulations for operations with and without involve-
ment of heating. In both cases, the regulations are further
separated into two types; the "emission limitation" type and the
"percent control" type.
For most states in which the majority of the rubber products
industry is located, the "emission limitation" type regulations
are 15 Ib/day for operations involving heating and/or where heat
is released and 40 Ib/day for operations with no heating involved
or generated. These limitations are not to be exceeded unless
85 percent or greater emission reduction is achieved. This 85
percent control requirement is a "percent control" type
regulation.
In the determination of E for an industry, a typical plant
o
size was first determined by dividing the total capacity by the
number of plants. In some SIC's, a percentage of plants utili-
zing rubber vs. plastic was estimated so as a plant size for
rubber operations only could be determined. These estimates are
presented in Table 48. The uncontrolled emissions from each
208
-------
source (listed in the second column of Tables 39 through 47)
were then applied to arrive at the average uncontrolled emis-
sion rate (mass/day). Depending on whether heating is involved
in the operation, the average emission rate was
Table 48. NO. OF PLANTS PER SIC
UTILIZED IN E CALCULATIONS
s
SIC
Code
2822
3011
3021
3031
3041
3069
3293
3357
7534
TOTAL
No. of Plantsa
(Predicast)
60
122
46
8
112
711
163
262
1,484
% of Rubber59
as Raw Material
-
-
50
-
70
-
50
5
No. of Plants
Processing Rubber
60
122
23
8
78
711
82
13
_b
Contractor files.
D0ne contractor data source has listed 2056 retread shops in
the United States. For this study, the capacity of a visited
plant was assumed representative.
209
-------
compared to the appropriate emission limitation. The following
procedure was used to determine whether control is needed under
baseline year regulations and, if so, the type of regulation
that is applicable. It was also used to obtain the percent
emission reduction required to meet the baseline year
regulations.
Supposing x = average uncontrolled emission rate
y - emission rate when the "percent control"
is applied
z = maximum allowable emission rate when
"emission limitation" is applied,
then y = x » (100 - 85J/100 - 0.15 x.
If x
-------
emissions. The factors for derivation of E for the nine
s
rubber products industries are summarized in Tables 39
through 47.
13.4 RESULTS OF PRIORITIZATION
The impact of NSPS on emissions from the nine rubber
products industries was evaluated by means of Model IV through
use of a computer program. A complete listing of the computer
program is given in Appendix E. Using the input variables
mentioned in Section 13.3, the intermediate variables B, C, T ,
a
T , and T were determined. The quantitative value of emission
s n
*
reduction by implementing the NSPS in 1975 was then calculated.
Table 49 summarizes all the input and output variables of
the computer program for the nine industries. The industries
are listed in decreasing order of emission impact. The Tires
and Inner Tube industry has the highest impact, meaning that
it has the highest potential for reduction of hydrocarbon
emissions by implementation of NSPS. This industry is
followed by the Fabricated Rubber Products industry, Gaskets,
Packing, and Sealing Devices industry, Synthetic Rubber indus-
try, the Rubber Hose and Belting industry, and the Tire
Retreading industry. Nonferrous Wiredrawing and Insulating,
Reclaimed Rubber, and Rubber Footwear have no impact because
of either zero or negative values of B and C.
211
-------
Table 49. INPUT AND OUTPUT VARIABLES FOR MODEL IV PRIORITIZATION OF RUBBER PRODUCTS INDUSTRIES
Emission source
Tires and inner tubes
Fabricated rubber products, N.E.C
Gaskets, packing, and sealing
devices
Synthetic rubber
Rubber hose and belting
Tire retreading and repair shops
Nonferrous wiredrawing and
insulating
Reclaimed rubber
Rubber footwear
k
0.89
0.89
0.89
0.89
0.89
0.85
0.89
0.75
0.70
Emission
units
g/kg rubber
g/kg product
g/kg product
g/kg product
g/kg product
g/kg rubber
g/kg rubber
consumed
g/kg product
g/kg rubber
Emission rates
Uncontrolled
E
u
30.23
4.31
4.02
4.1
18.83
6.04
0.64
30.00
95.49
Allowable
E
s
7.75
4.31
3.82
1.01
8.28
6.04
0.64
4.50
61.29
E
n
6.06
2.75
0.50
0.77
7.36
0.64
0.25
3.00
60.92
Growth rates ,
decimal/yr
P
c
0.0405
0.0485
0.0545
0.0325
0.0385
0.0025
0.0005
-0.0465
-0.0065
Pb
0.0455
0.0455
0.0455
0.0455
0.0455
0.0005
0.0005
0.0005
0.0005
to
H
NJ
-------
Table 49 (continued) . INPUT AND OUTPUT VARIABLES FOR MODEL IV PRIORITIZATION OF RUBBER PRODUCTS INDUSTRIES
Capacity units
Emission source per year
Tires and inner tubes 106 kg, rubber
Fabricated rubber products, N.E.C 103 metric tons,
rubber
Gaskets, packing, and sealing 10 3 metric tons,
devices rubber
Synthetic rubber 10 3 metric tons,
rubber
Rubber hose and belting 103 metric tons,
rubber
Tire retreading and repair shops 105 kg, rubber
Nonferrous wiredrawing and 103 metric tons,
insulating rubber consumed
Reclaimed rubber 103 metric tons,
rubber
Rubber footwear 106 kg, rubber
Capacity
A
1975
2,286.8
1,120.0
180.0
2,180.6
449.0
559.2
57.3
105.2
300.0
B
1985
1,029.0
504.0
81.0
981.3
202.0
0.0
0.0
0.0
0.0
C
1985
914.5
537.6
97.2
697.8
170.6
10.9
0.0
-48.4
-18.0
Emissions,
103 metric tons/yr
T
u
1975
86.444
6.380
0.995
10.543
10.422
2.943
0.033
1.266
i8. 749
T
a
1975
15.773
4.296
0.621
1.960
3.309
2.871
0.033
0.355
12.871
T
s
1985
22.161
6.380
0.945
2.597
4.583
2.943
0.033
0.190
12.034
T
n
1985
19.203
4.918
0.414
2.234
5.274
2.866
0.033
0.244
12.039
T -T
s n
3.000
1.500
0.530
0.360
0.310
0.080
0.000
0.000
0.000
T -T
s n
10 3 tons/yr
3.326
1.663
0.587
0.399
0.344
0.089
0.000
0.000
0.000
NJ
I—'
00
-------
14. REFERENCES
1. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Plastics Materials, Synthetic Rubber, and Man-Made
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Economic Statistics Administration, Bureau of the Census.
Washington, D.C. November 1974. 6 p.
2. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Tire and Inner Tubes, SIC 3011. U.S. Department
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Bureau of the Census. Washington, D.C. March 1974. 7 p.
3. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Rubber and Plastics Footwear, SIC 3021. U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 7 p.
4. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Reclaimed Rubber, SIC 3031. U.S. Department of
Commerce, Social and Economic Statistics Administration,
Bureau of the Census. Washington, D.C. February 1974.
6 p.
214
-------
5. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Rubber and Plastics Hose and Belting, SIC 3041.
U.S. Department of Commerce, Social and Economic Statis-
tics Administration, Bureau of the Census. Washington,
B.C. February 1974. 7 p.
6. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Fabricated Rubber Products, N.E.C., SIC 3069. U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 9 p.
7. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Gaskets, Packing, and Sealing Devices, SIC 3293.
U.S. Department of Commerce, Social and Economic Statis-
tics Administration, Bureau of the Census. Washington,
D.C. March 1974. 6 p.
8. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Nonferrous Wiredrawing and Insulating, SIC 3357.
U.S. Department of Commerce, Social and Economic Statis-
tics Administration, Bureau of the Census. Washington,
D.C. March 1974. 15 p.
9. Preliminary Report, 1972 Census of Manufacturers, Industry
Series, Tire Retreading and Repair Shops, SIC 7534. U.S.
Department of Commerce, Social and Economic Statistics
Administration, Bureau of the Census. Washington, D.C.
March 1974. 6 p.
215
-------
10. Current Industry Reports. U.S. Department of Commerce,
Bureau of the Census. Washington, D.C. Series M30A. 1972
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216
-------
16. Horn, D. A., D. R. Tierney, and T. W. Hughes. Source
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20. Pervier, J. W., et al, Survey Reports on Atmospheric
Emissions from the Petrochemicals Industry, Vols. 1-3
EPA-450/3-73-005-a-c, U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, North Carolina. April 1974.
21. Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Vol. 17. New York, John Wiley & Sons, Inc.,
1968. pp. 509-540.
22. Shreve, R. N. Chemical Process Industries, Third Edition.
New York, McGraw-Hill Publishing Company, 1967. 905 p.
217
-------
23. Rappaport, S. M. The Identification of Effluents from Rub-
ber Vulcanization. In: Proceedings of Conference on
Environmental Aspects of Chemical Use in Rubber Processing
Operations (March 12-14, 1975, Akron, Ohio). U.S. Environ-
mental Protection Agency. Washington, D.C.
EPA-560/1-75-002 (PB 244 172). July 1975. p. 185-216.
24. Kenson, R. E., P. W. Kalika, and S. Cha. Odor Sources in
Rubber Processes and Their Control. In: Proceedings of
Conference on Environmental Aspects of Chemical Use in Rub-
ber Processing Operations (March 12-14, 1975, Akron, Ohio).
U.S. Environmental Protection Agency- Washington, D.C.
EPA-560/1-75-002 (PB 244 172). July 1975. p. 17-36.
25. Guide for Compiling a Comprehensive Emission Inventory
(Revised). U.S. Environmental Protection Agency. Research
Triangle Park, N.C. Publication No. APTD-1135. March
1973. 209 p.
26. Assessment of Industrial Hazardous Waste Practices—Rubber
and Plastics Industry. (Prepared by Foster D. Snell, Inc.,
Florham Park, New Jersey, under EPA Contract 68-01-3194, for
presentation to the Environmental Committee of the Rubber
Manufacturers Association, Cleveland, Ohio, October 22, 1975.
27. van Lierops, B., and P. W. Kalika. Measurement of Hydro-
carbon Emissions and Process Ventilation Requirements at a
Tire Plant. (Presented at the 68th Annual Meeting of the
Air Pollution Control Association. Boston. June 15-20,
1975.) 23 p.
218
-------
28. Kalika, P. W. Hydrocarbon Emissions - Classification,
Regulation, Measurement, and Control. (Presented at the
3rd Environmental Conference of The Rubber Manufacturers
Association. Chicago, Illinois. October 29-30, 1973.)
18 pp.
29. Development Document for Proposed Effluent Limitations
Guidelines and New Source Performance Standards for the
Fabricated and Reclaimed Rubber Segment of the Rubber
Processing Point Source Category. U.S. Environmental
Protection Agency. Washington, D.C. EPA-440/1-7-030.
August 1974. 213 p.
30. Brothers, J. E. Reclaimed Rubber. In: Rubber Technology,
Second Edition, Morton, M. (Ed.). New York, Van Nostrand
Reinhold Co., 1973. p. 496-514.
31. Ananth, K. P., T. Weast, D. Bendersky, and L. J. Shannon.
Waste Material Trace Pollutant Study. Midwest Research
Institute, Kansas City, Mo., under EPA Contract 68-02-1324,
Task 10. May 1974. p. 96-106.
32. Stern, H. J. Rubber: Natural and Synthetic. London,
MacLaren & Sons, Ltd., 1954. 491 p.
33. Hawley, G. G. The Condensed Chemical Dictionary, Eighth
Edition. New York, Van Nostrand Reinhold Co., 1971. 971 p,
34. McPherson, A. T. , and A. Klemin. Engineering Uses of
Rubber. New York, Reinhold Publishing Corp., 1956.
pp. 265-269.
219
-------
35. Pervier, J. W., R. C. Barley, D. E. Field, B. M. Friedman,
R. B. Morris, and W. A. Schwartz. Survey Reports on Atmos-
pheric Emissions from the Petrochemical Industry, Volume IV.
U.S. Environmental Protection Agency. Research Triangle
Park, N.C. EPA-450/3-73-005-d. April 1974.
36. Package Sorption Device System Study. U.S. Environmental
Protection Agency. Washington, D.C. EPA-R2-72-202.
April 1973. 506 p.
37. North Atlantic Treaty Organization/Committee on the Chal-
lenges of Modern Society, Expert Panel for Air Pollution
Control Technology. Air Pollution: Control Techniques for
Hydrocarbon and Organic Solvent Emissions from Stationary
Sources, N. 19 Final Report. October 1973. 15 p.
38. Lund, H. F. Operating Costs and Procedures of Industrial
Air Pollution Control Equipment. In: Industrial Pollution
Control Handbook. New York, McGraw-Hill, Inc., 1971.
p. 26-1 to 26-11.
39. Exhaust Gas Conversion Factors. Pittsburgh, Air Pollution
Control Assocation, 1972. (Paper 72-88 presented at the
65th Annual Meeting of the Air Pollution Control Association,
Miami. June 18-20, 1972.) 16 p.
40. Chemical Process Industry. In: Compilation of Air Pollut-
ant Emission Factors. U.S. Environmental Protection Agency.
Research Triangle Park, N.C. GAP Pub-AP-42. February
1972. p. 5-1 to 5-26.
220
-------
41. Do Your Rubber Plant's Odors Bother Your Neighbors? Rub-
ber Age. 87_(5) :844-845. August 1960.
42. Hood Rubber Co. Cleans Up with Vapor Adsorption System.
43. Fight Against Air and Water Pollution. Rubber Age.
104_(7) : 51-52. July 1972.
44. Stack Heights. Rubber Age. 106 (5) :49-51. May 1974.
45. OSHA and the Rubber Industry. Rubber Age. 108(3):23-25.
March 1976.
46. OSHA and Environmental Considerations. Rubber Age.
108_(3) : 31-34. March 1976.
47. Downwind, Akron Stinks! Rubber World. 161(3):49-53.
December 1969.
48. GT Kicks the Smoke Habit. Rubber World. 161 (4) :53-55.
January 1970.
49. Downwind, Akron Stinks!, Vol. 2. Rubber World.
161^(4) : 73-75. January 1970.
50. Downwind, Akron Stinks!, Vol. 3. Rubber World.
161. (5) : 45-50. February 1970.
51. Solvent Recovery System Proves a Speedy Payout. Rubber
World. 165(5):44. February 1972.
52. Environmental Health Control for the Rubber Industry. Rub-
ber Chemistry and Technology. 4_4_(2) : 512-533 . April 1971.
53. Environmental Health Control for the Rubber Industry, Part
II. Rubber Chemistry and Technology. 4_5_(1) : 627-637 .
March 1972.
54. Vapor Adsorption System. Rubber Age. 101(6):63. June 1969.
221
-------
55. Hydrocarbon Pollutant Systems Study, Vol. 1 - Stationary
Sources, Effects, and Control. U.S. Environmental Protec-
tion Agency. Research Triangle Park, N.C. (PB 219 073.)
October 1972. 379 p.
56. Penn., W. S., PVC Technology, London, England, Applied
Science Publishers, Limited, 3rd Edition, 1971,
pp. 285-287.
57. Hopper, T. G., and W. A. Marrone. Impact of New Source
Performance Standards on 1985 National Emissions from
Stationary Sources, Vol. I. U.S. Environmental Protection
Agency. Research Triangle Park, N.C. EPA Contract
68-02-1382, Task 3. October 24, 1975. 170 p.
58. Survey of Current Business. U.S. Department of Commerce,
Bureau of Economic Analysis, Washington, B.C. 5j5(7) , 1976.
59. 1972 Census of Manufacturers, Industry Series. U.S. Depart-
ment of Commerce, Bureau of the Census. Washington, D.C.
1974.
60- Outlook 1976. Rubber World. 173(4);23. January 1976.
61. Rubber Consumption to Increase. Rubber World. 172(2); 83.
May 1975.
62. Asset Depreciation Guidelines. Internal Revenue Service,
Washington, D.C. Publication No. 534. 1976.
63. Hamersma, J. W., S. L. Reynolds, and R. F. Maddalone.
IERL-RTP Procedures Manual: Level 1, Environmental Assess-
ment. U.S. Environmental Protection Agency- Research
Triangle Park, N.C. EPA-600/2-76-160a. June 1976. 131 p-
222
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APPENDIX A
ASSOCIATIONS CONCERNED WITH THE RUBBER PROCESSING INDUSTRY
American Footwear Industries Association (Shoe)
1611 North Kent Street
Arlington, Virginia 22209 Phone: (703) 522-8070
Founded: 1869 Members: 500 Staff: 22
Manufacturers and suppliers of footwear. Provided information
on all aspects of industry; economic, statistical, technical,
also machinery, materials, and methods used in shoemaking
throughout the world. Has developed standards for men's and
women's footwear. Presents the Marketing Man of the Year Award,
annually. Sponsors: Conferences on footwear management,
management development and sales and marketing management; semi-
nars on personnel relations and traffic; National Shoe Fair
maintains a library of 2,000 books on International Trade,
Legislation, Footwear Marketing and Manufacturing. Committees:
Management Development; Market Research; Marketing; National
Affairs, Personnel Relations; Standards; Technical; Traffic.
Publications: (1) News Bulletin, biweekly; (2) Labor Bulletin,
weekly; (3) Market Trends, monthly; (4) Facts and Figures on
Footwear, annual; (5) Know Your Association, annual. Publishes
223
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books and pamphlets concerning the footwear industry. Formerly;
(1905) National Boot and Shoe Manufacturers Association, (1965)
National Shoe Manufacturers Association; (1969) National Foot-
wear Manufacturers Association; (1972) American Footwear
Manufacturers Association. Convention/Meeting: annual
American Footwear Institute (Shoe)
50 Rockefeller Plaza Phone: (212) 586-5777
New York, New York 10020 Alice Regensburg, Director
Founded: 1949 Members: 3,000 Staff: 9
Sponsored by four national associations of retailers, chain
stores, and manufacturers in the shoe industry- Conducts
public relations and promotion programs. Formerly: (1966)
National Shoe Institute, (1969) National Footwear Institute
American Retreaders Association (Tire) (ARA)
P.O. Box 7203 Phone: (502) 361-3535
Louisville, Kentucky 40217 P. Clark, President
Founded: 1957 Members: 800 Staff: 4
Tire dealers, retreaders and rubber company manufacturers; sup-
pliers to the retreading/tire industry; to upgrade the retread-
ing industry through exchange of ideas and technical information,
Publications: Retreader's Journal, monthly. Formerly: (1964)
Central States Retreaders Association. Convention/Meeting:
annual—always Apr., Louisville, Kentucky.
International Institute of Synthetic Rubber Producers
45 Rockefeller Plaza Phone: (212) 265-5253
New York, New York 10020 Ralph Lamberson, Mgn. Dir.
Founded: 1960 Members: 41 Staff: 5
224
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Synthetic rubber manufacturers. Promotes standardization of
synthetic rubber polymers; cooperates with governmental depart-
ments and agencies in matters affecting the industry; compiles
statistics. Has made research grants to universities and insti-
tutes in Japan, United States, France, United Kingdom, Germany,
and the Netherlands. European office is in Brussels, Belgium;
Far Eastern Office is in Tokyo, Japan. Latin American office
is in Rio De Janeiro, Brazil. Presents Institute Annual Award
for technical and/or general contributions to the synthetic
rubber industry. Committees: Environmental Control; Nomencla-
ture and Numbering; Operating; Packaging and Distribution;
Public Relations; Research and Development; Rubber in Asphalt;
Statistical; Transportation. Publications: (1) Directory of
Members, annual; (2) Proceedings, annual; (3) Elastomers Manual,
biennial. Convention/Meeting: annual—always Spring. 1975
Rio De Janeiro, Brazil; 1976 Williamsburg, Virginia.
Latex Foam Rubber Council (LFRC)
1901 Pennsylvania Avenue, N.W. Phone: (202) 785-2602
Washington, D. C. 20006 George A. White, Chm.
Founded: 1959 Members: 5 Staff: 5
Manufacturers of latex foam rubber and synthetic latex.
National Tire Dealers and Retreaders Association (NTDRA)
1343 L Street, N.W. Phone: (202) 638-6650
Washington, D.C. 20005 Jefferson Keith, Exec. V. Pres.
Founded: 1920 Members: 4,500 Staff: 27
State Groups: 23 Local Groups: 80
225
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Independent tire dealers and retreaders. Divisions: Tire
Retreading Institute. Publications: (1) Dealer News, weekly;
(2) Hotline, bimonthly; (3) Truck Tire Service Directory, annual
Affilitated with: Independent Tread Rubber Manufacturing Group.
Formerly: National Association of Independent Tire Dealers.
Convention Meeting: annual--1975 October 4-8, Boston,
Massachusetts. 1976 September 18-22, Houston, Texas. 1977
September 17-20, Anaheim, California. 1978 September 16-19,
Detroit, Michigan.
Rubber Manufacturers Association (RMA)
1901 Pennsylvania Avenue, N.W. Phone: (202) 785-2602
Washington, D.C. 20006 Malcolm R. Lovell, Jr., Pres.
Founded: 1915 Members: 170 Staff: 40
Manufacturers of tires, tubes, mechanical and industrial prod-
ucts, footwear, sporting goods, and other rubber products. Cora-
piles monthly, quarterly, and annual statistics on consumption,
production, and inventory of rubber and rubber products. Com-
mittees: Environment; Governmental Relations; Industrial Rela-
tions; Natural Rubber Public Relations; Statistics; Tax; Traffic.
Divisions: Coated Materials; Flooring; Footwear; Heel and Sole;
Industrial Rubber Products; Latex Foam; Molded and Extruded
Products; 0-Rings; Oil Seal; Sundries; Tires. Publications:
Rubber Highlights, monthly, also publishes booklets and a list
of free films and other teaching aids offered by the rubber
industry. Affiliated with: Rubber Shippers Association;
Natural Rubber Shippers Association; Latex Foam Rubber Council.
Formerly: (1909) New England Rubber Club; (1917) Rubber Club
226
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of America; (1929) Rubber Association of America. Convention/
Meeting:, annual—always third Thursday in November.
Tire Industry Safety Council
National Press Building, Suite 766 Phone: (202) 783-1022
Washington, D.C. 20004 Frank Holeman, Dir.
Founded: 1969 Members: 17 Staff: 5
U.S. manufacturers of passenger car tires united to promote
tire safety, tire care and public understanding of the tire
industry. Distributes news releases, radio and television
public service messages on tire safety, answers inquiries on
tires from news media and the general public, and publishes
tire care materials.
Tire Retreading Institute (TR)
1343 L Street, N.W. Phone: (202) 638-6650
Washington, D.C. 20005 Philip H. Taft, Dir.
Founded: 1955 Members: 1000 Staff: 10
Independent retreaders of tires. A division of National Tire
Dealers and Retreaders Association
Tire and Rim Association (TRA)
3200 West Market Street Phone: (216) 836-5553
Akron, Ohio 44313 C. N. Dykes, Exec. V. Pres. and Sec,
Founded: 1903 Members: 55 Staff: 4
Manufacturers of tires, rims, wheels, and related parts.
Establishes standards (primarily dimensional) for tires, tubes,
valves and flaps for passenger cars, motorcycles, trucks, buses,
airplanes and for earthmoving, road building, agricultural and
227
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industrial vehicles. Committees: Standards and Technical
Advisory. Divisions: Agricultural Tire and Rim; Aircraft Tire
and Rum; Cycle Tire and Rim; Industrial Tire and Rim; Off-the-
Road Tire and Rim. Passenger Care Tire and Rim; Truck Bus Tire
and Rim; Tube and Valve. Publications: Standards Year Book.
Convention/Meeting: quarterly
Wire Association
209 Montowese Street Phone: (203) 453-2777
Branford, Connecticut 06405 Charles H. Ellwanger, Exec. Sec.
Founded: 1930 Members: 2,700 Staff: 10
Professional society of operating executives, plant superintend-
ents, engineers, chemists, metallurgist, and others concerned
with production in wire mill and insulated wire plants producing
bars, rods, strip, wire, wire products and electrical wire and
cable. Studies production methods, new materials, and applica-
tions for existing materials; provides advisory service on tech-
nical and operating problems. Committees: Awards; Papers
Review. Divisions: Electrical; Ferrous, Non-Ferrous. Publica-
tions: (1) Wire Journal, monthly; (2) Wire Journal Directory/
Catalog, annual. Convention/Meeting: annual—1975 October 12-16,
Washington, D.C. 1976 October 25-28, Cleveland, Ohio.
1977 October 17-20, Boston, Massachusetts.
228
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APPENDIX B
PARTIAL PLANT LISTINGS
BY STANDARD INDUSTRIAL CLASSIFICATION CODE
Table B-l presents a partial geographical distribution of
rubber products plants, by state. Tables B-2 through B-9 give
available locations of plants in the nine standard industrial
classifications studied.
229
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Table B-l. A PARTIAL GEOGRAPHIC DISTRIBUTION OF RUBBER PRODUCTS PLANTS
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
TOTALS
SIC Code
2822
4
2
1
1
5
6
1
4
1
1
4
1
1
7
1
3
1
5
11
60
3011
7
4
15
2
6
5
3
3
1
2
1
3
2
2
1
3
1
2
7
18
5
1
11
3
5
5
2
1
1
122
3021
1
1
1
1
4
2
1
1
4
2
8
2
1
2
2
5
1
3
1
2
1
46a
3031
7
1
3
1
2
1
8
3041
2
3
3
8
1
1
2
1
1
8
3
1
4
5
4
1
6
4
8
8
1
15
1
4
3
5
6
1
1
1
112a
3069
2
4
8
64
1
23
1
8
30
36
39
3
2
3
2
2
5
36
35
19
5
11
2
7
49
31
17
108
7
4
40
11
7
1
29
17
4
15
5
5
13
711
3293
1
13'
4
1
1
23
2
1
4
1
5
7
2
2
1
1
13
13
2
14
5
3
12
2
1
4
16
1
3
5
16 3a
3357
2
4
4
19
18
3
4
7
15
20
1
1
6
2
3
23
9
2
5
3
25
29
9
9 .
8
12
3
3
6
4
3
262a
7534
"_b
Total
Plants
14
0
11
20
124
3
51
6
18
47
0
0
89
69
8
5
24
10
7
14
80
61
24
12
25
0
6
1
13
103
0
85
39
0
175
18
9
84
25
18
2
54
62
5
4
24
6
8
21
0
1,484
Includes plants consuming plastics as raw materials.
Number of plants unknown.
230
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Table B-2. SIC 2822: SYNTHETIC RUBBER (VULCANIZABLE ELASTOMERS)
Company name
American Cyanamid Industrial Chemicals
American Latex Fibre Corporation
American Synthetic Rubber
Amotex Plastics
Copolymer Rubber & Chemical Company
Copolymer Rubber & Chemical Company
Ashland Chemical Company
4
Atlantis Chemical Corporation
Goodrich Gulf Chemicals
B F Goodrich Chemical Division
B F Goodrich Chemical Division
Goodrich Gulf Chemicals
Bailey-Park Urethane Inc
Columbian Carbon Company
Allen Industries Inc
Dow Corning Corporation
Dow Corning Corporation
Dow Corning Corporation
Dow Corning Corporation
E I Du Pont De Nemours
E R Carpenter Company Inc
Exxon Chemical
Firestone Tire & Rubber Company
State
New Jersey
Massachusetts
Kentucky
Tennessee
Louisiana
Louisiana
Texas
Michigan
Texas
Kentucky
Ohio
Texas
Tennessee
Louisiana
Michigan
California
Connecticut
Michigan
California
Kentucky
Kentucky
Texas
Tennessee
City
Linden
Lawrence
Louisville
Nashville
Addis
Baton Rouge
Baytown
Troy
Port Neches
Louisville
Akron
Orange
Memphis
Lake Charles
Troy
Costa Mesa
Trumbull
Midland
Irvine
Louisville
Russellville
Baytown
Milan
231
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Table B-2 (continued). SIC 2822: SYNTHETIC RUBBER (VULCANIZABLE ELASTOMERS)
Company name
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Plastics Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
General Electric Company
General Tire & Rubber Company
General Tire S Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Grand Sheet Metal Products
Me Creary Industrial Products
Mearthane Products
Nassau Chemical Corporation
Norton Co. Chemical Div.
Perma Foam Inc.
Phillips Petro/Copolymer
Rubber Research Elastomrcs
Shell Chemical Company
Spe-De-Way Products Company Inc.
State
Texas
Louisiana
Ohio
Pennsylvania
Ohio
Pennsylvania
Indiana
New York
Texas
Ohio
Ohio
Texas
Tennessee
Pennsylvania
Rhode Island
New Jersey
Ohio
New Jersey
Texas
Minnesota
California
Oregon
City
Orange
Lake Charles
Akron
Pottstown
Akron
Corry
Elkhart
Waterford
Odessa
Mogadore
Akron
Houston
Chattanooga
Indiana
Cranston
Trenton
Akron
Irvington
Borger
Minneapolis
Torrance
Portland
232
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Table B-2 (continued). SIC 2822: SYNTHETIC RUBBER (VULCANIZABLE ELASTOMERS)
Company name
Kerr Mfg. Division Sybron
Foam & Plastics Tenneco
Petro Tex Chemical
Texas U S Chemical Company
Burkhart Mfg.
Thiokol Chemical Corporation
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc. Synthetic Rubber Div.
Texas US Chemical Company
Dewey & Almy Division W R Grace
State
Michigan
New Jersey
Texas
Texas
Illinois
Mississippi
Louisiana
Louisiana
North Carolina
Connecticut
Texas
Kentucky
City
Romulus
Carlstadt
Houston
Port Neches
Cairo
Moss Point
Baton Rouge
Geismar
Gastonia
Naugatuck
Port Neches
Owensboro
233
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Table B-3. SIC 3011: TIRES AND INNER TUBES
Company name
A M F Voit Inc.
Long Mile Rubber Company
Long Mile Rubber Company
Synthane Corporation
Armstrong Rubber Company
Armstrong Rubber Company
Armstrong Rubber Company
Armstrong Rubber Company
Armstrong Rubber Company
Armstrong Rubber Company
Armstrong Rubber Company
Goodrich Tire Company Inc .
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
B F Goodrich Company Inc.
Master Processing Corporation
Bandag Inc.
