i
EPA-600/R-95-0lla
April 1996
SOLVENT-BASED TO WATERBASED ADHESIVE-COATED
SUBSTRATE RETROFIT
VOLUME I: COMPARATIVE ANALYSIS
By:
Beth W. McMinn
W. Scott Snow
Dan T. Bowman
TRC Environmental Corporation
6340 Quadrangle Drive, Suite 200
Chapel Hill, North Carolina 27514
EPA Contract No. 68-D2-0181
Work Assignment No. 2/017
EPA Project Officer: Chester A. Vogel
Air Pollution Prevention and Control Division
Research Triangle Park, North Carolina 27711
Prepared for:
U.S. Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
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TECHNICAL REPORT DATA
(Plane nod Instructions on the reverie before completini
1. REPORT NO. 2.
EPA-600/R"95-0lla
3. RE
4. TITLE AND SUBTITLE
Solvent-Based to Waterbased Adhesive-Coated
Substrate Retrofit, Volume I. Comparative Analysis
S. REPORT DATE
April 1996
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Beth W. McMinn, W. Scott Snow, and
Dan T. Bowman
B. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
TKC Environmental Corporation
100 Europa Drive, Suite 150
Chapel Hill, North Carolina 27514
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D2-0181, WA 2/017
12. SPONSORING AGENCY NAME AND AOORESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 9/94 - 10/95
14. SPONSORING AGENCY CODE
EPA/600/13
".®UP0Po^ENTA"^NOTES AFPCDprojeet officer is Chester A. Vogel, Mail Drop 61, 919/
541-2827. This series includes four volumes.
i6. abstract This volume represents the analysis of case study facilities' experience
with waterbased adhesive use and retrofit requirements. (NCTE; The coated and
laminated substrate manufacturing industry was selected as part of NRMRL's sup-
port of the 33/50 Program because of its significant air emissions of toluene and
methyl ethyl ketone (MEK), IN'RMRL-RTP reviewed the potential equipment cleaning
benefits of retrofitting equipment for the use of waterbased adhesives. During the
investigation, it became apparent that retrofitting solvent-based equipment to accept
waterbased adhesives can be very complicated.) The volume is divided into six
chapters. Chapter 2 describes the information-collection phase used to screen out
facilities most appropriate for case study visits. Chapter 3 contains the methodology
used for site visits and briefly summarizes each case study site visit. Chapter 4 de-
tails the comparative analysis results of the case study site visits in conjunction
with additional information obtained from other sources in the industry. Chapter 5
summarizes the comparative analyses described in Chapter 4. Chapter 6 describes
information obtained during the case study site visits and from other industry sour-
ces on alternative coating technologies such as hot melt and radiation-curable adhe-
sives.
17. KEY WORDS AND DOCUMENT ANALYSIS
1. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COS ATI Field/Group
Pollution
Substrates
Equipment
Cleaning
Adhesives
boatings
Pollution Control
Stationary Sources
13B
11D
14 G
13 H
11A
11C
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
1?6
20. SECURITY CLASS {This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with pro-
tecting the Nation's land, air, and water resources. Under a mandate of national
environmental laws, the Agency strives to formulate and implement actions lead-
ing to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research
program is providing data and technical support for solving environmental pro-
blems today and building a science knowledge base necessary to manage our eco-
logical resources wisely, understand how pollutants affect our health, and pre-
vent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for
investigation of technological and management approaches for reducing risks
from threats to human health and the environment. The focus of the Laboratory's
research program is on methods for the prevention and control of pollution to air,
land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites and groundwater; and prevention and
control of indoor air pollution. The goal of this research effort is to catalyze
development and implementation of innovative, cost-effective environmental
technologies; develop scientific and engineering information needed by EPA to
support regulatory and policy decisions; and provide technical support and infor-
mation transfer to ensure effective implementation of environmental regulations
and strategies.
This publication has been produced as part of the Laboratory's strategic long-
term research plan. It is published and made available by EPA's Office of Re-
search and Development to assist the user community and to link researchers
with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
EPA REVIEW NOTICE
This report has been peer and administratively reviewed by the U.S. Environmental
Protection Agency, and approved for publication. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161.
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The coated and laminated substrate manufacturing industry was selected as part of
APPCD's support of the 33/50 Program because of its significant air emissions of toluene and
methyl ethyl ketone (MEK). APPCD reviewed the potential equipment cleaning benefits of
retrofitting equipment for the use of waterbased adhesives. During the investigation, it became
apparent that the retrofitting of solvent-based equipment to accept waterbased adhesives can be
a very complicated task. This volume represents the analysis of case study facilities' experience
with waterbased adhesive use and retrofit requirements.
The volume is divided into six chapters. Chapter 2 describes the information collection
phase used to screen out facilities most appropriate for case study visits. Chapter 3 contains the
methodology used for site visits and includes a brief summary of each case study site visit.
Chapter 4 details the comparative analysis results of the case study site visits in conjunction with
additional information obtained from other sources in the industry. Chapter 5 contains a
summary of the comparative analyses described in Chapter 4. Chapter 6 describes information
obtained during the case study site visits and from other industry sources on alternative coating
technologies such as hot melt and radiation-curable adhesives.
iii
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TABLE OF CONTENTS
Chapter Page
Abstract i i i
List of Figures v"ii
List of Tables vii
List of Acronyms vi i i
Executive Summary x
Conversion Factors xi i i
1 INTRODUCTION 1-1
1.1 Project Background 1-1
1.2 Project Objectives 1-2
1.3 Report Organization 1-5
1.4 Research Methodology 1-5
1.5 References 1-6
2 INFORMATION COLLECTION 2-1
2.1 General 2-1
2.2 Screening Current Sources for Information 2-1
2.3 Industry Segmentation 2-2
2.4 General Industry Description 2-4
2.4.1 Introduction 2-4
2.4.2 Industry Structure 2-4
2.4.3 Raw Materials and Products 2-5
2.4.4 Manufacturing Process Description 2-7
2.5 Emissions and Waste Streams 2-11
2.5.1 Introduction 2-11
2.5.2 Air Emissions from Solvents 2-11
2.5.3 Liquid Wastes 2-14
2.5.4 Solid Wastes 2-15
2.6 Facility Selection 2-15
2.6.1 Introduction 2-15
2.6.2 FLEXcon Company 2-16
2.6.3 Nashua Corporation 2-16
2.7 References 2-17
3 FACILITY VISITS 3-1
3.1 Methodology for Site Visits 3-1
3.1.1 Methodology Overview 3-1
3.1.2 Facility Profile Development 3-3
3.1.3 Process Equipment and Techniques 3-3
3.1.4 End Product Lines 3-4
3.1.5 Potential Future Change in Processes/Product Lines 3-6
i v
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TABLE OF CONTENTS (Continued)
Chapter Page
3.2 General Results from the Site Visits 3-7
3.2.1 Site Summary 3-7
3.2.2 Nashua Corporation 3-7
3.2.3 FLEXcon Company 3-13
3.3 References 3-16
4 COMPARATIVE ANALYSIS 4-1
4.1 General Description of Process Retrofit Cycle 4-1
4.1.1 Technical, Environmental, and Economic Considerations 4-1
4.1.2 Execution Stages of Retrofit 4-2
4.2 Technical Retrofit Barriers to Process Conversion 4-3
4.2.1 Introduction 4-3
4.2.2 Chemistry 4-5
4.2.3 Equipment 4-8
4.2.4 Personnel Issues 4-19
4.2.5 End Product Performance 4-19
4.2.6 Considerations for Dedicated and Batch Operations 4-22
4.3 Environmental Barriers to Process Conversion 4-24
4.3.1 Introduction 4-24
4.3.2 Multi-Media Environmental Impacts Associated with Retrofit . . . 4-25
4.4 Economic Barriers to Process Conversion 4-29
4.4.1 Introduction 4-29
4.4.2 Segment-Specific Economic Impact 4-30
4.4.3 Costs Incurred Due to Process Retrofit 4-32
4.4.4 Costs Saved Due to Process Retrofit 4-35
4.4.5 End Product Cost and Profitability/Competitiveness Impacts
Associated with Process Retrofit 4-37
4.5 References 4-39
5 SUMMARY AND CONCLUSIONS 5-1
5.1 Summary of Potential of Waterbased Technology by Industry Segment 5-1
5.1.1 Summary 5-1
5.1.2 Large and Small Facilities 5-1
5.1.3 High and Low Performance End Product Manufacturers 5-2
5.1.4 Dedicated and Batch Operations 5-3
5.2 Potential Benefits of Process Retrofit 5-4
5.3 Waterbased Adhesive Conversion Opportunities 5-6
5.4 References 5-7
v
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TABLE OF CONTENTS (Continued)
Chapter Page
6 Alternative Coating Technologies 6-1
6.1 Introduction 6-1
6.2 Hot Melt Adhesives 6-1
6.2.1 Process Description 6-2
6.2.2 Capital and Operating Costs 6-3
6.2.3 Emissions Reduction Potential 6-4
6.3 Radiation-Curable Adhesives 6-4
6.3.1 Process Description 6-5
6.3.2 Capital and Operating Costs 6-6
6.3.3 Emissions Reduction Potential 6-7
6.4 References 6-8
APPENDIX A QUESTIONS FOR FACILITY VISITS A-l
APPENDIX B COST COMPARISON FOR WATERBASED VERSUS
SOLVENT-BASED ADHESIVE COATING SYSTEMS B-l
APPENDIX C 1992 TRI DATA FOR ADHESIVE COATING INDUSTRY C-l
vi
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LIST OF FIGURES
Number Page
1-1 EPA's Pollution Prevention Research Plan 1-3
4-1 Applicability Range of Solvent-Based and Waterbased Adhesives 4-23
LIST OF TABLES
Number Page
4-1 Processing Requirements for Solvent-Based and Waterbased Adhesive Coating
in All Industry Segments 4-4
4-2 Typical Solvents in Increasing Order of Retention in Paints 4-9
4-3 General Information on Coating Head Types Currently Used in the
Adhesive Coating Industry 4-12
4-4 Important Coating Thickness Parameters for Various Coating Head Types 4-15
4-5 Final Dry Adhesive Coating Thicknesses of Commonly Used Products in the
Adhesive Coating Industry 4-16
4-6 Technical Barriers Associated with Process Retrofit by Industry Segment 4-20
4-7 Environmental Barriers Associated with Process Retrofit by Industry Segment. . . 4-25
4-8 Environmental Media Impacts for Solvent-Based and Waterbased Adhesives
in All Industry Segments 4-26
4-9 Economic Impacts Associated with Process Retrofit to Waterbased Adhesives . . .4-31
5-1 Waterbased Adhesive Potential Emissions Reductions 5-5
B-l Capital Costs for New Waterbased and Solvent-Based Coating Lines B-3
B-2 Capital Costs to Retrofit a Solvent-Based Coating Line to Waterbased B-4
B-3 Annual Costs for Waterbased and Solvent-Based Adhesive Coating Lines B-5
C-l 1992 Toxic Chemicals Release Inventory Data for SICs 2641, 2671, and 2672 .. C-2
vi i
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LIST OF ACRONYMS
AEERL
EPA, Air and Energy Engineering Research Laboratory (now APPCD)
AGST
above ground storage tanks
APPCD
EPA, Air Pollution Prevention and Control Division of NRMRL
BOD
biological oxygen demand
Btu
British thermal unit(s)
CAAA
Clean Air Act Amendments of 1990
CBI
confidential business information
CMM
converting machinery/materials
CO
carbon monoxide
EB
electron beam
EPA
U.S. Environmental Protection Agency
EVA
ethylene vinyl acetate
HAP
hazardous air pollutant(s)
IPA
isopropyl alcohol
IR
infrared
LAER
lowest achievable emission rate
LEL
lower explosive limit
LQG
large quantity generator
MACT
maximum achievable control technology
MEK
methyl ethyl ketone
n2
nitrogen
NO,
oxides of nitrogen
NRMRL
EPA, National Risk Management Research Laboratory
OSHA
Occupational Safety and Health Administration
OTA
Massachusetts Office of Technology Assistance
OWR
North Carolina Office of Waste Reduction
PIES
Pollution Prevention Information Exchange System
PLC
polymers, laminations, and coatings
POTW
publicly owned treatment works
PPIC
Pollution Prevention Information Clearinghouse
PSA
pressure sensitive adhesive
PSTC
Pressure Sensitive Tape Council
PVC
polyvinyl chloride
R&D
research and development
SBS
styrene-butadiene-styrene
SIC
Standard Industrial Classification (code)
SIS
styrene-isoprene-styrene
SQG
small quantity generator
TAPPI
Technical Association of the Pulp and Paper Industry
TCLP
toxicity characteristic leaching procedure
TLMI
Tag and Label Manufacturers Institute
TRI
Toxic Chemical Release Inventory
vi i i
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LIST OF ACRONYMS (Continued)
UST underground storage tank
UV ultraviolet
VOC volatile organic compound(s)
WWT wastewater treatment
ix
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EXECUTIVE SUMMARY
As a result of the Pollution Prevention Act of 1990, the U.S. Environmental Protection
Agency (EPA) established the 33/50 Program which calls for voluntary industry reductions in
releases of the following 17 high-priority toxic chemicals, which are listed by mass of emissions:
The goal of the 33/50 Program is to reduce the total amount of these chemicals released into the
environment and transferred off-site by 33 percent by the end of 1992 and by 50 percent by the
end of 1995. These reductions will be based upon the Toxic Chemicals Release Inventory (TRI),
with 1988 as the base year.1
In support of the 33/50 Program and the Agency's pollution prevention goals, EPA's Air
and Energy Engineering Research Laboratory (AEERL)* is investigating ways to reduce air
emissions of these 17 chemicals through pollution prevention. The Pollution Prevention Act of
1990 defines pollution prevention as source reduction or "any practice which reduces the amount
of any hazardous substance, pollutant, or contaminant entering the waste stream or otherwise
released to the environment (including fugitive emissions) prior to recycling, treatment, or
disposal; and reduces the hazards to public health and the environment associated with the release
of such substances, pollutants, or contaminants."2 Pollution prevention efforts offer economic and
reduced health and ecological risk benefits to many sectors of society that may not be available
through traditional pollution control methods.
In 1991, AEERL representatives met with industry, academia, and State environmental
agency representatives to identify several source categories deserving of pollution prevention
* Now EPA's Air Pollution Prevention and Control Division.
Toluene
Xylenes
1,1,1 -T richloroethane
Methyl Ethyl Ketone
Dichloromethane
Chromium and Compounds
Lead and Compounds
Trichloroethylene
Methyl Isobutyl Ketone
T etrachloroethy lene
Benzene
Chloroform
Nickel and Compounds
Cyanide and Compounds
Carbon Tetrachloride
Cadmium and Compounds
Mercury and Compounds
x
-------
research. Two criteria were used to select the industrial categories for study: annual toxics
emissions and the potential for pollution prevention opportunities. First, the TRI was reviewed
to identify categories with the greatest mass emissions of the 33/50 chemicals. Categories with
the greatest emissions were then ranked according to the potential for successful pollution
prevention projects resulting in significant reductions of 33/50 chemical releases. One of the
industries identified during the 1991 meeting was the adhesives-coated and laminated paper
manufacturing industry [Standard Industrial Classification (SIC) 2672]. This industry was chosen
because of significant air emissions of 33/50 Program chemicals methyl ethyl ketone (MEK) and
toluene as reported through the TRI.
In October of 1991, a Focus Group Meeting was held between AEERL, pollution prevention
experts, and representatives of the adhesives-coated and laminated paper manufacturing industry
to discuss specific pollution prevention projects that would support the 33/50 Program. Meeting
participants indicated that the coatings and coating application steps are the largest source of
toluene and MEK emissions, and, therefore, retrofitting equipment for the use of waterbased
adhesives would present a good opportunity for the implementation of pollution prevention
techniques. As a result of this meeting and preliminary industry inquiries, the scope of the
industry investigation was later expanded to include other coating and substrate varieties (such as
those included in SIC 2671-Coated and Laminated Packaging Paper and Plastics Film) because
the manufacturing methods are similar; therefore, technology transfer is possible over a wider
range of industries. The retrofit research project fulfills part of EPA's goal to stimulate the
development and use of products and processes that result in reduced pollution.
PROJECT OBJECTIVES
As part of the original scope of work for the Improved Equipment Cleaning in Coated and
Laminated Substrate Manufacturing Facilities (Phase I) project, TRC reviewed the potential
equipment cleaning benefits of retrofitting equipment for the use of waterbased adhesives.3
During the investigation, it became apparent that the retrofitting of solvent-based equipment to
accept waterbased adhesives can be a very complicated task. This report presents the results of
TRC's review of the issues and obstacles associated with retrofitting.
xi
-------
Using this report as a starting point, AEERL is examining the technology transfer potential
of demonstrating a retrofit and outlining the requirements for conversion so that other coated and
laminated substrate manufacturers can consider the benefits of retrofitting.
REFERENCES
1. U.S. Environmental Protection Agency. Pollution Prevention Fact Sheet: EPA's 33/50
Program. Office of Pollution Prevention, Washington, DC. August 1991.
2. Pollution Prevention Act of 1990, 42 U.S.C. §13101, et seq.
3. McMinn, B. W. and J. B. Vitas. Improved Equipment Cleaning in Coated and Laminated
Substrate Manufacturing Facilities (Phase I). EPA-600/R-94-007 (NTIS PB94-141157).
Air and Energy Engineering Research Laboratory. Research Triangle Park, NC. January
1994.
xii
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CONVERSION FACTORS
To Convert From
To
Multiply by
LENGTH
feet (ft)
meters (m)
0.3048
meters (m)
feet (fit)
3.281
inches (in)
centimeters (cm)
2.54
yard (yd)
meters (m)
0.9144
MASS OR WEIGHT
ounces (oz)
kilograms (kg)
0.02835
pounds (lb)
kilograms (kg)
0.454
pounds (lb)
tons
0.0005
tons
pounds (lb)
2000
tons
kilograms (kg)
907.2
kilograms (kg)
pounds (lb)
2.205
kilograms (kg)
tons
0.001102
VOLUME
gallons (gal)
liters (1)
3.785
gallons (gal)
cubic inches (inJ)
231
gallons (gal)
fluid ounces (oz)
128
gallons (gal)
cubic meters (mv)
0.00379
milliliters (ml)
fluid ounces (oz)
0.03381
liters (1)
gallons (gal)
0.2642
cubic inches (in3)
gallons (gal)
0.004329
fluid ounces (oz)
gallons (gal)
0.007813
fluid ounces (07)
milliliters (ml)
29.57
CONCENTRATION
pounds/gallon (lb/gal)
grams/liter (g/l)
119.8
grams/liter (g/l)
pounds/gallon (lb/gal)
0.008345
DENSITY
pounds/gallon (lb/gal)
grams/milliliter (g/ml)
0.1198
granis/niil 1 iliter (g'ml)
pounds/gallon (lb/gal)
8.345
PRESSURE
pounds/inch2 (psia)
mmHg or torr (mmHg)
51.71
pounds/inch2 (psia)
atmospheres (atm)
0.0680
millimeters of mercury
pounds/inch2 (psia)
0.1934
or torr (mmHg)
TEMPERATURE
Fahrenheit (°F)
Celsius (CC)
subtract 32,
then multiply by 0.5556
Celsius (CC) Fahrenheit (CF) multiply by 1.8,
then add 32
x i} i
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CHAPTER 1
INTRODUCTION
1.1 PROJECT BACKGROUND
As a result of the Pollution Prevention Act of 1990, the Environmental Protection
Agency (EPA) established the 33/50 Program which calls for voluntary industry reductions in
releases of the following 17 high-priority toxic chemicals, which are listed by mass of emissions:
The goal of the 33/50 Program is to reduce the total amount of these chemicals released into the
environment and transferred off-site by 33 percent by the end of 1992 and 50 percent by the end
of 1995. These reductions are based upon the Toxic Chemicals Release Inventory (TRI), with
1988 as the base year.1
In support of the 33/50 Program and the Agency's pollution prevention goals, EPA's Air
and Energy Engineering Research Laboratory (AEERL) is investigating ways to reduce air
emissions of these 17 chemicals through pollution prevention. The Pollution Prevention Act of
1990 defines pollution prevention as source reduction, or "any practice which reduces the amount
of any hazardous substance, pollutant, or contaminant entering the waste stream or otherwise
released to the environment (including fugitive emissions) prior to recycling, treatment, or
disposal; and reduces the hazards to public health and the environment associated with the release
of such substances, pollutants, or contaminants."2 Pollution prevention efforts offer economic
benefits reduced health and ecological risk to many sectors of society that may not be attainable
through traditional pollution control methods.