Bearcat Tire Company
State
Oregon
Texas
South Carolina
Pennsylvania
Tennessee
Mississippi
California
Iowa
Connecticut
Arkansas
Tennessee
Alabama
Ohio
California
Oklahoma
Indiana
Alabama
Pennsylvania
Ohio
Indiana
California
Iowa
Illinois
City
Portland
Dallas
Spartanburg
Oaks
Clinton
Natchez
Los Angeles
Des Moines
West Haven
Little Rock
Madison
Tuscaloosa
Akron
Los Angeles
Miami
Woodburn
Tuscaloosa
Oaks
St Paris
Fort Wayne
Lynwood
Muscatine
Chicago
234
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Table B-3 (continued). SIC 3011: TIRES AND INNER TUBES
Company name
Better Monkey Grip Company Inc.
Carlisle Corporation
Commercial Rubber Company Inc.
Cooper Tire & Rubber Company
Cooper Tire & Rubber Company
Cooper Tire & Rubber Company
Denman Rubber Mfg.
Dixie-Cap Rubber Company
Dunlop Tire & Rubber Company
Dunlop Tire & Rubber Company
Dunlop Tire & Rubber Company
Durkee Atwood Company Inc.
Ohio Rubber Company
Eaton Corp. Air Controls Division
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Sieberling Tire S Rubber
Dayton Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
State
Texas
Pennsylvania
California
Mississippi
Arkansas
Ohio
Ohio
Georgia
New York
New York
Alabama
Minnesota
Pennsylvania
North Carolina
California
California
Iowa
Illinois
Ohio
Ohio
Arkansas
North Carolina
Ohio
City
Dallas
Carlisle
Los Angeles
Clarksdale
Texarkana
Findlay
Warren
Athens
Buffalo
Tonawanda
Huntsville
Red Wing
Conneautville
Roxboro
Salinas
South Gate
Des Moines
Decatur
Barberton
Dayton
Russellville
Wilson
Akron
235
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Table B-3 (continued). SIC 3011: TIRES AND INNER TUBES
Company name
Firestone Tire & Rubber Company
Dayton Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire S Rubber Company
General Tire & Rubber Company
Golden West Rubber Product
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Kelly Springfield Tire Company
Kelly Springfield Tire Company
State
Tennessee
Oklahoma
Illinois
Georgia
North Carolina
Ohio
California
Texas
Kentucky
Georgia
Ohio
Illinois
California
Virginia
Kentucky
Washington
California
Kansas
Michigan
Ohio
Alabama
Illinois
Texas
City
Nashville
Oklahoma City
Bloomington
Albany
Charlotte
Bryan
City of Industry
Waco
Mayf ield
Macon
Akron
Mount Vernon
Los Angeles
Danville
Madisonville
Chehalis
Los Angeles
Topeka
Jackson
Akron
Gadsden
Freeport
Tyler
236
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Table B-3 (continued). SIC 3011: TIRES AND INNER TUBES
Company name
Kelly Springfield Tire Company
Lee Tire & Rubber Company Inc.
Goodyear Tire & Rubber Company
Lee Tire & Rubber Company
Kelly Springfield Tire Company
Goodyear Tire S Rubber Company
H B Egan Manfg. Company Inc.
Cupples Company Mfg. Inc.
Harrelson Rubber Company
Hercules Tire & Rubber
Poison Rubber Company Inc.
Long Mile Rubber Company
Maine Industrial Rubber
Penna Tire & Rubber Miss.
Mansfield Tire & Rubber Company
Martin Wheel Company Inc.
Me Creary Tire & Rubber
Michelin Renovex Corporation
Micheline Tire Corporation
Michelin Tire Corporation
Mitchell Industrial Tire
Mobat Tire S Rubber Company
Mohawk Rubber Company
State
Maryland
Pennsylvania
Massachusetts
Pennsylvania
North Carolina
Tennessee
Oklahoma
Missouri
North Carolina
Ohio
Ohio
Pennsylvania
Maine
Mississippi
Ohio
Ohio
Pennsylvania
Oklahoma
South Carolina
South Carolina
Tennessee
California
California
City
Cumberland
Conshohocken
New Bedford
Frazer
Fayetteville
Union City
Muskogee
St. Louis
Asheboro
Findlay
Garrettsville
Export
Westbrook
Tupelo
Mansfield
Tallmadge
Indiana
Oklahoma City
Sandy Springs
Greenville
Chattanooga
Livermore
Stockton
237
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Table B-3 (continued). SIC 3011: TIRES AND INNER TUBES
Company name
Mohawk Rubber Company
Mohawk Rubber Company
Mohawk Rubber Company
Mohawk Rubber Company Inc.
Mohawk Rubber Company
Model Tire Company
Acme Plastics Inc.
Bridgeport Brass Company
Oliver Tire & Rubber Company
Retreaders Tire Supply Company
Robbins Tire & Rubber Company
Schenuit Tire & Rubber
Schenuit Tire & Rubber
Technical Rubber Company Inc .
Tex Con Tire Inc.
Textile Rubber Company Inc.
Tru Flex Rubber Products
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
State
Arkansas
Ohio
Alabama
Virginia
Pennsylvania
California
Ohio
Connecticut
California
Georgia
Alabama
Maryland
Maryland
Ohio
Texas
Georgia
California
California
Wisconsin
Indiana
Michigan
Georgia
Massachusetts
City
Helena
Akron
Guntersville
Salem
Lancaster
Sacramento
Akron
Bridgeport
Oakland
Warrenton
Tuscumbia
Baltimore
Luthrvl-timnm
Johnstown
Houston
Bowdon
Los Angeles
Los Angeles
Eau Claire
Indianapolis
Detroit
Conyers
Chicopee
238
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Table B-3 (continued). SIC 3011: TIRES AND INNER TUBES
Company name
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc.
Washington Rubber Company
State
Pennsylvania
Oklahoma
Alabama
Pennsylvania
City
Wilkes Barre
Ardmore
Opelika
Canonsburg
239
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Table B-4. SIC 3021: RUBBER AND PLASTICS FOOTWEAR
Company name
Amedico Products Inc.
Amer Biltrite Footwear Division
Amer Biltrite Footwear Division
Head Ski Division Amf Inc.
Autry Rubber Company Inc.
Bata Shoe Company Inc .
Bata Shoe Company Inc .
Cambridge Rubber Company Inc.
Carroll Shoe Company Inc.
Cambridge Rubber Company Inc.
Carroll Shoe Company
Carroll Shoe Company
Carter Rubber Company Inc.
Servus Rubber Company Inc.
Servus Rubber Company Inc.
Edwin G. Smith Shoe Company
Converse Rubber Company
Converse Rubber-Tyer Division
Converse Rubber Company
Converse Rubber Company
Presque Isle Footwear
Converse Rubber Company
Converse Rubber Company
State
Ohio
Massachusetts
Massachusetts
Colorado
Texas
Indiana
Maryland
Maryland
Pennsylvania
Massachusetts
Pennsylvania
West Virginia
Pennsylvania
Illinois
Massachusetts
Tennessee
North Carolina
Massachusetts
Massachusetts
New Hampshire
Maine
Maine
Maine
City
Cleveland
Stoughton
Chelsea
Boulder
Dallas
Salem
Belcamp
Taneytown
Littlestown
Cambridge
Mont Alto
Summer sville
Wilkes Barre
Rock Island
Chicopee
Nashville
Lumberton
Andover
Wilmington
Berlin
Presque Isle
Presque Isle
Presque Isle
240
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Table B-4 (continued). SIC 3021: RUBBER AND PLASTICS FOOTWEAR
Company name
Converse Rubber Company
Converse Rubber Company
Gator Shoe Corporation
Arkansas Tech. Ind.
General Foams
Boulevard Shoe Division Genesco
Gerbo Footwear Corporation
Bonan Footwear Company Inc.
Joy Footwear Corporation
La Crosse Rubber Mills Company
Parsons Footwear Inc.
Randolph Mfg. Company Inc.
Rubber Corporation of Pa Inc.
Saddlecraft Inc.
Scottie Industries Inc.
Suave Shoe Corporation
Dorado Footwear Corporation
Sunstar Rubber Inc.
Tingley Rubber Corporation
Totes Inc.
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Inc. Footwear Division
State
Rhode Island
Massachusetts
Florida
Arkansas
Tennessee
Tennessee
Pennsylvania
Maine
Florida
Wisconsin
West Virginia
Massachusetts
Pennsylvania
North Carolina
New Hampshire
Florida
Florida
California
New Jersey
Ohio
Georgia
Georgia
Connecticut
City
Bristol
Lawrence
Miami
Batesville
Nashville
Nashville
Huntingdon
Auburn
Hialeah
La Crosse
Parsons
Randolph
West Hazleton
Cherokee
Hudson
Miami Lakes
Hialeah
Garden Grove
S Plainfield
Love land
Dublin
Thomson
Naugatuck
241
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Table B-5. SIC 3031: RECLAIMED RUBBER
Company name
Centrex Corporation
Howard Rubber Company
Huntingdon Industries Inc.
Laurie Rubber Reclaiming
Midwest Rubber Reclaim Del.
Nearpara Rubber Company
Passaic Rubber Company
U S Rubber Reclaiming
State
Ohio
New York
Pennsylvania
New Jersey
Ohio
New Jersey
New Jersey
Mississippi
City
Findlay
Maspeth
Hatfield
E Millstone
Barberton
Trenton
Wayne
Vicksburg
242
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Table B-6. SIC 3041: RUBBER AND PLASTICS HOSE AND BELTING
Company name
Ace Stretch Hose Company
Acme Hamilton Mfg. Corporation
Globe Albany Corporation
Swan Hose Division Amerace
Swan Hose Division Amerace
American Biltrite
Lewis Products Company Inc.
American Biltrite
American Biltrite Rubber
American Rubber Mfg. Company Inc.
Anchor Hose & Rubber Corporation
Kerona Plastic Extrusion
Atco Rubber Products
Atlantic India Rubber
Auburn Plastic Engrg
B F Goodrich- Akron Pit. #1
B F Goodrich- Akron Pit. #2
B F Goodrich Eng. Systems
Badger Powhatan
Bandag Inc.
Bandag Inc.
Buckeye Rubber Products
Buffalo Weaving & Belting
State
Illinois
New Jersey
New York
Oklahoma
Ohio
Tennessee
Tennessee
Massachusetts
Massachusetts
California
New York
California
Michigan
Indiana
Illinois
Ohio
Ohio
South Carolina
Virginia
North Carolina
Texas
Ohio
New York
City
Chicago
Trenton
Buffalo
Stillwater
Bucyrus
Lawrenceburg
Hohenwald
Cambridge
Cambridge
Oakland
Mount Vernon
Stockton
Grand Haven
Goshen
Chicago
Akron
Akron
Elgin
Charlottesville
Oxford
Abilene
Lima
Buffalo
243
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Table B-6 (continued). SIC 3041: RUBBER AND PLASTICS HOSE AND BELTING
Company name
Flexaust Co-Callahan Minin
Lawrence Hose Company Inc.
Continental Rubber
Cosmoflex Inc.
Crown Products Company
Crushproof Tubing Company Inc.
Custom Rubber Corporation
Dapol Plastics Inc.
Darling R E Company Inc.
Colorite Plastics Company
National Hose Company
Dayco Corporation
Dura Line Corporation
Durkee Atwood Company
E James & Company
Electric Hose & Rubber Company
Electric Hose & Rubber Company
Electric Hose & Rubber Company
Electric Hose & Rubber Company
Extremultus Inc.
Favorite Plastic Corporation
Corban Industries
Firestone Tire & Rubber Company
State
Massachusetts
New Jersey
Pennsylvania
Missouri
Nebraska
Ohio
Ohio
Massachusetts
Arizona
New Jersey
New Jersey
South Carolina
Kentucky
Minnesota
Illinois .
Texas
Delaware
Nebraska
Nebraska
New Jersey
New York
Florida
Indiana
City
Amesbury
Trenton
Erie
Hannibal
Omaha
McComb
Cleveland
Worcester
Tucson
Ridgefield
Dover
Walterboro
Middle sboro
Minneapolis
Chicago
Olney '
Wilmington
Alliance
Me Cook
Englewood
Brooklyn
Tampa
Noblesville
244
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Table B-6 (continued). SIC 3041: RUBBER AND PLASTICS HOSE AND BELTING
Company name
Prescott Industrial Products
Flexfab Inc.
Four D Mfg. Company Inc.
Kent Latex Products Inc .
Gates Rubber Company Inc.
Gates Rubber Company Inc.
Gates Rubber Company Inc.
Gates Rubber Company Inc.
Gates Rubber Company Inc.
General Rubber & Supply Company
Goodall Rubber Company
Goodall Rubber Company Inc.
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Hancock Gross Inc .
Haywood Company
Imperial Eastman Corporation
Industrial Tube Corporation
Insulated Duct & Cable Company
J E Rhoads & Sons
Jet Stream Plastics
John G Shelley Company Inc.
Kennerley Sprat ing Inc.
State
Arkansas
Michigan
West Virginia
Ohio
Kentucky
Colorado
Illinois
Arkansas
Kansas
Kentucky
Illinois
Texas
Nebraska
Illinois
Wisconsin
Pennsylvania
Tennessee
Texas
California
New Jersey
Delaware
Arkansas
Massachusetts
California
City
Prescott
Hastings
Glenville
Kent
Elizabethtown
Denver
Galesburg
Si loam Springs
lola
Louisville
Melrose Park
Houston
Lincoln
North Chicago
Sun Prairie
Philadelphia
Brownsville
Dallas
Wilmington
Trenton
Wilmington
Siloam Spring
Wellesley His.
Berkeley
245
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Table B-6 (continued). SIC 3041: RUBBER AND PLASTICS HOSE AND BELTING
Company name
Lasco Industries Inc.
Aeroquip Corporation
Aeroquip Corporation
Aeroquip Corporation
Manufacturers Rubber
Master Rubber Processing
Mechanical Rubber Products
Mercer Rubber Company Inc.
Flexible Products Comoany Inc.
Missouri Belting Company Inc.
Murray Corporation of Maryland
Parflex Plt/Parker-Hannif in
Parker Stearns & Company Inc.
Perma Pipe
Plastic Extruders Inc.
Plastiflex Company Inc.
Plastiflex Company Inc.
Plumley Rubber Company
Protective Coatings Inc.
R E Darling Company Inc.
Reeves Rubber Inc.
Resistoflex Corporation
Electro-Mech Div/Robintech
Delford Industries Inc.
State
California
Michigan
Ohio
Ohio
Tennessee
California
New York
New Jersey
Michigan
Missouri
Texas
Ohio
New York
Kentucky
Arizona
Illinois
California
Tennessee
Indiana
Arizona
Alabama
California
New York
New York
City
Montebello
Jackson
Van Wert
Youngstown
Memphis
Long Beach
Warwick
Trenton
Southfield
St. Louis
Palestine
Ravenna
Flushing
Middlesboro
Phoenix
Elk Grove Vlg.
Inglewood
Paris
Fort Wayne
Tucson
Albertville
Anaheim
Vestal
Middletown
246
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Table B-6 (continued). SIC 3041: RUBBER AND PLASTICS HOSE AND BELTING
Company name
Rubber Hose Inc.
Samuel Moore & Company Inc.
Scovill Mfg. Company
Semcor
Specification Rubber Products
Amoco Chemical Corporation
Cincinnati Rubber Mfg. Company
Stratoflex Inc.
Superior Rubber Supply
Te Company Inc.
Tuff Lite Corporation
Uniroyal Inc .
Fabric Fire Hose Company Inc.
Uniroyal Inc.
Uniroyal Inc .
Victor Balata & Textile
Vulcanized Rubber & Plastics
Fayette Tubular Products
Weatherhead Compay Inc.
Webb Belting Company Inc.
State
Georgia
Ohio
Ohio
Missouri
Alabama
Arkansas
Ohio
Texas
Illinois
Missouri
New Jersey
South Carolina
Connecticut
Iowa
Missouri
Pennsylvania
Pennsylvania
Ohio
Ohio
Missouri
City
Auburn
Mantua
Hebron
St. Louis
Alabaster
Magnolia
Cincinnati
Fort Worth
Chicago
St. Louis
Edison
Moncks Corner
Sandy Hook
Red Oak
Kennett
Easton
Morrisville
Fayette
Antwerp
Kansas City
247
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Table B-7. SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Kraco Enterprises Inc.
A B Boyd Company
ABC Rubber Company Inc.
A Baker Mfg. Company Inc.
A G I Rubber Company Inc.
A Lakin & Sons Inc.
California Foam Products
Ace Rubber Company Inc.
Ace Rubber Products Inc.
Ace Rubber Products Inc.
Acme Fisher Tank Linings
Acme Machell Company Inc.
Advance Latex Mfg. Company Inc.
Advance Rubber Company Inc.
AHP Medical Inc.
Air O Plastik Corporation
Air Seal Inc.
Airex Rubber Products Corporation
Akro Inc.
Alb Rubber Company Inc.
Albert Trostel Packings
Sperry Rubber & Plastics
Seiko Corporation
State
California
California
Illinois
Indiana
Connecticut
Illinois
California
California
Ohio
Georgia
Kentucky
Wisconsin
California
Minnesota
Georgia
New Jersey
Tennessee
Connecticut
Ohio
Massachusetts
Wisconsin
Indiana
Maryland
City
Compton
San Francisco
Chicago
South Bend
Bridgeport
Chicago
Culver City
South Gate
Akron
Waycross
Louisville
Milwaukee
Culver City
Minneapolis
Columbus
Carlstadt
Shelbyville
Portland
Canton
Somerville
Lake Geneva
Brookville
Kingsville
248
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Rice Chadwick Rubber Company
Aldan Rubber Company
Alliance Rubber Company Inc.
Alliance Rubber Company Inc.
Alliance Rubber Company Inc.
Almet of Tennessee
Alton Lamp Mfg. Company Inc.
Amerace Esna Corporation
Amerace-Wheel Products Division
Amerace Molded Products Division
Ripley Shoe Products Company
Accurate Mfg. Company
Boston Ind. Prod/AM Biltrit
Globe-Superior
Acushnet Company
Burma Latex Products Division AHSC
American Latex Corporation
American National Rubber
Patten Pan Avion Division
American Safety Flight System
American Sponge & Chamois
Ames Rubber Corporation
W J Voit Rubber Corporation
State
Ohio
Pennsylvania
Ohio
Arkansas
Kentucky
Tennessee
Texas
Tennessee
Alabama
Tennessee
Mississippi
New Jersey
Massachusetts
Pennsylvania
Massachusetts
Ohio
Indiana
West Virginia
Florida
Florida
New York
New Jersey
Oregon
City
Killbuck
Philadelphia
Alliance
Hot Spring NP
Franklin
Spring City
Humble
Piney Flats
Lineville
Johnson City
Ripley
Garfield
Boston
Philadelphia
New Bedford
Tallmadge
Sullivan
Ceredo
Miami
Miami
Long Island City
Hamburg
Portland
249
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Anchor Packing Company Inc.
Anchor Packing Company Inc.
Anderson Rubber Company Inc.
Apex Molded Products Company
Apollo Rubber Company
Approved Parts & Rubber Company
Archer Rubber Company Inc.
Arco Industries Corporation
Armada Rubber Mfg. Company Inc.
Connecticut Hard Rubber Company
Aronab Products Company
Arrowhead Mfg. Company
Art Anson Inc.
Arthur A Oliver & Son Inc.
Ashland Rubber Products
Ashtabula Rubber Company Inc.
Associated Rubber Company Inc.
Associated Rubber Inc.
Astro Molding Inc.
Atlantic Tubing & Rubber
Atlas Sponge Rubber Company
Avon Sole Company Inc.
R F Inc.
State
Pennsylvania
Pennsylvania
Ohio
Pennsylvania
Oklahoma
Massachusetts
Massachusetts
Michigan
Michigan
Connecticut
California
Tennessee
Pennsylvania
North Carolina
Ohio
Ohio
Georgia
Pennsylvania
New Jersey
Rhode Island
California
Massachusetts
West Virginia
City
Manheim
Philadelphia
Akron
Philadelphia
Tulsa
Winthrop
Milford
Schoolcraft
Armada
New Haven
San Francisco
Lebanon
Allentown
High Point
Ashland
Ashtabula
Tallapoosa
Quakertown
Old Bridge
Cranston
Monrovia
Avon
Grantsville
250
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
State
City
B F Goodrich Company Inc.
Rubber Fabricators Inc.
B F Goodrich Industrial Products Division
General Products Company
B F Goodrich General Products Dv.
Ball Rubber & Plastic Dv.
Ball Corp-Rubber & Plastic
Ball Brothers Industrial Rubber Good
Baltic Rubber & Plastic
Bardon Rubber Products Company Inc.
Earnhardt Mfg.
Barr Rubber Products Company
Barry Controls Inc.
BASF Wyandotte
Bauman Harnish Rubber Plastic
Bearfoot Corporation
Becton Dickinson & Company
Behtel Latex Products Inc.
Bell Rubber Company
Bendix Corporation
Blair Process Company Inc.
Stalwart Rubber Company Inc.
Bonair Boats Company Inc.
California
West Virginia
Tennessee
Tennessee
California
Michigan
Ohio
Michigan
Ohio
Wisconsin
North Carolina
Ohio
Massachusetts
Michigan
Indiana
Ohio
Ohio
Connecticut
Texas
Ohio
Ohio
Ohio
Kansas
Los Angeles
Richwood
Oneida
Clarksville
Modesto
St. Joseph
Chardon
St. Joseph
Baltic
Union Grove
High Point
Sandusky
Watertown
Troy
Garrett
Wadsworth
Canton
Bethel
Dallas
Toledo
Tallmadge
Bedford
Lenexa
251
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Bond Flex Rubber Company Inc.
Bond International Inc.
Brad Ragan Rubber Company Inc.
Bratman Brothers Inc.
Eagle Rubber Company Inc.
Bruckman Rubber Company
Ozite Corporation
Pioneer Rubber Sherwood Medc
Pioneer Rubber/Sherwood MD
Mac Gregor Division Brunswick
Pioneer Rubber/Sherwood MD
Brunswick Rubber Company Inc.
Dullard Clark Company
Burke Industries
Burton Rubber Processing
Burton Rubber Processing
Burton Rubber Processing
Bushings Inc.
Butterworth Company Inc .
Cactus Mat & Patch Mfg. Company
Cadillac Molder Rubber Inc.
Cadillac Rubber & Plastics
Calhoun Chemical & Coating
State
Indiana
Michigan
Virginia
New York
Ohio
Nebraska
West Virginia
Ohio
Ohio
Georgia
Texas
New Jersey
Connecticut
California
Ohio
Ohio
Ohio
Michigan
Indiana
California
Michigan
Michigan
Georgia
City
Columbia City
Dearborn
Radford
1 New York
Ashland
Hastings
Grafton
Willard
Attica
Covington
Dallas
Deans
Day vi lie
San Jose
Macedonia
Akron
Burton
Royal Oak
Marion
El Monte
Cadillac
Cadillac
Calhoun
252
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Calhoun Padding Inc.
Cardinal Rubber Company Inc.
Geauga Industries Company
Carolina Rubber Hose Company
Fulflex Inc.
Cartex Corporation
Cartex Corporation
Cellular Industries Inc.
Chamberlin Rubber Company Inc.
Chase & Sons Inc.
Chase Walton Elastomers
Chicago Allis Mfg. Corporation
Chicago Manifold Products
Chicago Rubber Company
Circle Rubber Company
Circle Rubber Corporation
Clark Foam Products Company Inc.
Clearview Products Inc.
Coast Craft Rubber Company
Cole Rubber & Plastics
Colonial Chemical Corporation
Colonial Rubber Company
Colox Corporation
State
Georgia
Ohio
Ohio
South Carolina
Rhode Island
Pennsylvania
Pennsylvania
Connecticut
New York
Massachusetts
Massachusetts
Illinois
Illinois
Illinois
Minnesota
New Jersey
Illinois
New York
California
California
Georgia
Ohio
Georgia
City
Calhoun
Barberton
Middlefield
Greenville
Bristol
Morrisville
Doylestown
Waterbury
Rochester
Randolph
Hudson
Chicago
Chicago
Waukegan
Eden Prairie
Newark
Chicago
New York
Torrance
Sunnyvale
Dalton
Ravenna
Dalton
253
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Gar lock Inc.
Columbia Rubber Mills
Comar Products Inc.
Comdaco Company
Commercial Rubber Corporation
Cone Mills Corporation
Consolidated Rubber
Controlled Rubber Products
Conveyor Belt Service
Riverside Industries Inc.
Cooper Herbert Company
Cooper Industrial Products
Cooper Industrial Products
Corduroy Rubber Company Inc.
Corry Rubber Corporation
Craig Industries Inc.
Cresskill Stillman Rubber
Crest Foam Corporation
Crest Rubber Company Inc.
Crossville Rubber Products
Crown Products Corporation
Crown Rubber Company Inc.
Custom Engineering Company
Custom Rubber Products Inc.
State
North Carolina
Oregon
New Jersey
Missouri
Indiana .
Tennessee
Mississippi
Michigan
Minnesota
New Jersey
Pennsylvania
Arkansas
Indiana
Michigan
Pennsylvania
Ohio
New Jersey
New Jersey
Ohio
Tennessee
Missouri
California
Pennsylvania
Texas
City
Gastonia
Portland
Butler
Kansas City
Goshen
Memphis
Natchez
South Haven
Duluth
Riverside
Genesee
El Dorado
Auburn
Grand Rapids
Corry
Canton
E Rutherford
Moonachie
Ravenna
Crossville
St. Louis
Pasadena
Erie
Houston
254
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
D S Brown Company Inc.
DA Pro Rubber Inc.
Dahlman Inc.
Dalton Carpet Coating
Central Rubber Company Inc.
Southwest Latex Corporation
Tupperware Company
Davis Rubber Company
Three Rivers Rubber Corporation
Dayco Corporation
Colonial Rubber Works Inc.
Dayco Corporation
Allen Ind. Inc. Div Dravo CP
Dean Rubber Mfg. Company
Delta Rubber Company Inc.
Detroit Rubber Company Inc.
Diaphragm Industries Inc.
Dike O Seal Inc.
Dipcraft Mfg. Company
Disogrin Industries
M R Plastics of Georgia
Domestic Film Products
Dixie Foam Products Inc.
State
Ohio
California
Minnesota
Georgia
Illinois
Texas
Rhode Island
Arkansas
Michigan
Missouri
Tennessee
North Carolina
Virginia
Missouri
Connecticut
Michigan
New Hampshire
Illinois
Pennsylvania
New Hampshire
Georgia
Ohio
North Carolina
City
North Baltimore
Van Nuys
Braham
Dalton
Belvidere
Seabrook
N Smithfield
Little Rock
Three Rivers
Springfield
Dyersburg
Waynesville
Richmond
N Kansas City
Moo sup
Detroit
Portsmouth
Chicago
Braddock
Manchester
Adairsville
Millersburg
Hickory
255
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Dow Chemical/Dowell Division
Dow Chemical Company
Dow Elco Inc.
Dresco Belting Company Inc.
Dunlap and Kyle Company
Dunne Rubber & Plastic Company
Durable Mat Company Inc.
Duracraft Corporation
Stuart Chase Corporation
E F Houghton & Company
E R Carpenter Company
E T Mfg. Company Inc.
Ohio Rubber Company
Ohio Rubber Oreo Division
Ohio Rubber Company Eagle Pichr.
Eastern Molding Company
Eaton Precision Rubber
Eaton Corporation Molded Products Dv.
Econo Products Inc.
El Monte Rubber Corporation
Elkhart Rubber Works Inc.
Elmhurst Rubber Company Inc.
Prestolite Company
State
Texas
Georgia
California
Massachusetts
Mississippi
Ohio
Ohio
Utah
Massachusetts
Virginia
Virginia
Wisconsin
Ohio
Connecticut
Connecticut
New Jersey
Indiana
Ohio
New York
California
Indiana
New York
New York
City
Wichita Falls
Dalton
Montebello
East Weymouth
Batesville
Ashtabula
Nor walk
Salt Lake City
Randolph
Lynchburg
Richmond
East Troy
Willoughby
Stratford
Norwich
Belleville
Bluffton
Akron
Rochester
El Monte
Elkhart
Elmhurst
Niagara Falls
256
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
USM Bailey Division
Enduro Rubber Company Inc.
Enrubco Inc.
A-S-H Molded Products
Mayfair Molded Products
Esco Rubber Company
J G Milligan Company Inc.
Exotic Rubber & Plastics
Ezon Products Company
Fabreeka Products Company Inc.
Falcon-Roxy Tire Corporation
Faultless Rubber Company
Fauver Molding Company Inc.
Featherlike Products Company
National 0 Rings
Ferro Disc Pad Company
Newport Industrial Product
Firestone Coated Fabric Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Firestone Tire & Rubber Company
Stansi Scientific Company
Flexan Corporation
State
New Hampshire
Ohio
Ohio
Pennsylvania
Illinois
California
Tennessee
Michigan
Tennessee
Massachusetts
New York
Ohio
Michigan
California
California
Michigan
Tennessee
Arkansas
Indiana
Ohio
New Jersey
Illinois
Illinois
City
Seabrook
Ravenna
Akron
Malvern
Schiller Park
Brea
Chattanooga
Farmington
Memphis
Dorchester
Bronx
Ashland
Morenci
Los Angeles
Downey
Mt. Clemens
Newport
Magnolia
Noblesville
Akron
West Caldwell
Chicago
Chicago
257
-------
Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Flexi Mat Corporation
Flexible Products Company
Fo Mac Enterprises Inc.
Foam Products Inc.
Fredericks Rubber Company
Fulfex of N C Inc.
Fullerton Mfg. Company Inc.
Akwell Industries Inc.
Akwell Industries
Gaco Western Inc.
G A F Corporation
GAP Corporation
Gant Industries Inc.
Gardena Rubber Company Inc.
Garland Arts
Garrett Flexible Products
Garrett Flexible Products
Gates Rubber Company Inc.
Gates Rubber Company Inc.
Gen Industries Inc.
General Elastomer Corporation
General Gasket Corporation
State
Illinois
Michigan
Oklahoma
Pennsylvania
Florida
North Carolina
California
Ohio
Alabama
Washington
Tennessee
Georgia
Tennessee
California
New York
Indiana
Indiana
Texas
Iowa
North Carolina
Ohio
Missouri
City
Chicago
Detroit
Tulsa
York Haven
Ft. Lauderdale
Scotland Neck
Fullerton
Akron
Dothan
Seattle
Chattanooga
Dalton
Memphis
Gardena
Brooklyn
Garrett
Garrett
Wichita Falls
Sioux City
Newton
Norwalk
St. Louis
258
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
General Latex & Chemical
General Latex & Chemical
General Latex & Chemical
Arkansas Technical
General Tire & Rubber Company
General Tire Company St. Louis
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
General Tire & Rubber Company
Wilson Rubber Company Inc.
Geneva Rubber Company Inc.
Glas Col Apparatus
Goad Larry & Company Inc.
Goodall Rubber Company Inc.
Goodall Rubber Company Inc.
Goodall Rubber Company Inc.
Goodman Gas Mn. Stpr. Mfg.
Goodwin Golf Mfr.
Goodyear Industrial Product
Goodyear Tire and Rubber Company
Goodyear Aerospace Corporation
State
Georgia
North Carolina
Massachusetts
Arkansas
Pennsylvania
Missouri
Indiana
Indiana
Illinois
Oklahoma
Arizona
Ohio
Ohio
Indiana
Missouri
Washington
New Jersey
Pennsylvania
New York
Ohio
New York
California
Arizona
City
Dalton
Charlotte
Cambridge
Batesville
Jeannette
St. Louis
Wabash
Logansport
Elk Grove Vlg.
Ada
Phoenix
Canton
Geneva
Terre Haute
St. Louis
Seattle
Trenton
Folcroft
Brooklyn
Youngs town
New York
Bakersf ield
Litchfield
259
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Goodyear Tire & Rubber Company
Gordon Rubber Packing Company
Goshen Rubber Company Inc.
Clevite Corporation
Gould Inc/Elastomer Division
Gould Inc.
Graflo Rubber Company Inc.
Lorraine Mfg. Company Inc.
Groendyk Mf g . Company Inc .
Rubatex Corporation
Bondtex Inc.
Griffith Rubber Mills Inc.
Griswold Rubber Company Inc.
GSH Corp/Goshen Rubber Inc.
Gulf Belting & Gasket Company
H A King Company Inc.
H C Lien Rubber Company Inc.
Porter H K Company
Haartz Mason Inc.
Hamilton Kent Mfg. Company Inc.
Harbor Rubber & Plastic
State
Ohio
Ohio
Ohio
Connecticut
Indiana
Ohio
Ohio
Indiana
Virginia
New Jersey
Virginia
Virginia
Virginia
Oregon
Connecticut
North Carolina
Louisiana
Michigan
California
Ohio
Massachusetts
Ohio
California
City
St. Marys
Logan
Marysville
Derby
Goshen
Milan
Napoleon
Angola
Radford
Maywood
Buchanan
Bedford
Bedford
Portland
Moo sup
Snow Hill
New Orleans
Detroit
Los Angeles
Bellefontaine
Watertown
Kent
Long Beach
260
-------
Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
State
City
Harlemark International
Harper Manufacturing Company
Harry B White Jr Company
Harry Goldman Company
Haweye Rubber Mfg. Company
Hawthorne Rubber Mfg. Corporation
Henrite Products Corporation
Henry Engineering Company Inc.
Hiawatha Rubber Company
Hickory Springs Mfg. Company Inc.
Home Rubber Company Inc.
Hoover Hanes Rubber Corporation
Hope Company
Byron Jackson Inc.
Byron Jackson Inc.
Huntington Rubber Mills
Huntington Rubber Mills
Hychex Products
IMCO
Imperial Industrial Sales Company
Industrial Electronic Rubber
Industrial Latex Company
Industrial Rubber Cement
Massachusetts
Georgia
Missouri
New York
Iowa
New Jersey
Tennessee
Illinois
Minnesota
Arkansas
New Jersey
Georgia
Massachusetts
California
Iowa
Washington
Oregon
Illinois
Indiana
Ohio
Ohio
New Jersey
California
Framingham
East Point
St. Louis
Bronx
Cedar Rapids
Hawthorne
Morristown
Moline
Minneapolis
Fort Smith
Trenton
Tallapoosa
Fitchburg
Los Angeles
Keokuk
Federal Way
Portland
Chicago
Huntington
Akron
Twinsburg
Wallington
City of Industry
261
-------
Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Inflated Products Company Inc.
Inmont Corporation
Intermountain Rubber Industry
International Plmbg. Product
International Track System
Interstate Mfg. Company Inc.
All American Engineering
Intl. Packings of Indiana
Intl. Packings of Indiana
Davol Inc.
Davol Dv. Int. Paper
International Foam Inc.
Irving B Moore Corporation
J M Cranz Company Inc.
Easthampton Rubber Thread
United Elastic Rubber Thread
Ja Bar Silicone Corporation
Jacobs Rubber /Bui lard
Jarvis Engineering Company Inc.
Jasper Rubber Company Inc.
Jasper Rubber Products Inc.
JBL Corporation
Jelsco Inc.
State
New York
Indiana
Colorado
New York
Ohio
Massachusetts
Delaware
Indiana
Indiana
Rhode Island
Rhode Island
Pennsylvania
Massachusetts
New York
Virginia
Massachusetts
New Jersey
Connecticut
Illinois
Georgia
Indiana
New Jersey
Ohio
City
Beacon
Huntington
Commerce City
New York
Ashtabula
Hudson
Wilmington
Morris town
Shelbyville
Providence
Cranston
Corry
Cambridge
Buffalo
Stuart
Easthampton
Andover
Dayville
Lyons
Jasper
Jasper
Hawthorne
Willoughby
262
-------
Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Jessup Mfg. Company
Jet Rubber Plastics Inc.
John G Milligan & Company
Arbrook Inc. Dv. J & J
Johnson Rubber Company Inc.
Joseph Dixon Crucible Company
Joslyn Mfg. Company Inc.
Judsen Rubber Works Inc.
K & M Rubber Company
Karman Rubber Company Inc.
Kaysam Corporation of America
Kee Industries Inc.
Keener Rubber Company
Keller Stamping Company
Keystone Rubber Products
Kirkhill Rubber Company Inc.
Kismet Products Inc.
La Favorite Rubber Mfg. Company
Koneta Rubber Company Inc.
Pretty Products Inc.
Latex Industries Inc.
Latex Products Inc.
Laurel Rubber Company Inc.
State
Illinois
Ohio
Wisconsin
Texas
Ohio
New Jersey
Ohio
Illinois
Illinois
Ohio
New Jersey
New York
Ohio
Georgia
New York
California
Ohio
New Jersey
Ohio
Ohio
Ohio
New Jersey
New Jersey
City
Me Henry
Rootstown
Oak Creek
Arlington
Middlefield
Jersey City
Macedonia
Chicago
Arlington Hts.
Akron
Pater son
Seaford
Alliance
Swainsboro
Buffalo
Brea
Painesville
Hawthorne
Wapakoneta
Coshocton
Chippewa Lake
Hawthorne
Garfield
263
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Lavelle Fabricators Inc.
Lavelle Industries Inc.
Central Foam Corporation
Lebanon Ball Company Inc.
Lee Foam Products
Lee Mac Inc.
Legg Company Inc.
Lehigh Rubber Corporation
Aeroquip Corporation
Aeroquip Corporation
Aeroquip Republic Rubber
Lifetime Foam Products Inc.
Ligonier Rubber Company Inc .
Hewitt Robins Rubber opns.
Hewitt Robins Inc.
Lloyd Mf g . Company Inc .
Foamcraft Inc.
Lord Kinematics
Lord Kinematics
Lotridge Rubber Company Inc.
Lubrikup Company Inc.
Ludlow Corporation
Crown Industries
State
Illinois
Wisconsin
Illinois
Pennsylvania
California
Michigan
Kansas
Pennsylvania
California
North Carolina
Virginia
Georgia
Indiana
California
New York
Rhode Island
Indiana
Pennsylvania
Pennsylvania
Ohio
Pennsylvania
California
Ohio
City
Chicago
Burlington
Chicago
Lebanon
Gardena
Ferndale
Halstead
Morrisville
Burbank
Forest City
Wytheville
Conyers
Ligonier
Los Angeles
Buffalo
Warren
Indianapolis
Erie
Cambridge Spg.
Botkins
Williamsport
Capstrano Bch.
Fremont
264
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Ludlow Corporation
Luxaire Cushion Company Inc.
Lycar Products
Magichemical Company Inc.
Manheim Mfg. & Belting Company
North American Rubber Company
Maple City Rubber Company Inc.
Marathon Rubber Products
Marsan Industries Inc.
Marsh-Armf ield Inc.
Martin Inc.
Master Dynamics Corporation
Maurell Products
Davidson Rubber Company Inc.
Davidson ^Rubber Company
Murray Rubber Company
Murray Rubber Company Inc.
Mercer Rubber Company Inc.
Mercer Rubber Corporation
Metro Rubber Products Corporation
Periflex Dv. Flexible Products
Michigan Rubber Products
Mid States Rubber Products
State
Missouri
Ohio
California
Massachusetts
Pennsylvania
Pennsylvania
Ohio
Wisconsin
Illinois
North Carolina
South Carolina
California
Michigan
New Hampshire
New Hampshire
Texas
Texas
Pennsylvania
New York
Illinois
Michigan
Michigan
Indiana
City
Cape Girardea
Newton Falls
Gardena
Brockton
Manheim
Primes
Norwalk
Wausau
Chicago
Conover
Greenville
Sunnyvale
Oswosso
Dover
Farmington
Houston
Houston
Philadelphia
New York
Morris
Southfield
Cadillac
Princeton
265
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Middlesex Research Mfg. Company
Midwest Plastics Inc.
Midwest Rubber Company
Midwestern Rubber Products
Minnesota Mining & Mfg.
Minnesota Rubber Company
Quadee Rubber Company
Minor Rubber Company Inc.
Califoam Corporation of America
Califoam Corporation of America
Moeller Mfg. Company Rubber Division
Mogul Rubber Corporation
Webster Rubber Company
Sas Rubber Company
Webster Rubber Division Beebe
Beebe Rubber Company Inc.
Mohican Rubber Company Inc.
Mold Ex Rubber Company
Molded Rubber Plastic Corporation
Monarch Gasket & Roller
Monarch Rubber Company Inc.
Teledyne Monarch
Monarch Rubber Company
State
Massachusetts
Minnesota
Michigan
Indiana
Ohio
Minnesota
South Dakota
New Jersey
California
California
Mississippi
Indiana
Maine
Ohio
Maine
New Hampshire
Ohio
Michigan
Wisconsin
California
West Virginia
Ohio
Maryland
City
Hudson
St. Paul
Deckerville
Goshen
Cincinnati
Minneapolis
Watertown
Bloomf ield
San Leandro
Santa Ana
Greenville
Goshen
Webster
Painesville
Sabattus
Nashua
Ashland
Farmington
Butler
Lynwood
Spencer
Hartville
Baltimore
266
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Monmouth Rubber Corporation
Mono Belting Corporation
Moore Manufacturing Inc.
Morenci Rubber Products
Morristown Foam Corporation
Morristown Molding Inc.
Mosites Rubber Company Inc.
Moxness Products Inc.
Mullins Rubber Products
Muscle Shoals Rubber Company
Patch Rubber Company Inc.
Ace Comb Dv. JB Williams
Nashua Corporation
Natco Products Corporation
National Brewery Rubber
National Latex Products Company
National Latex Products Company
National Rubber Mfg. Company
National Sponge Cushion Company
Nazar Rubber Company Inc.
Neff Perkins Company
Nemo Engineering Company
Neoplastic Industries
State
New Jersey
California
California
Michigan
Tennessee
Tennessee
Texas
Wisconsin
Ohio
Mississippi
Ohio
Arkansas
Illinois
Rhode Island
Wisconsin
Ohio
Ohio
New York
New Jersey
Ohio
Ohio
North Carolina
Minnesota
City
Long Branch
Auburn
Brisbane
Morenci
Morristown
Morristown
Fort Worth
Racine
Dayton
Batesville
Akron
Booneville
Chicago
West Warwick
Butler
Ashland
Ashland
Long Island Cy.
Trenton
Toledo
Perry
Charlotte
Minneapolis
267
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Netherland Rubber Company
New Jersey Rubber Company Inc.
New Jersey Rubber Mfg. Company
Niagara Rubber Corporation
Nichols Engineering Inc.
Norbalt Rubber Corporation
Northern Mining Equip Inc.
Norton Company Burma Latex Division
Charlston Prod-Norton Company
Charles Products Division Norton
Norwalk Foam Pillow Company
Nycoil Company
Nye Rubber Company Inc.
Oak Rubber Company Inc.
Fli Back Company
Oil States Rubber Company Inc.
Ok League For The Blind
Oliver Rubber Company
Oliver Tire & Rubber Company
Okonite Company
0 Sullivan Corporation
Ottawa Rubber Company Inc.
P C F Foam Corporation
State
Ohio
Massachusetts
New Jersey
New Jersey
Connecticut
Ohio
Minnesota
Ohio
South Carolina
South Carolina
Connecticut
New Jersey
Ohio
Ohio
North Carolina
Texas
Oklahoma
New Jersey
California
Pennsylvania
Virginia
Ohio
Indiana
City
Cincinnati
Taunton
Union City
S Plainfield
Shelton
N Baltimore
Hibbing
Tallmadge
Charleston
Clover
Norwalk
Fanwood
Barberton
Ravenna
High Point
Arlington
Oklahoma City
Flemington
Oakland
Philadelphia
Winchester
Bradner
Elkhart
268
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
PIC Corporation
Pacific Latex Company Inc.
Pacific Moulded Products
Packaging Assoc Medical
Paeco Rubber Company Inc.
Pam Company Inc.
Pandel Chemical Inc.
H 0 Canfield Company of Virginia
Paragon Rubber Corporation
Parflex Rubber Thread Corporation
Castle Rubber Company Inc.
Park Rubber Company Inc.
Paul Martin Rubber Corporation
Pawling Rubber Corporation
Pelmor Laboratories Inc.
Perl foam Company
Pierce Roberts Rubber Company
Pittman Products Inc.
Plabell Rubber Products
Plastic & Rubber Products Company
Plasticoid Company Inc.
Hodgman Rubber Company
Plymouth Rubber Company Inc.
State
Minnesota
California
California
Tennessee
Ohio
New Jersey
Georgia
Virginia
Massachusetts
Rhode Island
Pennsylvania
Illinois
Massachusetts
New York
Pennsylvania
Texas
New Jersey
California
Ohio
California
Maryland
Massachusetts
Massachusetts
City
Peterson
Los Angeles
Los Angeles
Columbia
Ravenna
Palisades Park
Cartersville
Iron Gate
Easthampton
Providence
East Butler
Lake Zurich
Holyoke
Pawling
Newton
Houston
Trenton
Huntington Park
Toledo
Ontario
Elk ton
Framingham
Canton
269
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Polysar Laytex Inc.
Precise Mfg. Corporation
Precision Associates Inc.
Precision Rubber Plate Company
Precision Rubber Products Corporation
Presray Corporation
Prices Stamp Manufacturing
Product Development & Mfg.
Proffitt Mfg. Company
Progressive Marking Products
Pulaski Rubber Company Inc.
Loren Products Division Purex
Hadbar Division purolator Inc.
Quabaug Rubber Company
Quality Products Mfg. Company
Quality Rubber Mfg. Company
Quality Rubber Mfg. "Company
Queen City Rubber
Quester Juvenile Products
R C Musson Rubber Company Inc.
Rai Research Corporation
Manhattan Rubber Mfg. Company
RCA Rubber Company
State
Tennessee
New Jersey
Minnesota
Indiana
Arizona
New York
Indiana
Minnesota
Georgia
California
Tennessee
Massachusetts
California
Massachusetts
California
Michigan
Illinois
New York
Ohio
Ohio
New York
Wisconsin
Ohio
City
Chattanooga
Fairfield
Minneapolis
Indianapolis
Phoenix
Pawling
Plainfield
St. Paul
Dalton
South Gate
Pulaski
Lawrence
Alhambra
N Brookfield
Gardena
Wakef ield
Elk Grove
Buffalo
Ravenna
Akron
Long Island City
Neenah
Akron
270
-------
Table B-7 (contineud). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
State
City
Readco Industries Inc.
Reeves Bros. Vulcan Ure Division
Reeves Bros. Inc.
Reeves Bros. Inc.
Reeves Bros. Inc.
Reeves Rubber Inc.
Reichhold Rubber Latex
Reliable Products Inc.
Reliable Rubber and Plastic
Reliable Rubber Products
Reppenhagen Inc.
Rex Hide Inc.
Chemprene Inc.
Hercules Packing Corporation
Southeastern Rubber Mfg.
Roanoke Belt & Rubber Company
Robin Industries Inc.
Rodhelm Reiss Inc.
Rodic Chemical & Rubber Company
Roller Corporation of America
Roppe Rubber Corporation
Royal Ind-Accurate
Royal Industries
Massachusetts
South Carolina
Virginia
North Carolina
Florida
California
Ohio
Tennessee
New Jersey
Pennsylvania
New York
Pennsylvania
New York
Ohio
Texas
Virginia
Ohio
New Jersey
New Jersey
New Jersey
Ohio
California
California
Reading
Spartanburg
Buena Vista
Hickory
Tampa
San Clemente
Cuyahoga Falls
LobeIvilie
North Bergen
Eddington
Buffalo
East Brady
Beacon
Conneaut
Paris
Roanoke
Cleveland
Belle Mead
North Brunswick
South Plainfield
Fostoria
San Diego
City of Indus
271
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Accurate Products Inc.
Royal Rubber & Mfg. Company, Inc.
Rubber & Silicone Products Company
Rubber Associates Inc.
Rubber Corporation of Arkansas
Rubber Drives Inc.
Rubber Engineering & Manufacturing
Rubber Engineering Development
Rubber Engineering of Arizona
Rubber Engineering of Arizona
Rubber Industries Inc.
Rubber Millers Inc.
Rubber Products Inc.
Rubber Right Products Inc.
Rubber Rolls Inc.
Rubber Service Inc.
Rubber Specialties
Rubber Teck Inc.
Rubbercraft Corporation Inc.
Rubbermaid Inc.
Rubbermaid Specialty Products
Rubbermaid Inc.
Stowe -Woodward Company
State
Illinois
California
New Jersey
Ohio
Arkansas
Minnesota
Utah
California
Arizona
Utah
Minnesota
Maryland
Florida
Illinois
Pennsylvania
California
Connecticut
California
California
Ohio
Georgia
Ohio
Washington
City
Chicago
South Gate
Fairfield
Barberton
De Queen
Crosby
Salt Lake City
Hayward
Phoenix
Salt Lake City
Shakopee
Baltimore
Tampa
Chicago
Meadow Lands
Huntington Park
Seymour
Gardena
Torrance
Wooster
La Grange
Chillicothe
Kelso
272
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
S.W. Industries Inc.
Stowe-Woodward Div. S.W. Industries
Stowe-Woodward Company
Samuel Furiness Mat. Company Inc.
Sandy Valley Rubber Company
Stillman Seal Division Sargent
Kirkhill Inc.
Scarp Heilman Company Inc.
Schacht Rubber Mfg. Company Inc.
Schall Martin Inc.
Schulman Inc.
Scorpion Inc .
Scottdel Inc.
Scougal Rubber Mfg. Company Inc.
M.A. Ferst Ltd. Inc.
Scully Rubber Mfg. Company Inc.
Sea Suits
Gia Mfg. Division Seagrave Ind.
Paramount Industries Div. Seagrave
Searer Rubber Company
Seiberling Latex Products
Shawsheen Rubber Company Inc.
Sheller Globe Corporation
State
Georgia
Massachusetts
Louisiana
New Jersey
Ohio
California
California
Minnesota
Indiana
New York
Illinois
Minnesota
Ohio
Washington
Georgia
Maryland
California
New Jersey
New Jersey
Ohio
Oklahoma
Massachusetts
Indiana
City
Griffin
Newton
Ruston
Edison
Waynesburg
Carlsbad
Downey
Minneapolis
Huntington
Staten Island
East St. Louis
Crosby
Swanton
Seattle
Atlanta
Baltimore
Costa Mesa
Piscataway
Piscataway
Akron
Oklahoma City
Andover
Montpelier
273
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Sheller Globe Corp
Sheilds Rubber Corporation
Shreiner Sole Company Inc.
Precision Rubber Products
Silicone Rubber Products
Silveco Rubber Products
Roth Rubber Company Inc.
Smith Rubber Company Inc.
Snyder Paper Corporation
Sonfarrel Inc.
South Haven Rubber Company Inc.
Southeastern Foam Rubber
Southern Graphite Company Inc.
Remington Rand Office
Odonnell Rubber Products
Sponge Rubber Products
St. Clair Rubber Company Inc.
Waukesha Rubber Operations
Illinois Industrial Rubber
Southern Latex Corporation
Standard Rubber Products
Star Glo Rubber Mfg.
Staunton Industries Inc.
State
Iowa
Pennsylvania
Ohio
Tennessee
Michigan
Illinois
Illinois
New York
North Carolina
California
Michigan
North Carolina
Tennessee
New Jersey
Ohio
Connecticut
Michigan
Wisconsin
Illinois
North Carolina
Massachusetts
New Jersey
Michigan
City
Keokuk
Pittsburgh
Killbuck
Lebanon
Inkster
Chicago
Chicago
Rochester
Hickory
Compton
South Haven
High Point
Shelbyville
New Brunswick
Cincinnati
Shelton
Detroit
Waukesha
Ladd
Concord
West Hanover
E . Rutherford
Royal Oak
274
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
State
City
Stedfast Rubber Company Inc.
Clifton Mfg Company Inc.
Stephenson and Lawyer Inc.
Sterling Laboratory & Dev.
Sterling Ventures
Stern Rubber and Tool Company
Stowe-Woodward Company
Superior Insulating Tape
Superior Plastic Products
Surco Inc.
Surety Rubber Company, Inc.
Syntex Rubber Company
Syracuse Rubber Products
T & M Rubber Specialties
T F Butterfield Inc.
Sun Rubber Company
Taylor Bros Company Inc.
Technical Rubber Inc.
Teledyne Mecca
Tenneco Chemicals Inc.
Tennessee Mat Company Inc.
Tennessee Wheel and Rubber
Testworth Laboratories Inc.
Massachusetts
Massachusetts
Michigan
New Jersey
California
Minnesota
South Carolina
Missouri
Rhode Island
Pennsylvania
Ohio
Connecticut
Indiana
Indiana
Connecticut
Ohio
Ohio
Connecticut
Texas
Pennsylvania
Tennessee
Tennessee
Indiana
North Easton
Boston
Grand Rapids
Monmouth Junction
Los Angeles
Staples
Spartanburg
St.. Louis
Cumberland
Hatfield
Carrollton
Bridgeport
Syracuse
Goshen
Naugatuck
Barberton
Cleveland
West Haven
Houston
West Hazleton
Nashville
Nashville
Columbia City
275
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Table B-7 (continued). SIC 3069: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Textile Rubber and Chemical
Thermo Fashion Corporation
Thomasville Products Inc.
Best Manufacturing Company
Pilgrim Latex Thread Company
Tillotson Corporation
Best Manufacturing Company
Tillotson Rubber Company Inc.
Tompkins Rubber Company Inc.
Topstone Rubber Company Inc.
Toyad Corporation
Trailer Equipment Warehouse
Trexler Rubber Company Inc.
Tri-State Products Inc.
Triad Products Company Inc.
Triangle Rubber Company Inc.
Trion Rubber Company Inc.
Tulsa Rubber Company Inc.
Twin City Rubber Works
U.S. Foam Pillow Inc.
Crest Inc.
Uniroyal Inc.
Uniroyal Inc.
State
Georgia
New York
Virginia
Georgia
Massachusetts
Massachusetts
Georgia
New Hampshire
Pennsylvania
Connecticut
Pennsylvania
Texas
Ohio
Tennessee
Ohio
Indiana
Georgia
Oklahoma
Minnesota
New York
Oklahoma
California
Indiana
City
Dalton
Brooklyn
Martinsville
Menlo
Fall River
Needham Heights
Armuchee
Dixville Notch
Plymouth Meeting
Danbury
Latrobe
Fort Worth
Ravenna
Cookeville
Springfield
Goshen
Macon
Tulsa
Minneapolis
New York
Tulsa
Los Angeles
Mishawaka
276
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Table B-7 (continued). SIC 3096: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
Uniroyal Inc.
Uniroyal Inc.
Uniroyal Consumer Products
Uniroyal Inc.
Uniroyal Inc.
Latex Riber Industries Division
United Foam Corporation
Affiliated Hospital Products
United Industries Inc.
United Rubber Corporation
Vail Rubber Works Inc.
Veri-Tech Inc/Vernay Labs
Vernay Laboratories Inc.
Viking Industries Inc.
Vip Rubber Company
Volunteer Foam and Supply
Vulcan Corporation
W.H. Salisbury and Company Inc.
W.J. Ruscoe Company
Parke Davis and Company
Weed Stamp and Seal Company
Wefco Rubber Manufacturing Corp.
West Company Inc.
State
Rhode Island
Georgia
Connecticut
Missouri
Pennsylvania
New York
Pennsylvania
Ohio
Connecticut
California
Michigan
Florida
Ohio
Minnesota
California
Tennessee
Tennessee
Illinois
Ohio
South Carolina
Michigan
California
Nebraska
City
Providence
Dal ton
Naugatuck
Maryville
Philadelphia
Beaver Falls
Allentown
Carrollton
Bristol
Los Angeles
St. Joseph
Pompan© Beach
Yellow Springs
Minneapolis
Anaheim
Cookeville
Clarksville
Skokie
Akron
Honea Path
Jackson
Santa Monica
Kearney
277
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Table B-7 (continued). SIC 3096: FABRICATED RUBBER PRODUCTS N.E.C.
Company name
West Company Inc.
West Company Inc.
West Company Rubber Division
Western Aspen
Western Rubber Company Inc.
White Rubber Company
Williams Bowman Rubber Company
Wisconsin Rubber Products
Yale Rubber Manufacturing Co. Inc.
Yale Rubber Manufacturing Co. Inc.
Yaleco Industries Inc.
Young Rubber Company
Youngs Drug Products Corp.
Youngs Rubber Corporation
Youngs Drug Products Corporation
Zamal Research Inc.
Zeller Machinery Company Inc.
State
New Jersey
Pennsylvania
Florida
Texas
Indiana
Ohio
Illinois
Wisconsin
Michigan
Georgia
Connecticut
Illinois
Georgia
New Jersey
New Jersey
New Jersey
Florida
City
Millville
Phoenixville
St. Petersburg
Arlington
Goshen
Ravenna
Cicero
Union Grove
Sandusky
Dawson
Guilford
Naperville
Atlanta
Trenton
Piscataway
Garfield
Jacksonville
278
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Table B-8 SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
A.B. Boyd Company
A.W. Chesterton Company
A.W. Chesterton Company Inc.
Accurate Felt and Gasket Mfg.
Composite Materials Corp.
Acushnet Process Company
American Gasket
American Packing and Gasket
Appalachian Gasket Company Inc.
Appleton Packing Gasket
Armstrong Cork Company Inc.
Armstrong Cork Company Inc.
Atlantic Asbestos Corporation
B.F. Goodrich Company Inc.
Badger Cork and Mfg. Company Inc.
Baldwin Ehret Hill Inc.
Banks Bros Corporation
Bignam Insulation and Sply
Marvel- Schebler-Borg Warner
Breeding Mfg Company
C.R. Industries
California Gasket Washing
Cap and Seal Company Inc.
State
California
Massachusetts
Massachusetts
Illinois
Connecticut
Texas
Illinois
Texas
Tennessee
Wisconsin
New York
Massachusetts
New York
Minnesota
Wisconsin
Pennsylvania
New Jersey
Florida
Missouri
Tennessee
South Dakota
California
Illinois
City
San Leandro
Stoneham
Everett
Chicago
Broad Brook
Fort Worth
Schiller Park
Houston
Elizabethton
Appleton
Fulton
Braintree
Red Hook
New Ulm
Trevor
Valley Forge
Kearny
Ft. Lauderdale
Ballwin
Goodlettsville
Springfield
Gardena
Elgin
279
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Table B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
Carolina Gasket and Rubber
Chambers Gasket and Mfg. Company
Chicago Gasket Company
Chicago Rawhide Mfg. Company
Chicago Wilcox Mfg. Company
Cincinnati Gasket Packing
Cleveland Gasket and Mfg. Company
Stemco Mfg. Company Inc.
Gar lock Inc.
Garlock Inc. Mech Rubber Division
Garlock Mech Seal Division
Columbia Asbestos Company
Conover C.E. and Company Inc.
Crane Packing Company Inc.
Dana Corporation
Dana Corp. -Victor Division
Victor Div.Dana Corp
Detroit Die Cutting Company
Detroit Die Cutting Company
Hunt Process Company Inc.
Durabla Manufacturing Company
Packing Engineering Inc.
Wolverine Fabricating and Mfg.
State
North Carolina
Illinois
Illinois
Illinois
Illinois
Ohio
Ohio
Texas
New Jersey
New York
Texas
Oregon
New Jersey
Illinois
Indiana
Illinois
Illinois
Michigan
Michigan
California
Pennsylvania
New Jersey
Virginia
City
Greensboro
Chicago
Chicago
Elgin
South Holland
Cincinnati
Cleveland
Longview
Camden
Palmyra
Houston
Portland
Fairfield
Morton Grove
Churubusco
Chicago
Robinson
Royal Oak
Sault St. Marie
Santa Fe Springs
Strafford
Cranford
Blacksburg
280
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Table B-8 (Continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
Ethylene Gulf Coast Corporation
F.D. Farnam Company
Reflective Laminates
Favorite Gaskets Inc.
Federal Mogul Corporation
Federal Mogul Corporation
Federal Mogul National Seal Div.
Felt Products Mfg. Company
Fibreflex Packing and Mfg. Company
Fitzgerald Mfg. Company
Flexitallic Gasket Company
Flexrock Company
Plasteel Industries
Fluorocarbon Mechanical Seal
Foilpleat Insulation Company
Forest City Foam Products
Forty Eight Insulations
G.T. Sales and Mfg. Inc.