Toluene
Xylenes
1,1,1-Trichloroethane
Methyl Ethyl Ketone
Dichloromethane
Chromium and Compounds
Lead and Compounds
Trichloroethylene
Methyl Isobutyl Ketone
T etrachloroethylene
Benzene
Chloroform
Nickel and Compounds
Cyanide and Compounds
Carbon Tetrachloride
Cadmium and Compounds
Mercury and Compounds
1-1
-------
In 1991, AEERL representatives met with industry, academia, and State environmental
agency representatives to identify several source categories deserving of pollution prevention
research. Two criteria were used to select the industrial categories for study: annual emissions
of toxic substances and the potential for pollution prevention opportunities. First, the TRI was
reviewed to identify source categories with the greatest mass emissions of the 33/50 chemicals.
Categories with the greatest emissions were then ranked according to the potential for successful
pollution prevention projects resulting in significant reductions of 33/50 chemical releases. One
of the industries identified during the 1991 meeting was the adhesives-coated and laminated paper
manufacturing industry [Standard Industrial Classification (SIC) 2672]. This industry was chosen
because of significant air emissions of 33/50 Program chemicals methyl ethyl ketone (MEK) and
toluene as reported through the TRI.
In October of 1991, a Focus Group Meeting was held between AEERL, pollution
prevention experts, and representatives of the adhesives-coated and laminated paper manufacturing
industry to discuss specific pollution prevention projects that would support the 33/50 Program.
Meeting participants indicated that the coatings and coating application steps are the largest source
of toluene and MEK emissions, and, therefore, retrofitting equipment for the use of waterbased
adhesives would present a good opportunity for implementing of pollution prevention techniques.
As a result of this meeting and preliminary industry inquiries, the scope of the industry
investigation was later expanded to include other coating and backing varieties (such as those
included in SIC 2671-Coated and Laminated Packaging Paper and Plastics Film) since the
manufacturing methods are similar; therefore, technology transfer is possible over a wider range
of industries. Figure 1-1 illustrates how the retrofit research project fulfills part of EPA's goal
to stimulate the development and use of products and processes that result in reduced pollution.3
1.2 PROJECT OBJECTIVES
As part of the original scope of work for the project Improved Equipment Cleaning in
Coated and Laminated Substrate Manufacturing Facilities (Phase I),4 the potential environmental
and economic impacts related to equipment cleaning when retrofitting equipment to use
waterbased adhesives were reviewed. During the investigation, it became apparent that the
1-2
-------
Demonstrate production and use
Identify, demonstrate, and
evaluate process techniques
Identify opportunities for
1) Stimulate the development and
use of products that result in
reduced pollution
2) Stimulate development and
implementation of technologies
and processes...
RESEARCH
TOPIC
AREA
Barriers to waterbased
adhesive coatings
RESEARCH GOALS
3) Expand reusability, recydabillty, and demand...
4) Identify and promote noo technological
approaches...
5) Conduct technology transfer and technical
assistance...
6) Identify and address future
environmental problems...
OBJECTIVES
PRODUCT RESEARCH PROGRAM
Establish standard methods
Evaluate products
Facilitate product development
PROCESS RESEARCH PROGRAM
Establsh standard methods
Conduct pollution prevention opportunity assessments
EPA
3roduct assessment methods
\lew products
Product substitutes
Trends in product-use patterns
INDUSTRY
Product substitutes
New products
Product applicability
INFORMATION NEEDS
OTHER AGENCIES
New products
Product assessment methods
CONSUMERS
New products
Product substitutes
SPECIFIC RESEARCH PROJECT
Solvent-based to Waterbased Adhesive-Coated Substrate Retrofit
Volume I: Comparative Analysis
1) Identify retrofit requirements (or watarbasad adhestvas
2) Segment adhesive coating Industry
3) Identify case study facilities to cover aegment endpotnts
4) Perform case study analyses
5) Determine technical and environmental barriers to using waterbased adhestvas
6) Evaluate the cost impacts for waterbased adheslves
Figure 1-1. EPA's Pollution Prevention Research Plan.3
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conversion from solvent-based adhesive-coated products to waterbased adhesives can be a very
complicated task. Therefore, EPA invested resources in documenting this conversion. The
results of this study are presented in a four volume series with the following titles.
SERIES: Solvent-based to Waterbased Adhesive-Coated Substrate Retrofit
Volume I: Comparative Analysis
Volume II: Process Overview
Volume III: Label Manufacturing Case Study: Nashua Corporation
Volume IV: Film and Label Manufacturing Case Study: FLEXcon Company
This document is Volume I in this series. It provides an overview of the results of the
study to identify the issues and barriers associated with retrofitting existing solvent-based
equipment to accept waterbased adhesives, and compares the compatibility of waterbased adhesive
performance levels with current solvent-based adhesive applications. Using this report, AEERL
is examining the technology transfer potential of documenting the impacts to several coated and
laminated substrate manufacturers who have converted some or all of their coating capacity from
solvent-based to waterbased adhesives so that other manufacturers can consider the benefits of
retrofitting. Volume II of this series contains a detailed description of the raw materials and
processes used in the adhesive coated and laminated substrate industries. These descriptions are,
for the most part, generated from current literature, technical publications, and textbooks on
adhesive coating and laminating technologies industries. Volume II also contains detailed
technical information on adhesive coating processing and technology, and introduces the retrofit
concepts which are more fully explored in this report. Volume III of this series contains a case
study of the waterbased retrofit for Nashua Corporation (Nashua). Volumes IV describes the
implications of and barriers associated with waterbased adhesive use at FLEXcon Company
(FLEXcon).
1-4
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1.3 REPORT ORGANIZATION
This report is divided into five chapters. Chapter 2 describes the process used to collect
the facility-specific retrofit information contained in this report. Chapter 3 summarizes the results
of the site visits performed for this project. Chapter 4 contains a comparative analysis among
industry segments including the technical, economic, and environmental barriers and benefits
associated with retrofitting existing solvent-based processing equipment to equipment used to
process waterbased adhesives. Chapter 5 summarizes the results and conclusions of the
comparative analysis. Appendix A contains a list of questions which were developed to guide
discussions during site visits. These questions were mailed to host sites prior to the visits.
Appendix B contains a comparison of the capital costs for a new solvent-based and a new
waterbased line, the costs to retrofit an existing solvent-based line to waterbased adhesives, and
annual operating costs for both line types. Appendix C lists 1992 TRI data for the adhesive
coating industry, encompassing SIC codes 2641, 2671, and 2672. SIC 2641 TRI data are
presented because some facilities still report under this SIC even though the SIC was discontinued
in the late 1980s and subdivided into SICs 2671 and 2672.
1.4 RESEARCH METHODOLOGY
To assess the potential for waterbased adhesive coating use in the adhesive-coated and
laminated web substrate industries, two site visits to facilities performing adhesive coating
operations were conducted. Before these site visits were undertaken, a methodology for
categorizing the adhesive coated and laminated substrate industries was developed. This
methodology, which is discussed in Chapter 2 of this report, bisects the industries along three
dimensions: size (large or small), coating line processing mode (batch or dedicated), and product
types (high performance or low performance). To ensure complete coverage of the dimension
endpoints, an effort was made to locate a large number of facilities with a mix of these
characteristics.
An extensive literature search was used to locate facilities. Databases at three local
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university libraries were searched to find information on adhesive coating and laminating. These
searches located numerous documents, journals, periodical reports, conference proceedings, and
textbooks containing information on various aspects of adhesive coating and laminating. This
information was used to provide background data, and to locate suitable facilities for site visits.
Information was also available from other EPA-sponsored projects that investigated the
adhesive-coated and laminated substrate industry. A previous study on equipment cleaning
practices at adhesive coating and laminated facilities became an important resource during the
initial phases of this project.4 Additionally, contacts in both government and industry had been
developed during conference visits and previous project activities. These contacts included
representatives of regulatory agencies, trade associations, raw material suppliers, and equipment
suppliers who proved valuable in completing this project.
1.5 REFERENCES
1. U.S. Environmental Protection Agency. Pollution Prevention Fact Sheet: EPA's 33/50
Program. Office of Pollution Prevention, Washington, DC. August 1991.
2. Pollution Prevention Act of 1990, 42 U.S.C. §13101, et seq.
3. U.S. Environmental Protection Agency. Pollution Prevention Research Plan: Report to
Congress. EPA-600/9-90-015. Office of Research and Development, Washington, DC.
March 1990.
4. McMinn, B. W. and J. B. Vitas. Improved Equipment Cleaning in Coated and Laminated
Substrate Manufacturing Facilities (Phase I). EPA-600/R-94-007 (NTIS PB94-141157).
Air and Energy Engineering Research Laboratory. Research Triangle Park, NC. January
1994.
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CHAPTER 2
INFORMATION COLLECTION
2.1 GENERAL
To meet the objectives of this comparative analysis, information specific to the retrofit of
adhesive-coating processes for web substrates was obtained from various sources. These sources
included current literature, various databases, industry and trade association contacts, conference
proceedings, and facility visits. The information obtained from these sources was used to
determine the technical, economic, and environmental obstacles associated with retrofitting
solvent-based adhesive coating processes to waterbased adhesives. This chapter presents the
techniques used and background information collected during the information-gathering phase.
Topics covered include industry segmentation, process descriptions, emissions characterization,
and facility site visit selection.
2.2 SCREENING CURRENT SOURCES FOR INFORMATION
To gain a broad perspective of the adhesive-coating industry, information was collected
from several sources including literature and database searches, facility visits, pollution prevention
experts, and industry and trade association personnel. In addition, industry-sponsored conferences
such as the Technical Association of the Pulp and Paper Industry's (TAPPI's) Polymers,
Laminations, and Coatings (PLC) conference and Converting Machinery /Materials (CMM)
conference/exposition were attended. These conferences/expositions provided the opportunity to
discuss coating technologies first hand with raw material and equipment suppliers and
manufacturing firms. This section discusses the sources used in developing this comparative
analysis report.
Current literature sources were screened for background and specific information regarding
the retrofit of solvent-based adhesive systems to waterbased systems. Literature searches of EPA
library and journal article databases, local university library databases, and Dialog* were
conducted. These searches identified trade magazines such as Tappi Journal' and Adhesives Age2,
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books, conference proceedings, and supplier literature. Newsletters such as the Adhesives and
Sealants Newsletter2 were also surveyed for current events and potential facility contacts in the
adhesive coating industry.
The Pollution Prevention Information Clearinghouse (PPIC) and the Pollution Prevention
Information Exchange System (PIES) were accessed monthly. The E-Mail capabilities of PIES
were also used to communicate with other PIES users with knowledge of the coated and laminated
substrate manufacturing industry.
In addition to conducting literature searches, contacts were made with industry and
pollution prevention experts with the Massachusetts Office of Technology Assistance (OTA), the
North Carolina Office of Waste Reduction (OWR), the Pressure Sensitive Tape Council (PSTC),
the Tag and Label Manufacturers Institute (TLMI), and equipment manufacturing firms. Also,
raw material and equipment suppliers, consultants, and facility personnel were contacted about
their experience with retrofitting solvent-based adhesive coating systems to waterbased adhesives.
Finally, project and industry information was compiled during a total of seven site visits,
five of which were conducted under previous EPA efforts.4 Facilities which have tried to convert
to waterbased adhesives were contacted to provide operational experience of the retrofit process.
The trip reports and associated data for these facilities were combined with information from two
additional trips. Many of the facilities expressed concern over the confidentiality of their process
lines and operations, which resulted in limits to the data which could be obtained from the
facilities. For this comparative analysis, those facilities which met the specifications for widest
industry coverage were selected for background information and case study visits.
Together, these information gathering efforts provided the background to accurately
describe the technical, economic, and environmental barriers associated with retrofitting solvent-
based adhesive coating processes to waterbased adhesives.
2.3 INDUSTRY SEGMENTATION5
To better determine the retrofit requirements for various manufacturers in the web
adhesive coating industry, the industry was segmented in three areas: (1) size of facility,
(2) production scheduling method, and (3) end product performance. This segmentation was
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based on information obtained from and conversations with industry representatives. Each facility
selected for a site visit was categorized in these three areas to ascertain its place in these three
areas. These classifications were designed to be used in this comparative analysis report and were
not meant to provide an accurate classification of the web adhesive coating market.
The first classification area was facility size. For this report, large facilities are defined
as those employing more than 100 full-time production workers, or those operating more than two
adhesive coating lines on a regular basis. Other facilities were considered small for the purposes
of this analysis.
The second classification area was production scheduling method. This classification
differentiates between those facilities who dedicate their equipment to the production of a
relatively small number of specific end products and those who manufacture a relatively large
number of end products in a batch mode on available equipment. Elements of each production
style are present in virtually all plants, therefore, this classification was evaluated carefully to
ensure adequate coverage among the facilities visited. One arbitrary element used to discern
between dedicated and batch facility was the average amount of time a production run would last.
If an average run lasted eight or more hours, the facility was more likely to be classified as a
dedicated facility. If an average run lasted less than eight hours, the facility was more likely to
be considered a batch facility.
The final classification area was end product performance. The performance requirements
of an end product, including tack, bond, shear strength, and durability under adverse exposures
determined whether the end product was classified as high performance or low performance.
High performance end products are generally products designed to adhere under extreme
environmental conditions or high stress applications. Many high performance products are
specialty products, meaning that they are produced for specialized, often unique, applications.
For instance, a circuit board manufacturer may require a tape for sealing electrical connections.
This tape may have to meet very stringent conductivity and heat transfer standards. Some high
performance products are produced in bulk for a variety of uses. In this case, the high
performance products are aimed at commodity markets. One common example of such a high-
performance product is a bumper sticker, which must withstand temperature and exposure
extremes.
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Low performance end products are designed to perform in moderate to low stress
conditions in moderate environments. Most low performance products are aimed at commodity
markets. One example of such a product is food packaging labels, which are generally exposed
to cold to moderate temperatures, and no other environmental extremes. However, some low
performance products, like masking tapes with individualized logos or imprinting, can be
considered specialty products. Performance level judgements for the facilities discussed in this
report were subjective, and were made relative to the end market for which the product was
intended.
2.4 GENERAL INDUSTRY DESCRIPTION
2.4.1 Introduction
This section provides a brief overview of the coated and laminated substrate manufacturing
industry. The section is divided into three subsections: (1) industry structure, (2) raw materials
and products, and (3) manufacturing process description. The industry structure subsection
briefly addresses the current market, materials used in the manufacturing process, products
manufactured, and product end uses. The raw materials and products subsection briefly addresses
the materials used in the manufacturing process, products manufactured, and product end uses.
The manufacturing process subsection gives an overview of the manufacturing process with
emphasis on the equipment and procedures used. Volume II in this series contains a more detailed
discussion of the industry structure, raw materials, and production processes.
2.4.2 Industry Structure
The coated and laminated substrate industry, as defined by SIC 2671 and 2672, consists
of firms that manufacture coated or flexible materials made of combinations of paper, plastic
films, metal foils, and similar materials for packaging (SIC 2671) and other purposes, including
pressure sensitive tapes (SIC 2672).6 According to the 1987 Census of Manufacturers, companies
in SIC 2671 employed 15,000 people in 21 states, and companies in SIC 2672 employed nearly
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31,000 people in 23 states. The leading states in employment of 2671 personnel, accounting for
42 percent of the industry's employment, were Wisconsin, Indiana, Pennsylvania, and Illinois.
Massachusetts, Ohio, Illinois, and Pennsylvania accounted for 38 percent of SIC 2672's
employment. Over 93 percent of SIC 2671 and 55 percent of SIC 2672 plants are small facilities
employing less than 20 people.7 These smaller facilities often provide a highly customized
product line marketed within a small geographic region. Some of the larger companies own
multiple manufacturing facilities and distribute products nationwide.
There are several additional SICs in the flexible packaging industry which are related to
SICs 2671 and 2672. These are SIC 2673 (plastics, foil, and coated paper bags), SIC 2374
(uncoated paper bags and sacks, and multiwall shipping sacks and bags), and SIC 3497 (metal foil
and leaf). Industries in these SICs may have an adhesive coating or lamination step in the
production of their products. However, coating and lamination activity occurs primarily in SICs
2671 and 2672. In addition, a facility that reports under a different SIC may perform coating
activities like those found in SICs 2671 and 2672. For instance, a facility that produces film or
coats only films may report under SIC 3081 (unsupported plastic films and sheets). However, that
facility could maintain extensive adhesive coating and laminating facilities.
2.4.3 Raw Materials and Products
2.4.3.1 Introduction
The products manufactured by the coated and laminated substrate industry are used in a
variety of applications. Generally, these products can be categorized as one of three product
types: tapes, labels, or miscellaneous products. Each of these product types consists of some
combination of backings and coatings that can be described in terms of raw material construction
or function. End use categories include hospital and first aid products, office and graphic arts
products, packaging and surface protection products, building industry materials, electrical
products, and automotive industry products.
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2.4.3.2 Raw Materials
The raw materials used in the coated and laminated substrate manufacturing process consist
of product backings, adhesives, and other coatings. Backings are the materials to which adhesive
coatings are applied by the coating head. Backings, which are generally used in roll form, may
include paper, film, foil, foam, or cloth materials. Backings are also referred to as substrates in
the adhesive coating industry. In this report, the term backing will be used to describe all
materials coated with adhesive in a process line. Adhesives include solvent-based and waterbased
formulations of rubber, acrylic, silicone, or other polymers. Other coatings include release
coatings, topcoats, and barrier coatings. A more detailed discussion of these raw materials is
found in the Volume II report.
2.4.3.3 Finished Products and End Uses
There are several types of products manufactured by coated and laminated substrate
manufacturers. Two of the largest product categories are tapes and labels. Classes of tape,
identified by construction, include woven and nonwoven fabric tape, paper tape, film tape, foil
tape, and foam tapes. Some of the backing materials identified in Section 2.4.3.2 are used with
glass, rayon, nylon, polyester, or acetate fibers to produce reinforced backings. Films such as
polyethylene, polyester, or polypropylene are often combined with these fibers to produce tapes
used in heavy-duty packing and bundling applications. Two-faced tapes are backings, usually a
foam or film, with an adhesive coating applied on both sides of the backing. Two-faced tapes
have both heavy-duty uses (e.g., carpet tapes and securing plates to a printing cylinder) and light-
duty uses (e.g., business forms and nametags).