Gasket Mfg. Company Inc.
Gasket Shop Inc.
Gaskets Inc.
Gatke Corporation
General Electric Insul. Mat.
State
Texas
Illinois
California
Illinois
South Carolina
Massachusetts
Ohio
Illinois
Pennsylvania
Connecticut
New Jersey
Pennsylvania
Texas
California
Massachusetts
Ohio
Illinois
Kansas
California
California
Wisconsin
Illinois
New York
City
Houston
Lyons
Newburg Park
Chicago
Summerton
Worcester
Van Wert
Skokie
Philadelphia
Torrington
Camden
Ph i lade Iphi a
Houston
Carson
Fall River
Wellington
Aurora
Wichita
Gardena
San Francisco
Rio
Chicago
Schenectady
281
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TABLE B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
Grefco Inc.
GNC Corp./Goshen Rubber Company
Greene Tweed and Company, Inc.
Harco Chemical Inc.
Higbee Rubber Company Inc.
Hoosier Gasket and Mfg. Corp.
Houston Gasket and Packing
Detroit Gasket and Mfg. Company
Detroit Gasket and Mfg. Company
Industrial Gasket and Shim
Industrial Gasket Inc.
Industrial Gasket Packing
Insulation Services Inc.
International Packings Corp.
J & J Readymix Inc.
J.M. Covington Corp.
Jarrow Products Inc.
Lindstrom and King Company
Johns Manville Products Company
Johns Manville Products Company
Joslyn Mfg. and Supply Co.
K. William Beach Mfg. Company
Keene Corporation
State
Kentucky
North Carolina
Pennsylvania
Connecticut
New York
Indiana
Texas
Tennessee
Ohio
Pennsylvania
Oregon
Oklahoma
Oklahoma
New Hampshire
Illinois
California
Illinois
New Jersey
New Jersey
New Jersey
California
Ohio
Pennsylvania
City
Florence
Wilson
North Wales
Bethel
Syracuse
Indianapolis
Houston
Newport
Fremont
Meadow Lands
Portland
Oklahoma City
Tulsa
Bristol
Maple ton
Santa Fe Springs
Chicago
Paterson
New Brunswick
Asbury Park
Los Angeles
Springfield
Valley Forge
282
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Table B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
L.B. Foster Company
Lamons of Louisiana Inc.
Lisco Fabrication Division Inc.
Longhorn Gasket and Supply
Mac Arthur Company
Mahoning Valley Gasket Company
Manufacturers Gasket Company
Marine and Petroleum
Mario Company Inc.
Me Cord Corporation
Metalclad Insulation Corporation
Metallo Gasket Company
Manufactured Rubber Products Co.
Mineral Fiber Mfg. Company Corp.
Mizell Bros Company
New Jersey Gasket and Mfg.
Nicolet Industries Inc.
Nordstrom Sterling Gasket
Selastomer Chicago Inc.
Selastomer Detroit Inc.
Ohio Gasket and Shim Co. Inc.
Oriental Gasket and Packing
Pamrod Products Company Inc.
State
Tennessee
Texas
Kentucky
Texas
Minnesota
Ohio
Ohio
Texas
New York
Michigan
California
New Jersey
Pennsylvania
Ohio
Georgia
New Jersey
Pennsylvania
Oklahoma
Illinois
Michigan
Ohio
Texas
Texas
City
Memphis
Houston
Louisville
Dallas
St. Paul
Warren
Cleveland
Houston
New York
Wyandotte
Compton
New Brunswick
Philadelphia
Coshocton
Atlanta
Almonesson
Ambler
Tulsa
Bensenville
Farmington
Akron
Dallas
Me Queeney
283
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Table B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
Parker Seal Company
Parker Seal Co/O-Seal Division
Parker Seal Company
Parker Seal Company
Parker Packing Division
Pettibone Mulliken Corporation
Phelps Packing and Rubber Company
Philadelphia Gasket Mfg.
Pilot Packing Company Inc.
Punch Products Mfg Company Inc.
Raybestos Manhattan Inc.
Rexnord Inc.
Rhopac Inc .
Richards Parents and Murray
Russell Gasket Company Inc.
Sacomo Sierra Inc.
Sar Company Inc.
Standard Packing National Metalisg.
Sealing Devices Inc.
Sealite Inc.
Seaman Products Inc.
Sepco Corporation
Mitchell and Smith
State
Texas
California
Kentucky
Kentucky
Utah
Oregon
Maryland
Pennsylvania
New York
Illinois
South Carolina
Illinois
Illinois
New York
Ohio
Nevada
Texas
New Jersey
New York
California
California
Alabama
Virginia
City
McAllen
Culver City
Lexington
Berea
Salt Lake City
Portland
Baltimore
Philadelphia
Sea Cliff
Chicago
Charleston
Wheeling
Skokie
Mount Vernon
Cleveland
Carson City
Houston
Cr anbury
Lancaster
San Leandro
Sylmar
Birmingham
Norfolk
284
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Table B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
State
City
Smith Products Inc.
Sonotherm Inc.
Southland Cork Company
Staff Gasket Company Inc.
Standard Washer and Mat Inc.
Sterling Packing and Gasket
Star Gasket and Rubber Corp.
Stevens Asbestos Products
Melrath Gasket Div. Tannetic
Tapecoat Company Inc.
Town and Sander Company
T P Company Inc.
Triangle Rubber Company Inc.
Triple P Inc.
Tulsa Pipe Coating Company
United Gasket Corporation
Utex Industries Inc.
Mr. Gasket Company
Wayne Gasket and Rubber Company
Web Seal Inc.
Penn Rillton Company
Williams Products Inc.
Wisconsin Gasket and Mfg. Company
Ohio
New York
Virginia
New York
Connecticut
Texas
Michigan
Oklahoma
Pennsylvania
Illinois
Ohio
New Jersey
New York
Wisconsin
Oklahoma
Illinois
Texas
Ohio
Michigan
New York
Pennsylvania
Michigan
Wisconsin
Cleveland
Buffalo
Norfolk
New York
Manchester
Houston
Mt. Clemens
Tulsa
Philadelphia
Evanston
Warsaw
Monmouth Junction
Bohemia
Necedah
Tulsa
Chicago
Houston
Independence
Mount Clemens
Rochester
W. Elizabeth
Troy
Milwaukee
285
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Table B-8 (continued) SIC 3293: GASKETS, PACKING AND SEALING DEVICES
Company name
York Insulation Company Inc.
Zone C J Mfg. Company Inc.
State
New Jersey
Missouri
City
Hillside
St. Louis
286
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Table B-9 SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Advance Wire Assemblies
Brand Rex Company
Tape Cable Corp
Brand Rex Company
Alcan Cable West
Alcan Cable Corporation
Rea Magnet Wire Co. Inc.
Rea Magnet Wire Co. Inc.
Rea Magnet Wire Co. , Inc.
Rea Magnet Wire Company Inc.
Alloy Industries Inc.
Plessey Connector Division
Alpha Wire Corporation
American Chain and Cable Co.
American Electric Cable Company
American Super Temp.
Western Electric Company Inc.
Western Electric Company Inc.
Western Electric Wire Mill
Western Electric Co. AT&T
Western Electric Co. AT&T
American Wire and Cable Company
Anaconda Wire
State
Illinois
Arkansas
New York
Connecticut
California
Georgia
Indiana
North Carolina
Indiana
Virginia
California
New York
New Jersey
Michigan
Massachusetts
Vermont
Maryland
New York
New Jersey
Georgia
Arizona
Ohio
Connecticut
City
Aurora
Si loam Spring
Rochester
Willimantic
Rocklin
Tucker
Lafayette
Laurinburg
Fort Wayne
Buena Vista
Garden Grove
Plainview
Elizabeth
Adrian
Holyoke
Winooski
Baltimore
Buffalo
Kearny
Nor cross
Phoenix
Cleveland
Hamden
287
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Anaconda Company
Anaconda Wire
Anaconda Wire and Cable
Anaconda Wire and Cable Company
Anaconda Wire and Cable Company
Anaconda Wire and Cable Company
Anaconda Wire and Cable Company
Continental Wire and Cable
Anaconda Systems Wire
Anaconda Wire
Anaconda Wire and Cable
Anchor Wire Corporation
Apex Wire and Cable Corporation
Asco Wire and Cable Company Inc.
Atlantic Wire and Cable Corp.
Auburn Wire Corporation
Aurora Cord and Cable Company
Carol Cable Company
Avent Inc.
Carol Wire and Cable Corporation
B & B Electronics Corporation
Belden Corporation
Electric Cord Products
State
Missouri
North Carolina
California
Indiana
Michigan
Illinois
Georgia
Pennsylvania
Arizona
North Carolina
Kentucky
Tennessee
New York
Connecticut
New York
New York
Illinois
Rhode Island
California
Rhode Island
California
Indiana
North Carolina
City
Harrisonville
Tarboro
Orange
Marion
Muskegon
Sycamore
Watkinsville
York
Phoenix
Eden
Summer svi lie
Goodlettsville
Hauppauge
Bridgeport
Flushing
Auburn
Yorkville
Warren
Los Angeles
Pawtucket
Idyllwild
Richmond
Franklin
288
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Table B 9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Jena Wire and Cable Company
Berkshire Electric Cable
Berkshire Technical Products
Boston Insulated Wire Co.
Bridgeport Enameled Wire
Bryan Mfg. Company Inc.
Burnside Mfg. Company Inc.
C & M Corporation of Conn.
Tensolite Insulated Wire
International Wire Pdt Division
Cerro CATV Products Plant
Cerro Corporation
Rockbestos Wire and Cable
Chester Cable Corporation
Cleveland Insulated Wire
Coleman Cable and Wire Company
Colonial Wire and Cable Company
Colonial Wire and Cable Company
Columbia Cable and Electric
Consolidated Aluminum Corporation
Conetics Inc .
Consolidated Reactive
Hatfield Wire
State
Louisiana
Massachusetts
Pennsylvania
Massachusetts
Connecticut
Indiana
Michigan
Connecticut
New York
New Jersey
New Jersey
New York
Connecticut
New York
Ohio
Illinois
New York
New York
New York
Alabama
Georgia
New York
New Jersey
City
Jena
Northampton
Reading
Boston
Stratford
N. Manchester
Spring Lake
Wauregan
Tarrytown
Wyckoff
Freehold
Maspeth
New Haven
Chester
Cleveland
River Grove
Locust Valley
Hauppauge
Brooklyn
Florence
Chamblee
Mamaroneck
Linden
289
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Hatfield Wire
Continental Copper and Steel
Superior Continental Corporation
Superior Continental Corporation
Superior Continental Corporation
Superior Continental Company
Corona Insulated Wire
Cove New York Inc.
Custom Control Panels Inc.
Rome Cable Div Cyprus Mines
Daburn Electronics Cable
Easy Heat Wirekraft Msp
Prestolite Wire Div. Eltra
Independent Cable Inc.
Excel Wire and Cable Company
Foley Corporation
General Cable Corporation
General Cable Corporation
General Cable Corporation
General Cable Apparatus Div.
General Cable Corporation
General Cable Corporation
General Cable Corporation
State
New Jersey
New Jersey
Iowa
Texas
North Carolina
North Carolina
New York
New York
Missouri
New York
New York
Indiana
Pennsylvania
Massachusetts
Ohio
Delaware
Michigan
Arkansas
California
Maryland
California
Texas
Tennessee
City
Hillside
Cranford
Mt. Pleasant
Brownwood
Hickory
Rocky Mount
Farmingdale
Freeport
Maryland Heights
Rome
Bronx
Rolling Prair
Hazleton
Hudson
Tiffin
Lewes
Quincy
Hot Spring NP
Lindsay
Frederick
Sanger
Bonham
Memphis
290
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
General Cable Corporation
General Cable Corporation
General Cable Corporation
General Cable Corporation
General Cable Corporation
General Cable Corporation
Philadelphia Insulated Wire
General Cable Corporation
General Cable Corporation
Cornish Wire Div General Cable
General Cable Corp
General Cable Corporation
General Electric Company
General Electric Company
General Electric Company
General Electric Company
General Electric Company
General Electric Company
General Electric Company
General Electric Clevelandwire
General Wire Products Company
Gore W L & Associates, Inc.
Collyer Insulated Wire Company
State
Missouri
Michigan
Illinois
Florida
California
Maryland
New Jersey
New Jersey
New Jersey
Vermont
Massachusetts
New Jersey
Ohio
California
Ohio
Connecticut
Connecticut
Connecticut
Massachusetts
Ohio
Massachusetts
Delaware
Rhode Island
City
St. Louis
Cass City
Monticello
Tampa
Colusa
Elkton
Moorestown
Perth Amboy
New Brunswick
Pownal
Williamstown
Bayonne
Cleveland
Oakland
Dover
Bridgeport
Bridgeport
Bridgeport
Lowell
Euclid
Worcester
Newark
Lincoln
291
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Kerite Company
Federal Fabricators Inc.
Haveg Industries Inc.
Hendrix Wire and Cable Corporation
Horning Wire
Howmet Corporation
Hudson Wire Company Inc.
Hudson Wire Company Inc.
Improved Seamless Wire Company
Times Wire and Cable Company
Phoenix Cable Company
Times Wire and Cable
American Components Inc.
Intercontinental Wire Company
Plastoid Corporation
Plastoid Corporation
ITT Suprenant Division
ITT Automotive and Electrical
ITT^Cable-Hydrospace Division
Jersey Specialty Company Inc.
Judd Wire Mfg. Corporation
Kaiser Aluminum and Chemical
Kaiser Aluminum and Chemical
State
Connecticut
New York
Vermont
New Hampshire
Illinois
Massachusetts
New York
Connecticut
Rhode Island
Virginia
Arizona
Connecticut
North Carolina
Pennsylvania
New Jersey
New Jersey
Massachusetts
Georgia
California
New Jersey
Massachusetts
California
Rhode Island
City
Seymour
Vestal
Colchester
Milford
Lake Zurich
Northampton
Ossining
Winsted
Providence
Chatham
Phoenix
Wallingford
Hayesville
Robesonia
Hamburg
Franklin
Clinton
Camilla
National City
Wayne
Turners Falls
San Leandro
Bristol
292
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Kaiser Aluminum and Chemical
Kalas Manufacturing Inc.
Kanthal Corporation
Keystone Seneca Wire Cloth
La Valle and Roy Inc.
Laribee Wire Inc.
Lasalle Wire and Cable
Riverside Manufacturing Inc.
Lenz Electric Mfg. Company Inc.
American Insulated Wire
Liberty Copper Wire Division
Jefferson Wire and Cable Corp.
Manger Electric Company Inc.
Kerrigan Lewis Mfg. Company
Metallonics Corporation
Miami Wire and Cable Corporation
Mohawk Wire and Cable Corp.
Molecu Wire Corporation
Montrose Products Company Inc.
Narragansett Wire Company
Kagan Dixon Wire Corporation
National Wire and Cable
Nehring Electrical Works
State
Rhode Island
Pennsylvania
Connecticut
Mississippi
Vermont
New York
Louisiana
Michigan
Illinois
Rhode Island
Illinois
Massachusetts
Connecticut
Illinois
Massachusetts
Florida
Massachusetts
New Jersey
Massachusetts
Rhode Island
New Jersey
California
Illinois
City
Portsmouth
Denver
Bethel
Brookhaven
Winooski
Camden
Jena
Dearborn
Chicago
Pawtucket
Downers Grove
Worcester
Stamford
Chicago
Boston
Hialeah
Leominster
Farmingdale
Auburn
Pawtucket
Rahway
Los Angeles
De Kalb
293
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Table B-9 (Continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
New England Electric Wire
New Haven Wire and Cable Company
American Flexible Conduit
Whitney Blake Company
Chicago Magnet Wire Corporation
Universal Mfg. Corporation
Okonite Company
Okonite Company
Okonite Company
Okonite Company
Okonite Company
Okonite Company Plant #6
Okonite Company
Owl Wire and Cable Inc.
Pace Wire and Cable Corp.
Paragon Wire and Cable Corp.
Paragon Wire and Cable Corp.
Paterson Wire Company
Pep Industries Inc.
Phelps Dodge Copper Products
Phelps Dodge Magnet Wire
Phelps Dodge Copper Products
Phelps Dodge Communication
State
New Hampshire
Indiana
Massachusetts
Connecticut
Illinois
Mississippi
Kentucky
California
New Jersey
New Jersey
Rhode Island
Massachusetts
New Jersey
New York
New York
Florida
New York
New Jersey
Tennessee
Arkansas
Indiana
Indiana
Kentucky
City
Lisbon
New Haven
New Bedford
New Haven
Elk Grove Vlg.
Gallman
Richmond
Santa Maria
Ramsey
New Brunswick
Rumford
Worcester
Paterson
Canastota
Oceanside
Longwood
Buffalo
Paterson
Nashville
Fordyce
Fort Wayne
Fort Wayne
Elizabeth town
294
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Phelps Dodge Communication
Phelps Dodge Corporation
Precision Cable Company Inc.
Radcliff Wire Inc.
Radix Wire Company Inc.
Raychem Corporation
Reynolds Metals Company Inc.
Reynolds Metals Alloys Plant
Reynolds Cable Plant
Rhode Island Insulating
Ristance Corporation
Gavitt Wire Cable Company
Gavitt Wire and Cable Company Div.
S. Burger Inc.
Vector Cable Company
Seal Wire Company Inc.
Secon Metals Corporation
Sigmund Cohn Corporation
Easy Heat Wirekraft Division
Southwire Company Inc.
Southwire Company
Spargo Wire Company Inc.
Standard Wire and Cable Company
State
New York
Ohio
Texas
Connecticut
Ohio
California
Pennsylvania
Alabama
Arkansas
Rhode Island
Indiana
California
Massachusetts
New Jersey
Texas
North Carolina
New York
New York
Indiana
Georgia
Kentucky
New York
California
City
Yonkers
Hebron
Beaumont
Bristol
Cleveland
Menlo Park
Chester
Sheffield
Malvern
Cranston
Bremen
Escondido
Brookfield
Middlesex
Sugar Land
Shelby
White Plains
Mount Vernon
Lakeville
Carrollton
Hawesville
Rome
Los Angeles
295
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Superior Insulated Wire
Techbestos Inc.
Thermatics Inc.
Western Wire and Cable
Teradyne Components Inc.
Kentucky Electronics Inc.
Texas Instruments Inc.
Thermon Mfg. Company INc.
Phalo Corporation
Triangle PWC
Triangle Conduit and Cable
Trio Wire and Cable Corporation
Crescent Wire and Cable Company
Holyoke Wire and Cable Corporation
Simplex Wire and Cable Company
Capital Wire and Cable Corporation
Gar let Inc.
United States Steel Corporation
Essex International Inc.
Essex International Power Conductor
Essex International Inc.
Essex International Inc.
Essex Wire Corporation
State
New York
New Jersey
North Carolina
California
Massachusetts
Kentucky
Massachusetts
Texas
Massachusetts
Connecticut
New Jersey
New York
New Jersey
Massachusetts
New Hampshire
Texas
Pennsylvania
Massachusetts
Kansas
Kentucky
Indiana
South Carolina
Illinois
City
Stony Point
Rutherford
Elm City
Los Angeles
Lowell
Owensboro
Attleboro
San Marcos
Shrewsbury
Jewett City
New Brunswick
Brooklyn
Trenton
Holyoke
Portsmouth
Piano
Old Forge
Worcester
Hoisington
Paducah
Vincennes
Bennettsville
Sycamore
296
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Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Essex Wire Power Conduc. Div.
Wauseon Mf g . -Essex International
Essex Wire Corporation
Essex International Inc.
Essex Wire Corporation
Essex Wire Corporation
Essex International
Essex Int-Magnet Wire Division
Essex Wire Corporation
Essex Wire Corporation
Essex International
Essex Intl-Wire and Cable Div.
Essex International
Essex International
Essex International
Victor Electric Wire
Viking Wire Company
Vincennes Wire and Cable Company
W.L. Gore and Associates Inc.
W.L. Gore and Associates Inc.
Alcoils Inc.
Washburn Wire Company
Waterbury Products Corporation
State
Indiana
Ohio
Illinois
Massachusetts
Illinois
Indiana
Michigan
Indiana
Michigan
Michigan
Indiana
Indiana
California
South Carolina
Illinois
Rhode Island
Connecticut
Indiana
Arizona
Delaware
Indiana
Rhode Island
New Jersey
City
Marion
Wauseon
Decatur
Peabody
Rockford
Ligonier
Quincy
Fort Wayne
Hillsdale
Three Rivers
Kendallville
Fort Wayne
Anaheim
Chester
Chicago
Warwick
Danbury
Vincennes
Flagstaff
Newark
Columbia City
E . Providence
Hightstown
297
-------
Table B-9 (continued) SIC 3357: NONFERROUS WIREDRAWING AND INSULATING
Company name
Western Insulated Wire
Westinghouse Wire Division
Westinghouse Wire Division
Westinghouse Wire Division
Westinghouse Electric Corporation
Whitaker Cable Corporation
Whitaker Cable Corporation
Wilbur B. Driver Company
Wire Products Inc.
State
California
Indiana
Pennsylvania
Georgia
Virginia
Missouri
Missouri
South Carolina
Florida
City
Los Angeles
Muncie
Sharon
Athens
Abingdon
Excelsior Spg.
N.Kansas City
Orangeburg
Ft. Lauderdale
298
-------
APPENDIX C
INSPECTION MANUAL FOR HYDROCARBON EMISSIONS
FROM RUBBER PROCESSING
1. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM SYNTHETIC
RUBBER MANUFACTURING
The synthetic rubber industry comprises establishments
primarily engaged in the manufacture of synthetic rubber by
polymerization or copolymerization. An elastomer, for the
purpose of this classification, is a rubberlike material capable
of vulcanization, such as copolymers of butadiene and styrene
or butadiene and acrylonitrile, polybutadienes, chloroprene
rubbers, and isobutylene-isoprene copolymers. Butadiene co-
polymers containing less than 50 percent butadiene are classi-
fied in industry 2821. Natural chlorinated rubbers are cyclized
rubbers are considered as semifinished products and are classi-
fied in industry 3069.1 A brief description of the manufacture
of styrene butadiene rubber, the major product type within the
synthetic rubber industry (SIC 2822), is presented below to
familiarize the inspector with the basic process operations.
Atmospheric emissions from styrene butadiene rubber (SBR) pro-
duction are also discussed in Section 1.2.
299
-------
1.1 Process Description
1.1.1 Emulsion Rubber Production (Crumb Rubber) - Monomers and
raw materials used in the production of synthetic rubber are
stored in the tank farm area. These storage vessels are equip-
ped with a safety relief to the flare where applicable. Poly-
merization inhibitors are removed from the monomers by caustic
washing in the tank farm area prior to transfer to the polymeri-
zation area.
In the pigment preparation area the soap solution used to
carry the polymer in suspension through the reactor is made up
and pumped to the reactor area. Also, batch preparation of
activator, antioxidants, belt spray solution and catalyst solu-
tion are performed in this area. Bulk materials received in
bags or drums are stored in the pigment building.
All charge ingredients are introduced to a precharge cooler
at the polymerization area just prior to entering the first of
several reactors. The reaction is initiated upon the addition
of a catalyst. Temperature of the reaction (an exothermic
reaction) is controlled by passing chilled methanol solution
through cooling coils located inside each reactor. The reaction
is terminated when the conversion target is achieved.
Unreacted monomers are recovered in the recovery area where
butadiene is drawn from the latex through vacuum tanks. Any
remaining butadiene and the residual styrene are stripped from
the latex by steam stripping through a multiplate column. The
stripped latex is stored in the finishing or processing area
300
-------
in large storage tanks. In the finishing area the latex is
extended with an extender oil and carbon black (on some rubber
types) prior to the coagulation of the latex. In coagulation,
an acid is added to the latex, converting the soap to an organic
acid, thus allowing the rubber to agglomerate into crumb. The
excess water is treated through the plant's wastewater treat-
ment facility as the rubber crumb is dewatered. Rubber is
dewatered by mechanically squeezing the crumb and passing the
partly dewatered crumb through a tunnel dryer. The finished
product is baled into 75-pound units. A flow schematic is
shown in Figure C-l.
1.1.2 Solution Rubber Production (Crumb Rubber) - In solution
rubber production, a solvent is used to carry the polymer
through the reactors and into storage. This solvent is stripped
from the rubber solution, returned, purified and reused. A flow
schematic is shown in Figure C-2.
In the purification area, the heavy and light impurities
are removed from the solvent. The light impurities are returned
to the monomer storage for reuse. The heavy impurities are
stored as waste oil and sold whenever a sufficient quantity is
generated. Also in this area, the monomer and solvent are
dried in preparation for the reaction step. The caustic washed
monomers are pumped to the reactor area from the storage area.
In the reactor area, all ingredients are properly intro-
duced into the reactor and reaction is initiated by the addition
of a catalyst. Polymerized monomers in solvent (cement) are
301
-------
CO
O
NJ
MONOMER
STORAGE
BUTADIENE
VACUUM
DISTILLATION
STYRENE
STORAGE
ATM. J
SOAP
l_
ACTIVATOR
CATALYST
MODIFIER
f ATM.
EXTENDER OIL
f
AND WASH
INHIBITED MONOMER
»•
TREATED
PROCESS
WATER
~T
SOAP SOLUTION M
EMERGENCY
FLARE
[—TREATED PROCESS WATER
•^
ACTIVATOR
CATALYST
MODIFIER
SOLUTIONS
to
J
' — 1 — f ATM.
EMERGENCY L!VE
EXTENDER OIL
CARBON BLACK SLURRY
CON
F
BOILER .
EXHAUST |ATM.
STEAM
COAGULATING
SULFURIC ACID
ANT 1 OX
M
PING
^'_
COAGULATING o
BRINE g:
L*J
DANT
/
LATEX
STORAGE
^
o'
,
COAGULATION
AND SCREENING
RETURN COAGULATION LIQUID
— »•
SCREENED COAGULATION LIQUID
a
AN
O
13
Cr
z
O
o
MAKEU
WATEF
/
2T
QL
C
ce
5
ijj
Z
Q±
P*
•ft
<
ce
ce
<
S
UJ
Z
QE
CRUMB RINSING
AND OEWATERING ~*
ATM.
LIVE-
STEAM
RETURN
TREATED
PROCESS
BOILER
HOUSE
BOILER FEED WATER
WATER
TREATMENT
UNITS
RAW INTAKE WATER
^VOLATILE ORGANICS
Figure C-l. Flow diagram for emulsion crumb rubber production.
-------
ATM.
EMERGENCY RARE
ATM.
TO FLARE
t
MONOMER
RECOVERY
ABSORBER
LIGHT
MONOMER
EMERGENCY
FLARE
SOLVENT
SEPARATION
SE
|
HEAVY
MONOMER
SEPARATION
COOLING
WATER RETURN
MAKEUP WATER COOLING
I • WATER SUPPLY
BUTADIENE
MONOMER
STORAGE
U)
o
GO
MONOMER
STORAGE
FLARE j
CATALYST
IN SOLVENT .
x* I
EMERGENCY
FLARE
LIVE STEAM.
CONDENSATE
BOILER (RETURN)
EXHAUST I
ATM.
TREATED
PROCESS
WATER
STEAM ^
SUPPLY
t
BOILER
HOUSE
BOILER FEED WATER
TREATMENT
UNITS
RAW INTAKE WATER
*VOLATILE ORGANICS
Figure C-2. Flow diagram for solution crumb rubber production.
-------
extended with an extender oil and then stored in the desolvent-
ization area.
The desolventization area removes the solvent from the
cement solution and replaces the solvent with water which is
used to carry the rubber to the dewatering and finishing area.
Solvent stripped from the cement with steam is condensed and
returned to the tank farm for storage and purification.
The rubber crumb is dewatered mechanically by squeezing,
followed by single-pass tunnel drying in the finishing area.
The finished product is packaged in 75-pound bales.
1.1.3 Emulsion Polymerization (Latex Rubber) - Butadiene is
received in tank cars. It is unloaded into storage tanks sub-
merged in concrete pits of water. Before using for reactions,
it is caustic washed to remove inhibitor and transferred to
washed butadiene tanks. Centrifugal pumps charge washed fresh
butadiene from these tanks. Pumps also charge recycled buta-
diene from recycle storage tanks and the two streams are blended
in the reactor areas for correct purity.
Styrene is received by tank car or trailer. It is unloaded
into tanks located in diked enclosures. Pure and recycled
styrene are pumped to the reactor areas and blended much the
same as butadiene.
Soap solutions are made up in tanks and charged to the
reactors by means of pumps via control meters.
Activator solutions are also made up and charged to the
reactor.
304
-------
Catalyst, which starts the reactions, is charged from a
weigh scale after other ingredients have been charged and when
the batch has been cooled down to operating temperature.
Control of reaction temperature is done by a cooling jacket
and coils. An agitator provides proper mixing of contents.
When the proper degree of reaction is reached, stopper is
added to stop further reaction. The reactor is discharged to
the receiver where steam is added to warm the contents and in-
crease the pressure of the residual butadiene.
The warmed latex is pumped to the degas column which is
held at a vacuum. The butadiene vapors rise via the top vapor
line to the vacuum pump and compressor. The compressed and
cooled butadiene returns to storage tanks as a liquid to be
later reblended for recharging to reactors.
The degassed latex is pumped from the degas tank to the
top of the stripping column. Steam is introduced at the bottom.
The latex flows down across 8 to 10 perforated plates where
the steam strips the styrene from the latex. The steam and
styrene vapors rise to the top and are condensed to liquid.
The styrene-water mixture is drained to a decanter where the
styrene rises to the top and the water is drained off the
bottom. The styrene is returned to storage for reblending.
The stripped latex is pumped from the bottom of the strip-
ping column to a blend tank where it is held for concentration.
The dilute latex in the stripping column blend tank is
pumped via a flow meter to the concentrator.
305
-------
After a latex level is reached in the concentrator, recir-
culation is started. The latex circulating pump recirculates
the latex through the heater to the spray nozzle in the concen-
trator to mix with the incoming dilute latex. The excess heat
causes flashing of the latex and evaporation of the water
vapors. The latex falls to the pool of latex being recirculated,
Vapors go over the top outlet to the condenser. The condensate
flows to the decanter.
When latex reaches the proper solids, part of the latex
is diverted to the finished latex blend tank by means of a
flow controller.
When the latex blend tank is filled to the desired level,
it is tested. The loading of the latex into tank cars, tank
trucks, or drums is done as dictated by shipping schedules.
1.2 Atmospheric Emissions
Potential sources of atmospheric emissions from synthetic
rubber production are listed in Table C-l.
It is presently impossible to determine which specific
hydrocarbons are emitted during SBR production, as "volatile
organics." However, the monomers, styrene and butadiene, and
the solvent, hexane, are known to be the major hydrocarbon
emissions.
2. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM TIRE
MANUFACTURING
The tire and inner tube industry includes establishments
primarily engaged in manufacturing pneumatic casings, inner
306
-------
Table C-l. EMISSIONS MJD CONTROL - SYNTHETIC RUBBER
U)
o
Emi ssion
source
Styrene storage
(breathing)
Solvent storage
(fugitive)
Reactor section
(fugitive)
Recovery area
(fugitive)
Butadiene recovery
Coagulation, dewatering
drying
Styrene storage
(breathing)
Hexane storage
(breathing)
Storage (fugitive)
Purification area
(fugitive)
Reactor area
(fugitive)
De solvent! zation
(surge vent)
Desolventization
(fugitive)
Uncontrolled
emissions ,
gAg
0.02
0.07
0.4
0.1
0.6
0.6
0.02
0.5
0.07
0.2
0.61
2.7
0.2
Best control
technique
Control
efficiency
NSPS
emissions,
g/kg
Average
uncontrolled
emission rate,
Ib/day
Permissible
emission rate,
Ib/day
Emulsion polymerization (90 percent of total production capacity)
Floating roof
Housekeeping
Housekeeping
Housekeeping
Incineration
Incineration
Solution polymeri
Floating roof
Floating roof
Housekeeping
Housekeeping
Housekeeping
Improved steam
stripping
Housekeeping
80%
50-80%
50-80%
50-80%
90%
90%
zation (10 perc
80%
80%
50-80%
50-80%
50-80%
50%
50-80%
0.004
0.035
0.2
0.05
0.6
0.06
ent of total i
0.004
0.1
0.035
0.1
0.3
1.4
0.1
4
14
78
20
490
120
iroduction capacit
4
98
14
39
119
530
39
40
40
40
40
18a
18a
Y)
40
40
40
40
40
260b
40
Emission
reduction
required
0
0
49%
0
85%a
85%a
0
59%
0
0
66%
50%3
0
Regulated
emissions,
g/kg
0.02
0.07
0.2
0.1
0.09
0.09
0.02
0.2
0.04
0.2
0.12
1.4
0.2
COMPOSITE TOTAL:
4.1*
aThe regulation of 85 percent reduction is applied.
"50 percent control represents maximum reduction feasible.
E = 0.9 (1.79) + 0.1 (24.5)
= 1.61 + 2.45
= 4.1
E_ = 1.01
-------
tubes, and solid and cushion tires for all types of vehicles,
airplanes, farm equipment, and children's vehicles; tiring; and
camelback and tire repair and retreading materials.2 A brief
discussion of the manufacture of tires is presented below to
familiarize the inspector with the basic process operations.
Atmospheric emissions from tire manufacture are discussed in
Section 2.2.
2.1 Process Description
The compounding and processing of rubber involves not only
the thorough incorporation of proper amounts of ingredients but
also the development of characteristics which will enable the
compound to be easily handled and will provide the desired
qualities in the finished product.
Though highly desirable qualities in the finished article,
the inherent toughness and resilience of rubber make it a some-
what intractable material which frequently requires the repeated
persuasion of powerful machinery to convert it into the final
form.
The development of the finished tire requires a precise
mixture of several polymers, chemicals, resin, oil and carbon
black. This is a mechanical mixture with controls to maintain
low heat. Chemical change occurs in the curing press under
heat and pressure but in a completely closed vessel. Once
cured the polymers link with the chemical additives that form a
link that is difficult to break down.
2.1.1 Breakdown - To facilitate compounding and subsequent pro-
cessing it is necessary to "break down" or work and soften the
308
-------
rubber by passing it one or more times through one or more spe-
cial machines. Another function of the breakdown process is to
combine several rubbers of different sources or types into one
homogeneous product. Because of the high viscosity (or low
plasticity) of rubber, it absorbs considerable power which is
converted by friction within the rubber into sensible heat. As
a consequence, rubber breakdown and mixing machines are usually
water cooled to keep the rubber temperature below some critical
figure that is determined by its composition. Oppositely, some
machines are deliberately heated to shorten processing time,
reduce power requirements, or promote a desired reaction.
2.1.2 Plasticator - The plasticator, which is often used for
breaking down either crude or synthetic rubber, is actually a
large extrusion machine which can handle considerable quantities
at one time. Its working action is so thorough that one pass-
through usually produces the desired plasticity. The machine
consists essentially of a specially designed rotor or screw
rotating in a cylinder equipped with a suitable extruding head
and driven by a large electric motor through a heavy speed-
reducing gear set. Provision is made to heat or cool the
working parts.
2.1.3 Compounding and Mixing - After rubber stock has been
broken down, the next step is to add and mix all the several
ingredients that may be required to produce the desired charac-
teristics in the final product. There are probably thousands
of such materials, though only a few are likely to be used in
309
-------
any single product. The order in which they are added can also
affect the quality of the blend. While this order can vary
widely among different manufacturers of a given final blend,
the following list of materials and addition sequence is pre-
sented as a general illustration:
1. Rubber constituents
2. Plasticizers, softeners, processing oils,
antisofteners
3. Special carbon blacks
4. Accelerators, retarders, antioxidants, sun-check
inhibitors, activators
5. Reinforcing and inert fillers, color pigments,
stiffeners
6. Vulcanizers, fungicides, odorants
7. Abrasives, blowing agents
In general those ingredients which are inert or slowacting
and require maximum mixing can be added quite early in the
sequence. On the other hand, the addition of volatile materi-
als, vulcanizers and other quick-acting chemicals, and machine-
damaging abrasives, is postponed as long as possible.
Rubber becomes more plastic as a consequence of the break-
down process and temperature increase; however, further increase
i
in plasticity can be obtained by the addition of softeners, com-
monly referred to as "processing oils." These softeners repre-
sent a large variety of materials, including petroleum oils,
special petroleum derivatives, waxes and asphalts. The use of
a softener will generally reduce mixing and processing tempera-
tures, aid in dispersing and incorporating dry compounds,
310
-------
improve flow during molding, and reduce "nerve" (strength or
resistance) during extrusion and calendering. Synthetic rub-
bers generally require more softener than the natural type.
Since a softener can greatly influence the characteristics of
the final compound, great care is exercised in selecting the
type and quantity used.
Contrary to common misimpression, the special petroleum-
derived carbon blacks are not mere coloring materials nor inert
fillers but extremely valuable additives which greatly increase
the toughness and wear resistance of rubber. Of particular
value in automobile tire tread stock, carbon blacks have vastly
increased the useful mileage life of tires.
Sulfur is still the principal vulcanizing or curing agent
for natural rubber and is also used with the synthetics except
neoprene in which zinc oxide or magnesium oxide are employed.
The sulfur used is a fine, yellow powder of about 99.9 percent
purity. The amount of sulfur used varies, depending on the
type of rubber being processed, but generally falls in the
range of from 0.5 to 4.0 percent. As a general rule, vulcaniza-
tion of natural rubber requires about 50 percent more sulfur
than the synthetics.
Proper mixing provides uniform blending of the ingredients
throughout the rubber. Two types of machines can be used for
this process, the rubber mill and the internal mixer.
Rubber mills - Rubber mills are widely used for many pur-
poses such as breakdown, grinding rubber and scrap materials,
311
-------
and warming stock in preparation for the calender or tubing
machines. Mills are also used for mixing rubber and compound-
ing ingredients but to a lesser extent since the faster and
more thorough internal mixer ("Banbury") has come into such
universal use.
Mixing in a mill requires skilled handling. Broken rubber
is applied to the mill and the various ingredients are added in
proper order. The blend has to be continually folded and
rolled to get the ingredients evenly dispersed. This method is
slow and hard to control and it is generally being displaced by
the internal mixer.
Internal mixers - In the larger modern mills, rubber ingre-
dients are blended in internal (Banbury) mixers which provide
both fast and uniform blending.
The internal mixer is of very rugged construction because
of the heavy duty work it must perform and consequent high
power application. The machine consists essentially of an
enclosed trough or mixing chamber inclosing two mixing rotors
or blades, a hopper into which the raw materials are fed, and a
sliding door in the bottom through which the mixed batch is
discharged. The blades of the rotors are formed in interrupted
spirals and the rotors are driven at slightly different speeds
so as to apply a rubbing and "smearing" action to the rubber
mix between them. Water sprays are installed around the body
of the machine and in the rotors to control working temperature
Closely fitting end-thrust adjustments are provided to absorb
312
-------
the slight axial forces developed by the spiral blades, to pre-
vent rubber stock from working out through the housings, and to
facilitate maintenance of close fits and followup as wear occurs.
2-1.4 Calendering - A calender machine usually contains three
adjustable rolls which are used to roll flat sheets of rubber
compound or to press it into either or both sides of fabric or
tire cording.
The necessary heat to maintain the plasticity of the rub-
ber is furnished by steam heating the rolls. Since the roll
bearings carry very heavy loads, it is usually necessary to
cool them with water to prevent bearing damage.
Many problems may arise during calendering such as scorch-
ing of the sheeting, sticking, tearing, blistering or roughness.
Compounders and operators must be able to recognize and correct
the adverse conditions causing these difficulties.
2.1.5 Extrusion - Extrusion is a continuous process for con-
verting rubber stock into long strips of specific cross section,
such as rods, tubes, moldings, sheets or filaments. Extrusion
machines are usually of the screw type in which warm rubber
stock is fed into the top hopper and forced out by the screw
through the forming die.
Like calendering, this process requires operators with
skill and knowledge in order to meet the numerous problems that
may arise. Rate of feed, speed of machine, temperature, plas-
ticity of the rubber stock and presence of dirt are factors
that influence the quality and quantity of product delivered by
the machine.
313
-------
2.1.6 Tire Building - Stock components are mechanically
assembled at the tire building machine where a skilled operator
"builds" the tire. The operation is accomplished on a variety
of machines depending upon tire construction and degree of auto-
mation. In all cases, however, the assembly is accomplished
without the addition of heat or mechanical energy.
2.1.7 Curing - Rubber vulcanization is accomplished in a
curing press where the addition of heat, pressure and time pro-
duces a finished product. The automated tire-curing press is a
sophisticated electronically controlled piece of equipment
where the three variables are controlled to produce the desired
end product.
A flow schematic is shown in Figure C-3.
2.2 Atmospheric Emissions
Potential sources of hydrocarbon emissions from tire manu-
facturing are listed in Table C-2. It is presently impossible
to determine which specific hydrocarbons are emitted from these
operations.
3. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM RUBBER
AND PLASTIC FOOTWEAR MANUFACTURING
The rubber and plastics footwear industry includes estab-
lishments primarily engaged in manufacturing all rubber and
plastics footwear. . .having rubber or plastic soles vulcanized
to the uppers.3 Processes specific to the utilization of
plastics within this industry are excluded from further consid-
eration here. A brief description of the manufacture of canvas
314
-------
F
- RUBBER
- BLACK
-OILS
- CHEM.
- PIGMENTS
/*
COMPOUND
'REPARATION
BANBURY)
l»-WASTE
1, 2, 5
-
TIRE
CORD -*•
FABRIC*
STEEL
WIRE*
TYPE OF WASTE CODE
1 - PAPER, CARDBOARD
2 -RUBBER COMPOUND
3 -TEXTILE MATERIALS
4 - METAL
5 - OTHER
FABRIC
COATING
( CALENDERS )
*
CONSTRUCT
TIRE
BEAD
PREPARE TREAD
AND SIDEWALL
( EXTRUDER )
s
WASTE
1, 3, 5
-j -^
WASTE
2, 3,4
S*
1
WASTE
2, 4
CARCASS
PLY
CUTTING
\
BUILD
"GREEN"
TIRE
"1
WASTE y*
9 3 /
{., 3 '
MOLD
» AND
LUKL 1 IKL P
IX. 1 *
T * T WA5
WASTE WASTE , 2, 3
2' 3' 4 2 REJECTS
2, 3, 4
QUALITY
• CONTROL
AMr> TFCTIMP
AINU IL.J I IINU
>TE
4
i
PRODUCT
SHIPPED
^VOLATILE ORGANICS
Figure C-3. Schematic diagram of tire manufacturing process.
-------
Table C-2. EMISSIONS AND CONTROL - TIRES AND INNER TUBES
CTl
Uncontrolled
emissions, Best control
Emission source
Compounding
Milling
Calendering
Fabric cementing
Tire building
Extrusion
Undertread cementing
Treadend cementing
Green tire spraying
Curing
Solvent storage
TOTAL : E
a
g/kg
0.1
0.05
0.043
5b
3.6
d
0.01
1.256
0.25f
19.7
0.22
0.01
= 30.23
Average
NSPS uncontrolled
Control emissions, emission rate,
technique efficiency g/kg Ib/day
Incineration
Incineration
Incineration
Ventilation and
incineration
Scheduling change
Process change
Carbon adsorption
or incineration
Carbon adsorption
or incineration
Water base spraying
Ventilation and
incineration
—
90% 0.01 10
60% 0.02 5
55% 0.02 4
60% 2 500
50% 1.8 370
80% 0.01 1
90% 0.12 125
90% 0.025 25
90% 1.97 1,970
60% 0.09 22
0.01 1
E = 6.06
n
. -on t-
Permissible Emission Regulated
emission rate, reduction emissions.
Ib/day required g/kg
15 0 0.1
15 0 0.05
15 0 0.04
200C 60%° 2
40 50%b 1.8
15 0 0.01
40 68% 0.4
40 0 0.25
2959 85%g 2.95
15 32%C 0.15
40 0 0.01
Es = 7.75
Fabric cementing is assumed to be utilized in the production of tires in 50 percent of the final product weight.
C60 percent control represents maximum reduction feasible.
Extrusion is assumed to be utilized in the production of tires in 20 percent of the final- product weight.
SUndertread cementing is assumed to be utilized in the production of tires in 50 percent of the final product weight.
Treadend cementing is assumed to be utilized in the production of tires in 10 percent of the final product weight.
9The regulation of 85 percent reduction is applied.
-------
footwear, the major product type within the rubber and plastics
footwear industry (SIC 3021), is presented below to familiarize
the inspector with the basic process operations. Atmospheric
emissions from rubber footwear manufacture are also discussed,
in Section 3.2.
3.1 Process Description
The production of canvas footwear involves six steps:
compounding of rubber stocks, molding of the soles, cutting and
fabricating canvas parts, extrusion of other rubber components,
construction of the final product from all these items, and cur-
ing of the final product. Figure C-4 is a schematic flow dia-
gram of the manufacturing process, which is described briefly
in this section.
The various rubber stocks received at a canvas footwear
plant are compounded with other processing chemicals in Banbury
mixers or roll mills and then sheeted out. The sheeted stock
is next cooled and dipped in an anti-tack solution to prevent
sticking during storage.
A canvas shoe is built from four major components: soles,
inner soles, canvas uppers, and foxing. The soles are gener-
ally formed using injection, compression, or transfer molding
techniques. Compression molding is now more common, but it pro-
duces more molding waste than do automated injection techniques.
After deflashing in a buffing machine, the molded soles are
coated with latex adhesive and then dried in an oven, which may
be electric.
317
-------
CO
PRODUCT
SHIPMENTS
WATER
* VOLATILE ORGAN ICS
Figure C-4. Schematic flow diagram for the production
of typical canvas footwear items.
-------
In the production of inner soles, flat, cellular rubber
sheets are prepared by extruding or calendering a rubber stock
containing blowing agents; e.g., sodium bicarbonate or azodi-
carbonamide. The extruded sheet is continuously cured by
passing through heated presses, during which the blowing agents
decompose and expand the sheet into cellular sponge. The inner
soles are die-cut from this material.
Individual sheets of canvas material are coated with latex,
drawn together, and passed over a steam-heated drum to form two-
or three-ply fabric. These fabricated sheets are cut to the
proper dimensions using a die and a press. The different can-
vas pieces making up the footwear uppers are then stitched
together on sewing machines.
The foxing, or edging, is extruded as a long strip from
rubber stock.
The shoe is assembled from its four basic components on a
form called a last. The canvas upper is cemented at its edges
and placed over the last. The inner sole is attached to the
bottom of the last. The bottom of the inner sole and canvas
combination is dipped in a latex-adhesive solution. Finally,
the outer sole, the foxing, and the toe and heel pieces are
attached to the shoe.
The finished shoes are inspected and placed on racks in an
air-heated autoclave for curing. Anhydrous ammonia is injected
into the autoclave to complete the cure, the amount required
ranging from 0.9 kg to 2.3 kg of NH3 per thousand pairs of
319
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shoes cured. The curing cycle lasts about 1 hr, at the end of
which the ammonia-air mixture is vented to the atmosphere.
3.2 Atmospheric Emissions
Potential sources of atmospheric emissions from rubber
footwear manufacture are listed in Table C-3.
It is presently impossible to determine which specific
hydrocarbons are emitted from rubber footwear manufacture as
"volatile organics." Organic particulates from compounding,
mixing, milling, and deflashing will consist of fine particles
of natural and/or synthetic rubber. Several factors will
affect the species and quantities emitted from rubber footwear
production. The most important of these are temperatures
achieved during manufacturing operations and the boiling points
(i.e., relative volatility) of rubber processing chemicals used.
Also pertinent is the exact amount of ammonia used in curing
the finished shoes, the reported range being from 0.9 kg to
2.3 kg per thousand pairs of shoes.
4. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM RUBBER
RECLAIMING
The rubber reclaiming industry includes establishments
primarily engaged in reclaiming rubber from scrap rubber tires,
tubes, and miscellaneous waste rubber articles by processes
which result in devulcanized, depolymerized or regenerated
replasticized products containing added ingredients. These
products are sold for use as a raw material in the manufacture
of rubber goods with or without admixture with crude rubber
320
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Table C-3. EMISSIONS AND CONTROL - RUBBER FOOTWEAR
Emission
source
Compounding
Milling
Calendering
Rubber Cementing
Latex dipping and drying
Molding
Curing
Uncontrolled
emissions,
g/kg
0.1
0.05
0.05
95
0.1°
o.nd
0.08e
Best control
technique
Incineration
Incineration
Incineration
Incineration
Process change
Ventilation and
incineration
Ventilation and
incineration
Control
efficiency
90%
60%
55%
36%a
90%
60%
60%
NSPS
emissions,
g/kg
0.01
0.02
0.02
60.8
0.01
0.04
0.03
Average
uncontrolled
emission rate,
Ib/day
6
3
3
5,240
6
6
4.4
Permissible
emission rate,
Ib/day
15
15
15
b
3,350
15
15
15
Emission
reduction
required
9%
0
0
36%b
0
0
0
Regulated
emissions,
g/kg
0.1
0.05
0.05
60.8
0.1
0.11
0.08
U)
ho
TOTAL:
a
E =95.49
u
E = 60.92
E = 61.29
40 percent of rubber cementing that is performed in a spray booth can be controlled by 90 percent. The other 60 percent of cementing is done in
open space and is not controllable.
These represent the maximum reduction feasible.
CLatex dipping is assumed to be utilized in 20 percent of the final product weight.
Molding is assumed to be utilized in 50 percent of the final product weight.
SCuring is assumed to be utilized in 50 percent of the final product weight.
-------
or synthetic rubber.11 A brief description of the reclaiming of
rubber is presented below to familiarize the inspector with the
basic process operations. Atmospheric emissions from rubber
reclaiming are discussed in Section 4.2.
4 .1 Process Description
J. M. Ball originally defined reclaimed rubber, in the
first edition of Rubber Technology, as "the product resulting
from the treatment of vulcanized scrap rubber tires, tubes and
miscellaneous waste rubber articles by the application of heat
and chemical agents, whereby a substantial 'devulcanization' or
regeneration of the rubber compound to its original plastic
state is effected, thus permitting the product to be processed,
compounded, and vulcanized. Reclaiming is essentially depoly-
merization; the combined sulfur is not removed. The product is
sold for use as a raw material in the manufacture of rubber
goods, with or without admixture with crude rubber or synthetic
rubber."30 The United States Department of Commerce has
adopted this definition in the report on Reclaimed Rubber for
the 1972 Census of Manufacturers.
There are currently three different process technologies
used by the rubber reclaiming industry in the United States:
the digester process, the pan (or heater) process, and the
mechanical process. The most common reclaiming technique is
the digester process, which has almost replaced the pan pro-
cess, the oldest of the three. The mechanical process is the
least conventional one, and, as such, it is not widely
322
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practiced. All three processes use similar methods of rubber
scrap separation and size reduction. The differences show up
in the depolymerization and final processing.
4.1.1 Metal Removal, Size Reduction, and Fiber Separation - •
Scrap rubber received at a reclaiming plant is first sorted to
remove steel-belted or studded tires, which can be either sent
to special processing facilities or discarded as waste. Brass
and steel valve stems and valve seats are manually removed
from the remaining tires. The bead wire, which serves to
secure the tire to the wheel rim, may also be cut out of the
tire at this time.
Next, the scrap rubber is size reduced using either crack-
ers or hammer mills. The cracker is a two-roll machine, having
working roll lengths of 76 cm to 107 cm and diameters of 46 cm
to 81 cm.11 Each roll is axially corrugated, and the two
rotate in opposite directions at different speeds. As the rub-
ber is dropped into the cracker, the slower roll corrugations
momentarily "hold" the waste while the faster roll corrugations
shear, slice, crush, and abrade the waste. This process is
repeated until all the material passes through a screen of
some predetermined mesh size. Some reclaimers undertake fur-
ther size reduction down to less than 10 mesh using secondary
and tertiary crackers.
A hammer mill is essentially a high-speed rotating drum
which hammers the scrap rubber with pivoting "T" or "I" bars
or with knives mounted on the drum's periphery. There may be
stationary knives located on the frame within which the drum
323
-------
revolves, with or without a perforated plate or screen that
retains the scrap until it is sufficiently size reduced to
pass through. The machine containing drum knives may have a
special feeding device to control the input of the rubber waste.
Wastes containing reinforcing fiber materials, such as
cotton, rayon, nylon, polyesters, fiberglass, and metal, require
either mechanical fiber separation or chemical fiber degrada-
tion. The ground rubber-and-fiber mixture is first separated
into streams of different particle size by a screener. These
streams are conveyed to separation tables which effectively
separate loose fiber from clean rubber by vibration and air
flotation. This is a continuous operation with recycle and
with free scrap being added at all times.
The fiber and rubber-fiber portions are next fed into
hammer mills for hammering or scraping. After the material
has been sufficiently size reduced to pass through a peripheral
screen, it is fed to sifters or beaters™ In these machines,
loose rubber particles separate from the fiber and pass through
a retaining screen, while the fiber is conveyed for recycle,
either to the screener or to another set of hammer mills.
The final operation of the fiber separation process is
baling the waste fiber. This baled fiber is made up of small
strands, less than 3.8 cm long, and contains a small amount of
entrapped rubber.11 This fiber is discarded unless there is
a market for its reuse.
Fiber-separated rubber is next subjected to fine grinding.
Crackers, similar to those used for primary size reduction,
324
-------
grind the rubber to -30 mesh or smaller. Hammer mills can be
used for fine grinding but are not as efficient as crackers.
The finely ground rubber is then screened. Particles that pass
through the screens are ready for depolymerization, while the
remaining material is recycled for further size reduction.
4.1.2 Depolymerization -
Digester process - Digestion is a wet process using rubber
scrap that has been ground to thicknesses between 0.63 cm and
0.95 cm.29 The fine, fiber-free rubber particles are mixed
with water and reclaiming agents and fed to a jacketed auto-
clave. These digesters can accommodate about 2,300 kg to
2,700 kg of scrap, water, and chemicals in each reclaim batch.30
The digester is agitated by a series of paddles on a shaft
which is continuously driven at a slow speed to maintain the
charge in motion for uniform heat penetration. The digestion
liquor is heated by the injection of steam, at pressures
generally around 1.38 MPa (200 psi) for a residence time of
8 to 12 hours.30 Another reference indicates a residence time
of 5 to 24 hours at a digester temperature of 188°C to 207°C.29
Reclaiming agents are fed to the digester with the scrap rubber
to accelerate depolymerization and to impart desirable pro-
cessing properties to the rubber. Rubber scrap which has not
been mechanically defibered requires chemical degradation during
digestion. Therefore, defibering agents and plasticizing oils
are added to complete the charge.
When the digestion is complete, the resultant slurry is
blown down under internal pressure into a blowdown tank. From
325
-------
here, the rubber slurry is pumped to a holding tank where
additional water is added for dilution and washing. After agi-
tation, the mixture is discharged onto vibrating screens where
a series of spray nozzles wash the rubber free from the diges-
tion liquor and hydrolyzed fiber. The washed scrap is then
passed through a dewatering press. A small amount of residual
moisture is necessary to prevent excessive buildup of heat
during subsequent refining.
A flow schematic is shown in Figure C-5.
Pan (or heater) process - Fiber-separated, fine-ground
scrap is reduced to an even smaller particle size by grinding
on smooth steel rolls. The rubber is next blended with reclaim-
ing oils in an open mixer and then placed in stacked shallow
pans. The depth of treated scrap in these pans may be 15 cm
to 20 cm.30 The stacked pans are placed on a carriage that
can be wheeled into a large horizontal heater, which is a
single-shell pressure vessel.
In this method of depolymerization, live steam at 1.38 MPa
(200 psi) to 1.55 MPa (225 psi) is introduced to the heater to
directly contact the rubber scrap.30 Another reference states
that depolymerization is carried out at 185°C [saturated steam
pressure ^1.12 MPa (163 psi)] for 2 to 18 hours.29 After
this treatment, the heater is opened, and the reclaimed scrap
is unloaded and cooled. No drying is required because the
small amount of water remaining will assist in refining.
A flow schematic is shown in Figure C-6.
326
-------
RUBBERSCRAP
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
FIBER SEPARATION
FURTHER SIZE
REDUCTION
SCREENING
.REUSE OR
DISPOSAL
WATER
CHEMICALS-
AND OILS
OIL
RECYCLE
DIGESTIVE
DEPOLYMERIZATION
SLOWDOWN
T
DRYING
FILLERS
AND LIQUIDS
MIXING
REFINING
STRAINING
^VOLATILE ORGANICS
RECLAIMED
RUBBER
Figure C-5. Schematic flow diagram of digester process
for reclaiming rubber.31
327
-------
FIBER-FREE
RUBBER SCRAP
RECLAIMING OILS
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
SCREENING
sir
MIXING
AUTOCLAVE
DEPOLYMERIZATION
FILLERS
AND LIQUIDS'
MIXING
REFINING
STRAINING
•^VOLATILE ORGANICS
RECLAIMED
RUBBER
Figure C-6. Schematic flow diagram of pan process
for reclaiming rubber.31
328
-------
• Mechanical process - Unlike the other two processes,
mechanical reclaiming is continuous. Fiber-separated, fine-
ground rubber scrap is fed into a high-temperature, high-shear
machine. The machine is a horizontal cylinder in which a screw
forces material along the chamber wall in the presence of
reclaiming agents and depolymerization catalysts. Tempera-
tures generated are in the range of 177°C to 204°C with time
requirements between 1 and 4 minutes.3 ° The discharged re-
claimed rubber needs no drying.
4.1.3 Mixing, Refining, Straining, and Packaging - Reinforcing
materials such as clay, carbon black, and softeners are
most commonly mixed into the rubber using a horizontal ribbon
mixer. This is an enclosed rectangular box with a rounded
bottom in which mixing is accomplished by a horizontally
driven continuous ribbon, paddles, or a combination of the two.
The mixed rubber and filler compounds are next intimately
blended in a Banbury internal mixer. It usually takes between
1 and 3 minutes to blend the material in a single batch. Since
extruders permit continuous processing, more reclaimers are
converting to that method of blending.
The reclaim next undergoes preliminary refining on a
short two-roll mill called a breaker refiner. The smooth
rolls are of different diameters and rotate at different speeds
so that there is a high friction ratio which tends to form the
stock into a smooth clean sheet, approximately 0.3 mm thick.
The temperature of the rolls is controlled by water cooling.
329
-------
The sheet is dropped into a screw conveyor which carries
the reclaim to a strainer. The strainer is a heavy-duty extrud-
er which contains a wire screen (10- to 40-mesh openings) held
between two perforated steel plates in the head of the machine.
Straining removes such foreign materials as glass, metal, wood,
or sand from the rubber. After straining, the rubber goes on
to a second refiner called a finisher, which is the same type
of machine as the breaker. The final thickness of the clean
reclaim is between 0.05 mm and 0.25 mm.11
Each reclaimer may complete his operations by sending his
product to the customer in the form of slabs, stacked on pal-
lets, or in bales. Slabs are made by allowing the thin sheet
of reclaim to wrap around a windup roll until the proper thick-
ness is obtained. The wrapped layers are then cut off the roll,
forming a solid slab of a certain length, width, and weight.
Each slab, weighing approximately 14 kg to 16 kg, is dusted
with talc to prevent sticking.30 After quality control approval,
the slabs are piled on pallets until the total weight is 680 kg
to 910 kg, ready for shipment.30 As an alternative to the slab
process, the reclaim sheet can be air conveyed to a baler,
where the rubber is compacted to form a bale of controlled
weight. The bales are dusted, bagged, stacked on pallets,
tested, and shipped.
A flow schematic is shown in Figure C-7.