Label manufacturing is similar to pressure sensitive tape manufacturing, with the primary
defining characteristics being backing, printability, flatness, ease of die cutting, and release paper
components. A label manufacturer may sell its product either in rolls or sheets as a final product,
or as a raw product to printing and die cutting operations.8-9 Other adhesive-coated and laminated
product lines include adhesive-coated floor tiles, wall coverings, automotive and furniture
woodgrain films, and decorative sheets.
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2.4.4 Manufacturing Process Description
2.4.4.1 Introduction
Coated and laminated substrate facilities use numerous methods to process a wide variety
of products. Manufacturing variables include the design and capabilities of the coating equipment,
the type of backing, the type and viscosity of the coatings being applied, and the drying or curing
method. The manufacturing process generally consists of the following four steps:
• raw material mixing
• coating application
• drying/curing
• rolling, printing, cutting, packaging, and product shipment
Each of these steps is described briefly in the following subsections.
2.4.4.2 Raw Material Mixing4
Many coating and laminating facilities formulate their coatings on-site in a central mix
room. The complexity of the mixing process depends on the size of the facility and the number
of products manufactured. Large facilities operating dedicated lines often formulate their own
coatings from raw materials. Smaller coating and laminating facilities and batch facilities may
choose to purchase premixed coatings which they can modify to satisfy customer needs.
Modification of premixed coatings typically consists of directly adding small amounts of
performance-enhancing chemicals, such as tackifiers or defoamers, into the adhesive shipping
container. Once the coatings are formulated, they are either pumped to storage tanks or
transferred via barrel-type containers or dedicated piping to specific process lines for immediate
use.
A number of solvents, most typically toluene and MEK, are used in solvent-based adhesive
formulations. The function of the solvent in a solvent-based adhesive formulation is to dissolve
adhesive solids and other additives, allow easy transfer of the adhesive to a coating device, and
permit smooth, even coating of adhesive on a backing. The solvent is then forced to evaporate
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in a drying oven, leaving the backing coated with a uniform layer of adhesive. Most of the
solvents used for solvent-based adhesives contain volatile organic compounds (VOC), some of
which may also be hazardous air pollutants (HAP).
2.4.4.3 Coating Application4
The application of a coating to a flexible web involves four major functions: (1) transport
of the web, (2) delivery of the coating supply, (3) metering of the coating, and (4) transfer of the
coating from the supply vessel to the backing. In web transport, the mechanisms used to tension
and advance the web may require minor adjustments to compensate for the different speeds and
transport requirements of waterbased coatings. These mechanisms include items such as rollers,
gear boxes, belts, and equipment housings. Their design is influenced by the properties of
waterbased and solvent-based adhesives. The mechanisms used to supply, meter, and apply
coating may also require adjustment. The following paragraphs briefly describe the supply,
metering, and application functions, along with some common coating equipment configurations.
After mixing, coatings are stored in permanently installed tanks, movable tote vessels, or
drums. The coating is then transferred from storage locations to a reservoir on the coating head,
from which it is made available to the coating apparatus. The reservoir normally uses dams and
spill pans to capture any spilled coating. Transfer to the reservoir is accomplished through
permanently installed piping and manifold systems or through portable lines that are attached to
mobile storage vessels. Various types of pumps are used to maintain a flow of coating materials
through these distribution networks.
Transfer of a coating from a reservoir to a web is most commonly accomplished with a
roll coating mechanism. Roll coaters are a series of one or more cylinders that remove coating
from the reservoir and then contact the web, transferring a portion of the coating to the web
surface. If the cylinder that contacts the coating in the reservoir also contacts the web the roll
coater is known as a direct roll coater. If a roller removes the coating from the reservoir and then
transfers the coating to a counter-rotating cylinder before it reaches the web, the device is called
an offset roll coater. Offset roll coaters are capable of greater control of the coating deposit, but
require more exacting process control. Gravure coaters may also be used for coating application.
These are similar to roll coaters in that they transfer coating to the surface of a web through the
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rotational motion of a cylinder. The major difference is that gravure cylinders are engraved while
the surface of standard coating rollers is mirror smooth.
The coating roller must completely wet the web surface with coating, but not in excess of
the design thickness for the application. The thickness of the applied coating can be partially
controlled through adjustment of the supply system and the coating's viscosity. Fine adjustments
are accomplished by a metering device. Metering occurs before or after the coating is applied to
the web. The most common metering mechanisms are (1) a metering roller, (2) a doctor blade,
(3) a metering rod, and (4) nip rollers. A metering roller removes excess adhesive from the coated
web by reverse rolling action against the web. A doctor blade is typically a metal blade which
extends the width of the web and removes excess adhesive by scraping the surface of the web.
A metering rod works in much the same way as a metering roller, although it generally has a
tightly wound wire around it to assist in the transfer of adhesive away from the web. Nip rollers
follow the coating rollers. The web passes through a small space between two rollers. The width
of this space, which is called the nip, is the desired coating and web thickness. Additional
metering mechanisms include air knives, high speed curtains of air that blow excess coating back
as an application roller rotates towards the web, and mechanisms uniquely associated with a single
coating application, such as the engravings in a gravure cylinder.
2.4.4.4 Drying and Curing
Ovens serve two primary functions: to dry the coating by evaporating the vehicle (solvent
or water) and/or to cure a polymer coating. Curing involves the chemical crosslinking of
polymeric adhesives. Important characteristics of an oven are the source of heat, the operating
temperature, the residence time (a function of web speed and the length of web path through the
oven), the allowable hydrocarbon concentration, and the oven circulation (a function of air
velocity).
Ovens are of two types: indirect-fired and direct-fired. An indirect-fired oven involves
heat exchange. Ail incoming air stream is heated by steam or combustion products, but does not
mix with them. The steam may be heated by fuels, such as natural gas or propane, or by
electricity. Combustion products used for heat exchange are generally derived from natural gas
or propane. Direct heating routes the hot products of combustion (blended with ambient air to
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achieve the desired temperature) directly into the drying zone. The fuels for a direct-fired oven
are usually either natural gas or liquefied petroleum gas (e.g., propane) because they both bum
cleanly and are easily controlled,810
Oven drying involves raising a coating's temperature to evaporate the vehicle solvent
quickly while keeping the temperature elevated long enough for entrapped solvents to migrate to
the surface of the adhesive and evaporate. The time required to drive off vehicle solvents at the
boiling temperature is known as the drying residence time. In most coating processes,
approximately 80 to 95 percent of the vehicle solvent evaporates and exits with the oven exhaust
either to the atmosphere or to a control device, depending on the nature of the exhaust, the
quantity of release, and the location of the facility.10 Another important oven consideration is the
oven's temperature profile. Most ovens have a number of zones in which the temperature and
airflow can be independently controlled. If the initial drying proceeds too quickly, voids may
develop in the coating. Conversely, if drying occurs slowly at low temperatures, longer ovens
may be necessary to achieve sufficient residence time. Multi-zone ovens can generally be
optimized to overcome these difficulties. Large drying and curing ovens may have six or more
zones ranging in temperature from 110° to 400°F (43° to 204°C). Facilities may also employ
recirculating ovens to provide better drying efficiency.
2.4.4.5 Rolling, Printing, Cutting, and Product Shipment1
Many coating operations also offer value-added converting services to their customers.
Such services include custom slitting and roll winding, printing, die-cutting, and sheeting. A roll
of coated product may weigh up to 5,000 pounds (2,268 kilograms) and be 30 inches
(76 centimeters) wide when it comes off the production line. Such products are generally slit to
a customer-specified width, and automatically rolled onto standard cores for customer use in
automatic dispensers. Many facilities have the ability to slit and wind product on-site, however,
some facilities send finished rolls to contract converters to be sized. Coaters may customize label
and packaging products by printing a logo and die-cutting to size. The product is generally cut,
with the waste removed and the web rolled and packaged for shipping.
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2.5 EMISSIONS AND WASTE STREAMS
2.5.1 Introduction
This section discusses the emissions and waste streams associated with web adhesive
coating manufacturing. Characterization and, where available, quantification of the air emissions,
liquid wastes, and solid wastes from adhesive coating processes are presented. Facility-specific
information is also provided based on site visit assessments, TRI reporting requirements, and
permit information.
2.5.2 Air Emissions from Solvents
2.5.2.1 Emissions from th e Industry
A number of solvents, most typically MEK and toluene, are used in solvent-based adhesive
formulations. These solvents typically contain both VOC and HAP. In 1992 the total of all MEK
releases to the air by facilities operating under SIC 2671 was 1.1 million pounds (500,000
kilograms). Toluene air releases totalled 6.4 million pounds (2.9 million kilograms). SIC 2672
facilities emitted nearly 5.2 million pounds (2.4 million kilograms) of MEK and 19 million pounds
(8.6 million kilograms) of toluene.11 Most coated and laminated substrate manufacturing facilities
calculate these emissions based on raw material consumption. Therefore, total emissions reflect
solvent losses occurring during raw material mixing, coating processing (including fugitive
releases), equipment cleaning, and material storage.
The primary impacts of VOC and HAP reductions depend on the facility location. In
heavily industrialized areas, the reduction of VOC emissions may produce a corresponding
reduction in local hydrocarbon levels, and thus a reduction in ozone formation. In rural areas,
lower VOC and emissions may result in lower overall ambient hydrocarbon levels, helping to
reduce the transport of ozone precursors to urban areas. In addition, the reduction of VOC
emissions will lead to reduced environmental impacts on other media. For example, improperly
handled chlorinated materials (e.g., methyl chloroform) often result in contaminated soil and
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groundwater. Reducing the quantities of these materials used for cleaning will reduce the
potential for contaminated aquifers, drinking water wells, and soils.
Emissions during the application of solvent-based coatings are often directed to an
emissions control device. The devices most often employed for emissions control are carbon
absorption systems, catalytic incinerators, or thermal incinerators. Most facilities utilizing these
devices control emissions from the drying/curing ovens. However, some facilities also add to the
emissions stream exhaust from the raw material storage/mixing area, coating application room,
and coating head trough. While such control devices reduce VOC and HAP emissions, the use
of incineration will actually increase ambient levels of carbon monoxide (CO) and oxides of
nitrogen (NO,) in the ambient air.
The following subsections (subsections 2.5.2.2 through 2.5.2.6) describe solvent emissions
from specific areas of the adhesive coating process.
2.5.2.2 Solvent Storage
Facilities that formulate their own solvent-based adhesives can have both breathing and
working losses resulting in emissions during storage of the solvent. Air emissions may result
from vapor displacement during solvent delivery to solvent storage tanks, which may be above-
ground storage tanks (AGSTs) or underground storage tanks (USTs). Also, solvents stored in 55-
gallon (208-liter) drums located within the facility may release evaporated solvent when opened.
2.5.2.3 Transfer and Formulation Losses
During transfer of the solvent from the formulation tank, air emissions may result from
equipment leaks or the opening of solvent drums. Also, equipment leaks may occur during the
adhesive formulation process. Facilities which buy pre-formulated adhesives may conduct
additional blending during which solvent vapor may escape from the blending tanks or drums.
Dedicated coating equipment normally includes dedicated closed-loop adhesive delivery systems
which reduce solvent evaporation during transfer of the adhesive to the coating head trough.
Batch coating equipment may experience somewhat higher evaporation rates due to more frequent
transfer of the solvent-containing coatings to the coating equipment. Spills and/or accidents
involving solvent-based adhesives are also a potential source of VOC and HAP emissions.
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2.5.2.4 Adhesive Coating/Coating Application
Another potential source of solvent evaporation is the adhesive trough. Upon delivery of
the adhesive to the coating head, the coating is placed in a trough where the pick-up roll contacts
the adhesive and transfers it directly to the web or to the application roll. Solvent can evaporate
from the trough during this operation. Many facilities maintain a partial enclosure over the
coating trough to minimize solvent evaporation to the atmosphere. Air circulating in the enclosure
is often vented through the oven to a control device.
2.5.2.5 Ovens
The primary source of VOC and HAP emissions in a solvent-based coating line is the
oven. During the drying/curing stage, the solvent is evaporated from the coating and is exhausted
through the oven vent. Many facilities employ a destruction or recovery device to destroy or
capture and reclaim these solvent vapors. The capture and destruction efficiencies of these
devices are the most critical factor determining solvent emissions.
2.5.2.6 Equipment Cleaning
Industry representatives estimate that one to ten percent of total solvent releases are due
to equipment cleaning.4 The amount emitted depends on the degree to which the facility operates
in batch or dedicated mode. Generally, more batch coating results in higher levels of equipment
cleaning releases, as more equipment cleaning is necessary in batch operations. These emissions
represent the greatest source of fugitive emissions from coated and laminated substrate
manufacturing. These emissions are difficult to control with add-on devices, so some facilities
are attempting to find alternative cleaning products and methods. Depending upon the cleaning
chemicals used (e.g., toluene, methyl chloroform, mineral spirits), VOC and/or HAP may be
emitted.
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2.5.3 Liquid Wastes
Liquid wastes, both hazardous and non-hazardous, are generated from waste or spent
adhesive and cleaning solvents, cleaning wastes, and spills and accidents. Spent cleaning solvents
are the largest liquid waste produced by coated and laminated substrate manufacturers. Spent
cleaning solvents include those used to flush coating delivery systems {e.g., tanks, piping, coating
head trough) and those used to wipe or soak coating equipment. Many of these solvents are
recoverable through distillation and can be incorporated in a coating; however, they may also be
sent off-site for disposal. A second liquid waste stream consists of excess or off-specification
coating. Waste or spent adhesives include those whose shelf-life has expired or batches that were
incorrectly formulated.
Another source of liquid wastes may be air emissions control equipment. Facilities using
carbon adsorption systems (usually associated with controls on dryers or ovens) have the potential
to discharge contaminated water from condensation of the steam used to desorb the carbon beds.
Facilities typically have three options for disposing of this waste: (1) use the water for boiler feed;
(2) use the water for cooling towers; or (3) discharge the water into a wastewater treatment facility
or local sewer for further treatment. Spills and/or accidents involving solvent-based adhesives
are also a potential source of liquid waste.
Facilities are responsible for the environmental impacts their water may have on a sewer
or water system. A facility should always consider the effects of a new liquid waste stream on
plant wastewater treatment (WWT) operations or on publicly owned treatment works (POTW).
Some cleaners may reduce toxicity, hazardous waste, and air emissions, but can create excursions
from effluent limitations.
Facilities that formulate their own waterbased adhesives will generate deionized water.
The chemicals and minerals deposited during the deionization process must be disposed of in some
manner. These materials may be included in the effluent and sent to the POTW, or disposed of
as solid wastes. In addition, the deionization process will create a wastewater stream which may
be sent to the POTW or collected and sent off-site for disposal as a non-hazardous waste.
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2.5.4 Solid Wastes
Solid wastes from the manufacturing operations may be classified into three areas:
cleaning waste, waste adhesive-coated backing, and solidified coating waste. Solid waste from
cleaning includes items such as rags, floor coverings, machinery coverings, and coating filters.
Disposal requirements for waste adhesive-coated backing generated from the edge of paper rolls,
at the beginning and ending of a run, and from cutting and packaging operations depend on local
and state regulations. The characteristics of the solvent on the substrate affect its classification
as solid waste.
Solid waste may be created by emissions control equipment. Activated carbon from
carbon adsorption systems must be replaced periodically, and spent carbon must be disposed of
according to state and local regulations. The remains from incineration or catalytic oxidation must
also be disposed of as solid waste. The carbon may be able to be reused for fuel or recycled for
other uses. Waste from incineration or oxidation may also have alternative uses.
As stated in Section 2.5.3, facilities which formulate waterbased adhesives onsite generate
deionized water. The chemicals deposited during the deionization of water are often disposed of
as solid wastes.
2.6 FACILITY SELECTION
2.6.1 Introduction
Although information on conversion to waterbased adhesives was obtained during a
number of facility site visits under previous EPA projects in the adhesive coating industry, two
additional site visits were conducted specifically for this study. These site visits consisted of one
background information gathering visit at FLEXcon Company in Spencer, Massachusetts, and one
case study of a waterbased retrofit effort at Nashua Corporation in Omaha, Nebraska. These site
visits covered several of the categories of industry segmentation (i.e., large and small facilities,
dedicated and batch facilities, and high and low performance products) which were described in
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Section 2.3 of this report. A brief description of the criteria for selecting of these sites is
presented in this section.
2.6.2 FLEXcon Company
FLEXcon Company (FLEXcon) located in Spencer, Massachusetts, was chosen as a site
at which to gather background information on waterbased adhesive retrofit because it met the
industry classification categories of (1) a large facility that (2) used a batch mode of operation to
generate (3) high performance end products. FLEXcon's Spencer, Massachusetts facility employs
approximately 600 production personnel. FLEXcon officials describe their coating lines as
operating in a batch mode. FLEXcon coats both waterbased and solvent-based adhesives on a
wide variety of backings including vinyl, polyester, acrylic, acetate, polyethylene, polypropylene,
and polystyrene.
2.6.3 Nashua Corporation
Nashua Corporation (Nashua) located in Omaha, Nebraska, was chosen as a case study site
because of its current retrofit efforts. Nashua fulfilled the industry categories of (1) a relatively
large facility operating primarily in (2) a dedicated mode manufacturing (3) commodity, generally
low performance, end products. Nashua's Omaha, Nebraska facility employs approximately 200
to 300 production personnel and operates two adhesive coating lines. Nashua officials also
described their operations as primarily dedicated, although some batch operations are performed.
Nashua manufactures approximately 30 to 40 end products using eight or nine waterbased
adhesive formulations and about ten different types of paper face stock (i.e., label backing). At
the time of the site visit, Nashua was nearing the end of a six-year effort to convert their coating
processes from solvent-based to completely waterbased adhesives. This conversion was completed
by December 31, 1993.
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2.7
REFERENCES
1. TAPPI. Tappi Journal (periodical). ISSN 0734-1415. Norcross, GA.
2. Argus Business. Adhesive Age (periodical). ISSN 0001-82IX. Atlanta, GA.
3 Adhesive Information Services. Adhesives & Sealants Newsletter (periodical).
ISSN 0890-0884. Mishawaka, IN.
4. McMinn, B. W. and J. B. Vitas. Improved Equipment Cleaning in Coated and Laminated
Substrate Manufacturing Facilities (Phase I). EPA-600/R-94-007 (NTIS PB94-141157).
Air and Energy Engineering Research Laboratory. Research Triangle Park, NC. January
1994.
5. Memorandum. Beth McMinn, TRC Environmental Corporation, Chapel Hill, NC, to
Chet Vogel, U.S. Environmental Protection Agency, Research Triangle Park, NC.
Segmentation of Adhesive Coating Industry. August 25, 1993.
6. Standard Industrial Classification Manual, Office of Management and Budget.
Washington, DC. 1987.
7. U.S. Department of Commerce. 1987 Census of Manufacturers, Industry Series:
Converted Paper and Paperboard Products, Except Containers and Boxes, MC87-1-26C.
Bureau of the Census. Washington, DC. 1990.
8. Satas, D. (ed). Handbook of Pressure-Sensitive Adhesive Technology. Van Nostrand
Reinhold Company. New York, NY. 1989.
9. Memorandum. Geary McMinn and Scott Snow, TRC Environmental Corporation, Chapel
Hill, NC, to Mike Kosusko, U.S. Environmental Protection Agency, Research Triangle
Park, NC. Site Visit - Nashua Corporation - Label Division, Omaha, NE. April 1, 1993.