4.2 Atmospheric Emissions
Potential sources of atmospheric emissions from rubber
reclaiming are listed in Table C-4. At this time, it is not
330
-------
FIBER-FILE
RUBBER SCRAP
RECEIVING
AND SORTING
VALVE STEMS
AND VALVE SEATS
REMOVAL
SIZE REDUCTION
SCREENING
HIGH -TEMPERATURE,
HIGH - SHEAR
DEPOLYMERIZATION
MIXING
^VOLATILE ORGANICS
REFINING
I
STRAINING
SLABBING/
BALING
RECLAIMED
RUBBER
Figure C-7. Schematic flow diagram of mechanical process
for reclaiming rubber.31
331
-------
Table C-4. EMISSIONS AND CONTROL - RECLAIMED RUBBER
Emission
source
Depolymerization
Uncontrolled
emissions.
g/kg
30
Best control
technique
Condenser and
scrubber
Control
efficiency
90%
NSPS
emissions.
g/kg
3.0
Average
uncontrolled
emission rate.
Ib/day
1,790
Permissible
emission rate,
Ib/day
270a
Emission
reduction
required
85%a
Regulated
emissions ,
gAg
4.5
OJ
co
to
TOTAL: E = 30
The regulation of 85 percent reduction is applied.
E = 3.0
= 4.5
-------
possible to identify the individual hydrocarbon species.
5. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM HOSE AND
BELT MANUFACTURE
The hose and belting industry includes establishments pri-
marily engaged in manufacturing rubber and plastic hose and
belting, including garden hose.5 (Processes specific to the
utilization of plastics within the rubber and plastic hose and
belting industry are excluded.) A brief discussion of the manu-
facture of hose and belting is presented below to familiarize
the inspector with the basic process operations. Atmospheric
emissions from hose and belt manufacture are discussed in
Section 5.2.
5.1 Process Description
5.1.1 Belting - Conveyor or Flat Type
Materials - Rubber belting usually consists of a multiple-
ply, rubberized-fabric carcass sandwiched between two layers of
rubber sheeting. Natural rubber is the most widely used raw
crumb in both the frictioning and sheeting stocks, but syn-
thetic polyisoprene, Hypalon, and reclaimed rubber are also
used.21 Due to its inferior properties, reclaim is sometimes
used as an extender for the more expensive polymers. In belt-
ing which requires a high degree of oil resistance, Neoprene
is commonly used.
Depending upon the choice of raw crumb, a wide variety of
loading pigments, accelerators, plasticizers, antioxidants, and
vulcanizing agents are incorporated into the stock during mixing,
333
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Compounding - Compounding and mixing are usually carried
out in Banbury mixers, although compounding mills may be used
in some facilities. After mixing, the rubber stock is sheeted
out on a sheeting mill and dipped in a soapstone slurry to
reduce its tack. The rubber leaves the rolling mill in a
ribbon several feet wide and less than 1/2 inch thick.26
Both the frictioning and sheeting stocks are worked on
warmup mills prior to subsequent forming operations.
Particulate emissions occur when the dry compounding ingre-
dients such as carbon black and zinc oxide are charged to the
Banbury mixers. Hydrocarbon emissions from this area are pri-
marily rubber stock volatiles, generated by the heat of mixing
and milling operations.
Forming operations - The hot sheeting stock passes from
the warmup mill through an extruder-calender machine where its
dimensions are fixed. Wire reinforcement may be extruded with
the rubber stock during this operation to increase the strength
of the belting. After calendering, the sheet rubber is cooled
in a water spray tank, dried via passage over hot air vents,
and rolled up for storage.
The frictioning compound passes from the warmup mill to
a friction calender where it is impregnated into the fabric
used to build the carcass of the belt. This fabric, usually
rayon or nylon, is pretreated by dipping in latex and/or cement
and drying to a moisture content of less than one percent.
Drying is carried out immediately prior to frictioning by
334
-------
passing the dipped fabric over steam-heated cylinders or
platens kept at 115°C,32 or in other types of ovens.
Extrusion, calendering, latex dipping and drying are all
potential sources of volatile organic emissions. However, the
fabric pretreatment operations may not be conducted in the belt-
ing plant itself, but in a separate, specialized facility.
Building - The rubberized, single-ply fabric leaving
the calender is used to build belt carcasses of multiple-ply
thickness. A variety of techniques are employed in this opera-
tion, depending on the specifications of the final product.
Once built, the carcass is sandwiched between two layers of
rubber sheeting by a calendering operation.
Some minor volatile emissions may be generated by the
calendering process.
Curing - Belt vulcanization is performed in presses, roto-
cures, or hot-air curing ovens. A rotocure employs a combina-
tion of steam, cooling water, and electric heaters to continuously
vulcanize the belting as it passes around the curing drum. Press
curing is effected by two heated belts which hold the belting
between them under pressure, turn, and drag the belting through
the press. Unlike the rotocure, the press curing technique is
a batch operation. Vulcanization requires about 30 minutes at
140°C.32
After curing, the belting is inspected, cut to length, and
stored before shipment.
Due to the high operating temperatures of the curing equip-
ment, a wide array of volatile organics are released to the
335
-------
atmosphere. These include residual monomers and other impuri-
ties in the raw rubber, a variety of processing aids and dilu-
ents in the stock, and any number of trace impurities in these
technical-grade compounding ingredients.
Miscellaneous operations - Fugitive dust emissions result
from a variety of handling and storage operations involving dry,
powdery rubber additives; e.g., carbon black. Some plants use
wet scrubbers to control emissions of this type, particularly
in the compounding area.
A flow schematic is shown in Figure C-8.
5.1.2 Machine-Wrapped Ply Hose -
Materials - Machine-wrapped ply hose consists of three
components: the tube (lining), the reinforcement, and the
outer cover. The reinforcement is constructed from rubber-
impregnated fabric, while the tube and cover are made entirely
from rubber.
Natural rubber and a wide variety of synthetic polymers
are used, including butyl rubber, EPM, EPDM, Hypalon, Neoprene,
nitrile rubber, and polyisoprene. Reclaimed rubber is also used
in conjunction with one of the more expensive polymers.18/21'22
Any number of fillers, softeners, accelerators, activators,
antioxidants, pigments, and vulcanizing agents may be combined
with the raw crumb. The recipe is varied to fit the service
requirements of the final product.
Compounding - The rubber stock is usually compounded and
mixed in a Banbury mixer and sheeted out on a roll mill in a
ribbon several feet wide and approximately 1 inch thick.26
336
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COOLING
(WATER SPRAY TANK:
ANTI-TACK
TREATMENT
DRYING
(AIR VENTS)
CALENDERING
CURING
! PRESS, ROTOCURE,
HOT-AIR OVEN)
INSPECTION
CUTTING TO LENGTH
—*-T STORAGE J
Figure C-8. Belting flowsheet.
337
-------
This rubber sheet is subsequently dipped in an anti-tack slurry
and hung up to dry for further processing.
Emissions from the compounding area include both hydro-
carbons and particulates. The particulates are generated when
the dry compounding ingredients are charged to the Banbury.
The hydrocarbon emissions are generated by the heat of mixing,
which volatilizes many of the organic additives.
Tube formation - After drying, the sheeted stock is con-
tinuously extruded to form a seamless rubber tube of the desired
diameter and wall thickness. As it leaves the extruder, the
tube is cooled in an open tank by direct contact with cooling
water, dipped in a tank of anti-tack agent such as a zinc
stearate solution, and coiled up for storage. Soapstone solu-
tion is not used in this dipping operation because its anti-tack
properties are undesirably permanent.
Emissions from the tube forming operations are probably
negligible. Some minor hydrocarbon emissions may result from
the extrusion process due to the elevated operating temperatures.
Reinforcement preparation - The fabric used for reinforce-
ment is received from textile mills in large rolls and impreg-
nated with rubber on both sides by friction calendering. The
frictioned fabric is then cut on a bias and cemented together
with overlapped seams to form a long strip just wide enough to
provide the required number of plies plus an overlap when
wrapped around the tube.
338
-------
Some organic volatiles in the rubber stock may also be
released during the friction calendering procedure.
Outer cover formation - The hose cover is formed by
calendering a thin sheet of rubber stock to the required thick-
ness and cutting it to the width necessary for a slight overlap
on wrapping.
Some organic volatiles may be released from the rubber
stock during calendering.
Mandrel insertion - From storage, the formed tube is
taken to the building area where it is temporarily enlarged
via air pressure and mounted on a rigid mandrel. Lubricants
are injected into the tube to prevent it from sticking to
itself or to the mandrel.
Organic emissions probably occur from volatilization of
the lubricants or release agents used.
Building - The actual hose building is carried out on a
special purpose "making machine" which consists of three long
steel rolls. Two of the rolls are fixed parallel to each other
in the same horizontal plane, while the top roll is mounted on
lever arms so it can be raised and lowered. One or more of
the rolls are power driven.
When the forming operations are completed, the mandrel-
supported tube is placed in the trough formed by the two
bottom rolls of the making machine. One lengthwise edge of
the cut fabric is adhered to the tube and the top roll is
339
-------
brought down into contact with it. The pressure exerted by
the top roll causes the tube and mandrel to rotate as the
bottom rolls rotate, so the fabric is drawn into the machine
and wrapped around the tube. The pressure from the top roll
serves the dual purpose of compacting the carcass as it is
formed. This same procedure is repeated with the cover to
complete the building operation.
Vulcanization - The uncured hose is transferred from the
building area to the curing area where it is loaded into an
open steam autoclave for vulcanization at some predetermined
temperature and pressure. The necessary pressure is maintained
by cotton or nylon wraps.
When vulcanization is complete, the autoclave is vented,
the hose is removed and cooled, and the cloth wrap is stripped
away- The hose is then removed from the mandrel with compressed
air or water and hydraulically tested before final storage and
shipment. Machine-wrapped ply hose is commonly produced and
shipped in lengths of about 50 m with internal diameters
ranging from 5 mm to 75 mm.29
A host of volatile organic additives are emitted during
the relatively high-temperature curing process. Most of these
volatiles are probably released to the atmosphere when the auto-
clave is vented.
Miscellaneous operations - Particulate emissions are gener-
ated by a variety of handling and storage operations involving
dry compounding ingredients.
340
-------
No information is available concerning the use of control
equipment in this industry -
A flow schematic is shown in Figure C-9.
5.1.3 Hand Built Hose -
Materials - Ply hose is built by hand if it is too large
in diameter or too long to fit on the three-roll making machine,
or if it requires special ends, metal reinforcement, or
specially layered fabric reinforcement. The raw rubber and
compounding ingredients used are the same as those used in the
production of machine-wrapped ply hose.
Forming operations - For hose with internal diameters
less than 100 mm, the tube is extruded and mounted on the man-
drel as before.29 For larger hose, the tube is formed by
wrapping calendered stock around the mandrel with a slightly
overlapping seam. The steel mandrel is mounted on a series
of double roller stands with one end held in the jaws of a
power-driven chuck used to rotate it during the building
operation.
The fabric is frictioned and cut as before, and the cover
stock is calendered to the desired thickness.
Building - In the making process, the pretreated fabric
is applied to the mandrel-supported tube by hand. It is rolled
down progressively as the mandrel is turned. The cover stock
is applied in a similar manner.
Wire reinforcement is used in many types of hand-built
hose: to prevent collapse in suction hose, to prevent kinking
341
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RUBBER
CEMENT
FABRIC
^VOLATILE ORGANICS
DRYING
ANTI-TACK
TREATMENT
MANDRa
INSERTION
BUILDING &.
CEMENTING
WRAPPING
VULCANIZATION
COMPOUNDING
'
ROLL MILL ING
i
ANTI-TACK
TREATMENT
TUBE EXTRUSION
COOLING
(TANK )
COOLING
WRAP REMOVAL
MANDREL REMOVAL
TESTING
STORAGE
SHIPMENT
Figure C-9. Ply hose flowsheet.
342
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in pressure hose curved in small radius loops, and to add strength
in high pressure hose. The wire in suction hose is usually placed
underneath the main fabric plies for rib support against external
pressure. In pressure hose, the wire is placed over the fabric
reinforcement for hoop strength against high internal pressure.
For a combination of these reinforcement properties the wire is
placed midway in the fabric plies.
Wire reinforcement is usually in the form of a closely spaced
helix opposing radial stress but adding little strength in the
axial direction. If axial strength is also required, the hose
is constructed with two or more even numbers of wire layers.
Each layer consists of many strands of solid round wire or cable
spiralled around the hose, forming an angle greater than 45°
with its axis. The direction of the spiral is reversed with
each layer for balanced strength.
In the actual making process, the wire is applied by hand
or by a simple machine using a power-driven chuck to rotate the
mandrel and hose.
All other manufacturing steps are very similar to those
used in the production of machine-wrapped ply hose.
The same emissions may be expected whether the hose is
built by hand or by machine.
5.1.4 Braided Hose -
Materials - Braided hose refers to the type of construction
and method of manufacture in which strands of reinforcement are
interlaced as well as spiralled around the tube. Thus, the
343
-------
reinforcement consists of yarn or wire rather than sheeted
fabric. The raw rubber and compounding ingredients used are
essentially the same as those used to make ply hose.
Tube formation - Processing usually begins with the ex-
trusion of unsupported tubing, providing that the rubber stock
is firm enough in the raw state to resist excessive deformation
and stretching. When the tubing is too thin, too soft, or when
the internal diameter must be kept within a narrow range, it
must be extruded onto a flexible rubber or plastic mandrel.
The mandrel is at least as long as the tubing itself, and may
have a wire core to prevent stretching. Once formed, the tube
is temporarily stored on a circular tray or reel.
Small quantities of organics may be emitted during the
extrusion process.
Building - From storage the tube is taken to the braider
where the reinforcement is applied. The tube is drawn through
the center of the machine while the braid is forming on its
surface. Braid formation is carried out by yarn or wire
carriers weaving in and out on a circular track. The angle
of braiding is adjusted by changing the surface speed of the
overhead takeoff drum or capstan. When braiding is completed,
the hose passes through a crosshead extruder where a seamless
rubber outer cover is applied.
Some volatile organics from the cover stock are likely to
be the only emissions from this section of the plant. These
volatiles are released during the extrusion of the outer cover.
344
-------
Vulcanization - A substantial portion of all braided hose
is vulcanized by the lead sheath process. The lead casing
used in this operation is formed by means of a lead press or
extruder. A lead press deforms solid lead into a continuous
sheath; a lead extruder works with molten lead. In either case,
the lead sheath is formed around the uncured hose as it parses
through the press or extruder.
If the lead-sheathed hose is nonsupported, it is filled
with water under pressure, wound on reels, and loaded into an
open steam pressure vessel. The internal water pressure is
maintained throughout the curing cycle to force the hose
against the lead casing. After curing, the water is drained
from the hose and the lead casing is stripped away for recycle.
If the hose is supported, the lead sheath itself applies
some initial pressure by squeezing it against the flexible
mandrel. However, most of the internal pressure necessary
for a solid, homogenous product is supplied by the expansion
of the hose during the high-temperature vulcanization. At the
end of the curing period, the lead sheath is removed by mechani-
cally slitting and pulling away from the cured hose. The
mandrel is removed by means of a high-pressure hydraulic system.
Volatiles from the uncured hose are emitted to the atmos-
phere as a result of the high operating temperatures encountered
in the lead extruder and curing vessel. In theory, some lead
particulates could also be generated by the lead pressing or
reclaiming operations.
345
-------
A flow schematic is shown in Figure C-10.
5.1.5 Spiralled Hose - In spiralled hose, all the strands
in a given layer are aligned in one direction parallel to
each other. At least two layers of reinforcement aligned in
opposite directions are thus required for balanced strength.
Spiralled hose reacts to internal pressure in the same
way that braided hose does, and can be produced at a much
faster rate due to the relative simplicity of the spiralling
machines. However, spiralled hose is not manufactured in as
broad a size range as braided hose.29
5.2 Atmospheric Emissions
Potential sources of atmospheric emissions from hose and
belting manufacture are listed in Table C-5. It is not possi-
ble at this time to identify specific hydrocarbon species
contained in these emissions.
6. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM FABRI-
CATED RUBBER GOODS MANUFACTURE
This industry includes establishments primarily engaged
in manufacturing industrial and mechanical rubber goods, rub-
berized fabrics and vulcanized rubber clothing, and miscellaneous
rubber specialties and sundries.6 A brief discussion of the
manufacture of fabricated goods is presented below to familiarize
the inspector with the basic process operations. Atmospheric
emissions from fabricated rubber goods manufacture are dis-
cussed in Section 6.2.
346
-------
BRAIDER OR
SPIRALLING MACHINE
COVER EXTRUSION
LEAD EXTRUDER
OR PRESS
VULCANIZATION
* VOLATILE ORGANICS
SHEATH REMOVAL
MANDRa REMOVAL
TESTING
STORAGE
SHIPMENT
Figure C-10. Braided or spiralled hose flowsheet.
347
-------
Table C-5. EMISSIONS AND CONTROL - HOSE AND BELTING
Emission source
Compounding
Milling
Calendering
Extrusion-hose
Fabric cementing
Rubber cementing
Curing
Uncontrolled
emissions,
g/kg
0.1
0.05
0.05
0.02a
12. 5b
6.0
0.16
Best control
technique
Incineration
Incineration
Incineration
Process change
Incineration
—
Ventilation and
incineration
Control
efficiency
90%
60%
55%
80%
90%
—
60%
NSPS
emissions,
g/kg
0.01
0.02
0.02
0.004
1.25
6.0
0.06
Average
uncontrolled
emission rate,
Ib/day
3
1.5
1.5
0.6
390
186
5
Permissible
emission rate,
Ib/day
15
15
15
15
58C
40
0
Emission
reduction
required
0
0
0
0
85%C
0
0
Regulated
emissions,
g/fcg
0.1
0.05
0.05
0.02
1.9
6.0
0.16
CO
>£.
CO
TOTAL:
E = 18.83
u
E = 7.36
n
Extrusion of hose is assumed to be utilized in 50 percent of the final product weight.
Fabric cementing is assumed to be utilized in 50 percent of the final product weight.
CThe regulation of 85 percent reduction is applied.
E = 8.28
s
-------
6.1 Process Description
6.1.1 General Molded Products - This category includes items
such as battery parts, rubber rolls, rubber heels and soles,
water bottles, fountain syringes, nipples, pacifiers, rubber
bands, finger cots, erasers, brushes, combs, mouth pieces, and
a wide variety of mechanical goods.
Rubber molding typically consists of the following
operations:
• Compounding of the rubber stock
• Preparation of the mold preforms or blanks
• Molding
• Deflashing
6.1.2 General Extruded Products - General extruded products
include rods, tubes, strips, channels, mats and matting, floor
and wall covering, and stair treads.
Compounding - The rubber stock is compounded from the
basic ingredients on a compounding mill or in a Banbury mixer.
A wide variety of raw rubbers and compounding ingredients are
used, the choice of which depends on the service requirements
of the product. After mixing, the compound is sheeted out on
a sheeting mill and dipped in a soapstone slurry.
Extrusion - After compounding, the rubber stock passes
through a warmup mill and then through an extruder where it is
continuously formed into the shape of the final product. This
green product is cooled in a cooling tank prior to vulcaniza-
tion and, in some cases, dipped in a soapstone slurry for
temporary storage.
349
-------
Vulcanization - In the vulcanizing process, extruded
articles are placed in pans which are set on a truck and rolled
into a large steam chamber or heater. Varnish or lacquer may
be applied before vulcanization to produce a smooth, glossy
finish.
Rubber articles that would sag or flatten under their own
weight before they could completely set up must be supported
during vulcanization. In most cases, such articles are embedded
in talc or powdered soapstone. However, rubber tubing is placed
on a mandrel and wrapped with fabric to insure proper curing.
Vulcanization usually requires about 30 minutes at 140°C to
150°C.18
6.1.3 Coated Materials - Rubber-coated materials generally
consist of woven or nonwoven fabrics impregnated with a rubber
compound. Synthetic rubber materials such as acrylic rubber,
butadiene-acrylonitrile, butadiene-styrene, chloroprene,
chloro-sulfonated polyethylene, fluorinated polymeric compo-
sitions, polyisobutylene, polysulfide, and silicone polymers
are used to impart physical properties, such as water and
solvent resistance, surface-release characteristics, abrasion
resistance, and good aging. Typical uses for rubber-coated
textiles include raincoats, balloon bags, diaphragms, inflat-
able life rafts, pontoons, friction tape, and tarpaulins.
Compounding - Before the coating process, the rubber
stock is compounded by mixing a variety of extenders, pigments,
accelerators, and antioxidants with the raw crumb. The fabric
350
-------
to be coated is usually pretreated at a separate facility, but
may be dipped in latex at the coating plant itself.
Coating - Rubber coating is performed by three- or four-
roll calenders. The three-roll calender applies the coat to
one side of the fabric, while four-roll calenders coat both
sides of the fabric simultaneously. The top roll of the three-
roll calender and the bottom and offset rolls of the four-roll
calender are run at different speeds than the center roll to
friction the rubber into the fabric in a uniform manner.
Vulcanization - Rubber-coated fabrics are cured at elevated
temperatures for periods of time ranging from ten minutes to
several hours. For long cures, the ovens may be as much as
30 feet high and hundreds of feet long. For shorter curing
cycles, the ovens are usually from 6 to 8 feet in height and
8 to 20 feet in length.29 Regardless of size, the curing
oven must have a uniform temperature distribution to obtain
uniform product quality. After curing, the coated fabric is
cooled and rolled up for storage.
Building - Products such as rainwear, rafts, and pontoons
are built using dies or jigs to cut the coated material and
rubber cements to join the various sections. This building
operation may or may not take place in the coating plant.
6.1.4 Latex-Based Dipped Goods - The largest volume latex-
based dipped goods are household gloves, surgical gloves,
prophylactics, and balloons. The very thin-walled goods are
produced by a straight-dip method; thicker walled items are made
by coagulation dipping.
351
-------
Compounding - Regardless of which dipping technique is
employed, the rubber latex and compounding ingredients must
first be brought into solution or dispersion form. Solution
is used when all of the ingredients are water soluble.
Frequently, however, the ingredients are not water soluble,
and it is necessary to emulsify the liquid ingredients and
disperse the solid materials in water.
Dispersions are prepared from coarse slurries of powder
and water containing small quantities of dispersing agents and
stabilizers. Typical dispersing agents are sodium 2-naphthylene
sulfonate with formaldehyde and an alkyl metal salt of sulfon-
ated lignin. These materials are usually employed in concen-
trations of less than one percent by weight.18
Physically, the dispersions are prepared with grinding
equipment such as colloid mills, ball and pebble mills, ultra-
sonic mills, and attrition mills. Colloid mills, which break
aggregates but which do not change particle size, are used for
clay, precipitated whiting, zinc oxide, and other such mate-
rials. The other types of mills mentioned are used to prepare
dispersions of sulfur, antioxidants, and accelerators which
require both aggregate and particle-size reduction.
Emulsions are prepared by exposing a coarse, aqueous
suspension of ingredients to intense shearing in a colloid
mill, an ultrasonic mill, or a homogenizer. A homogenizer is
a machine that forces the emulsion through a fine orifice
under high pressure.
352
-------
In itself, the preparation of the latex compound is a
very simple operation consisting of weighing and mixing the
proper amounts of various solutions, emulsions, and dispersions.
This is done in a large tank with a mechanical agitator.
A flow schematic is shown in Figure C-ll.
Coagulation dipping - The coagulation solution is usually
a mixture of coagulants and organic solvents, such as ethanol
and acetone. Typical coagulants are calcium nitrate, calcium
chloride, and zinc nitrate. A surfactant is sometimes added
to the mixture to ensure good "wetting" of the forms, and
release agents are added in cases where the form has a compli-
cated shape and removal of the dipped goods is difficult. Talc,
clay, and diatomaceous earth are commonly used release agents.
The actual dipping operations is carried out with glazed porce-
lain or polished metal forms transported through the various
processing units by a closed-loop conveyor. These forms are
dried and heated to 100°C to 120°C in a conditioning oven prior
to dipping in the coagulation bath.29
After coating with coagulants, the forms are dipped in
the rubber latex compound. The coagulant film on the surface
of the form causes the rubber emulsion to "break." The latex
solids coalesce to produce a film of rubber that covers and
adheres to the form. These coated forms are passed through a
preliminary drying oven so that the film does not disintegrate
and wash away in the subsequent washing step.
353
-------
FORM
DRYING
on
o;
s
COAGULANT LATEX DIP PREL
DIP *" TANK DRY
SPILLS SPILLS
LEAKS LEAKS
WASHDOWN WASHDOWN
1 I
WASTEWATER WASTEWATER
OJ ^-k ^
Ln /^ ^
**" LATEX LATEX
STORAGE COMPOUNDING
CLEANING AGENT
AND RINSE WATER
RINSE
WATER
1
IMINARY PRODUCT
NG OVEN """" RINSE
SPENT
RINSE WATER
1
WASTEWATER
\
FORM CLEAN FORM RETURN VIA CLEANING OPERATION
AND RINSE ""
'
SPENT CLEAN ING
AND RINSE WATER
WAST^ATER " ~| ^EASE AGENT-,
^ S* \ \
H nran nni i IMP •» rnr?i MP — M. COOLING
STAMPING
™ COOLir
i- § OVE
Sd 1
=• g *
ft; WASTE
STERILIZATION
TANK
If '| * — COOLING
M- COOL ING "— *- WAT£R
SPILLS ^ WATER SPILLS WA™
LEAKS LEAKS
WASHDOWN WASHDOWN
RINSE
WATER .•
\ /
PRODUCTS FORM PRODUCT DRYING
"" STRIPPING " RINSE *° DUSTING
p/\rK«,r,iNn
JG WATER t3
}ROW g
CXL
Q_
WATER =•
on
SPENT
RINSE WATER
1
WASTEWATER
STERILIZATION
RINSE
SP
RINSE
ENT
WATER
I
WASTEWATER
WASTEWATER
WASTEWATER
SPILLS
LEAKS
WASHDOWN
I
WASTEWATER
*VOLATILE ORGANICS
Figure C-ll. Flow diagram for the production of typical latex-based dipped items.29
-------
In the washing operation, the soluble constituents of
the rubber film are leached out and rinsed away in a water
bath maintained at 60°C to 71°C.29 Important constituents of
the leachate are the emulsifiers used in the original produc-
tion of the latex and metal ions from the coagulant mixture.
The washed forms are sent through a drying oven. In some
applications, such as rubber gloves manufacture, the goods are
not only dried, but they are heated sufficiently to roll the
rubber coating downward on itself to form a reinforced cuff
bead. Usually, the rubber goods are stamped with proprietary
brands and other information, such as size, in a stamping unit
after the drying process.
The rubber products are cured in an oven at temperatures
ranging from 65°C to 95°C.18'29 After curing, the items are
cooled in a water cooling tank and mechanically stripped from
the forms, usually with the aid of a lubricating detergent.
The detergent is subsequently washed from the goods in a rinse
tank. The final manufacturing operation consists of drying
the goods, dusting them inside and outside with talc to pre-
vent sticking, and packaging.
In cases where sterilized products are required, such as
surgical gloves, the goods are immersed in a chlorine dip tank.
The free chlorine concentration in this tank is typically
1,000 mg/1. After disinfection, the goods are dipped in a
75°C to 80°C water bath to remove residual chlorine. These
two operations generally occur between the postcure cooling
tank and the final drying and packaging operation.29
355
-------
About once a week, it is necessary to clean the forms in
a bath containing a cleaning agent. If porcelain forms are
used, this cleaning agent is usually chromic acid (mixture of
potassium dichromate, sulfuric acid, and water). Once cleaned
the forms are passed through a rinse tank equipped with a fresh
water makeup and overflow to blow down the accumulation of
cleaning agent.
Straight dipping - The straight-dip method is the simplest
of the latex dipping operations. The forms are dipped directly
in the latex and removed slowly. After dipping, the form is
slowly rotated while the film is drying to ensure a uniform
thickness. The films are dried at room temperature or in
warm air at 50°C to 60°C.29
Thicker articles can be made by a multiple-dipping pro-
cess with intermittent drying. Latex deposits vary from
0.005 to 0.10 inch per dip, depending on the viscosity of the
latex compound.29
6.1.5 Cement-Based Dipped Goods - Various products are
formed by cement dipping, most notably protective gloves worn
by electrical workers. The following discussion focuses on
this glove manufacturing process.
Compounding - The solid gum rubber for the cement recipe
is compounded in small Banbury mixers or compounding mills.
The gumstock additives include antioxidants, curing agents,
and pigments.
356
-------
After mixing, the stock is milled into small particles
to facilitate its dissolution in the solvent. These rubber
particles are separated by weight into predetermined quantities
and placed in storage bins.
Rubber cement preparation - The rubber cement is prepared
in blend tanks using fixed amounts of rubber stock and solvent.
The solvent is usually aliphatic, e.g., hexane, or a blend of
petroleum spirits.
The blended cement is pumped to storage tanks prior to
the dipping operation. Several cements of different colors
and physical properties are prepared and stored simultaneously.
Dipping - The gloves are formed by dipping glazed porcelain
forms into the rubber cement. The dipping is carried out auto-
matically and repeated until the desired thickness is reached.
In between dips, the gloves are allowed to drip dry. The
temperature and humidity of the air in the drying room are con-
trolled to ensure good drying conditions.
When dipping and drying operations are completed, the
gloves are stamped with size and brand information and the
cuff bead is formed by rolling the existing cuff back on itself.
Curing - Vulcanization is carried out in an open steam
autoclave. The temperature and length of the cure depend on
the type of glove being worked and the properties of the rubber
used in its formation.
At the end of the curing cycle the gloves are removed
from the vulcanizer and partially air cooled. Prior to final
357
-------
cooling they are dipped in a soapstone slurry. The slurry
dries, leaving a powder on the gloves, which are then stripped
from the form, dusted with talc in a rotating drum, and sent
to the inspection area.
Periodically, the forms require cleaning. This opera-
tion is carried out with a scouring slurry followed by rinsing
in water.
6.1.6 Rubber Goods From Porous Molds - Dolls, squeeze toys,
and other rubber sundries are produced by the porous mold
technique.
The molds used in this process are made from plaster of
Paris or unglazed porcelain with pore siz.es smaller than the
smallest rubber particles. Latex, compounded in the manner
previously described, is poured through a funnel-shaped opening
into the mold where it is allowed to dwell until a deposit of
the desired thickness has developed on the mold wall. The
mold is then emptied of excess compound and placed in an oven
to dry at 60°C.29 The interior surfaces of the rubber article
are dusted with talc to prevent sticking when it is removed
from the mold. Once it is removed, the article may be returned
to the 60°C oven for 30 minutes.