10. Goodwin, D.R. Pressure Sensitive Tape and Label Surface Coating Industry -
Background Information for Proposed Standards: Draft EIS. EPA-450/3-80-003a (NTIS
PB81-105942). Office of Air Quality Planning and Standards. Research Triangle Park,
NC. August 1980.
11. Toxic Chemical Release Inventory Database. U.S. Department of Health and Human
Services, National Institute of Health, National Library of Medicine. Bethesda, MD.
Toxicology Information Program Online Services TOXNET® Files. 1992.
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CHAPTER 3
FACILITY VISITS
3.1 METHODOLOGY FOR SITE VISITS
3.1.1 Methodology Overview
The methodology for the site visits conducted during this project began with identifying
potential host facilities. As information was gathered on the waterbased adhesive coating
industry, potential candidate facilities for case studies were identified. Any facility performing
waterbased adhesive coating operations was considered a potential candidate. For each of the 18
facilities identified, an initial telephone contact describing the project goals was made. Initial
telephone contacts that responded favorably were sent an information packet containing a cover
letter, the project's background, and a list of specific questions concerning facility operations and
retrofit experience. The list of questions was developed to guide discussions during the site visits
and was meant to provide the facility with examples of the kind of information sought during site
visits. The questions are included in Appendix A and covered the following topics:
• General facility information (size, market profile, etc.)
• Costs of retrofitting solvent-based adhesive equipment to process waterbased adhesives
• Product performance and quality issues related to the use of waterbased adhesives
• Process equipment requirements of waterbased adhesives
• Environmental impacts associated with the use of waterbased adhesives
• Labor impacts associated with retrofitting to waterbased adhesives
After receiving the information packet, a follow-up call was placed to the potential
candidate facilities. Receipt of the information packet was confirmed and the candidate facilities
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were further questioned on their end products, processes, and adhesives. If a facility proved to
be an appropriate candidate for the project, it was asked for its agreement to participate.
Ten of the 18 facilities contacted for this project were unwilling to participate; six of the
remaining eight facilities were only willing to participate at a minimal level. Minimal
participation consisted of developing a one-page summary of the facility and its operations, with
no site visit or additional information-gathering activities occurring. The two remaining facilities,
in addition to participating at the minimal level, also agreed to participate further as case study
subjects. Nashua Corporation in Omaha, NE, and FLEXcon Company, Inc. in Spencer, MA,
agreed to host site visits by TRC personnel to gather information related to the use of waterbased
adhesives. Upon agreeing to participate, site visit dates were scheduled.
Each facility site visit conducted for this project began with a opening discussion of the
site visit purpose, project goals, and confidential business information (CBI) issues. Specific
questions were evaluated by the facilities to ensure the information gathered during the site visit
was not confidential. A subsequent plant tour was conducted followed by a closing meeting to
discuss final issues related to report generation, facility review, and project schedule.
After completing the site visits, reports were generated detailing each facility's process
equipment and waterbased adhesive coating experience. Each report covered four general topics:
(1) a general facility description, (2) the facility's attempted conversions to waterbased adhesive
or a discussion of the obstacles to converting, (3) environmental issues of coating both solvent-
based and waterbased adhesives, and (4) a summary of the conclusions about waterbased adhesive
use at the facility. Although discussed in each report, these four topics were organized differently
as applicable to each facility.
After completing a draft report on each site visit, the document was sent to the applicable
facility for review. The facility was responsible for ensuring the technical accuracy of the report
and appropriately marking any information considered proprietary. Both the Nashua and
FLEXcon site visit reports were found to contain a minor amount of CBI which was removed or
altered to preserve the report's status as entirely nonconfidential. A revised copy of each report
was then submitted to EPA.
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3.1.2 Facility Profile Development
The foci of the facility visit investigations were the potential for use of waterbased
adhesives as replacements for solvent-based adhesives and the modification of current solvent-
using activities (e.g., equipment cleaning with solvents, process and fugitive solvent emissions
control) to reduce solvent emissions. A profile of each facility was developed to obtain a
complete understanding of the factors affecting emission levels and their potential reduction.
Three areas were critical to the development of these profiles: the facilities' processing techniques,
end product lines, and future plans.
3.1.3 Process Equipment and Techniques
Although many similarities exist between the coating and laminating processes used by the
various facilities in the industry, differences in these processes can account for significant
differences in emissions sources. For example, one facility may enclose and ventilate a coating
head to an emissions control system to capture releases from the trough and coating application.
Facilities not employing total or partial enclosures around the coating application apparatus often
release substantially more fugitive emissions.
A number of process-related issues were studied during the site visits. Most important
among these were coating line operating techniques. As discussed in Chapter 2, the distinction
between batch and dedicated processing of the coating line is one key factor in determining the
potential for waterbased adhesive use at a facility. The coating head configuration used at a
facility is also key to determining which backings and adhesives can be used in the coating head,
and at what processing speeds the line can operate. Facilities with more than one coating head
configuration have increased flexibility among backings, adhesives, and application speeds which
can be used.
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Adhesive delivery systems were also analyzed. These systems generally consist of pumps
and piping used to transfer adhesive from a storage vessel [e.g., a large storage tank or a 55-
gallon (208-liter) drum] or holding tank used for temporary storage or additive mixing. Oven
operations were also studied during the plant visits. The three criteria used to evaluate oven
operations were the number of separate temperature zones within the oven, the maximum and
minimum potential temperatures within those zones, and the distribution of temperature and
airflow generally used during coating line operation. Finally, other process-related equipment,
such as heat exchangers or infrared (IR) heaters, were noted during the site visit.
Process-related issues and practices were also examined during site visits. Equipment
cleaning practices were observed to determine the differences in solvent-based and waterbased
practices, emission losses, and potential emissions reduction. Emissions control equipment used
by each facility, such as thermal and catalytic oxidizers, carbon adsorbers, and outside ventilation
systems, were examined. Using data provided by the facilities on solvent purchasing, utilization,
and destruction or recovery by emissions control devices, emissions levels at the sites were
roughly estimated.
3.1.4 End Product Lines
A complete assessment of a facility's product lines includes an examination of its current
mix of end products, marketing strategies for selling product, performance requirements for end
product application, and the future changes, additions, and goals of product line development.
Generally, manufacturers of adhesive-coated products either supply a specific type of product or
attempt to fully service specific customers. Batch processors, who often use solvent-based
adhesives or a mix of mostly solvent-based adhesives with a small amount of waterbased
adhesives, often attempt to provide complete product lines for each of their clients. To
accomplish this, varied adhesives and backings are employed to generate products suitable for a
wide spectrum of applications. These full-service batch-processing operations may not
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manufacture every product in their product lines; instead, they may purchase some products from
other manufacturers to complete their client's product lines. By providing complete product lines
for their clients, these facilities allow discounts to their loyal clients and discourage them from
looking elsewhere for adhesive-coated products.
While batch coaters generally produce relatively small amounts of a large number of
adhesive-coated products, dedicated coaters generally produce large amounts of a small number
of adhesive coated products. These firms rarely attempt to produce full-service product lines for
their clients. Instead, they manufacture a relatively small number of end products. Because
dedicated processors do not possess the diversity of product output, and therefore the flexibility
of batch processors, it is imperative that their end products are in relatively high demand markets.
An excellent example of a high demand market product is adhesive-coated paper labels used in
room temperature or colder applications. Paper labels are used extensively in food packaging,
supermarket labeling, and office supplies. Since the end product demands do not vary widely
over time, paper labels make an excellent dedicated-line output product.
During the site visits, each facility's product line was assessed to determine to which of
the two categories it belonged. Once the product line categorization was assessed, marketing
targets were established. Each facility uses certain marketing strategies in order to sell end
products and expand its markets. Some facilities have a loyal clientele that they depend on for
consistent sales without significant marketing efforts. If marketing efforts can be kept to a
minimum, product prices may be kept low. Other facilities pursue more aggressive marketing
strategies. Marketing strategists may travel domestically or internationally to cultivate client
growth. Most adhesive coating firms develop an extensive catalog of brochures and mailers
containing information on their end products and applications. These facilities may also be
members of various adhesive coating and laminating trade associations where they can develop
client contacts and leads for business development. Some facilities assist their marketing efforts
by presenting themselves as specialists in certain application areas. For instance, a facility may
concentrate product line development within a small number or even a single industrial or
commercial area to become recognized as a specialist in this area.
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Although coordinated marketing efforts assist in developing a client base, a client's major
considerations when purchasing adhesive-coated products are price and performance. The
adhesive coated and laminated substrate industry is highly competitive, so it is imperative that
manufacturers maintain competitive pricing. Competitive pricing is most critical in low
performance, generally commodity markets, while product performance is most critical in high
performance, generally specialty markets. For high performance manufacturers, end product
performance must meet exacting, often extreme customer specifications. While cost of product
is important to high performance manufacturers, performance levels cannot be sacrificed.
Individual coating facilities must maintain an optimum balance between low pricing and high
performance suitable for their client's applications.
3.1.5 Potential Future Changes in Processes and Product Lines
The information contained in this paragraph was derived from the case study facilities and
others in the adhesive coating industry. The future plans for both process and product additions,
changes, and improvements are critical factors to ensure the long-term profitability of a company.
In the past several years, adhesive coating and laminating firms have undergone tremendous
pressures on a number of fronts including environmental constraints, increasing competition, a
turbulent economy, and changing foreign trade conditions. Facilities must remain flexible in the
short-term and still plan for the long-term. An effective gauge of a facility's long-term strategies
is its plans for additions, changes, and improvements to its process manufacturing profile, such
as the addition of a new coating line, change of its coating head, or conversion of a solvent-based
adhesive product to waterbased adhesives. Planned end product line changes are also indicators
of a facility's strategy for the future. New product introductions, elimination of products, and
product improvements must be planned to meet changing market conditions.
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3.2 GENERAL RESULTS FROM THE SITE VISITS
3.2.1 Site Summary
As discussed previously, two facility site visits were conducted to obtain information about
potential conversions from solvent-based to waterbased adhesives. The two sites selected were
Nashua Corporation in Omaha, Nebraska; and FLEXcon Company, in Spencer, Massachusetts.
Nashua recently completed a six-year effort to convert its paper label end products from solvent-
based to waterbased adhesives. This effort is documented in Volume III of this report series.1
FLEXcon is a batch operation which coats a wide variety of backings using solvent-based and
waterbased adhesives. The site visit report to FLEXcon comprises Volume IV of this report
series.2 The results of the two site visits are discussed in this section.
3.2.2 Nashua Corporation
3.2.2.1 Introduction
Nashua Corporation began operating its Omaha, Nebraska plant in 1966. The plant was
originally built in 1959 and operated by the International Paper Company. Nashua's Omaha
facility currently employs approximately 90 administrative and management personnel and 200
to 300 production personnel. Since it employs 300 to 400 personnel and annually produces
approximately 200 to 300 million square yards (167 to 251 million square meters) of end product,
Nashua is designated a large facility. The Omaha plant operates 24 hours per day, five to seven
days per week, depending on customer demand, and produces pressure sensitive labels, roll-stock,
and custom label products.
Nashua produces 30 to 40 adhesive coating and paper backing combinations (i.e., finished
products) for its customers. At first glance Nashua might be considered a batch operation, since
it produces different products on its individual coating lines. However, Nashua generally sets up
a coating line to run for many hours (ten or more) before switching to another product. Also,
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while an adhesive's chemical makeup and the paper backing to which it is applied may differ, the
coating process generally remains the same for each product line, excluding several relatively
easily controlled variables such as line speed, coating thickness, and oven temperature and
airflow. In light of these attributes (e.g., long product runs, similar coating processes for
different products), Nashua believes the term dedicated processor most accurately describes its
operations.
Nashua is a commodity (i.e., lower performance) processor. While possessing the
capability to manufacture end products meeting a wide range of specifications, Nashua generally
produces large amounts of a small number of end products for application in moderate
environmental conditions (e.g., low humidity, small temperature exposure range).
3.2.2.2 Waterbased Adhesive Use at Nashua
Nashua currently produces all of its end products using waterbased adhesive formulations.
Nashua discontinued their last solvent-based adhesives before December 31, 1993. The reasons
for this conversion, which included the various regulatory costs associated with solvent-based
adhesives and environmental considerations, are discussed in detail in Reference 1. Nashua
discontinued one product line in order to meet this goal, since it could not find a suitable
waterbased adhesive formulation to replace the solvent-based coating used for the product line.
However, this product line was a relatively small percentage of the plant's output, and Nashua
expects that the loss can be offset with increased sales of its other products.
Nashua operates three coating lines in the Omaha plant. Prior to 1989, Line 1 ran 100
percent solvent-based adhesives. Line 2 is the release coating line which applies a 100 percent
solid-catalyzed silicone release coating to paper stock. This line formerly applied a solvent-based
silicone release coating. Line 3 is another pressure sensitive adhesive coater/laminator label line
which has operated with 100 percent waterbased coatings since 1982 when it was converted from
a waterbased heat seal coating line.
Nashua started the change to waterbased adhesives in 1982 because company executives
felt that waterbased products would have a strong future in the label manufacturing industry. To
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make the changeover, Nashua purchased several new adhesive holding tanks, made of glass-fiber,
in which adhesive could be stored and agitated before use. Polyvinyl chloride (PVC) piping and
new pumps were installed to transfer the product to the coating heads. Nashua experimented with
coating speeds, thicknesses, and drying oven temperatures to determine the optimum conditions.
Within one week, Nashua was able to produce a viable waterbased adhesive-coated product.
Nashua began a complete facility conversion from solvent-based adhesives to waterbased
adhesives in the Omaha plant in 1987. Conversion was a corporate decision although the time
frame for the changeover apparently was not specified. The main factors driving the conversion
were the economic and environmental advantages of waterbased adhesives. Nashua adopted a
policy to replace its solvent-based products with waterbased products which had qualitative
improvements, such as lower production cost and increased temperature range before adhesive
failure. Nashua's research and development (R&D) department was charged with seeking out and
testing new waterbased formulations. Where product improvements were feasible, Nashua
incorporated new waterbased adhesives into its products and offered the improved products to its
customers. The products were not marketed as replacement products for its solvent-based
adhesive-coated products (both were offered as alternatives).
With the passage of the Clean Air Act Amendments of 1990 (CAAA), Nashua decided to
expedite its conversion to waterbased coatings, and to eliminate all solvent use. At that time,
Nashua set a goal of complete conversion to waterbased adhesives by December 31, 1993.
Despite some setbacks, it managed to remain on schedule, and met its goal of complete conversion
to waterbased adhesives.
3.2.2.3 Nashua's Waterbased Adhesive Performance Requirements
For Nashua's niche in the marketplace, there are two primary environmental exposures
to which its products are subject: temperature extremes and varying surface energy of the
adherents (i.e., the surface to which the product is applied). Since each adhesive formulation
generally has limited environmental conditions in which it properly functions, Nashua has
designed its entire adhesive product line to cover a broad range of temperatures and surface
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conditions. Nashua's product lines attempt to cover application temperatures from -30° to 150°F
(-34° to 66°C) on surfaces ranging from corrugated cardboard to smooth plastics.
Nashua was able to cover this spectrum of environmental exposures using solvent-based
adhesives. In its move to waterbased adhesives, it was necessary for Nashua to retain coverage
of this spectrum of applications, or risk losing market segments. For the most part, Nashua has
had success finding waterbased adhesive formulations which met or exceeded the spectrum of
applications of the solvent-based adhesive formulations they replaced.
Nashua described a recent successful waterbased adhesive replacement of two
solvent-based adhesives. Nashua had one client who formerly purchased two label products
manufactured with solvent-based adhesives. One product was used by the client for room
temperature applications, while the other was used at low temperatures. The room temperature
solvent-based adhesive cost Nashua approximately $1.00 per pound (S2.20 per kilogram) of wet
adhesive. The low temperature solvent-based adhesive cost Nashua approximately $1.50 per
pound (S3.30 per kilogram) of wet adhesive. Nashua was able to obtain one waterbased adhesive
product which, at a cost of approximately $1.15 per pound ($2.53 per kilogram), performs in both
the room temperature and cold environments.
Nashua found that some inherent qualities possessed by waterbased adhesives are superior
to solvent-based adhesives for some of Nashua's end product applications. For example, the tack
of waterbased adhesives is generally somewhat lower than for solvent-based adhesives. For the
application of some labels, lower tack is beneficial. If a label is improperly placed, it can be
removed and reapplied without destroying the label. This property leads to additional applications
for waterbased adhesives, including removable/reusable labels. Nashua found that final adhesive
bond strength is generally greater with waterbased formulations, so permanent bonding can be
stronger than with solvent-based adhesives.
While Nashua has had success replacing most of its solvent-based adhesives with
waterbased adhesives, duplicating the performance of every product has not been possible.
Nashua personnel had to cease production of one product for which a suitable waterbased adhesive
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alternative was not found. This product represented a small portion of Nashua's production
volume.
3.2.2.4 Costs of Waterbased Adhesive Conversion
Nashua's conversion to waterbased adhesives required a significant investment of time and
capital. Since 1987, Nashua has purchased 13 glass-fiber tanks for blending and storing
waterbased adhesives. These tanks range in cost from $5,000 to $75,000, excluding installation
costs which are approximately two to three times the purchase cost of each tank. Nashua
purchased new piping and air pumps to transfer the waterbased adhesive to the coating heads on
an as-needed basis as its capacity to coat waterbased adhesives has increased. Piping is relatively
inexpensive while air pumps range from $500 to $2,000 each. Nashua also installed three heat
exchangers to ensure that the waterbased adhesive remains at a constant temperature during
coating. The heat exchangers cost up to $5,000 each with additional installation costs of $2,000
to $3,000 each.
Nashua has incurred additional cleaning costs associated with waterbased coatings. While
the stainless steel tanks and piping of the solvent-based system rarely required cleaning, the
glass-fiber tanks used with waterbased adhesives must be cleaned every six months. Cleaning the
tanks requires approximately 16 man-hours and a labor cost per tank of about $1,000 per year.
Also, waterbased adhesives are more difficult to clean from equipment, resulting in increased
labor.
Nashua also stated that increased output of wastewater has resulted from the conversion.
Wastewater disposal costs are approximately $350 per week higher than before conversion. This
cost includes increased wastewater generated and shipping costs.
In addition to these relatively quantifiable costs, Nashua has incurred some costs associated
with learning to use waterbased coatings. The amount of time spent by Nashua personnel learning
to mix, transfer, coat, and dry waterbased adhesives was significant, although not easily
quantified. Nashua's largest learning costs revolved around the pumping system for transferring
waterbased adhesives to the coating head. Nashua found that waterbased acrylics have a strong
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tendency to dry in the valves of the pumps, causing them to stick. Cleaning the pumps is costly,
time consuming, and can interfere with the production process. Nashua could not quantify the
labor hours that have been spent on pumping problems; however, Nashua considers it a significant
cost of using waterbased adhesives.
3.2.2.5 Reasons for the Conversion
Nashua personnel indicate that there were three motives behind the corporate decision to
switch to waterbased adhesives. One motive was to avoid future regulatory costs. Nashua felt
that future regulations might become stringent enough to make solvent-based adhesive use
unprofitable. Nashua believed that the trend towards higher emissions fees would continue, so
solvent-free waterbased adhesives seemed an appealing alternative to solvent-based adhesives.
A second motive for converting to waterbased adhesives was to become involved in a
developing field of adhesive technology. Nashua plays an active role in professional organizations
and in development work with adhesive formulators and equipment suppliers. According to
Nashua personnel, there was essentially no continuing research aimed at improving current
solvent-based adhesives. Nashua personnel believed that adhesive formulators realized that
solvent usage would be phased out, so the formulators were concentrating their research and
development efforts on other adhesive technologies, such as waterbased, hot melt, and two-part
reactive adhesives. Nashua found that, for its purposes, waterbased adhesives possessed the
performance levels (e.g., tack, adhesion, temperature sensitivity) required by its customers.
Currently, the costs of formulating solvent-based adhesives and purchasing waterbased adhesives
are approximately the same for Nashua [$1 to $4 per dry pound ($2.20 to $8.81 per dry
kilogram)]. With continuing research, Nashua feels that future waterbased adhesive prices may
drop as performance levels increase.
A third motive expressed by Nashua personnel for the conversion to waterbased adhesives
was the company executives' belief that moving towards waterbased adhesives was
environmentally correct. Nashua personnel indicated that the company had other compelling
reasons to convert to waterbased adhesives, as mentioned in the previous paragraphs. However,
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they believed that the executive decision to convert to waterbased adhesives was an attempt to
move into a more environmentally sound means of production, above and beyond monetary
considerations.
3.2.3 FLEXcon Company
3.2.3.1 Introduction
FLEXcon Company, Incorporated began operating one adhesive coating plant in Spencer,
Massachusetts in 1955. Five additional FLEXcon plants have been added to the Spencer complex
since 1955 as increased capacity has been required. Additional production facilities are located
in Connecticut, Minnesota, and Nebraska. Warehousing facilities are located in six different
locations throughout the Unites States and Canada. FLEXcon currently operates within SIC code
3081 (Unsupported Plastics Film and Sheet), although their operations are more typical of an SIC
2671 or SIC 2672 facility. In 1993, FLEXcon had approximately $220,000,000 in sales.
FLEXcon employs approximately 1,100 people company-wide. Of those, 800 employees,
including 600 production staff, are located in the Spencer complex. Normal operating schedules
are two 12-hour shifts per day seven days per week. FLEXcon's Spencer complex has
approximately 570,000 square feet (53,000 square meters) of production space and is composed
of six plants, including coating plants and finishing plants. These six plants differ in their age,
capacity, and end products manufactured.
FLEXcon manufactures six main categories of pressure-sensitive products: graphic films,
packaging labels, electronic printing labels, microembossed films, medical films and labels, and
custom-performance products. The company coats various types of films and many of their end
products require high performance standards such as humidity and corrosion resistance. For these
reasons, FLEXcon considers itself a high performance, specialty pressure-sensitive film
manufacturer.
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3.2.3.2 Waterbased Adhesive Use at FLEXcon
FLEXcon made an effort to convert some of its solvent-based coating lines to waterbased
adhesives in 1983. This effort, which is discussed in detail in Volume IV of this report series,2
was abandoned shortly after its inception. FLEXcon's current waterbased product lines are not
replacements for solvent-based products, but are new product lines aimed at different market
segments. FLEXcon uses a total of approximately 50 adhesive-coating formulations in
manufacturing. Approximately ten of these are waterbased adhesives, while the remainder are
solvent-based adhesives. Waterbased product lines have been growing at an annual rate of 30 to
35 percent per year in the last few years.
FLEXcon began producing a waterbased adhesive-coated product approximately 20 years
ago, using existing equipment. FLEXcon's next experience with waterbased adhesives came
nearly ten years later when they experimented with a large number of waterbased adhesive
coatings before selecting two new products to introduce in 1984. Since 1984, FLEXcon has
steadily increased the number of waterbased adhesive-coated products it manufactures. However,
almost all of FLEXcon's increases in waterbased production have been due to new products, not
replacements for solvent-based adhesive-coated products.
FLEXcon is not currently contemplating any additional waterbased adhesives as
replacements for current solvent-based adhesives. However, it actively pursues improvements
in waterbased adhesives that will allow it to develop new products to expand waterbased adhesive
use in the future.
3.2.3.3 Limitations of Waterbased Adhesives
FLEXcon personnel indicated that significant adhesive performance issues must be
addressed before waterbased adhesives can be fully used in FLEXcon's market segments.
According to FLEXcon, there are currently no waterbased adhesive formulations that can meet
the performance requirements of its clients. The main limitations of waterbased adhesives in
FLEXcon's product market are their lower peel strength, lower sheer strength, limited backing
compatibility, lower humidity resistance, and unsuitability for direct skin contact.
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Many of FLEXcon's products must withstand exposure to extreme temperatures, humidity,
rain, ultraviolet radiation, and high stress conditions. Its products must also be suitable for direct
skin contact and use on low energy backings (e.g., plastic films). FLEXcon manufacturers
adhesive-coated products for use in the electronics industry, which must meet rigorous
performance standards. Its adhesive products designed for medical applications must also meet
exacting performance characteristics. The current spectrum of available waterbased adhesive
coatings does not encompass the breadth of environmental conditions to which FLEXcon's
products are subject.
Additional difficulties in processing waterbased adhesives increase the barriers to their
more widespread use. These processing difficulties are discussed in detail in Volume IV of this
report series.2 However, as previously discussed, the lower performance characteristics associated
with waterbased adhesives are the limiting factor to more extended use. For FLEXcon to
adequately service the needs of its current client base, it must continue to use solvent-based
adhesives.
3.2.3.4 Future Potential for Waterbased Adhesives
Although FLEXcon personnel noted that it would currently be impossible to eliminate
solvent-based adhesive use without drastically altering its client base and market segments, there
are many opportunities for waterbased adhesive use at FLEXcon in the future. As the
performance characteristics of waterbased adhesives continue to improve, new markets are
becoming accessible. FLEXcon continually searches for these new markets in which to sell
waterbased adhesives. It does not see similar opportunities for solvent-based adhesives. For
FLEXcon, sales of solvent-based adhesive-coated products over the past few years have stayed
fairly constant. As a result, FLEXcon is increasing production of waterbased adhesive-coated
products while maintaining current production levels of solvent-based adhesive-coated products.
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In the future, there may be opportunities for FLEXcon to reduce the use of solvent-based
adhesives. Other adhesive technologies, like radiation-cured and two-part reactive adhesives,
might achieve performance breakthroughs allowing replacement of solvent-based adhesives. Key
factors in the development of a radiation-cured system would be a significant reduction in the cost
for radiation sources and the introduction of lower toxicity chemicals than those currently used
in the process. Waterbased and hot melt adhesives are currently better suited for low performance
applications, but continuing research may increase their applicability. FLEXcon personnel
predicted that performance levels of these various adhesive technologies might be high enough to
warrant replacement of many high performance solvent-based adhesives within ten years. As the
performance and marketability of waterbased and other adhesives continue to increase, FLEXcon
personnel believe they will be able to achieve significant conversions from solvent-based
adhesives.
3.3 REFERENCES
1. McMinn, B.W., W.S. Snow, and D.T. Bowman. Solvent-Based to Waterbased Adhesive-
Coated Substrate Retrofit - Volume III: Label Manufacturing Case Study: Nashua
Corporation. EPA-600/R-95-01 lc (NTIS publication number not yet available). National
Risk Management Research Laboratory. Research Triangle Park, NC. December 1995.
2. McMinn, B.W., W.S. Snow, and D.T. Bowman. Solvent-Based to Waterbased Adhesive-
Coated Substrate Retrofit - Volume TV: Label Manufacturing Case Study: FLEXcon
Company Incorporated. EPA-600/R-95-01 Id (NTIS publication number not yet
available). National Risk Management Research Laboratory. Research Triangle Park,
NC. December 1995.
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CHAPTER 4.0
COMPARATIVE ANALYSIS
4.1 GENERAL DESCRIPTION OF PROCESS RETROFIT CYCLE
4.1.1 Technical, Environmental, and Economic Considerations
Despite the enormous variety of products manufactured using waterbased and
solvent-based adhesive coating and laminating equipment, the processes used to manufacture these
products are generally quite similar. All adhesive coating and laminating involves depositing an
adhesive layer of some thickness onto a backing. In waterbased and solvent-based coating, the
types of equipment used to perform this function at different facilities are almost identical: an
adhesive delivery system consisting of pumps and piping, a coating head of some design to apply
adhesive to a backing, an oven to dry the adhesive, and a roller to rewind the backing and dried
adhesive. Some systems also employ a transfer coating system to move adhesive from one
backing to another.
Coating head and oven design are often identical for waterbased and solvent-based
adhesive coating. Only the settings used in these devices (i.e., coating application thickness, oven
temperature and zoning, etc.) vary significantly. Waterbased and solvent-based adhesives must
employ separate adhesive delivery systems, but the cost for these systems is minimal (i.e., tens
of thousands of dollars) when compared to coating head and oven costs (i.e., hundreds of
thousands of dollars).
For most adhesive coaters, the primary factor affecting the decision to convert to
waterbased adhesives is the available performance levels of the adhesives. Waterbased adhesives
do not provide the variety of adhesive strengths of solvent-based adhesives nor the diversity of
environmental conditions in which solvent-based adhesives function well. Waterbased adhesive
performance levels are improving, as many companies are conducting research and development
efforts to enhance their applicability. However, limited performance is still a key drawback to
waterbased adhesives.
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If waterbased adhesives can meet the performance requirements of a manufacturer, a
conversion can yield significant environmental benefits. Full conversion to waterbased adhesives
virtually eliminates solvent emissions and hazardous waste production at a facility, unless solvents
are still used for cleaning purposes. These environmental benefits can translate into economic
benefits for a facility, as emissions control devices and hazardous waste disposal are both very
costly and add no value to end products. However, waterbased adhesives do have some
environmental impacts. Wastewater and adhesive waste sludge (e.g., waste solids from
waterbased adhesive coating) must be disposed of with varying costs, depending on local
regulations.
When both technical and environmental issues have been addressed, a facility can
determine if waterbased adhesive use will produce an economic benefit at the facility. Generally,
low performance and dedicated-line coaters will find waterbased adhesives most attractive. Batch
operations and high performance coaters generally find only limited use for waterbased adhesives,
or may find them economically unsound for their operations. The reasons for this are explained
in Sections 4.2 through 4.4, which discuss technical, environmental, and economic issues related
to waterbased adhesive use in various segments of the industry.
4.1.2 Execution Stages of Retrofit
If a facility has determined that waterbased adhesives are applicable to some or all of its
end products, it can begin to implement a retrofit. The first step in a retrofit is to identify
waterbased adhesives which can meet or exceed the performance levels of currently used solvent-
based adhesives. It is best to first replace lower performance solvent-based adhesives, since
waterbased adhesives generally exhibit lower performance levels. To locate suitable adhesives,
a number of adhesive manufacturers should be contacted. There may be several adhesive
manufacturers with waterbased adhesives that meet the required criteria. Once several potentially
suitable adhesives have been identified and purchased, small-scale performance testing can be
conducted in-house. This process can narrow the potential waterbased adhesive formulations to
a small number. These adhesives can be further tested and evaluated with the help of the clientele
4-2
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for which they are intended. With input from clientele, a final decision can be made as to the
appropriateness of conversion, and which formulation will best meet customer needs.
Once both the facility and the customers are satisfied with a formulation for conversion,
the facility can address equipment issues. For instance, equipment cleaning with waterbased
adhesives is a more onerous task than with solvent-based adhesives. New pumps and piping will
have to be purchased. Coating heads and ovens will require adjustments or additional equipment.
To achieve maximum processing speed, these items may eventually need to be replaced.
To profitably retrofit its solvent-based lines with waterbased capability, a facility must
allow a suitable amount of time. Attempting to perform a retrofit quickly is likely to disrupt
operations and client relationships. A Ml conversion to waterbased adhesives should not be
attempted immediately, but instead waterbased products should be phased in over time to the
maximum extent possible. By slowly introducing waterbased adhesive technology to their plants
and clients, adhesive coaters are much more likely to keep clients happy and remain profitable.
4.2 TECHNICAL RETROFIT BARRIERS TO PROCESS CONVERSION
4.2.1 Introduction
This section discusses the technical considerations associated with converting from solvent-
based to waterbased adhesives. Technical barriers can be divided into three general categories:
chemistry, equipment, and performance issues. Adhesive chemistry issues relate to chemical
characteristics and composition of the adhesive. Equipment issues involve coating supply and
delivery systems, coating head and auxiliary equipment, oven, and cleaning requirements.
Performance issues relate to waterbased adhesives' ability to conform to customer specifications.
These issues are discussed for all industry segments with specific considerations identified for
large versus small and dedicated versus batch facilities. Because performance issues are a
separate topic, they are discussed from the standpoint of high and low performance product
manufacturers. The facility requirements for coating both solvent-based and waterbased adhesives
are summarized in Table 4-1.
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TABLE 4-1. PROCESSING REQUIREMENTS FOR SOLVENT-BASED AND
WATERBASED ADHESIVE COATING IN ALL INDUSTRY
SEGMENTS
Item
Solvent-based Adhesives
Waterbased Adhesives
Storage Area
Must be explosion-proof
No requirements
Backing Materials
Relatively easy to coal on most types of
backings
Primarily coated on paper and some plastic
films
Chem ical /'Corona
Pretreatment
Required for some low surface energy backing
materials
May be required for many non-paper backing
materials
Storage/Mixing/
Holding Tanks
Storage tanks (minimal cleaning requirements)
Stainless steel construction
Above ground (to ease cleaning)
Glass-fiber construction
Agitation required to prevent settling of solids
Piping
Stainless steel
Explosion-proof
PVC or other water-resistant materials
Pumps
High-shearing (diaphragm) explosion-proof
Low-shearing (air)
Adhesive Coating
Properties
Uses solvent vehicle
Solids content generally lower than
waterbased
Foaming is not a problem
Uses water vehicle
Solids content generally higher than solvent-
based
Emulsion instability can cause coating
problems (foaming)
Coating Viscosity
Relatively stable
Must be monitored and altered to ensure
optimum coating viscosity
Heat Exchanger
Not usually required
Sometimes used to control coating viscosity
Coating Head
Most types are satisfactory (e.g.. reverse roll,
air knife, gravure, slot die)
Can coat with most types: however, gravure,
slot die. and Mayer rod may offer fastest line
speeds
Static Grounding
Required to prevent explosive potential
Not usually required
Drying/Curing Oven
Low initial temperature, rising through oven
Volatile solvents evaporate quickly
Requires VOC level monitoring
Sufficient airflow required to maintain solvent
concentrations below LEL
High initial temperature, sometimes dropping
through oven
No VOC monitoring required
May require more energy to evaporate water
Sufficient airflow required to increase heat
transfer (i.e.. water evaporation)
Misting System
Not required due to low oven temperature
May be required to replace natural moisture
content in paper substrates
Emissions Control
Carbon adsorption, thermal or catalytic
oxidation
No emissions control required
Cleaning
Flushing with solvents
No adhesive particle settling
Required more often
More scraping and peeling of settled solids
required (if solvents are not used in cleaning)
4-4
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4.2.2 Chemistry
4.2.2.1 Solvent-based and Waterbased Adhesive Chemistries
Solvent-based adhesives are solutions, in which adhesive resins are completely dissolved
by the solvent (e.g., toluene or MEK). Waterbased adhesives are emulsions, in which adhesive
particles are suspended in water. Waterbased adhesives typically have larger particle sizes than
solvent-based adhesives.1 Due to the emulsion state and larger particle size, settling of waterbased
adhesive particles poses adhesive transfer problems. Settled particles will not readily re-enter the
emulsion state as they would in solution adhesives.1 Settled particles that may become
re-entrained during the coating of waterbased adhesives will cause defects in the adhesive-coated
product.2
Foaming is another critical factor in waterbased adhesive use. Excessive agitation in the
storage tanks or excessive pumping rates can trap air bubbles in a waterbased adhesive. These
trapped air bubbles can create foaming in the storage or mixing tanks, foaming at the coating
head, or can cause unevenness or gaps in the adhesive coating on the web. Foaming is not a
problem with solvent-based adhesives, since these formulations are in solution and tend not to trap
air bubbles.
Viscosity control is also critical for waterbased adhesives to attain good wetout (i.e.,
coating smoothness and evenness) and coating thickness control. Viscosity control is difficult
because waterbased adhesives are an emulsion, rather than a solution. The desirable waterbased
adhesive coating viscosity must be thoroughly examined before pumps, transfer lines, and coating
configurations are designed and installed.3 Facilities may have to employ viscometers at the
storage, mixing, or delivery tanks to monitor and maintain coatable viscosities. Since viscosity
is related to temperature and humidity, some waterbased adhesives require temperature controls
to maintain optimum coating viscosity. Ingredients may also be added periodically to the mixing
tank to adjust viscosity.1-4 Solvent-based adhesive viscosities tend to be lower than waterbased
adhesive viscosities and are less susceptible to temperature fluctuations.1
Nashua found that for its process, waterbased coating viscosities in the range of 500 to
2,000 centipoise are best. For other manufacturers, the optimal coating viscosity will vary
4-5
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depending on the coating technique used. Sometimes Nashua uses a heat exchanger prior to
adhesive delivery to the coating head to ensure optimal coating temperature.1
Coating application thickness is another element of waterbased adhesives requiring strict
control. In general, waterbased adhesives have a higher solids content than solvent-based
adhesives. Proper coating thickness requires adhesive metering control adjustment. To adjust
thicknesses on a reverse roll coater, the nip gap distance and reverse roll speed must be adjusted.
In direct coating operations, the doctor blade or similar device used for metering would require
adjustment.
At Nashua, the waterbased coating thickness is generally similar to comparable solvent-
based coatings. This is because Nashua's waterbased coatings have the same solids content range
as its old solvent-based coatings (waterbased 30 to 60 percent, solvent-based 30 to 70 percent
solids).1 At FLEXcon, the solids content of waterbased adhesives is higher than solvent-based
adhesives, allowing lower coating thicknesses.4 Nashua's coating thicknesses range from 0.001
to 0.003 inches (0.025 to 0.076 millimeters) for both types of adhesives.1 FLEXcon's solvent-
based adhesive coating thicknesses range from 0.001 to 0.003 inches (0.025 to 0.076 millimeters)
while their waterbased adhesive coating thicknesses range from 0.001 to 0.002 inches (0.025 to
0.051 millimeters).4
When considering retrofitting, a manufacturer must determine whether to purchase
pre-formulated adhesives, or formulate adhesives onsite. Manufacturers who currently formulate
their own solvent-based adhesives may see advantages and disadvantages to formulating
waterbased adhesives. Advantages include reduced solvent usage, disposal, and emissions;
elimination of solvent-containing storage tanks; elimination of explosion-proof storage areas,
pumps, and motors; and the potential to reduce raw material costs, as solvents are invariably more
expensive than deionized water. Disadvantages may include difficultly in controlling coating
viscosity, generation of wastewater during the deionized water manufacturing process, and
additional wastewater streams generated from the waterbased coating process.
Nashua noted that the same amount of time (three to four hours) is typically required for
formulating its solvent-based adhesives or making additions to their preformulated waterbased
adhesives. However, some of its waterbased adhesives require agitation between additive
additions, increasing the total mix time to a maximum of eight hours.1 No other information was
4-6
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available on the time, labor, or material requirements of formulating waterbased versus solvent-
based adhesives.
4.2.2.2 Solvent Retention
When an adhesive is dried in an oven, a small amount of solvent must be left in the
adhesive in order to allow for adhesive flexibility and proper tack. The term solvent retention
describes the amount of solvent that remains in the adhesive after it has left the oven. This
amount varies, but is generally less than one percent of the solvent that was initially in the
adhesive. Proper solvent retention is critical in ensuring that the adhesive functions appropriately.
A discussion of solvent retention is included here to facilitate the reader's understanding of
solvent-based adhesive coating and the potential emissions from different solvents and coating
practices.