6.1.7 Latex Thread - Latex thread is produced by extruding
the latex compound through fine orifices into a coagulant bath
where it is gelled. The thread is then toughened, washed,
dried, and cured. Dilute acetic acid is commonly used as the
coagulant.
358
-------
6-1-8 Latex Foam - The latex used in foam manufacture may
consist of natural rubber, SBR, or a combination of the two.
Before processing, this latex is compounded with a variety of
ingredients as described in the latex dipping procedure.
The foams produced are generally in slab or molded form
in the density range of 64 to 128 kg/m3 (4 to 8 lb/ft3).29
They are used to manufacture automotive seating, mattresses,
pillows, carpeting, scatter mats, upholstery, and many other
products.
Dunlop process - In the Dunlop process, the foam is pro-
duced by mechanically whipping the latex to a froth. This can
be done on a batch basis, but the Oakes continuous mixer is
the standard piece of equipment for this operation.
Once frothed, the latex must be coagulated to give a
stable foam. This coagulation, or gelation, is effected by
adding sodium silicofluoride and zinc oxide to the mix. These
gelling agents remain dormant long enough to allow the froth
to be poured into molds. When stable latexes are used,
secondary gelling agents may be required to induce coagulation.
Cationic soaps, other salts, and amines are commonly used for
this purpose.
As soon as the gelling agents are added, the foam is
poured into steam-heated molds and cured. The product is
removed when the curing cycle is completed and washed with
water to remove those ingredients in the latex recipe which
are not permanently held in the foam matrix. The foam is then
359
-------
dried in a hot-air dryer and inspected prior to storage and
shipment.
A flow schematic is shown in Figure C-12.
Talalay process - In the Talalay process, the froth is
produced by chemical rather than mechanical means. Hydrogen
peroxide and enzymatic catalysts are mixed into the latex, and
the mixture is placed into a mold. The enzyme decomposes the
peroxide, thus liberating oxygen, which causes the latex mix
to foam up and fill the mold. This foam is rapidly chilled,
and carbon dioxide is introduced to effect gelation. The
gelled foam is handled in a manner similar to that used in
the Dunlop process.
Foam backing - For supported, flat-stock foam, a different
type of gelatin agent is used in place of the sodium silico-
fluoride formula used in latex foam. Either ammonium acetate
or ammonium sulfate is employed in combination with zinc oxide.
The froth is prepared with an Oakes mixer, the gelling
agent is added, and the foam is applied to the fabric by direct
spreading. The gelling is carried out at elevated tempera-
tures, usually with the aid of infrared lamps.
To prevent uneven shrinkage, the fabric is carried through
the high-temperature zone and drying ovens on tenters.
6.2 Atmospheric Emissions
Potential sources of atmospheric emissions from fabri-
cated rubber goods manufacture are listed in Table C-6.
In some cases, the foam is spread on a belt which transfers
it to the fabric.
360
-------
CONDENSER
— COOLING
WATER
CONDENSATE
WASTEWATER
WATER
COMPOUNDING AND
CURING AGENTS
LATEX
STORAGE
FREEZE
AGGLOMERATION
VAPOR
LATEX
CONCENTRATION
BY
EVAPORATION
r
CONCENTRATED
LATEX
CARBON }
DIOXIDEGAS
y*
INTERMEDIATE
LATEX
STORAGE
SPI
WASH
LLS
30WN
S*
COMPOUNDING
X
5
1
GROUND
CURING
I
SPILLS
WASHDOWN
BALL MILL
GRINDING OF
COMPOUNDING
AGENTS
SPI
s*
i j
! "-*• COOL ING
WATER
LLS
WASTEWATER
WASTEWATER
FOAM PRODUCT
STORAGE AND
SHIPMENT
FOAM
DRYING
W
jtr SU
CLEAN
FOAM
ATER
PPI V -i
FO
RIN5
STE
\M
>ING
PS
RINSE WATER
I COUNTER-
CURRENT
FO
RINS
STE
m
ING
PS
\
FOAM
PRODUCT
Q.
o
o
FOAM CUR ING
PRESSES
LEAKS
WASHDOWN
CARBON
"DIOXIDEGAS
* VOLATILE ORGANICS
RINSE
WASTEWATER
SPILLS
WASHDOWN
WASTEWATER
Figure C-12. Flow diagram for the production of typical latex foam items.
29
-------
Table C-6. EMISSIONS AND CONTROL - FABRICATED ROBBER PRODUCTS
Emission source
Compounding
Milling
Calendering
Extrusion
Bonding of parts
Latex dipping
Adhesive spraying
Curing
Molding
Uncontrolled
emissions,
g/kg
0.1
0.05
0.025°
0.0153
2.0
0.13b
1.8
O.OS3
o.na
Best control
technique
Incineration
Incineration
Incineration
Process change
—
Process change
Ventilation and
incineration
Ventilation and
incineration
Ventilation and
incineration
Control
efficiency
90%
60%
55%
80%
—
90%
70%
60%
60%
NSPS
emissions,
g/kg
0.01
0.02
0.01
0.003
2.0
0.01
0.54
0.03
0.04
Average
uncontrol led
emission rate,
Ib/day
1
0.5
0.2
0.15
17
1
15
0.7
0.9
Permissible
emission rate,
Ib/day
15
15
15
15
40
15
40
15
15
Emission
reduction
required
0
0
0
0
0
0
0
0
0
Regulated
emissions,
g/kg
0.1
0.05
0.025
0.015
2.0
0.13
1.8
0.08
0.11
CO
CPl
NJ
TOTAL:
E = 4.31
u
E = 2.75
• n
E = 4.31
Assumed to be utilized in 50 percent of the final product weight.
Assumed to be utilized in 25 percent of the final product weight.
-------
7. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM SEALS
AND GASKETS MANUFACTURE
This industry includes establishments primarily engaged
in manufacturing gaskets, gasketing materials, compression
packing, molded packings, oil seals, and mechanical seals.
Included are gaskets, packing, and sealing devices made of
leather, rubber, metal, asbestos, and plastics.7 A brief
discussion of the manufacture of seals and gaskets is presented
below to familiarize the inspector with the basic process
operations. Atmospheric emissions from this type of manu-
facturing are discussed in Section 7.2.
7.1 Process Description
The principal method of manufacturing gaskets, packing
and sealing devices is molding. This process description29
will consist mainly of general explanations of the three com-
mon molding techniques - compression, transfer, and injection.
The selection of a particular method depends on the rubber
stock used in the production economics. All three molding
techniques are commonly practiced at a single plant location.
Information specific to SIC 3293, as obtained from two selected
plants,29 will follow the general discussion.
Larger molding facilities, or those using special recipes
or nonstorable stocks, compound their own rubber stock from
basic ingredients. Compounding is performed in either a Ban-
bury mixer or a compounding mill. In some plants, airborne
particulates generated during compounding are controlled by
wet scrubbing equipment.
363
-------
7.1.1 Compression Molding - After compounding, the rubber
stock is processed on a warmup mill and formed to the approxi-
mate shape required for molding by either calendering or extru-
sion. The formed rubber is cooled, often in an open tank, and
then dipped in an anti-tack agent, generally a zinc stearate
solution or its equivalent. Soapstone slurry is not used
because of its adverse effects on the quality of the subsequent
molding operation.
The preforms are prepared from the calendered or extruded
rubber stock by cutting, slicing, or stamping. Cutting may be
performed by hand or by machine. Slicing is usually carried
out on a meat slicing machine or guillotine. Although the
exact shape of the preform is not critical, it must contain
sufficient rubber to fill the mold.
The preforms are placed into the open mold, usually by
hand. Sometimes, this is preceded by application of release
agents (powder or liquid) on the mold surfaces. The mold is
closed and held, normally by hydraulic oil pressure, during
the curing cycle. The molds are generally heated by steam
flowing through channels in the mold plates. Some older sys-
tems are electrically heated.
When the molding cycle is complete, the items are removed
and sent on to the deflashing operation. The rubber overflow,
or flash, must be removed from each piece before shipping.
Usually, deflashing is accomplished using a grinding wheel or
press-operated dies. In cases where the rubber is not freeze
364
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resistant, the molded articles are tumbled in dry ice (solid
carbon dioxide) using machines similar to cement mixers. The
thin rubber flash becomes brittle and breaks off during tumbling
while the larger main body of the part is not cooled as much
and remains flexible.
Although not strictly a part of rubber processing, the
manufacture of metal-bonded items, which consist of a molded
rubber component attached to metal, is often undertaken in the
same plant as the molding operation. Grease on the metal
parts, picked up during their production or applied later for
storage and shipping purposes, must first be removed. Degreas-
ing may be performed in a rotating drum wherein the metal part
is contacted with a suitable solvent, such as trichloroethylene
(CHC1=CC12) .
The metal surface to which rubber is to be molded must be
further prepared to provide satisfactory adhesion. In a few
cases, the metal part is pickled with acid. More often, the
bonding surface is sandblasted for roughening and then coated
with rubber cement. This last operation is done by hand for
small items, whereas larger metal surfaces are sprayed with
cement. The prepared metal part and its mating rubber com-
ponent are then placed in the mold cavity and processed in the
same way as an all-rubber product. Deflashing is done by hand
or with a grinding wheel.
In some molding plants, molded items of poor quality are
recycled to reclaim the metal component. The reject rubber is
365
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ground and buffed from the metal, which is then sand blasted
clean. Grinding and buffing create airborne particulates,
which are controlled by wet scrubbers.
7.1.2 Transfer Molding - Rubber for transfer molding is
compounded in the same way as that for compression molding.
The rubber stock blanks, to be fed into the mold's transfer
pot, take the form of slabs as they are cut from extruded or
sheeted rubber stock. The weight of the blanks is brought
within a specified tolerance by trimming. Underweight blanks
and trimmings are recycled to the sheet-out mill.
The transfer cavity, into which a rubber blank is placed,
is fitted with a ram or piston. The applied force plus the
heat from the mold cause the rubber to be softened and flow
into the molding cavity, curing simultaneously- Transfer
molds are normally heated by steam and operated by hydraulic
oil systems. The molded item is deflashed by one of the
methods described for compression-molded items.
Articles containing metal inserts are usually manufactured
by transfer molding, preparation of the metal component fol-
lowing that described for compression-molded products.
7.1.3 Injection Molding - Injection molding, the newest
technique, is basically the same as transfer molding except
that the rubber stock is injected into the mold cavities.
There are three types of injection-molding machines - one
uses a ram to force the soft rubber through runners into the
cavities; another uses a screw; the third uses a reciprocating
366
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screw, a combination of the first two. As the rubber flows
through small passages under high pressure, the temperature
increases and the compound is cured.
The molds are often mounted on a revolving turret which
permits cyclic operation. To make injection molding profitable,
very short cycle times are required, generally ranging from
45 seconds to 90 seconds.29 This necessitates curing tempera-
tures of approximately 204°C.29 Deflashing can be carried
out by any of the techniques used for compression- and
transfer-molded products.
7.2 Selected Plants -
7.2.1 Plant A - This plant manufactures oil seals, o-rings,
rubber-to-metal molded items, and miscellaneous molded rubber
products, using compression and transfer molding. Its average
daily rubber consumption is 340 kg.29
The plant's flow sheet contains the following apparatus
described in the discussion of compression molding:
• Warmup mill
• Extruder
• Guillotine (for cutting)
• Modified meat slicer (for slicing)
• Hydraulic mold presses
• Steam-heated molds
Two operating parameters are given. The mold presses
operate at 13.8 MPa (2,000 psi)-29 Steam used for heating the
molds is at 177°C and 862 kPa (125 psi)-29
367
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Molded items are deflashed in a "wheelabrator" machine,
which freezes the item with liquid nitrogen and then blasts it
with steel shot that is 0.18 mm to 0.30 mm in diameter.29 The
rubber fines and shot are separated, and the fines and dust
are collected in a bag collector.
Metal parts for composite products are degreased using
perchloroethylene (C12C=CC12) vapor. The bonding surface is
then sand blasted and finally painted with a bonding agent such
as rubber cement.
/
7.2.2 Plant B - This plant produces rubber pipe seals,
weather stripping, and rubber-to-metal molded items. The
daily rubber consumption is 10,100 kg.29
Compounding is done using a Banbury mill. Rubber stock,
batched off in sheets, is protected against sticking during
storage by dipping it in soapstone.
Pipe seals, weather stripping, and molding plugs are
formed using short- or long-barrelled extruders. The former
require warmup and strip-feed mills, whereas the latter do not.
The extruded pieces are cooled, dipped, cut, and placed in
pans for autoclave curing. The rubber articles are then cured
with steam at 690 kPa (100 psi).29
The ends of pipe seal rubber are cemented together in an
electric press to form large, o-ring-type pipe seals. When
bonding rubber to metal, the metal part is degreased, using
trichloroethylene in a closed system, and then sprayed with an
adhesive. The rubber is transfer molded to the metal part.
368
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A flow schematic is shown in Figure C-13.
7.3 Atmospheric Emissions
Emissions from the manufacture of seals and gaskets are
presented in Table C-7. It is not possible at this time to
identify specific hydrocarbon species contained in these emis-
sions.
8. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM INSU-
LATED WIRE AND CABLE PRODUCTION
The nonferrous wiredrawing and insulating industry includes
establishments primarily engaged in drawing, drawing and insu-
lating, and insulating wire and cable of nonferrous metals
from purchased wire bars, rods, or wire.8 A brief description
of insulating wire with rubber compounds is presented below to
familarize the inspector with the basic process operations.
Only extrusion is discussed, since it is the preferred method
of applying rubber insulation or protective covering to wire
or cable. Atmospheric emissions from this industry are also
discussed, in Section 8.2.
8.1 Process Description
Manufacture of insulated wire and cable involves three
basic steps: extrusion, vulcanization, and protective covering.
Figure C-14 is a schematic flow diagram of the process used
for thermosetting polymers, i.e., butyl rubber, neoprene,
nitrile rubbers, silicone rubbers, and styrene butadiene rub-
ber. In actual use, these materials are compounded with
reinforcing fillers, pigments, antioxidants, and other typical
rubber processing chemicals.
369
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00
-J
o
^VOLATILE ORGWIICS
Figure C-13. Schematic flow for manufacture of molded rubber products.29
-------
Table C-7. EMISSIONS AND CONTROL - GASKETS, PACKING, AND SEALING DEVICES
Emission source
Compounding
Milling
Calendering
Molding
Adhesive spray
Uncontrolled
emissions,
9/kg
0.1
0.05
0.05
0.22
3.6
Best control
technique
Incineration
Incineration
Incineration
Ventilation and
incineration
Incineration
Control
efficiency
90%
60%
55%
60%
90%
NSPS
emissions,
g/kg
0.01
0.02
0.02
0.09
0.36
Average
uncontrolled
emission rate,
Ib/day
1.5
0.5
0.5
2.6
42
Permissible
emission rate,
Ib/day
15
15
15
15
40
Emission
reduction
required
0
0
0
0
6%
Regulated
emissions,
g/kg
0.1
0.05
0.05
0.22
3.4
TOTAL:
E = 4.02
u
E = 0.5
n
3.82
-------
CO
JACKETING
CURE MILL
EXTRUSION
INSULATOR
CONTINUOUS
VULCANIZER
JACKETING
* VOLATILE ORGANICS
PRODUCT
SHIPMENT
Figure C-14. Schematic flow diagram for production of insulated wire and cable
using thermosetting polymers (i.e., butyl rubber, neoprene, nitrile
rubbers, silicone rubbers, styrene-butadiene rubbers).
-------
A wire to be covered is passed through a right-angle or
side-delivery extruder head. In this operation, the wire is
fed through the head in a direction perpendicular to the axis
of the extruder screw. The head is designed so that the rub-
ber compound is deflected 90° and completely surrounds the wire.
The covered cable is pulled through the machine by a
variable-speed hauloff. A satisfactorily uniform coating is
ensured by regulation of the drawing speed.
Continuous vulcanization of insulated wire is accomplished
by extrusion directly into a suitable curing device. This is
usually just a tube fixed to the nozzle of the extruder and
filled with steam at pressures from 1.38 MPa to 1.72 MPa
(13.6 to 17.0 atm).18 Such tubes may be 30.5 meters to 61
meters (100 to 200 feet) in length.18 Residence time for the
insulated wire is approximately 15 seconds.18 Glands through
which the cable exits the tube prevent leakage of steam. Large
cables are usually processed in vertical units but horizontal
or catenary-shaped tubes are also available.
The exterior of insulated wire or cable must be protected
against mechanical and sometimes chemical deterioration. The
type of protective covering applied will depend on the ultimate
end use of the cable. Small wires are covered with a braid,
normally of cotton but possibly of rayon or fine metallic
wire. Another means of protection, tough rubber sheathing
(T.R.S.), can be applied to the insulated wire using an
extruder with a side-delivery head as described previously-
373
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The sheathing may consist of neoprene (polychloroprene) or
another oil-resistant rubber. Lastly, some insulated wires
and cables may be covered by an extruded lead sheath applied
earlier as a means of support during vulcanization.34
8.2 Atmospheric Emissions
Potential sources of atmospheric emissions from manufac-
tures of insulated wire and cable are listed in Table C-8.
The specific hydrocarbons emitted as "volatile organics"
and the composition of organic particulates are undetermined.
There are a few factors which affect both the species and the
quantities of emissions from insulated wire and cable manufac-
ture. Glands used to trap steam in the vulcanizer tube may or
may not be able to control the emission of organic materials.
The particular combination of rubber processing chemicals used
in which manufacturing operations and the temperatures involved
have an important effect on both the identity and quantity of
hydrocarbons emitted. Note that vulcanization, the primary
source of volatile organics in the process described above, is
not required for the production of thermoplastic insulation
made from polysulfide rubbers. Hence, such production poses
no pollution problem.
9. PROCESS DESCRIPTION AND ATMOSPHERIC EMISSIONS FROM TIRE
RETREADING
This industry includes establishments primarily engaged
in repairing and retreading automotive tires. Establishments
classified here may either retread customers' tires or retread
tires for sale or exchange to the user or the trade.9
374
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Table C-8. EMISSIONS AND CONTROL - NONFERROUS WIREDRAWING AND INSULATING
Emission
source
Extrusion
Curing
Uncontrolled
emissions,
g/kg
0.04
0.6
Best control
technique
Process change
Incineration
Control
efficiency
80%
60%
NSPS
emissions,
g/kg
0.008
0.24
Average
uncontrolled
emission rate,
Ib/day
0.9
0.14
Permissible
emission rate,
Ib/day
15
15
Emission
reduction
required
0
0
Regulated
emissions,
g/kg
0.03
0.6
U)
^4
cn
TOTAL:
0.64
E = 0.25
n
0.64
-------
A brief discussion of the retreading of tires is presented
below to famaliarize the inspector with the basic process
operations. Atmospheric emissions from this industry are
discussed in Section 9.2.
9 .1 Process Description
The tire retreading process consists of a series of eight
unit operations through which worn tires are rendered service-
able and fit for resale. With the exception of studded snow
tires, nearly every tire size and design is utilized by the
industry- The majority of retreaders receive their tires from
scrap dealers, but turn-ins are also a popular source of supply.
Raw camelback is nearly always purchased from an outside
supplier. Very few retreaders compound their own stock.
9.1.1 Receiving and Sorting - On arrival, the tires are first
inspected to determine whether or not the casing and carcass
are in good condition. There should be no cuts or visible
deterioration of the reinforcing fabric. Hidden ply separa-
tions, the major cause of tire failure, are detected by inject-
ing air into the tire shoulders. Since trapped air itself may
cause ply separation, the tire is vented in the bead area so
the air can escape during molding or on highway flexing.
Tires unfit for retreading are usually passed on to the
reclaiming industry„
9.1.2 Buffing - After sorting, the tires are sent to the buf-
fing area where the remaining tread is ground off with a grind-
ing wheel. This process generates rather large quantities of
376
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rubber particulates. Very few plants control these emissions,
but low-efficiency gravity collectors, low-temperature fabric
filters, and medium-efficiency centrifugal collectors are known
to be operating at some facilities.
9.1.3 Cleaning - The surface of each newly buffed tire is
rendered dust free with a stiff wire brush. This generates the
same type of particulate emissions as the buffing process, and
the same types of control are used.
9.1.4 Measuring - The clean tire is measured in order to
select the correct curing rim and to assure a tight fit in the
matrix. Tires can grow up to seven percent of their original
width from road use, so both the width and wall thickness must
be measured.11
9.1.5 Rubber Cement Spraying - Once measured, the tires are
taken to the spray area where they are coated with vulcanizable
rubber cement. Hydrocarbon emissions from this operation have
been reported, but are apparently not controlled.
9.1.6 Tread Winding - When the surface of the tire is coated
with cement, strips of tread rubber are wound circumferentially
around it and cut to length.
Some retreaders "program" the tread on. In this opera-
tion, the machinist selects a profile to build and the machine
automatically wraps the thin strand of tread until the exact
contour is obtained. The tread winding process typically
requires about 10 pounds of camelback per passenger-car tire
and 35 pounds per truck tire.29
377
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9.1.7 Curing - Each tire goes into a mold for curing at some
specified temperature for some predetermined length of time.
Most curing molds are steam heated, but some older ones are
electrical.
It is likely that the curing process releases some volatile
organics from the raw tread to the atmosphere.
9.1.8 Finish Buffing - After curing, the rubber flash is buffed
off and the finished product is inspected and shipped.
This buffing operation should generate the same emissions
and require the same control equipment as the other buffing
operations previously discussed. A flow schematic is shown
in Figure C-15.
9.2 Atmospheric Emissions
Emissions from tire retreading are presented in Table
C-9. It is not possible, at this time, to identify hydro-
carbon species contained in these emissions.
10. HYDROCARBON SAMPLING AND ANALYSIS PROCEDURES
The inspector is referred to the sampling and analysis
procedures outlined in the IERL-RTP Procedures Manual; Level 1,
Environmental Assessment.63 The manual presents all necessary
information for sampling and analysis of hydrocarbons.
63Hamersma, J. W., S. L. Reynolds, and R. F. Maddalone. IERL-
RTP Procedures Manual: Level 1, Environmental Assessment.
U.S. Environmental Protection Agency. Research Triangle Park,
North Carolina. EPA-600/2-76-160a. June 1976. 131 p.
378
-------
RECEIVING
AND SORTING
BUFFING
CLEANING
MEASURING
RUBBER
CEMENT
SPRAYING
CURING
TREAD
RUBBER
TREAD
WINDING
BUFFING
INSPECTION \
^VOLATILE ORGANICS VAND SHIPPING/
Figure C-15. Schematic flow diagram for production of
insulated wire and cable using thermoplastic
polymers (i.e., polysulfide rubbers).
379
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Table C-9. EMISSIONS AND CONTROL - TIRE RETREADING
Emission source
Cement spraying
Curing
Painting and
trimming
Uncontrolled
emissions,
g/kg
2.75
0.09
3.2
Best control
technique
Incineration
Ventilation and
incineration
Process change
(detergent
wash)
Control
efficiency
90%
60%
90%
NSPS
emissions ,
g/kg
0.275
0.04
0.32
Average
uncontrolled
emission rate,
Ib/day
7.2
0.2
8.3
Permissible
emission rate,
Ib/day
40
15
40
Emission
reduction
required
0
0
0
Regulated
emissions,
g/kg
2.75
0.09
3.2
co
00
o
TOTAL:
E =6.04
u
E = 0.635
n
E = 6.04
-------
In visiting a specific plant, the inspector should be
aware of the types of sampling that will be required. These
requirements will vary considerably from one emission point to
another. This variation in sampling requirements is identified
by emission point in the following discussion.
In testing the compounding operation, the inspector will
be able to source test due to the existence of a vent or stack
on the process. Particulate control equipment will probably
already be installed. Sampling should be done both before and
after the particulate control equipment in order to evaluate
whether this control is also acting to reduce the hydrocarbon
emissions.
For milling operations, the inspector will see both hooded
and unhooded mills. There will be some question of whether the
hood is 100 percent efficient in collection and whether any
concentrations measured are from the mill alone or from a com-
bination of mill emission concentrations and plant ambient
concentrations. Sampling based both on mass balance and source
testing is recommended.
Extrusion operations will not be hooded; thus, mass bal-
ance measurements will have to be made to verify emissions
from this source.
Calendering operations also are not hooded and will require
mass balance measurements.
Molding operations have been observed to be hooded in
some plants and source testing will be possible in these cases.
381
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Again, the inspector is advised to run mass balances on these
operations because the question of 100 percent efficiency of
the collection device will potentially arise.
Cementing activities not carried out in a ventilation
enclosure also will need to be sampled using mass balance.
Solvent usage for each operation should be noted. Cementing
activities carried out in a booth can be source tested. Resi-
dence time of the material being sprayed should be increased
for the purposes of source testing to assure that all evapora-
tion of the solvent is occurring in the booth. Fabric cementing
operations will be vented when an oven is included and source
testing will therefore be possible. Where air drying is
involved, mass balance measurements will be necessary.
Curing operations for tires and some belting will be
unhooded, thus requiring mass balance measurements. In the
case of batch curing, the operation will be vented, making
source testing possible.
In rubber reclaiming, the devulcanization operation is
vented, usually with an absorber or scrubber already installed.
Again, source testing both before and after scrubbing should
be done.
A checklist, applicable to most operations to be source
tested, is provided below.
CHECKLIST
1. Operation that produces emissions
2. Emission point
382
-------
Stack, vent, other
Height
Diameter
Direction of Discharge
Exit gas
Batch or continuous
Batches/day
Minutes/batch
scfm (70°F/atm)
Velocity
Temperature
Pressure
Specific gravity
Raw materials
Type of materials
Amount of each used per minute
Total weight of materials to
process per minute
Total weight of materials from
process as product per minute
Total weight of materials from
process as waste per minute
Amount into process - Amount out of process as product
- Amount out of process as waste
= potential mass as pollutant
11. HYDROCARBON EMISSION CONTROL METHODS
11.1 Incineration
Incineration is a well-developed technique used to control
organic emissions by oxidation of the combustible portion of
waste gases, with water and carbon dioxide as the desired
ultimate product of combustion.
383
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Streams containing low concentrations of organic vapors
lack sufficient fuel value to attain stable, self-sustaining
combustion temperatures. Such streams are supplied with a
secondary fuel source, usually natural gas, and then burned in
a device called a direct-flame afterburner. Two types of
equipment are used to burn waste gases whose heating values
are such that additional fuel is not required. The device is
called a flare if there is no air premixing or an incinerator
if the waste gases are premixed with air before combustion.
11.1.1 Afterburners -
Direct-flame - Direct-flame afterburners rely on intimate
contact of waste gases with a flame to accomplish oxidation of
organic emissions. Complete combustion (>90 percent) of most
hydrocarbon species to C02 and water can be achieved at about
650°C to 760°C (1,200°F to 1,400°F). Removal efficiencies can
be as high as 95 percent. Burning time varies with types of
effluent and specific technique of incineration from 0.3 second
to 0.6 second.
For most hydrocarbons, the lower explosive limit (LEL)
corresponds to a heating value of approximately 52 Btu/scf.
For reasons of safety, however, waste gas streams are usually
diluted to 25 percent or less of the LEL concentration before
addition of the secondary fuel and combustion.
Proper design and performance of direct-flame afterburners
depends upon knowledge of the types of organic species in the
gaseous emissions. As with any incineration process, the degree
384
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of completion of oxidation is an important consideration here.
Even when direct-flame incineration gives 98 percent or 99 per-
cent complete combustion, the result may be intermediate oxi-
dation products more noxious than the original waste gases. A
further drawback is that attempts to increase the efficiency of
combustion of hydrocarbons result in more favorable conditions
for the formation of nitrogen oxides.
Finally, it is unwise to control organic vapors containing
halogens or sulfur by incineration alone. Secondary purifica-
tion, such as by liquid scrubbing, may be required to remove
inorganic contaminants from the gas stream to be vented to the
atmosphere.
Catalytic - Catalytic oxidation is most often applied for
control or elimination of organic emissions when recovery of
the materials present is not desired or economical. Therefore,
catalytic afterburners are used when the concentrations of con-
taminants in waste streams are very low. The advantage of
catalytic over direct-flame incineration is that dilute emis-
sions can be oxidized using only small amounts of supplemental
fuel and at much lower operating temperatures [340°C to 680°C
(650°F to 1,250°F)]. A disadvantage is that the efficiencies
of catalytic afterburners are usually somewhat lower than those
of direct-flame units.
A significant advance in catalytic incineration has been
the recent development of improved catalyst support systems,
namely honeycomb ceramics. Even so, knowledge of the types
385
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and concentrations of materials in the waste stream being incin-
erated is required to select and design a properly performing
catalytic system. It is known that emissions containing sulfur,
halogens, silicon, or heavy metals will poison the platinum-
and palladium-type catalysts normally used. Particulates also
interfere with the function of catalytic afterburners. If any
of these catalyst poisons are present in the waste gas stream,
the use of a direct-flame afterburner is preferred.
11.1.2 Flares - A flare is a device for burning waste gases
whose heating value is such that a secondary fuel source is
not needed. In an elevated flare, smokeless combustion is
achieved by the injection of an inert gas, often steam, into
the combustion zone to promote turbulence and to supply air.
However, the desired smokeless combustion may be accompanied
by an intolerable increase in unburned hydrocarbon emissions
due to the reduced flame temperature.
Incineration can be justified as an economical emission
control process when a combustible solvent cannot be recovered
in either a sufficient quantity or an uncontaminated condition
for reuse in production. The presence of catalyst poisons -
sulfur, particulates, halogens - or hydrocarbons that are dif-
ficult to oxidize catalytically suggests a preference for
direct-flame incineration. Even so, secondary purification,
such as by liquid scrubbing, may be necessary for the removal
of inorganic contaminants.
386
-------
The concentration of organic species in the waste gas
stream is the most important factor influencing control pro-
cess economics in the case of incineration. A direct-flame
system is more economical at concentrations above 13 percent
to 18 percent LEL; catalytic incineration is preferred at
organic contaminant levels below this range.
11.2 Adsorption
During the adsorption process, organic vapors are col-
lected on the internal surfaces of a solid, usually activated
carbon.