The most important factor in determining solvent retention is the choice of solvent used
in the adhesive formulation. Different solvents have markedly different vaporization temperatures
and evaporation rates, as well as other properties that affect solvent retention. Oven configuration
(e.g., temperature, air flow, and drying time) is the second most important factor in determining
solvent retention. Since coating head type has little to do with solvent retention, no correlation
was attempted between these two parameters.
An attempt was made to evaluate solvent retention times for adhesives. A solvent's
retention time can be defined as the amount of time that it requires to evaporate in comparison to
other solvents under similar drying conditions with other variables (e.g., coating makeup and resin
hardness) kept constant. Solvent retention time is a critical factor in determining the necessary
process line setup to allow for proper solvent retention.
Unfortunately, few data were found during the research for this report on solvent retention
times for adhesives. There are information sources on solvent retention times for paints;
however, these sources are dated (i.e., 1975 and before), and the dissimilarities between paints
and adhesives might lead to variations in retention times. However, some characteristics of
solvents and resins affecting retention times can be evaluated. These characteristics include molar
volume, solvent volatility, polymer-solvent interactions, size and shape of the solvent molecule,
and resin hardness.
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Molar volume is the volume that a gram mole (i.e., formula weight in grams) of liquid at
standard temperature and pressure (i.e., 0° Celsius and 1 atmosphere). Molar volume depends
on a number of factors, including molecule size, polarity, and other molecular attributes and
interactions. It is the most significant solvent or resin characteristic effecting solvent retention.
Smaller molecules can be expected to occupy smaller molar volumes, and differences in molecular
polarity can cause either smaller or larger molar volumes. Generally, as the molar volume
decreases, less solvent retention can be expected.
Solvent volatility (i.e., evaporation rate) also depends on molecule size, polarity, and other
molecular attributes. As with molar volume, smaller molecules can be expected to have higher
volatility. Also, decreasing polarity is coupled to increasing volatility. Generally, as solvent
volatility increases, less solvent retention can be expected.
The final three characteristics affecting solvent retention are generally less important than
the first two (i.e., molar volume and solvent volatility). Polymer-solvent interactions are
generally complex and depend on solvent and polymer characteristics. These interactions may
increase or decrease molecular attraction between the solvent and polymer. Larger and more
complex shapes of solvent molecules have greater retention. Increasing resin hardness causes
increased retention.
Evaluation of the above characteristics should be an excellent indicator of solvent retention
times from a solvent/adhesive system. An evaluation of these variables, along with actual coating
experiences with the system, should allow oven configurations to be altered to ensure proper
drying of the adhesive. The most logical way to evaluate solvent retention is to examine each
solvent/adhesive combination individually. However, no studies could be found that have
performed such examinations for adhesives. Table 4-2 lists 27 common solvents in increasing
order of retention from one such study for paints.5
4.2.3 Equipment
As stated in Section 4.2.1, the equipment barriers associated with waterbased adhesives
are common to all adhesive coating industry segments because the processing equipment used
to manufacture adhesive-coated and laminated substrates is quite similar for solvent-based and
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TABLE 4-2. TYPICAL SOLVENTS IN INCREASING ORDER OF
RETENTION IN PAINTS
Solvent
Molar Volume (cm3)
Evaporation Rate
(n-butyl acetate = 1.0)
Methanol
40
4.1
Acetone
73
10.2
2-Methoxyethanol
79
0.51
Methyl ethyl ketone
90
4.5
Ethyl acetate
97
4.8
2-Ethoxyethanol
97
0.35
n-Heptane
146
3.3
2-Butoxyethanol
130
0.076
n-Butvl acetate
132
1.0
Benzene
88
5.4
2-Methoxyethy] acetate
117
0.35
2-Ethyloxyethyl acetate
135
0.23
Dioxan
85
NA
Toluene
106
2.3
Chlorobenzene
101
NA
2-Nitropropane
90
1.5
m~Xylene
122
0.75
Methyl isobutyl ketone
124
1.4
Isobutyl acetate
133
1.7
2,4-Dimethyl pentane
148
5.6
Cyclohexane
108
5.9
Diacetone alcohol
123
0.095
Pent-oxone
143
0.26
Methyl cyclohexane
126
3.5
Cyclohexanone
103
0.25
Methyl cyclohexanone
122
0.18
Cyclohexyl chloride
118
NA
NA- Not available
4-9
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waterbased adhesives. The number of coating lines may vary from a small facility to a large
facility, but, in most cases, the equipment is only slightly different.
4.2.3.1 Adhesive Storage/Delivery
In most instances, above-ground glass-fiber lined storage tanks are used for waterbased
adhesives. These tanks usually contain agitation blades to minimize the amount of solids that
settle in the tank and to maintain coatable viscosities.13,6 As stated in Section 4.2.2, waterbased
adhesive storage tanks normally require continuous viscosity measurement to ensure proper
coating viscosity.1
An advantage of waterbased adhesives is that pumps and piping are not required to be
explosion-proof like solvent-based pumps and piping.' However, pumps and piping used with
waterbased adhesives must be water-resistant and easily cleanable. Nashua uses PVC piping to
transfer its waterbased adhesives and replaces them when they become fouled.1 Stainless steel
piping may also be used; however, waterbased adhesives may eventually clog this piping, thus
prohibiting the sale of replaced piping as scrap metal.7 High-shearing pumps are typically used
with solvent-based adhesives; however, waterbased adhesives require lower shearing pumps, such
as the air cylinder type.1,4
As discussed in Section 4.2.2, waterbased adhesives have larger particle sizes than solvent-
based adhesives. Therefore, a conversion to waterbased adhesives would require new filters with
larger mesh sizes to allow filtering of waterbased adhesives.1
Due to the difficulties in formulating adhesives, many adhesive coaters buy pre-mixed
adhesives, store them in their shipping containers, and then directly transfer the adhesive via
pumps to the coating head.4 Any additional mixing required of the supplied adhesive occurs in
the shipping container. This direct delivery eliminates the need for lengthy piping systems and
allows waterbased coating viscosity to be monitored directly as the coating is delivered to the
coating head. Cleanup time is also reduced by direct delivery. The only required cleaning would
take place in the coating trough and coating head. Some manufacturers line their coating troughs
with plastic or another thin liner to reduce the cleanup requirement between batch jobs.4
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4.2.3.2 Coating Head
One of the most important equipment retrofitting requirements for waterbased adhesives
is the coating head. In many instances, the coating head used for solvent-based adhesives may
be used to adequately apply waterbased adhesives with little or no modification.8,9 However, in
order to achieve optimal coating speed of waterbased adhesives, the coating head may have to be
altered or replaced.
For example, prior to conversion Nashua used direct and direct reverse gravure coating
heads to apply solvent-based adhesives. After conversion, Nashua used the same reverse-roll
gravure coating technology, with some adjustments to maintain the process line speeds at their
solvent-based levels [ranging from 300 to 1,200 feet (91 to 366 meters) per minute].1 The coating
of waterbased adhesives can, however, be faster than coating solvent-based adhesives for two
reasons: (1) the generally higher solids content and lower coating weights required of waterbased
adhesives allows less coating to be applied (less coating applied results in faster line speeds), and
(2) the lower speeds at which solvent-based lines may be required to operate at to limit the
potential for VOC emissions from the coating process.1,4
Many conventional facilities that coat solvent-based adhesives with reverse roll coating
heads may be required to convert to other technologies to achieve faster line speeds with
waterbased formulations. Two manufacturers noted that they were currently at maximum speeds
with waterbased coating using reverse roll, and that increasing their line speeds will require
switching to another coating technology such as gravure or slot die.1,4
While researching this report, ten general coating head types were identified as currently
in use in the adhesive coating industry. These coating head types are described in Table 4-3 along
with their respective adhesives, backings, and waterbased adhesive experiences. As indicated in
Table 4-3, several coating heads are capable of producing waterbased adhesive-coated product.
As previously discussed, waterbased adhesive coatings are generally used in products
aimed at the commodity sector of the adhesive coated product marketplace. Since these products
are usually not subject to the rigorous performance requirements of specialty or high-performance
products, end product characteristics are not as critical in most waterbased adhesive-coated
products. However, as performance levels of waterbased coatings increase with advances in
research, several of the coating methods will likely prove to be preferable in waterbased coating
4-11
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TABLE 4-3. GENERAL INFORMATION ON COATING HEAD TYPES CURRENTLY USED IN THE ADHESIVE
COATING INDUSTRY
Coating Head Type Description
Applicable Adhesives Applicable Backings'
Uk Level in
Industry
Description of
Potential or Actual
Use with Waterbased
Adhesive*
-i^
I
(3
Blade/Knife over
Roll, Floating or
Trailing
Blade/Knife
Costers'
Dip and Squeeze
Coaler
Air Knife Coater
Offset Application
Roll
Slot-Die Coater*
Direct Application
Roll Coater
Reverie Roll Coater
Blade/knife removes excess
adhesive from backing
Backing is immersed in
adhesive and then squeezed
between two rollers to
remove excess adhesive
Similar to blade/knife
coaters, except high speed
air is used to remove excess
adhesive, which is captured
in a blow-off hood
One roller picks up adhesive
and transfers it two a second
roller, which applies the
adhesive to the backing9
Adhesive coated on backing
in tank; slot in tank removes
excess
Adhesive applied by roller
travelling in direction of
backing
Adhesive applied by roller
traveling In reverie
direction of backing
Knife: solvent-based
Blade: solvent-based
and waterbased
Solvent-based
Solvent-based, low
weight waterbased
Silicone, low weight
waterbased and
solvent-based
Mostly hot melt
adhesives, some
waterbased and
solvent-based use
Solvent-based and
waterbased
Solvent-based and
waterbased
Paper, plastic, fabric
Paper, fabric
Paper, plastic, fabric
Fabrics and plastics,
some high performance
paper
Plastics, some high
performance paper
Paper, plastic
Paper, plastic
Extensive but
decreasing use
Limited use
Limited use
Limited but
increasing use
Limited but
increasing use
Widely used
Widely used
Knife results in
uneven coating;
blade produces
acceptable product
Might be applicable
for products
requiring an
adhesive-soaked
backing
Applies adhesive
well, but can cause
foaming problems at
application line
Applicable Tor rough
substrates and
viscous adhesives
Applicable; limited
use with waterbased
adhesives
Applicable:
waterbased adhesives
used frequently
Applicable;
waterbased adhesives
used frequently
(continued)
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TABLE 4-3. GENERAL INFORMATION ON COATING HEAD TYPES CURRENTLY USED IN THE ADHESIVE
COATING INDUSTRY (continued)
Coating Head Type
Description
Applicable Adhesives
Applicable Backings'
U#t Level In
Industry
Description of
Potential or Actual
Uae with Waterbased
Adhesires
Metering Roll
Coater*
Metering roll traveling In
opposite direction to
applicator roll removes
excess adhesive
Solvent-based and
waterbased
Paper, plastic
Widely used
Applicable;
waterbased adhesives
used frequently
Metering Rod
Coater1
Similar to a metering roll,
except the metering roll has
a wire wound around Its
length
Low weight solvent-
based and waterbased
Paper, plastic, fabric
Widely used
Applicable;
waterbased adhesives
used frequently
Direct or Reverse
Roll Gravure Coater
Adhesive applied by etched
or engraved roller, roller
may be forward or reverse
roll
Solvent-based and
waterbased
Paper, plastic
Widely uied
Applicable; gravure
density must be
smaller than for
solvent-based
application
'Many backing materiili (especially plastics and fabric*) are not compatible with waterbased adhesive* because of the high surface tension of the emulsions.
'These are all aimllar coating methods, in which • flexible blade or rigid knife is used to remove excels adhesive and smooth the surface adhesive after coating
in an adhesive trough or by a direct or reverse roll coating roller.
'Usually, the firit roller is an etched or engraved (i.e., gravure) roller. In this case, this coating method may be known as offset gravure coating.
'Metering rolls are often used in combination with a direct or reverse roll coater.
'This is also known u a bar coater or Mayer rod coater. Metering rods are often used in combination with a direct or reverse roll coater.
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application. Currently, the adhesive application industry is dominated by gravure, metering rod,
metering roll, blade, and knife coating.1011 The coating methods with proven industrial
experience with waterbased adhesives include direct or reverse roll gravure, metering rod, and
metering roll coating.
Although most amenable to retrofitting from solvent-based to waterbased application, the
gravure density of the application roller must be increased to allow for an even coating of high
surface-tension waterbased adhesives. Metering rod and metering roll coating can be retrofitted
as well, although the metering device must be kept clean to reduce fouling. Fouling is prevalent
in metering rolls, which contain crevices that can trap adhesive solids. Knife coating is generally
not used in waterbased adhesive application, as fouling of the knife eventually results in uneven
coating and an unacceptable product. Blade coating can also be subject to fouling problems, but
blade coating production lines have been successfully adapted to waterbased adhesive application.
Since each coating line and product have different characteristics and requirements, retrofitting
capabilities must be examined on an individual basis.11
Coating thicknesses can be controlled by altering various parameters in the coating head
configuration. Since coating heads differ markedly in design, these parameters vary widely as
well. For instance, for a gravure coater, gravure density is the most important variable in
determining coating thickness. For a blade or knife coater, blade or knife pressure on the
substrate is the most important variable.1011 Table 4-4 displays important coating thickness
variables for different coating heads.
Although the parameters listed in Table 4-4 markedly affect coating thickness, they must
be adjusted to achieve the desired qualities of the adhesive. For example, a typical high surface
tension waterbased adhesive will have a thicker application than a typically lower surface tension
solvent-based adhesive using the same coating head configuration.Adhesive coating thicknesses
on the backing are typically described in thousandths of an inch, or "mils".
Adhesives are usually described in terms of their solids content. For example, a solvent-
based or waterbased adhesive may be 33 percent solids, with the remaining 67 percent composed
of the carrier (i.e., solvent and/or water). In this instance, the thickness of the final coating,
which will be primarily composed of adhesive solids with a small percentage of residual carrier,
will be approximately 33 percent of the wet application thickness. In this case, a three mil
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TABLE 4-4. IMPORTANT COATING THICKNESS PARAMETERS FOR
VARIOUS COATING HEAD TYPES
Coating Head Type Important Coating Thickness Parameters
Blade/Knife over Roll, Floating
Blade or knife pressure on the substrate
or Trailing Blade/Knife Coaters
Dip and Squeeze Coater
Squeeze roller pressure on the substrate
Air Knife Coater
Air pressure from the blowers on the substrate
Offset Application Roll
Pressure between pickup and application rollers,
application roller pressure on backing
Slot-Die Coaters
Slot/die width
Direct Application Roll Coater
Application roller pressure on backing
Reverse Roll Coater
Pressure between pickup and application rollers,
application roller pressure on backing
Metering Roll Coater
Metering roll pressure on substrate
Metering Rod Coater
Wire gauge used on metering rod, metering rod
pressure on substrate
Direct or Reverse Roll Gravure
Gravure density, application roller pressure on
Coater
backing, pressure between pickup and
application rollers (reverse roll gravure coating
only)
adhesive application at the coating head would translate to a one mil coating thickness at the end
of the oven. Table 4-5 displays typical ranges of dry coating thicknesses in some commonly used
adhesive coated products.
4.2.3.3 Oven
Another major equipment consideration for waterbased adhesive retrofit is the oven. A
retrofit to waterbased adhesives involves oven temperature and airflow reconfiguration. Water
has a heat capacity of 972 British thermal units (Btu) per pound (540 calories per gram) and
4-15
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TABLE 4-5. FINAL DRY ADHESIVE COATING THICKNESSES OF
COMMONLY USED PRODUCTS IN THE ADHESIVE
COATING INDUSTRY
Product Type Range of Coating Thickness (mils)
Paper labels
1.0
Paper transfer tape
1.0
Plastic labels and decals
1.0 to 1.5
PVC finger bandage
1.5 to 2.0
Silicone electrical tape
1.5 to 2.0
Diaper tape
1.5 to 2.0
Polyester packaging tape
2.0 to 3.5
Polypropylene strapping base
2.5 to 4.0
Acetate office tape
2.5 to 3.0
Aluminum foil duct tape
2.5 to 3.5
Printable computer tape
3.0
Porous hospital tape
3.0 to 4.0
Trainer's tape
4.0 to 5.0
Velcro strip
5.0 to 7.0
Glass-reinforced polyester tape
5.0 to 7.5
Film labels and decals
6.0
Paper masking tape
6.0 to 7.0
Coated cloth packaging tape
12.0
Corrosion protection tape
12.0 to 15.0
requires heating above 212°F (100°C) to achieve rapid evaporation. Typical solvents, such as
toluene or MEK, have heat capacities in the range of 180 to 360 Btu per pound (100 to
200 calories per gram) and may only require oven temperatures as high as 180°F (82 °C). At both
FLEXcon and Nashua, the temperature settings through the oven for waterbased coatings are
generally around 250°F (121 °C), although Nashua stated that the last oven zone temperatures are
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generally cooler than 250CF (121 °C). Both facilities also used approximately the same oven
temperature configuration for solvent-based adhesives with initial zone temperatures around 200JF
(93CC) and final zone temperatures nearing 100°F (38°C). Also, FLEXcon and Nashua employ
IR heaters in the oven zones to assist in evaporating the water from waterbased adhesives thus
reducing drying time and oven heating requirements.1,4 The IR heaters were not required for
solvent-based adhesives.1,4
The higher heat capacity of waterbased adhesives may necessitate an increase in oven
capacity. However, the exact amount of oven capacity required is plant-specific and process-
specific. For example, Nashua had enough oven capacity to convert from solvent-based to
waterbased adhesives without increasing oven length or reducing process speeds. The limiting
factor for process coating speed at Nashua is the coating head. Nashua noted that its overall
energy requirements and total airflow in its ovens have remained approximately the same after
conversion, although temperature and airflow configurations have changed.1 However, a
manufacturer with significantly smaller ovens may be required to either decrease process line
speed or increase oven capacity. Oven capacity increases may be hampered by space limitations
within a facility.
Airflow is an important variable to consider in oven design and retrofitting, and
significantly effects the maximum temperature {i.e., heat transfer rate) at which the oven can
operate. The type of airflow nozzles used, the distance of nozzles from the adhesive surface,
spacing between the nozzles, and other variables of nozzle design and arrangement are not
amenable to frequent change or adjustment. This is because proper airflow arrangement is very
important to uniform drying (heat transfer) across the web width, especially as oven temperatures
increase.11 Proper airflow for waterbased adhesives is more easily attained in ovens with high
heat transfer capacities. For example, Nashua's ovens had tremendous excess capacity for
processing solvent-based adhesives. This allowed the transfer to waterbased adhesives to proceed
without great effects on oven airflow configuration.1
The maximum oven temperature increase to accommodate the higher heat capacity of
waterbased adhesives is also limited by the properties of the backing. Some backings, such as
metal foils, are unaffected by high oven temperatures, but other backings, like papers and plastic
films, must be carefully monitored to ensure that backing deformation does not occur. For
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example, the high temperatures required to dry and cure waterbased adhesives tend to remove the
natural moisture content from paper backings. This causes the paper to curl, which is detrimental
to subsequent lamination and finishing processes. Facilities applying waterbased adhesives to
paper backings may employ a re-moisturizing system either at the oven exit or in the last zone(s)
of the oven. FLEXcon and Nashua both employ systems designed to re-moisturize the
waterbased-coated paper backings to reduce curl and ease laminating, topcoat, and other finishing
operations.14
A benefit of waterbased adhesives is that lower explosive limit (LEL) meters are not
required in the ovens to measure VOC concentration levels. These meters can be expensive to
maintain.
4.2.3.4 Cleaning
Cleaning requirements are generally increased with waterbased adhesives. Once a
waterbased formulation has dried, the solid particles do not readily re-emulsify. These solids
form a hard layer which water will not penetrate. Generally, increased scraping and peeling,
combined with cleaning solutions consisting of soap and water or low volatility solvents, are
required to effectively clean dried adhesive residue.1
4.2.3.5 Emissions Control
Other equipment considerations include the emissions control equipment and solvent
recycling system. Obviously the elimination of solvent-based adhesives would eliminate the need
for emissions control equipment. This equipment would have to be decommissioned, and
probably removed and disposed of or sold. However, for an existing facility which converts only
some of its end products to waterbased adhesives, the system would have to remain functional.
A bypass would have to be installed so that when operating with waterbased adhesives, the
captured water vapor is directed to the atmosphere instead of the control equipment. Water vapor
can severely foul a carbon adsorption system and is very costly to incinerate.
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4.2.4 Personnel Issues
Both solvent-based and waterbased adhesive-coating facilities have a similar number of
production employees in proportion to the number of coating lines at the facility. This is because
coating line processes and equipment are very similar for high or low performance and batch or
dedicated facilities.
Nashua noted that maintenance requirements have remained approximately the same as
before their conversion. This is because the new maintenance requirements associated with
waterbased adhesives have absorbed maintenance capacity previously associated with
solvent-based adhesives (e.g., maintenance on the carbon adsorption system).1
Depending on the level of operator and engineer expertise with waterbased adhesives,
some additional training time will be required during conversion to waterbased adhesives. Due
to the differences in coating techniques for waterbased adhesives, a facility generally undergoes
a learning period during the retrofitting process. This learning period involves adjusting
equipment, raw materials, and expertise to match the characteristics of waterbased adhesives. As
operators become more experienced with waterbased adhesives, problems such as foaming and
improper coating will become less frequent.
In addition, personnel safety issues are generally reduced with the use of waterbased
adhesives. For example, electrical grounding of coating and finishing equipment and/or
humidifier use in manufacturing areas are normally required to run solvent-based adhesives.1,13
These actions reduce the explosive potential that an inadvertent spark could cause if generated in
the vicinity of a solvent. Solvent-free waterbased adhesives exhibit no such explosive potential.
Also, elimination of solvent usage reduces Occupational Safety and Health Administration
(OSHA) requirements for monitoring VOC concentration levels in and around the work area to
protect production workers.
4.2.5 End Product Performance
The primary retrofit barrier associated with waterbased adhesives in any industry segment
is their limited end use applications due to end product performance restrictions. Many high
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performance end product manufacturers stated that waterbased adhesives do not exhibit the high
performance levels of solvent-based adhesives. The differences between retrofit requirements for
high or low performance facilities, as well as large or small and batch or dedicated facilities, are
summarized in Table 4-6.
TABLE 4-6. TECHNICAL BARRIERS ASSOCIATED WITH PROCESS
RETROFIT BY INDUSTRY SEGMENT
Industry Segment
Barriers
Large or Small
High Performance or
Low Performance
Dedicated or Batch
Larger facilities may have difficulty redesigning their floor space to
accommodate longer ovens, wastewater treatment operations, and new
waterbased adhesive storage and transfer equipment.
Small facilities may be in a better position to incorporate new equipment
and grow.
Waterbased adhesives do not yet exhibit all of the high performance
characteristics of solvent-based adhesives.
Many backing materials are not compatible with waterbased adhesives
because of the high surface tension of the emulsion.
Waterbased adhesives perform better in dedicated facilities or long batch
operations due to the longer time required for them to equilibrate on the
coating web and the increased cleaning time between jobs.
Dual coating facilities that convert some of their solvent-based products to
waterbased will have to maintain separate adhesive storage, transfer, and
waste handling systems; require adjustment of the coating head, oven
temperature profile, and oven airflow configuration, and an emissions
control equipment bypass.
Waterbased adhesives are not compatible with many backings. For some high
performance products, backings include low surface energy materials such as plastic films, metal
foils, vinyls, and foams. Water is a relatively high surface tension material and has difficulty
achieving proper coating dispersion, or wetout, on these backings. Additional process steps such
as chemical or corona pretreatment of the backing may be required to increase the backing's
surface energy. However, solvents exhibit low surface tensions and will readily wetout most
backings. Paper is a relatively high surface energy material on which waterbased adhesives can
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generally be coated with no pretreatment. Many transfer coating processes use a silicone-coated
paper release liner to transfer the waterbased adhesive to its backing material.
Many low performance applications, such as paper labels and masking tapes for low to
moderate end use environments, have been readily converted from solvent-based to waterbased
adhesives. This is due to the low end product performance requirements and ease of coating
waterbased adhesives on those particular backings.
Many facilities coat both commodity and specialty products for their customers. These
facilities may have the potential to convert some of these products to waterbased adhesives.
However, conversion of a few products rather than an entire end product line requires additional
equipment for the coating line and additional waste separation and disposal activities. The two
facilities noted that it is possible that some of their lower performance solvent-based adhesives
could be replaced with a combination of waterbased adhesives.4 However, the conversions are
not currently economically feasible for the particular products that could be converted.
FLEXcon officials noted that while there are process difficulties associated with coating
waterbased adhesives, the primary limiting factor for waterbased coatings are their lower
performance characteristics.4 The chemistry of waterbased adhesives has not evolved to rival
solvent-based adhesives in most applications. The main limitations of current waterbased
adhesives for use at FLEXcon are listed below:
• Lower peel strength at room temperature
• Lower sheer strength at high temperatures
• Less flexibility in adhesion to a broad range of backings
• Lower humidity resistance
• Limited products that can be used for direct skin contact
An important aspect of adhesive performance was discussed during all of the site visits
conducted for this comparative analysis report. The performance of any given waterbased
adhesive cannot exactly overlap the performance of a particular solvent-based adhesive. This is
illustrated in Figure 4-1. The figure shows that a given solvent-based adhesive will cover an area
of applicability for a certain range of backing surface energies and temperatures. Although a
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particular waterbased adhesive may overlap this area and cover additional temperature ranges and
backing surface energies, no waterbased adhesive can completely fill the area of the conventional
solvent-based adhesive. To make a complete conversion to waterbased adhesives, a
manufacturing firm would have to change the configuration of its end product line to
accommodate the different range of performance among its products. This re-configuration can
disturb its customers, who may not be willing to alter their purchasing arrangements.
Conversions to waterbased adhesives must nearly always involve customer input during the
development of the new product to make sure that the new product can achieve or exceed the end
product performance of the old solvent-based product.
4.2.6 Considerations for Dedicated and Batch Operations
The technical retrofit considerations for dedicated versus batch segments of the adhesive
coating industry are primarily related to coating equipment and cleaning operations. The
differences between retrofit requirements for dedicated or batch facilities, as well as large or small
and high or low performance facilities, are summarized in Table 4-6.
One limitation identified with waterbased coatings is that they perform better in dedicated
facilities or those that perform long (i.e., greater than eight hours) batch operations. Waterbased
adhesives typically require longer production runs than solvent-based adhesives in order to get
usable end product. Waterbased adhesives require stricter process controls than solvent-based
adhesives, as coater conditions must be optimum before process speeds can be increased. Solvent-
based adhesives are well-suited for short production runs (i.e., batches) due to their excellent
wetout properties. FLEXcon officials noted that their waterbased product must be run at least
approximately 2,500 yards (2,300 meters) in backing length to ensure a profit on the production
run. For solvent-based products, production runs of approximately 250 yards (230 meters) may
be performed profitably and without coating complications.4
One factor causing longer production runs is that waterbased adhesives require additional
equipment cleaning time. Extensive cleaning is necessary when alternating between solvent-based
and waterbased adhesives. One manufacturer noted than when alternating between solvent-based
to solvent-based or waterbased to waterbased coatings, the cleaning time is normally less than one
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Low—Smooth
Plastics
Surface
Energy
High-Corrugated
Cardboard
Solvent—based
Adhesive §4
"t
Waterbased
Adhesive #2
r
1
Solvent—bosed I
Adhesive § 1
~i
Waterbased
Adhesive #4
Solvent—based
Adhesive #3
Waterbased
Adhesive #1
r"
i
i
i
Solvent-based
Adhesive §5
I!
J
Waterboeed
Adhesive
Solvent—based
Adhesive #2
-30*
Temperature "F
150"
Figure 4-1. Applicability range of solvent-based and waterbased adhesives.
-------
hour. However, when alternating between solvent-based and waterbased coatings, cleaning time
is one to two hours.1
A second factor causing longer production times is that waterbased adhesives take some
time to equilibrate on the backing during a production run. This causes excess coated paper waste
before the coating head begins producing marketable product. For solvent-based coated products,
a 50-yard (46-meter) production run is possible without coating problems.4 For waterbased
adhesives, minimum production runs are longer, although the increase varies depends on a
number of factors, including the compatibility of the adhesive with the backing. However,
waterbased adhesive runs are almost always in the hundreds of yards (meters), since cleaning
requirements between runs are extensive.
In addition, for batch or dedicated operations which convert a process line to dual coating
capability, the technical retrofit requirements are more complicated. Solvent-based coating lines
which convert to dual coating capability will require new storage tanks, mixing/holding tanks,
adhesive delivery systems, and coating heads compatible with waterbased adhesives, in addition
to their existing solvent-based equipment. Separate equipment for solvent-based and waterbased
adhesives is a necessity, since the cleaning requirements for both are very different. Normal
solvent-based cleaning operations involve solvent flushing between batches, with the residual
solvent and adhesive mixture collected for disposal or reuse in the next adhesive batch.
Waterbased operations require flushing with water, and sometimes detergent, which can be very
detrimental if mixed with a subsequent batch of either waterbased or solvent-based adhesive. In
the operating environment of a coating line, in which cleaning operations and waste disposal are
both costly procedures, it is not practical to consider using one delivery system for both
waterbased and solvent-based adhesives.
4.3 ENVIRONMENTAL BARRIERS TO PROCESS CONVERSION
4.3.1 Introduction
The environmental impacts associated with converting to waterbased adhesives may be
summarized as reducing solvent air emissions and hazardous waste streams while increasing
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TABLE 4-8. ENVIRONMENTAL MEDIA IMPACTS FOR SOLVENT-BASED
AND WATERBASED ADHESIVES IN ALL INDUSTRY SEGMENTS
Environmental
Media
Solvent-based Adhesives
Waterbased Adhesives
Air
Wastewater
Hazardous Waste
Non-hazardous
Waste
Stack and fugitive emissions from:
Emissions control exhaust
Equipment leaks
Adhesive storage and transfer
Cleaning operations
Coating application
Most liquid waste from solvent-based
operations contains some amount of
solvent and must be disposed of as
hazardous waste.
Hazardous waste generated from:
Spent adhesive
Spent cleaning solvents
Recovered solvents (via
emissions control equipment)
Non-hazardous waste generated from:
Line start-up
Finishing operations
Solvent-free waterbased adhesives
generate no stack or fugitive air
emissions.
Wastewater generated from:
Cleaning operations
Waste adhesive
Deionized water
Hazardous waste may continue to be
generated if solvents are used in
waterbased cleaning operations.
Non-hazardous waste generated from:
Line start-up
Cleaning operations
Finishing operations
Wastewater sludge
The two primary environmental benefits of converting to waterbased adhesives are
reduction or elimination of VOC and HAP air emissions and reduction in hazardous waste
generation.14 VOC and HAP emissions are virtually eliminated with waterbased adhesives
because solvents are not used or are used in much smaller quantities than in solvent-based
adhesives. Fugitive solvent air emissions from storage and transfer, equipment leaks, and
cleaning operations are also eliminated. Hazardous waste generation will also decline dramatically
because spent adhesive and cleaning wastes containing solvents are eliminated. Some hazardous
waste may continue to be generated if solvents are used in waterbased cleaning operations.
The status of emissions control equipment is an important issue for a facility when
considering a waterbased adhesive retrofit. If they do not already have a sufficient control device
in place, facilities may choose to invest in state-of-the-art VOC emissions control equipment rather
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than convert to waterbased adhesives. Using emissions control devices, however, may present
additional environmental concerns such as disposal or treatment of contaminated steam from
carbon adsorption stripping. Some of these control devices can capture, destroy, or recover 98
percent of solvent emissions if used with enclosed coating heads that are ventilated to the
emissions control device.4 If facilities spend their capital on emissions control equipment for
solvent based adhesives, they may limit the resources available to use waterbased adhesives.
The primary environmental disadvantages of converting to waterbased adhesives for all
industry segments is the associated increase in both wastewater and solid waste generation. This
increased generation results from two factors: waste adhesive which was formerly hazardous may
now be considered non-hazardous and disposed of as such, and the water used on waterbased
adhesive equipment most likely must be disposed of as wastewater. A third waste stream would
be generated from the deionization of water if a facility manufactured its own waterbased
adhesives. This waste could either be disposed of as a solid waste or in wastewater depending on
facility operations and preferences.
Depending on both the amount of wastewater generated and state and local regulations
concerning wastewater, a facility may find it necessary to treat its wastewater onsite. To perform
wastewater treatment, the plant must operate and maintain a wastewater treatment plant.
Non-hazardous solids (e.g., sludge) collected by the wastewater plant may then be disposed of in
a landfill, resulting in generation of solid waste. If these solids are found to be hazardous through
testing, disposal costs increase exponentially. Treated wastewater can either be transported to the
local POTW or recycled for use in cleaning operations. FLEXcon treats wastewater on-site and
uses recovered water for equipment cleaning.4 Facilities which formulate waterbased adhesives
may be able to reuse this treated water in their formulations; however, no facilities were identified
in this study which accomplish this type of recycling.
Wastewater from waterbased adhesives is generally an ideal medium for the growth of
microbes because bacteria thrive on the adhesive solids found in the wastewater. Microbe growth
can be controlled by the use of biocides. However, this will preclude the recycling of the water
into an adhesive formulation, as biocides adversely affect adhesive properties. Some POTWs may
find microbe-containing wastewater desirable, as the bacteria help to digest other wastes during
wastewater treatment.
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Several facilities noted that formulating and processing waterbased adhesives require more
labor than solvent-based adhesives. Waterbased adhesives generally require more water flushing,
scraping, and peeling during equipment cleaning operations. One manufacturer noted that while
solvent-based storage systems require essentially no cleaning maintenance, a waterbased storage
tank of approximately 8,000 to 10,000 gallon (2,114 to 2,642 liter) capacity required cleaning
with a jet spray of water approximately two times per year. This cleaning requires 16 man-hours
or more and generates approximately 3,000 gallons (11,355 liters) of wastewater.1
Excess coated paper generated during setup of waterbased adhesive-coated product runs
and wastewater sludge add to the solid wastes requiring disposal associated with waterbased
adhesives.4
Large solvent-based operations located in ozone nonattainment areas may enjoy many
environmental benefits if converting their operations to waterbased adhesives is technologically
and economically feasible. Ozone nonattainment areas generally have stiff restrictions on VOC
levels emitted by a facility. Larger facilities with greater emissions are more likely to be required
to install and operate emission control systems to reduce their solvent air emissions. Hazardous
waste generation at larger facilities, and resulting disposal costs, may be considerably greater than
for smaller facilities. Waterbased adhesives use does not require either of these expensive
controls.
A disadvantage of waterbased adhesives for large facilities is the large volume of
wastewater generated, which may require on-site treatment before disposal. POTWs located near
large municipalities may not accept large amounts of untreated wastewater from an adhesive
coater. However, Nashua's local POTW is generally receptive to its waterbased adhesive
wastewater because its high biological oxygen demand (BOD) content aids in treating the local
wastewater.1 However, most facilities have BOD limits on their discharges. Those facilities
which have difficulty disposing of their wastewater may require the addition of an on-site
wastewater treatment facility. FLEXcon uses an on-site wastewater treatment facility to recycle
its water for cleaning operations.4
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Facilities operating dual coating lines generally separate their solvent and wastewater
releases to all media at the coating line to reduce the volume of hazardous wastes requiring off-site
disposal. In many instances, off-site energy recovery facilities will not accept or will charge high
rates to dispose of mixed wastes due to the lower energy content, so separating waste streams for
dual coaters is critical.
As stated in Section 4.2.2, many facilities which perform dual coating operations simplify
their waste handling procedures by delivering adhesives directly to the coating line where they are
pumped to the adhesive trough. This eliminates much of the flushing wastes from pipes and
pumping equipment used to transfer adhesive from the storage tanks to the coating line.
Facilities operating dual coating lines may install ductwork to bypass emissions control
equipment when coating waterbased adhesives. Commonly used controls for solvent-based
adhesives, such as thermal oxidation and carbon adsorption beds, are not designed for waterbased
adhesive use. Thermal oxidation of emission streams with high moisture content is extremely cost
prohibitive and unnecessary. Also, carbon adsorption beds experience reduced solvent control
potential when fouled with water. Therefore, when dual coating capabilities are essential, a
facility will need to install ductwork to bypass emissions control equipment and vent oven exhaust
(from waterbased adhesives) directly to the atmosphere.
Batch operations generate considerably more wastes with short-run waterbased adhesive
batches than dedicated operations. This increased waste is generated during the start of a run
(primarily composed of make-ready substrate) and from increased cleaning wastes.
4.4 ECONOMIC BARRIERS TO PROCESS CONVERSION
4.4.1 Introduction
The economic impacts associated with a process retrofit to waterbased adhesives are highly
plant-specific. The possibility of retrofitting depends on many variables including technical
feasibility of retrofit, end product performance, state and local environmental costs, and
profitability/competitiveness of the company. These issues and how they relate to a
manufacturer's decision to retrofit its process to waterbased adhesives are discussed in this
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section. The complexity of these issues reflect the highly competitive nature of the adhesive-
coated and laminated substrate industry and its concerns about divulging proprietary information.
4.4.2 Segment-Specific Economic Impact
In most instances, the economic impacts of process retrofit to waterbased adhesives are
plant-specific rather than segment-specific. However, some economic impact generalizations can
be drawn for the different industry segments defined in this report. One factor of equal
importance to all industry segments is the geographic location of the facility. Facility location will
determine how state and local regulations or federal nonattainment status affect a firm's decision
to retrofit. State and local regulations can influence the decision of a plant which may
technologically be able to convert some or all of their end products to waterbased adhesives.
Facilities must weigh the economic impact of capital investment for new equipment versus the
costs of current and/or potential future environmental regulations. Geographic cost impacts
include local rates for water and sewer, hazardous waste disposal, solid waste disposal, air
permitting, and insurance. For example, those facilities designated large quantity generators
(LQGs) of hazardous waste may realize more economic benefits from conversion to waterbased
adhesives than small quantity generators (SQGs).
Generally, large companies have more capital and personnel available to dedicate to the
study of waterbased adhesives. For smaller, profitable firms, capital may not hinder a retrofit to
waterbased adhesives; however, the smaller number of personnel may hinder research and
development efforts on waterbased adhesive replacement.