Carbon adsorption for solvent recovery is a standard
operation, particularly where the vapor concentration is
relatively high (>500 ppm). "Packaged" systems are available
from several commercial sources. The main advantage that
activated carbon has over the adsorbents is its ability to
strongly but reversibly adsorb a wide variety of hydrocarbons,
even in the presence of water vapor.
Adsorption is an efficient control technique generally
applied when recovery of the adsorbed material, particularly
solvents, is economically desirable. However, the method has
also seen use in control of very low concentrations of noxious
organics not readily handled by catalytic incineration. Pre-
liminary studies have been made to evaluate adsorption as a
means of collecting and concentrating dilute hydrocarbon emis-
sions from subsequent disposal by incineration.
387
-------
Adsorption does have some drawbacks. Particulates in a
waste gas stream may plug and damage the carbon bed. This may
be avoided by filtering or scrubbing the gases prior to adsorp-
tion. If the gas to be treated contains several organic com-
pounds, adsorption of the various species will not be uniform.
Generally, compounds are adsorbed in an approximate inverse
relation to their volatilities. Finally, if a system is to
operate continuously, it must include two or more adsorbent
beds. One can be used normally for adsorbing organics while
the other is being regenerated for further use. Cycle time
between steam regenerations is in fact a critical design
variable.
Activated carbon adsorption with solvent recovery should
be used for emission control where the recovered solvent is
free enough, or can feasibly be made free enough, of contaminants
for reuse in the production process. Under such circumstances,
there is not a more economical control system.
Adsorption with incineration cannot be justified on an
economic basis under any conditions which permit normal incin-
erator operations. Adsorption-incineration without heat recovery
does appear to be attractive for disposal of dilute emissions
(vapor concentration <500 ppm) that cannot be controlled by
catalytic incineration (i.e., that contain catalyst poisons).
11.3 Absorption
Absorption involves the transfer of a soluble component
of a gas mixture into a relatively nonvolatile liquid. In
388
-------
waste gas purification, the most commonly used absorbents are
water and mineral oil.
Though usually classified as production equipment, not
emission control devices, absorbers are used, profitably, when
solvent vapor concentrations are high. Low concentrations
require long contact time and large quantities of absorbent.
Both of these requirements increase costs unless the absorbent
can be regenerated or the solution can be used as a process
makeup stream.
Packed and spray towers are preferred to bubble-plate
columns because the former produce lower pressure losses.
Spray towers have the advantage of being able to handle waste
gas streams containing particulates without plugging; however,
they are the least effective method of absorption per se.
In emission control applications, absorption is best
used with other techniques, such as incineration or adsorption.
11.4 Condensation
Condensation is a means for the collection and control of
organic emissions by lowering the temperature of a waste gas
stream. The approach is most feasible for hot vapors that
would be liquid at ambient conditions.
During condensation, the partial pressure of the material
remaining in the gas phase decreases rapidly, and complete
removal is not possible by this method alone. Condensers must
usually be followed by another pollution control device, such
as an afterburner. For this reason, incineration and adsorption
389
-------
are both preferred to condensation for control of volatile
organic emissions.
Condensers have found application in the organic chemical
industry for the purpose of collecting concentrated vapors in
the primary process rather than for the reduction of losses to
the atmosphere.
11.5 Process or Equipment Modification
11.5.1 Solvent Reformulation and Substitution - Since the
advent of legislative codes concerning organic solvents, refor-
mulation has been a widely practiced and accepted method of
controlling solvent emissions. Higher homologs in any organic
series will have lower vapor pressures, and their use may not
require process or equipment modification.
In the case of vapor degreasing of metal surfaces, inves-
tigation of alternative organic solvents resulted in the selec-
tion of inhibited 1,1,1-trichloroethane as a satisfactory
replacement for trichloroethylene.
11.5.2 Storage Tank Controls - Storage and transfer of volatile
organics have been identified as a significant source of atmo-
spheric emissions. The most widely used device for the reduc-
tion of emissions from storage is the floating-roof tank. This
includes an impermeable cover which floats on the stored liquid
and provides a seal between the floating roof and the tank wall
to prevent evaporation.
390
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APPENDIX D
PARTIAL LISTING OF RAW MATERIALS USED IN THE RUBBER INDUSTRY
1. VULCANIZATION MATERIALS
Accelerators
Aldehyde-amine condensation products, butyraldehyde-
aniline condensation products, dithiocarbamates,
tetramethylthiuram disulfide, benzothiazole sulfen-
amides, benzothiazoles, hexamethylene tetramine,
furfurylamines, thioureas
Activators
Fatty acids, lead-free zinc oxide, magnesium oxide
Retarders
Phthalic anhydride, n-nitroso diphenylamine
Vulcanizing and curing agents
Phenol-formaldehyde resins, elemental sulfur,
magnesium oxide
2. PROTECTIVE MATERIALS
Antioxidants, antiozonants, and inhibitors
Naphthylamines, phenylamines, cresols, phenylene
diamines
391
-------
Chemical and heat stabilizers
Barium-cadmium organics, organotin chemicals, barium-
zinc organics, lead organics
3. PROCESSING MATERIALS
Plasticizers and softeners
Fatty acids, dialkyl phthalates, chlorinated paraffins
coal tar oil, petroleum oils, castor oil, polyesters,
stearates
Peptizers
Thioxylenols, zinc thiophenate
Processing aids and dispersing agents
Paraffins, acidaffins, nitrogen basis in combination
Tackifiers
Phenolic resins, phenol-formaldehyde resins
4. EXTENDERS, FILLERS AND REINFORCING MATERIALS
Carbon black, channel type
Carbon black, furnace types
Carbon black, thermal furnace types
Nonblack materials
Aluminum silicate, magnesium silicate, calcium
carbonate, hard clay, barium sulfate, calcium sulfate,
vulcanized vegetable oil
5. COLORING MATERIALS
Inorganic colors
Black, blue, brown, grey, green, orange, red, silver,
violet, white, yellow
392
-------
Organic colors
Black, blue, brown, orange, green, red, violet, white,
yellow
Colors, multiple types
6. SURFACE MATERIALS
Dusting, dying, and washing materials
Aluminum, magnesium, and calcium silicates
Finishes
Synthetic waxes, paraffin waxes
Lubricants (mold and internal)
Fatty acids, sodium alkyl sulfates, low molecular-
weight polyethylene
7. AUXILIARY MATERIALS
Adhesives and bonding agents
Phenol-formaldehyde resins
Blowing agents and blow promoters
Urea, ammonium carbamate, azodicarbonamide, sodium
bicarbonate, sodium carbonate,. N,N-dinitroso
pentamethylene tetramine
Odorants and anti-staining agents
Activated carbon, aromatic compounds
Polymerization materials
40% sodium dimethyl dithiocarbamatei alkanolamide|
sodium alkyl sulfonates; benzoyl peroxide;
1,4-butanediol, anhydrous; benzoyl peroxide, plain or
in solution with silicone oils or various phthalates
and phosphates; solution of cobalt 2-ethylhexoate in
393
-------
benzene, 12% metal; mixture of long-chain mercaptans,
primarily dodecyl mercaptan (DDM); di-tertiary butyl
peroxide, 97 wt %, min.; lauryl mercaptan; 1,4-bis
(2-hydroxylpropyl)2-methylpiperazine; organic acid;
electrically-neutral fatty acid condensation product;
diethyl zinc; free acids of complex organic phosphate
esters; methyl dodecyl benzyl trimethyl and methyl
dodecyl xylene bis trimethyl ammonium chloride;
hydrogenated animal fatty acid; hydrogenated tallow
fatty acid; hydroquinone-di(b-hydroxyethyl) ether;
partial anhydrous soap of a disproportionated dis-
tilled tall oil having a ratio of 1:1 rosin-fatty
acids; partial potassium soap of disproportionated
distilled tall oil; liquid potassium soap of a
modified rosin; disproportionated rosin; chemically
modified fatty acid derived from tall oil; lauryl
mercaptan; tertiary dodecyl mercaptan; t-dodecyl
mercaptan; 60:20:20 weight % mixture based on
mercaptan content of C\2i Cm, and Cjg tertiary
mercaptan; 97% cupric acid, 2% lauric acid, 1%
caprylic acid; 92.5% palmitic acid, 5% stearic acid,
1% myristic acid, 1% margaric acid, 0.5% pentadecylic
acid; hydrogenated tallow soap chips (potassium);
sodium ferric ethylenediaminetetracetate; 40% sodium
dimethyldithiocarbamate; 50% potassium dimethyldithio-
carbamate; hydrogenated tallow soap chips (sodium);
394
-------
sodium alkyl naphthalene sulfonate; tertiary dodecyl
mercaptan; ethylene oxide adduct of castor oil;
sodium salts of a condensed naphthalene sulfonic acid;
50% aqueous solution of potassium dimethyl
dithiocarbamate; 40% aqueous solution of sodium
dimethyl dithiocarbamate; alkyl aryl polyethers;
amine polyglycol condensate; modified polyethoxy
adduct; sodium alkylaryl polyether sulfate; dioxtyl
sodium sulfosuccinate; alkylaryl polyether alcohols;
alkyl polyether alcohols; sodium alkylaryl polyether
sulfonates; stearyldimethyl benzyl ammonium chloride;
disproportionated resin; sodium dimethyl
dithiocarbamate
Solvents
Acetone; dipentene, ^70%; other terpene HCs, -x/26%;
terpene alcohols, ^4%; moisture, 0.05%; mixture of
terpene HCs; toluene; xylol; cyclohexane; petroleum
naphtha; petroleum naphthas, with aromatic content
from 46% to 86%; amyl acetate; commercial benzene;
normal butyl acetate; secondary butyl acetate; normal
butyl alcohol; secondary butyl alcohol; butyl ether;
butyrolactone; secondary octyl alcohol; aromatic
solvent; cyclohexanol; cyclohexanone; dichloroethyl
ether; dimethyl ketone, 99.5% wt, min.; aliphatic
solvent; ethyl acetate; ethyl alcohol; ethylene
dichloride; ethylene glycol monobutyl ether (butyl
395
-------
"cellosolve"); ethylene glycol monobutyl ether;
normal heptane; hexane; isobutyl acetate; isobutyl
alcohol; essentially 100% isoparaffinic; isopropyl
acetate, normal; methyl chloride; methyl ethyl
ketone; methyl isobutyl ketone, 99% wt, min. ;
methylene chloride, sometimes with stabilizer added;
methyl isoamyl ketone; monochlorobenzene; aliphatic
petroleum naphtha; perchloroethylene; propylene
dichloride; 2-pyrrolidone; aliphatic naphtha; ali-
phatic petroleum solvent; aromatic organic solvent;
proprietary ethyl alcohol; tetrachloroethylene
(perchloroethylene), sometimes with added stabilizer;
tetrahydrofuran cyclic ether stabilized with 0.025%
butylated hydroxytoluene (BHT); tetrahydronaphtha-
lene; industrial toluene; trichloroethylene; gum or
wood turpentine; petroleum fractions; industrial
xylene
396
-------
APPENDIX E
MODEL IV COMPUTER PROGRAM
A printout of the Model IV computer program starts on the next
page.
397
-------
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
DATE TODAY: 1/25/77
PROGRAMMER AT MRC: K. FLAYLER
REQUESTOR: T. HUGHES
MODEL IV COMPUTER PROGRAM
CHARGE NUMBER 13-022-760-13
200-3117
PROGRAM ORIGINATED AT TRC
THE RESEARCH CORPORATION OF MEW
ENGLAND, AUTHOR: THOMAS HOPPER
DATED at OCTOBER 1975
HOPPER IS NOW WITH EPA BOSTON
PHONE: 617 223-5610
TITLE OF REPORT:
IMPACT OF NEW SOURCE PER-
FORMANCE STANDARDS ON 1985
NATIONAL EMISSIONS FROM
STATIONARY SOURCES VOLUME I
FINAL REPORT...MAIN TEXT AND
APPENDICES I THRU III
TRC PROJ NO: 32391
PHONE AT TRC: 203 56
PROGRAM MODIFIED 1/28/77
INTEGER L,S,CR
DIMENSION IRPB(200),IRPC(200) ,
1ITD(200),IPLTNT(10,15),PK(200) ,
2ES(200),EN(200),EU(200),PB(200),A(200),PC(200),B(200),
3c(200),TU(200),TA(200),TS(200),TN(200),TD(200),IEUNIT(10,200),
"+IIUNIT(10,200),ISOURC(20,200),15(200),16(200),I ALFA(5,8),
5IBETA<<*,8)
DATA L,S/1H6,1HS/
DATA IALFA /'GM•,•/K','G «,' '.« ',
2 'GM','/P','AI',«R ' , ' ' ,
3 'GM«,'/T'.'IR»,«E ' , • ' ,
DATA IBETA
•G/' , n
/ • ',
'PA',
•TI',
'US' ,
•E6'.
'E9',
(G1 ,
'
IR'
RE'
ED'
*
G'
U«
'
«S
'S
,
,
•M
, <
,
,
.
,
5E'
'D
/
2
3
t
5
6
CR = 1
LP = 5
K = l
READ IN THE NUMBER OF POLLUTANTS
READ(CR,99) Kl
REAC IN THE TABLE NUMBER AND THE
NUMBER OF SOURCES OF EACH POLLUTANT
50 READ(CRi100) 11,12
READ IN POLLUTANT NAME
398
-------
MEAD(CR,101)
GO TO 81
80 B(I)=10.*A(I)*PB(I)
81 IF(IRPC(I).EQ.S) GO TO 82
C(I) = ( (1.0+PCd) )**10-1.0)*A(I)
GO TO 83
82 C(I)=10.*A(I)*PC(I)
C
C CALCULATE TOTAL EMISSIONS IN
C TONS/YEAR
C
83 TU=10*ITD(I)
GO TO 91
88 ITD(I)=TO(I)/100+0.5
TDd)=ITD(I)
TD(D=100.*TD(I)
GO TO 91
399
-------
89 ITD(I)=TU(I)/1000+0.5
TDI)iJ=l»20)
IF(PK(I).EQ.0.0) 60 TO 330
IF(A(I).SE.1000..OR.B(I).GE.1000..OR.C(I).GE.1000, ) 60 TO 305
GO TO 304
305 A(I)=Ad)/1.0E6
B(I)=B(I)/1.0E6
C(I)=C(I)/1.0E6
TD(I)=TD(T)/1.0E3
304 WRITE(LP.306) PK(I ) , ( lEUNlT(J.I)«J = lt5) i
lES(I)«EN(I),EU(I),PB(I)»IRPB(I),PC(I)tIRPC(I)«
2( IIUNITJ Jtl) . J=l.f) . Ad) tB(I) «C(I)
3TD(I)
DO "+00 J = l,<+
tOO IIUNIT(J,I)=IBETA(J,I5(I))
WRITE(LP,310)
-------
100 FORMATJ2I5)
101 FORMAT(10A2)
102 FORMAT(20A2)
103 FORMAT(F7.0,l3,4F10.0,Al«FlO.O,Al«I3«Ell,0)
300 FORMAT* lril//35Xi'MODEL IV PRIORIHZATION OF RUBBER INDUSTRIES'//
21X,'POLLUTANT/SOURCE, '.10A2//30X»'EMISSION RATES'.SX,
*•GROWTH RATES•«t8X,'EMISSIONS'/lX,«INDUSTRY',5X»»EMISSION'.7X,
5'ALLOW ABLE UNCOIMT•,2Xt'DECIMAL/YEAR'»2Xi'INDUSTRY't7X,'CAPACITY'
1.20X»'1.0E9 GRAINS/YEAR' >
301 FORMAT(3X»'K' »HXi 'UNITS't8X«'E« . 7X. «E' ^X« 'E' i 5X • »P' »6X i
1«P'.7X«'UNITS'»5X»'A'.5X.'B'i5X,'C'«1(7X,'T'),6X.'T -T'/
229Xt'S'.7X.MM',7X«'U'»5Xi'B'.6X,'C'i37X'U'i7X.'A'i7X,'S1«7Xt•N'»
36X,'S N'/lX,131('-'»
303 FORMAT(/1X»20A2)
306 FORMAT(1X.F5.2.7X«5A2t3F8.2»2(F6.3.Al«IX)«3X»«VA2»3F6.
!
-------
APPENDIX F
CALCULATION OF EMISSION FACTORS FOR RUBBER
VOLATILIZATION EMISSION SOURCES
Throughout the rubber industry, operations are performed
that convert rubber directly into usable end products or into
a physical state where it can then be processed into saleable
end products.
In the process of this converison, heat is added to the
rubber stock and thus permits certain organics contained in
the rubber to volatilize. The amount of rubber volatiles formed
is the question of considerable debate at the present time as
(1) little source testing of these emission sources has been
done, (2) the chemical composition of rubber used in the indus-
try varies considerably.
During this study, actual source testing data were not
found to allow an accurate calculation of emission factors.
The only available literature information consists of the
Rappaport23 thesis and some unpublished research on curing
emissions supplied by one company. The Rappaport thesis re-
ports on emission tests run on industry supplied rubber stock.
From this research, Rappaport's data allows for a postulated
temperature - percent weight loss equation, which is
402
-------
C = 0.00212T - 0.15328
where C = amount of hydrocarbon lost,
% weight fraction of rubber
T = curing temperature, °C
Solving for zero weight loss, the critical temperature is
72.3°C. Thus, any operation generating more than 72°C can,
according to Rappaport, produce hydrocarbon emissions.
The following operations can thus potentially generate
hydrocarbons:
• Compounding
• Milling
• Calendering
• Extrusion
• Molding
• Curing
Since insufficient data are available, emission factors
for these operations were estimated as follows.
The highest temperatures generated are in curing. Rappaport
calculated emission factors for tire curing in the 160°C to
200°C range that averaged 2.23 g/kg of rubber stock. Unpub-
lished research by one tire company reports that Rappaport's
estimate failed to account for water loss, and based on their
data, 90% of the reported weight loss can be attributed to
water loss. Using this figure, the curing emission factor was
estimated to be 0.223 g/kg of rubber stock. This estimate is
used in the report.
403
-------
An additional calculation can be made based on concentra-
tion of species found by Rappaport. Such species and their
concentration are shown in Table F-l. The TLV for toluene is
375 mg/m3. Cost calculations presented in this report use a
flow rate of 20,000 cu ft/min for curing and an average tire
production of 7,320 tires/day.
Table F-l. MATERIALS EMITTED DURING RUBBER VULCANIZATION23
Material emitted
Toluene
4-Vinyl-l-cyclohexene
Ethyl benzene
m-Xylene
p-Xylene
Styrene
t-Butylisothiocyanate
1, 5-Cyclooctadiene
Benzothiazole
N-sec-butylaniline
1, 5,9-Cyclododecatriene
Methyl naphthalenes
Butadiene trimer
Ethyl naphthalene
Dimethyl naphthalene
Diphenyl guanidine
Source in rubber stock
Polybutadiene rubber
Polybutadiene rubber
Aromatic oil extender
Aromatic oil extender
Aromatic oil extender
Styrene-butadiene rubber
Polybutadiene rubber
Accelerator
Antiozonant
Polybutadiene rubber
Aromatic oil extender
Polybutadiene rubber
Aromatic oil extender
Aromatic oil extender
Accelerator
Relative
cone. ,a'b
ppm by
volume
1.120
0.071
0.078
(0.035)
(0.035)
0.084
(0.090)
0.0063
(0.080)
(0.030)
0.0158
(0.090)
(0.015)
0.010)
0.010
(0.100)
TLV
ppm
100
NA
100
100
100
100
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cone.
TLV
0.01
—
0.0008
0.0004
0.0004
0.0008
—
—
—
—
—
—
—
—
—
—
a
Relative concentrations were obtained by sampling the atmosphere within
the curing room. The values reported indicate concentrations of the
individual compounds within the curing room.
b
Parentheses around data indicate estimates of concentrations made by
Monsanto Research Corporation from Rappaport's published raw data.
404
-------
To find the flow rate per tire, assume that an average
tire weighs 10.9 kg of which 65% is rubber stock.
Flow rate/tire = 20'°0° ft3/min 1,440 min 2.83 x 10~2 M3
7,320 tires/day 1 day x ft3
1 tire
x
g k x 0.65 = M3/kg of rubber stock
= 6.64 M3/kg rubber stock
Assuming the concentration of toluene is at the TLV:
Emission factor = (.375 g/M3)(6.64 M3/kg) = 2.49 g/kg of rubber
stock.
In addition, using Rappaport's observed concentration
(.01 TLV), the emission factor can be estimated
(.01) (.375) (6.64) = .025 g/kg of rubber
Therefore, a curing emission factor can be calculated theoret-
ically to range from .025 to 2.5 g/kg. This report lists the
factor as .22 g/kg of stock.
For the other sources, since no emission data are avail-
able, the emission factors are assumed to vary in proportion
to their temperature, using the curing emission factor as a
basis.
For compounding, the operating temperature is assumed to
be 100°C. The temperature basis for the curing emission factor
is 180°C. In addition, due to carbon black particulate, 20% of
the generated emission is assumed to be adsorbed on the carbon
black and thus becomes organic particulate. Therefore, the
emission factor for compounding is:
405
-------
(0.8) (100/180) (.223) = .099 = 0.1 g/kg of rubber stock
For milling, an operating temperature of 80°C is assumed.
Assuming that 50% of the emissions condense immediately upon
formation due to their temperature being close to the critical
temperature of 72.3°C, the milling emission factor is
(0.5) (80/200) (.223) = .05 g/kg of stock
Extrusion and calendering are assumed to have the same
operating temperatures as milling (80°C) and to also have 50%
condensation immediately upon formation. Thus the emission
factors are also .05 g/kg of rubber stock. For some extrusion
operations other than tire manufacture, the temperatures are
less than 80°C and their emission factors are lower than for
tires.
Molding emissions are assumed to be identical to curing
emissions (same temperature) and the emission factor assumed
equal to that of press curing.
Other curing processes (batch, continuous) assume differ-
ent percent condensibles based on temperature and physical
operation and are both lower than for press curing. These
estimates are shown in the appropriate emission sections for
batch and continuous curing.
As is evident from these estimates, source testing data
is required to prove or improve the values given in this
report.
406
-------
APPENDIX G
AVERAGE PLANT SIZE FOR EACH INDUSTRY
For the purpose of estimating the cost of control for each
volatile organic emitting source in each industry, an average
plant size was defined for each industry to provide the basis
for cost calculations. This average plant size was used to
derive the rate of exhaust gas flow to be treated. It was also
used to calculate the concentration of volatile organics in the
gas stream by material balance using the appropriate emission
factor.
For SIC's 2822, 3021, 3031, 3041, and 3357, the annual
production for average plants was obtained by dividing the
1975 total national production by the total number of plants.
For SIC's 3011, 3069, and 3293, about 50% of total plants are
small ones producing less than 5% of goods in the respective
industries. These small plants have less than 50 employes in
SIC 3011 and less than 20 employes in SIC's 3069 and 3293.
For SIC 7534 (tire retreading), owing to lack of data on the
total number of plants and the plant size distribution, an
annual production of 450 metric tons of product/yr was assumed
for the average plant. The annual production for average
plants is summarized in Table G-l.
407
-------
Table G-l. AVERAGE PLANT SIZE FOR EACH INDUSTRY
Annual production,
Industry metric tons/yr
Synthetic rubber
(SIC 2822) 120,000
Tires and inner tubes
(SIC 3011) 20,000
Rubber footwear
(SIC 3021) 2,700
Rubber reclaiming
(SIC 3031) 14,000
Hose and belting
(SIC 3041) 6,500
Fabricated rubber goods
(SIC 3069) 1,700
Gaskets, packing, and sealing
devices (SIC 3293) 1,700
Wire insulating
(SIC 3357) 3,000
Tire retreading
(SIC 7534) 450
408
-------
APPENDIX H
ECONOMIC ASSUMPTIONS IN COST ESTIMATES
In the cost estimates for add-on control systems, capital
cost, annualized operating cost, and cost effectiveness
($/metric ton of organics removed) were calculated. Items in-
cluded in the capital cost and the operating cost are listed
in Tables H-l and H-2, respectively. Cost effectiveness was
obtained by dividing the annualized operating cost by the total
weight of organics removed per year from the exhaust gas by the
control device. Table H-3 gives the assumptions used in devel-
oping cost estimates for catalytic and noncatalytic incinera-
tors. The economic assumptions for carbon adsorbers are pre-
sented in Table H-4.
409
-------
Table H-l. TYPICAL ITEMS INCLUDED IN INVESTMENT COST
OF ADD-ON CONTROL SYSTEMS
Basic Collection Equipment
Auxiliary Equipment
Air movement equipment
Fans and blowers
Hoods, ducts
Electrical (motors, starters, wire conduits, switches, etc.)
Liquid movement equipment
Pumps
Electrical (motors, starters, wire conduits, switches, etc.)
Piping and valves
Settling tanks
Instrumentation for measurement and control of:
Air and/or liquid flow
Natural gas and/or fuel oil flow
Temperature and/or pressure
Operation and capacity
Power
Research and Development - this might include as stream measure-
ment, pilot plant operations, personnel costs, etc.
Installation
Labor to install
Cleaning the site
Yard and underground
Building modification
Inspection
Support construction
Protection of existing facilties
Supervising and engineering
Startups
Storage and Disposal Equipment
Contingencies
Sales Tax
410
-------
Table H-2. TYPICAL ITEMS INCLUDED IN ANNUAL COSTS
OF ADD-ON CONTROL SYSTEMS
Capital Charges
Operating Costs
Utilities needed to operate the control equipment
Materials consumed (such as fuel) in operating the
control system
Waste disposal operations
Overhead
Property taxes
Insurance
Maintenance Costs
Replacement of parts and equipment
Supervision and engineering
Repairs
Lubrication
Surface protection (such as cleaning and painting)
Offsetting Cost Benefits from Operating Control System
(such as recovery of valuable byproduct)
411
-------
Table H-3. ASSUMPTIONS USED IN DEVELOPING COST ESTIMATES FOR
CATALYTIC AND NONCATALYTIC INCINERATORS
Noncatalytic incinerators designed for both oil and natural gas
operation
Catalytic incinerators designed for natural gas and propane
operation
Catalytic incinerators capable of .80CTF operation below 6% LEL;
1200°F design capability for operation from 6% to 25% LEL
3-year catalyst life
Costs based on outdoor location
Rooftop installation requiring structural steel
Fuel cost of $1.50 million Btu (gross). Correction factors are
provided to determine operating costs at higher fuel prices.
Electricity at $0.03 kw-hr
Depreciation and interest was taken as 16% of captial invest-
ment. Annual maintenance was assumed to be 5% of captial cost,
taxes and insurance, 2%, and building overhead, 2%.
Direct labor assessed at 0.5 hr/shift x 730 shifts/yr x $8.00/hr =
$2,920/yr direct labor expense.
Operating time: 2 shifts/day x 8 hr/shift x 365 days/yr =
5,840 hr/yr. Correction factors are provided to determine
annual cost at different operation times.
The noncatalytic incinerator utilized was based on:
• 1500°F capability
• 0.5 s residence time
• Nozzle mix burner capable of No. 2 thru No. 6 oil firing
• Forced mixing of the burner products of combustion using a
slotted cylinder mixing arrangement. This cylinder allows
the burner flame to establish itself before radial entry
of the effluent thru slots in the far end of the cylinder.
• A portion of the effluent to be incinerated is ducted to
the burner to serve as combustion air. This allows the
burner to act as a raw gas burner, thus saving fuel over
conventional nozzle mix burners. This design can thus be
used, however, when the 02 content of the oven exhaust is
17% by volume or above.
The catalytic afterburner was costed for two design points, 800
and 1200°F, the higher temperature design is required for LEL
levels exceeding 6%. (At 600°F into the catalyst and a 6% LEL,
the outlet temperature of the catalyst is approximately 800°F;
at a 25% LEL condition and a minimum initiation temperature of
500°F, the catalyst reaches an outlet temperature of around
1200°F.
412
-------
Table H-4. ASSUMPTIONS USED IN DEVELOPING COST
ESTIMATES FOR CARBON ADSORBERS
Exhaust gases contain benzene and hexane (50/50 wt %) mixture
in air.
Fuel costs of $1.50/million Btu
Electricity at $0.03/kw-hr
Activated carbon at $0.68/lb
Water at $0.04/thousand gallons
Steam at $2/thousand Ib
5-yr life of activated carbon
Adsorber operating at 100°F
Market value (December 1975) of benzene = $0.85/gallon
Market value (December 1975) of hexane = $0.465/gallon
Normal retrofit situation
Direct labor assessed at 0.5 hr/shift x 730 shifts/yr x $8/hour =
$2,920/yr
Annual maintenance, taxes, insurance, building overhead, depre-
ciation, and interest on borrowed money taken as 25% of capital
investment
Operating time = 5,840 hr/yr
413
-------
TECHNICAL REPORT DATA
(Please read Instruction! OH the reverse before completing)
1 REPORT NO.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Identification and Control of Hydrocarbon
Emissions from Rubber Processing Operations
6. REPORT DATE
November 23, 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S) . n _ .
T. J. Hoogheem, C. T. Chi, G. M. Rinaldi,
R. J. McCormick, and T. W. Hughes
8. PERFORMING ORGANIZATION REPORT NO.
MRC-DA-654
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corporation
Dayton Laboratory
1515 Nicholas Road
Dayton, Ohio 45407
1O. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
No. 68-02-1411, Task 17
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report provides the necessary guidance for development of
regulations to limit emissions of volatile organic compounds (VOC) of
hydrocarbons associated with rubber processing operations of nine indus-
tries: Synthetic Rubber; Tires and Inner Tubes; Rubber Footwear;
Reclaimed Rubber; Rubber Hose and Belting; Fabricated Rubber Goods, N.E.C.;
Seals, Gaskets, and Packing Devices; Wiredrawing and Insulating; and
Tire Retreading. This guidance includes control alternatives and esti-
mated costs of these alternatives.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air pollution
Synthetic rubber; tire and inner
tubes; rubber footwear; reclaimed
rubber; rubber hose and belting;
fabricated rubber goods; seals,
gaskets, and packing devices; wire-
drawing and insulating; and tire retreading
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Organic Vapors
COSATI Field/Group
8 DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
429
20 SECURITY CLASS (This pagr)
Unclassified
22. PRICE
tPA Form Z2ZO-I (»-73)
414
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