Waterbased adhesives are not well-suited for short (i.e., eight hours or less) batch
operations. They work more effectively and are more profitable in dedicated operations or long
batches (i.e., more than eight hours). One batch manufacturer noted that waterbased adhesives
have to run approximately 2,500 yards (2,300 meters) of product to be profitable while
solvent-based need only run 250 yards (230 meters).4
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TABLE 4-9. ECONOMIC IMPACTS ASSOCIATED WITH PROCESS
RETROFIT TO WATERBASED ADHESIYES3
Item
Existing Solvent-based
Adhesive Svstem
Retrofitted Waterbased Adhesive
Svstem
Capital Costs
Storage/Mix/Hold Tanks
Piping
Pumps
Adhesive Filler
Heat Exchanger
Coating Head
IR Heater
Control Panel for IR
Heaters (maximum of 4)
Oven
Pretreatment
Annual Costs
Environmental
Air
Water
Hazardous
Solid
Energy
Oven
Emissions Control
Adhesive Cost
Emissions Control
Thermal oxidizer
Catalytic oxidizer
Carbon adsorber
N/Ah
N/A
N/A
N/A
Not Required
N/A
Not Required
Not Required
N/A
Usually Not Required
$25/ton (Title V permitting)
Minimal
$100 - $600/55-gallon drum
$40/ton tipping fee
Solvents evaporated readily
560,000 (carbon adsorber)
Varies with price of solvents
Natural gas
Catalyst replacement
Carbon bed replacement
$7,000 - 60,000 each'
$0.50/linear foot for PVC
$500 - $1,200 each (air pump)
$2,000 each
$7,500 each'
$0 - $600,000 each
$20,000 eachc
$60,000
$0-S 1,000,000"
Costs not available
None
Site specific, but generally higher
than solvent-based
None (except solvent cleaning)
Increased volume generated
Higher heat capacity for water
None
Generally lower than solvent-based
Not required
8 Costs are in 1993 dollars and were compiled from several industry sources; average costs will vary
depending on facility size, product lines, performance requirements, etc.
b N/A - Not Applicable. Capital equipment costs are not incurred for existing solvent-based system.
c Price includes installation.
J Cost range reflects the level of oven modification required to retrofit to waterbased adhesives, from
no modification ($0) to new purchased ovens ($1,000,000).
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4.4.3 Costs Incurred Due to Process Retrofit
The costs incurred as a result of process retrofit consist of both easily quantifiable and
difficult to quantify items. Difficult-to-quantify items are extremely site-specific and are discussed
qualitatively later in this section. The easily quantifiable economic impacts are summarized in
Table 4-9 and include the capital and annual operating costs associated with retrofitting an existing
solvent-based adhesive coating line to waterbased adhesives. Therefore, there are no capital
equipment costs incurred for the solvent-based adhesive coating system. These average costs were
derived from numerous industry sources including coating facilities, equipment manufacturers,
and raw material suppliers. Appendix B contains a detailed example cost comparison for a
masking tape coating line which converts operations from solvent-based to waterbased adhesives.
The equipment items specified in Table 4-9 do not necessarily require retrofit in each
facility attempting a conversion to waterbased adhesives. Each item listed depends on site-specific
factors to determine whether or not retrofit is required. For example, facilities which formulate
their own solvent-based adhesives and deliver them to the coating head via an extensive
configuration of piping and pumps may require new or additional piping and pumps for
waterbased adhesives. However, those facilities that purchase pre-mixed adhesives and locate
them directly beside the coating head to be delivered via a small pump and minimal piping will
not incur these costs.
Two of the most important cost issues associated with waterbased adhesives are related
to the drying ovens. One is the potential for increased energy requirements and the other involves
speeds). As stated in Section 4.2.1, water has a much higher heat capacity than most solvents
andtherefore requires more energy to evaporate in the oven. However, since waterbased
adhesives eliminate the potential for LEL exceedance and airflow volumes may be decreased,
energy consumption may be reduced.10 Energy consumption for drying both solvent-based and
waterbased adhesive coatings appears to be site-specific criteria.
Some manufacturers have excess capacity ovens for which the conversion to waterbased
adhesives may require only an oven temperature and airflow configuration adjustment. Nashua
is one example of a coater with excess oven capacity. Nashua was able to dry its waterbased
adhesives at approximately the same coating line speeds using the same ovens used for solvent-
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based adhesives with the addition of IR heaters.1 Installation of IR heaters adds another
waterbased conversion cost. Other manufacturers, however, may use smaller ovens on their
solvent-based adhesives and would require either increased oven capacity or slower line speeds
to coat waterbased adhesives. Slower line speeds are almost never an option for adhesive coating
manufacturers, as less product would be produced and profitability would be jeopardized. When
considering the conversion to waterbased adhesives, a balance must be weighed among energy
requirements, oven size, additional equipment {e.g., IR heaters), and production line speeds.
Another factor to consider when oven temperatures and airflows must be adjusted is the
backings which will be coated with waterbased adhesives. Because of the higher temperatures
used in drying ovens with waterbased adhesives, some backings may not be suitable for use with
waterbased adhesives. For instance, some plastic film backings may become soft or disfigured
when heated excessively. The most practical backing to coat with waterbased adhesive is paper
due to its high surface energy. However, the relatively high oven temperatures may cause the
natural moisture content in the paper to evaporate during drying. This causes paper curl which
is detrimental to lamination, rewind, and finishing operations. Some paper coating facilities add
a misting system at the oven exit to re-moisturize the paper before it is laminated and/or rewound.
This results in an additional cost and maintenance item for the coating of waterbased adhesives.
Another backing-dependent cost incurred due to retrofit relates to the surface energy of
the backing used in the end product. Many non-paper substrates require chemical or corona
pretreatment to promote the adherence of waterbased adhesives. This requires an additional
expense to a process line which may add little or no value to the end product.
Some of the equipment costs incurred from retrofitting result from the installation costs
of process equipment. Table 4-9 includes easily quantifiable installation costs. In some instances,
these costs can be reduced by performing installation with in-house personnel. Equipment such
as pumps, valves, and piping may be changed by plant personnel to avoid excessive costs.
Costs incurred during retrofitting which are either too site-specific to quantify or not
readily quantifiable include those costs of reduced production levels (e.g., increased cleaning
downtime and increased start-up wastes with waterbased adhesives), new or increased wastewater
and solid waste generation, increased energy requirements in the oven (if applicable), and research
and development costs (e.g., operator and engineer training, internal research and development
4-33
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for new adhesive development, customer support during development of new waterbased
adhesives, etc.). Research and development efforts involving both product and equipment may
cause production delays and result in engineering expenses as well as lost production.2
Increased cleaning requirements for both the adhesive coating line and auxiliary equipment
result in reduced operating time of the coating line. Many facilities noted that the hard polymeric
coating that forms when waterbased acrylics have dried is difficult to clean and requires more
operator labor time and cleaning supplies. In some instances, these increases may be offset by
reduced maintenance requirements on solvent-based equipment such as emissions control
equipment and storage areas.
Waterbased adhesives generally require more raw materials (backing and adhesive) for
start-up on a coating line. This increases raw material and production time necessary to obtain
a marketable end product.4
Increases in wastewater generation (from waste adhesive, cleaning operations, and
potentially deionized water production) and the potential increase in solid waste (from treated
wastewater and excess start-up adhesive-coated backing) may increase waste disposal costs for the
facility. These potential costs are extremely site-specific and depend on the increased volume of
waste generated as well as local POTW and landfill practices and costs. Nashua noted that its
wastewater disposal costs are approximately $350 per week (volume and shipping cost) higher
than before conversion.1 In some instances, the increased wastewater generation may require the
addition of an on-site wastewater treatment facility either to filter the wastewater (landfilling
recovered solids) or recover some of the increased water and sewer costs.
Another unquantifiable cost involves the facility learning curve when converting to
waterbased adhesives. In most instances, facilities must conduct either internal research and
development or work closely with adhesive suppliers to develop a waterbased adhesive best suited
for replacing their solvent-based adhesives. In addition, many facilities work closely with their
customers to assure them that the new adhesive technology will, at a minimum, equal the
performance of the conventional solvent-based product. Also, coating line operators will be
required to adapt to the new coating application. Nashua operators indicated that they spent more
time adjusting the nip gap (for coating thickness) and reverse roll speed during the coating of
waterbased adhesives than while coating solvent-based adhesives. Nashua management indicates
4-34
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that this is an expected implication of the learning curve with waterbased adhesives.1 One
manufacturer noted that foaming was a problem upon initial conversion; however, with
experience, operators were able to develop effective responses.12
4.4.4 Costs Saved Due to Process Retrofit
The costs saved as a result of process retrofit also consist of many quantifiable and
unquantifiable items. The quantifiable economic impacts are summarized in Table 4-9 and include
primarily solvent disposal costs, air permitting costs, and emissions control equipment costs
associated with the process retrofit. Unquantifiable items are extremely site-specific and are
discussed qualitatively in this section.
Solvent disposal costs saved due to retrofit include solvent collected from emissions control
systems (e.g., carbon adsorber) for energy recovery purposes, solvent cleaning wastes, and waste
solvent adhesive. For example, Nashua estimates that its annual shipment of solvent waste to a
local energy recovery facility has dropped from 30 55-gallon (208-liter) drums to one 55-gallon
(208-liter) drum per month during its conversion. Shipping costs average $25 to $50 and disposal
costs range from $100 to $600 per 55-gallon (208-liter) drum. Assuming an average cost of $180
per drum for shipping and disposal, the savings amount to $60,000 per year.1 However, Nashua
has experienced an increase in wastewater disposal costs of approximately $18,000 per year.
Nashua hoped to eliminate hazardous waste shipments after the conversion, but complete
elimination of hazardous waste production could not be confirmed prior to publishing this report.
Another cost savings from complete conversion is realized when emissions control systems
(e.g., carbon adsorber, thermal or catalytic oxidizer) used to collect or destroy solvent emissions
are eliminated. Facilities with dual coating lines may experience a drop in costs relative to the
amount of solvent-based adhesives converted to waterbased. Energy cost savings depend on the
amount of solvent-based adhesives converted to waterbased and the type of emissions control
system used at a facility. The cost savings depend on reductions in steam production for carbon
adsorption stripping, fuel costs for thermal oxidation, and catalyst costs for catalytic oxidation.
Maintenance costs are important because emissions control system problems can lead to lost
production time and profits if the coating line must be shut down until the problem is fixed.
4-35
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FLEXcon noted that the cost of the natural gas used in its thermal oxidizers is the primary
operating cost for its emissions control system. FLEXcon is required to monitor and report the
performance of its oxidizers to the state. While the cost of this monitoring is not readily
quantifiable, FLEXcon considers it to be a significant operating cost of producing solvent-based
adhesive-coated product.4
Nashua noted that before conversion, it experienced a maintenance problem approximately
once a week with its carbon adsorption system resulting in significant coating line downtime. The
charcoal bed used in Nashua's carbon adsorption system requires replacement about every five
years at a cost of $75,000. The spent charcoal must also be disposed of, adding another cost.1
Depending on the state and local regulations pertinent to a facility, Title V CAAA
permitting costs may be approximately $25 per ton ($22.70 per megagram) of regulated pollutant.
Also, future regulations [e.g., maximum achievable control technology (MACT) and lowest
achievable emission rate (LAER)] may require additional emissions control systems. The effect
of these emissions fees and emission control device costs may offset certain cost disadvantages
associated with a transition to waterbased adhesives. In addition, the costs of converting to
waterbased adhesives may be offset in future expansion efforts because the permitting
requirements for increasing facility emissions would require reducing emissions elsewhere in the
plant.2
Another potential cost savings of a conversion is a reduction in waterbased adhesive cost.
Prices for the solvents used in solvent-based adhesives vary with the cost of oil.4 The cost of
producing deionized water will invariably be less than purchasing equivalent volumes of solvent,
although water-deionization equipment prices were not determined for this report.
Complete conversion to waterbased adhesives would eliminate the requirement that the
storage area, tanks, piping, and pumps for adhesives be explosion-proof. For dual coating
facilities, this equipment would still be required to use solvent-based systems. Another savings
would result from the elimination of systems used to discharge static electricity in solvent-based
operations, such as tinsel and humidifiers.
4-36
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4.4.5 End Product Cost and Profitability/Competitiveness Impacts Associated with Process
Retrofit
All of the cost impacts discussed in Sections 4.4.1 through 4.4.3 will have some impact
on the operating cost and thus the end product cost for a facility. Manufacturers must determine
the economic feasibility of process retrofit based on current technology and consider current and
future environmental regulations when deciding whether to proceed with process retrofit.
The capital investment required to convert almost certainly will increase the operating costs
of a facility. A manufacturer's first instinct might be to offset these operating costs by increasing
product costs, however, this action might result in lost market share. Therefore, manufacturers
are likely to maintain current price levels if feasible.
Some manufacturers who find it advantageous to convert their entire process to waterbased
adhesives may be forced to drop a number of product lines in order to be completely solvent-free.
If these dropped product lines were minor volume products, increased sales of waterbased
products could make up for their loss. However, many manufacturers may decide not to convert
large sales-volume products if profits would be jeopardized by a conversion to waterbased
adhesives.
Some facilities may re-direct their investment capital to pay for the costs of retrofit. These
increased capital expenditures are normally viewed as capital improvements (investment) for new
technologies which in the long term will reduce operating costs and open up new markets for end
products produced with the new technology. Nashua is an example of one facility which has
successfully spread retrofit costs over many years.
If a facility decides that it is technically infeasible to convert to waterbased adhesives, they
may choose to spend investment capital on improved emissions control technologies to comply
with current and future potential regulations. In fact, some companies are installing new control
equipment that will allow them to enter markets lost to waterbased converters while remaining in
compliance with the regulations.13
In general, waterbased adhesives cost less to apply than solvent-based adhesives. Solvents
typically cost $1 to $4 per gallon ($0.26 to Si.06 per liter), while deionized water costs
approximately S0.05 per gallon ($0.01 per liter).7 With the inclusion of surfactants, defoamers,
4-37
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1
fillers, and a higher solids content, waterbased adhesives may cost more per volume than
comparable solvent-based adhesives. However, because of the higher solids content, the coating
coverage per unit volume of adhesive is higher for waterbased adhesives.2 This reduces the
waterbased adhesive's applied cost as compared to solvent-based adhesives. Nashua personnel
indicated that the cost of pre-mixed waterbased adhesives is approximately the same per unit
volume as the cost was for formulating their own solvent-based adhesives, but coverage per
volume is higher. However, Nashua noted that by far the largest contributing cost in the end
products is the raw paper cost.1
One of the main cost impacts of conversion is the effect on competitiveness. As stated
earlier, waterbased adhesives cannot replace solvent-based adhesives one to one due to their
differing performance levels. To convert to waterbased adhesives, some changes in end product
lines to meet both customer needs and waterbased capability are necessary.4 Only by changing
the end product lines can a facility successfully convert to waterbased adhesives and remain
competitive in the industry. As shown in Figure 4-1 and discussed in Section 4.2.3, this results
in an end market product reconfiguration for a facility.
The long term cost impacts of process conversion appear to be an overall reduction in
operating costs. Costs for emissions control equipment maintenance and operation are reduced
by the level of solvent-based adhesive conversion to waterbased. Learning curve cost impacts
diminish with time as engineers and operators become more familiar with the waterbased process
and can operate more efficiently. Hazardous waste disposal costs and air permitting costs are
eliminated for the long term. Also, the potential for new markets increases as waterbased
adhesive product lines are developed.
In some instances, competing manufacturers of an end product may have already converted
their product from solvent-based to waterbased adhesive. In this situation, the adhesive
technology is obviously available to facilitate conversion. Some facility contacts have identified
that the lower costs associated with producing waterbased product have resulted in both lower
prices and lower profit margins for their end products. Companies manufacturing products in
market areas where waterbased adhesives can be used may be forced to convert from a
solvent-based to a waterbased process in order to remain competitive.
4-38
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4.5
REFERENCES
1. McMinn, B.W., W.S. Snow, and D.T. Bowman. Solvent-Based to Waterbased Adhesive-
Coated Substrate Retrofit - Volume III: Label Manufacturing Case Study: Nashua
Corporation. EPA-600/R-95-01 lc (NTIS publication number not yet available). National
Risk Management Research Laboratory. Research Triangle Park, NC. December 1995.
2. McMinn, B.W., W.S. Snow, and D.T. Bowman. Solvent-Based to Waterbased Adhesive-
Coated Substrate Retrofit - Volume II: Process Overview. EPA-600/R-95-01 lb (NTIS
publication number not yet available). National Risk Management Research Laboratory.
Research Triangle Park, NC. December 1995.
3. Doyle, Daryl J. "Criteria for Proper Adhesive Selection: From Application to Viscosity"
Adhesives '90. Society of Manufacturing Engineers. Dearborn, MI. October 1990.
4. McMinn, B.W., W.S. Snow, and D.T. Bowman. Solvent-Based to Waterbased Adhesive-
Coated Substrate Retrofit - Volume IV: Label Manufacturing Case Study: FLEXcon
Company Incorporated. EPA-600/R-95-011d (NTIS publication number not yet
available).National Risk Management Research Laboratory. Research Triangle Park, NC.
December 1995.
5. Newman, D. J., and Nunn, C. J., Prog. Organic Coatings. 3: 221-243 (1975).
6. Bond, Karen. "Rubber-to-Metal Waterborne Eliminates Emissions and Odors" Adhesives
Age, 32 (2). Communication Channels, Inc. Atlanta, GA. February 1990.
7. Laucis, Peter K. "Technology Trends in Pumps for High-Viscosity Materials" Adhesives
Age, 32 (3). Communication Channels, Inc. Atlanta, GA. March 1990.
8. Prentice, David L. et al. "WB PSA Technology Advances to Rival Solventborne
Adhesives" Adhesives Age, 35 (2). Communication Channels, Inc. Atlanta, GA.
February 1992.
9. Memorandum. Geary McMinn and Scott Snow, TRC Environmental Corporation, Chapel
Hill, NC, to Mike Kosusko, U.S. Environmental Protection Agency, Research Triangle
Park, NC. Site Visit - Nashua Corporation - Label Division, Omaha, NE. April 1, 1993.
10. Temin, Samuel C. "Pressure-Sensitive Adhesives for Tapes and Labels." Handbook of
Adhesives. Third Edition. Edited by Irving Skeist. Van Nostrand Reinhold. New York,
NY. 1990.
11. Satas, D. (ed). Handbook of Pressure-Sensitive Adhesive Technology. Van Nostrand
Reinhold Company. New York, NY. 1989.
4-39
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"Water-Based Acrylic Improves Polyester-to-Paper Bonds." Adhesives Age, 31 (2).
Communication Channels, Inc. Atlanta, GA. February 1989.
"Tape Manufacturer Widens Its Scope." Converting Magazine. Delta Communications
Inc. April 1989.
4-40
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9. Ellerstein, S.M., and Lee, S.A. "UV and EB Curable Laminating Adhesives," 1987
Polymers, Laminations and Coatings Conference. Technical Association of the Pulp and
Paper Industry (TAPPI). 1987.
10. Nunez, C.M., McMinn, G., and Vitas, J. "Barriers to the Use of Radiation-Curable
Adhesives in the Coated and Laminated Substrate Manufacturing Industry." Journal of
Hazardous Materials, 45: 59-78, 1996.
6-9
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APPENDIX A
QUESTIONS FOR FACILITY VISITS
A-l
-------
QUESTIONS FOR FACILITY VISITS
GENERAL
1. When was this facility built?
2. What products are produced here (by name and SIC)?
3. Which of your products are produced using waterbased coatings?
4. How large is this facility?
• number of employees
• square footage
• annual sales
• annual production
• capital investment
• market share
• number of production lines
5. How long has this facility been using waterborne coatings?
6. What prompted your conversion from solvent-based adhesive products to waterbased
products?
7. When you identified the potential to make a conversion from solvent-based products to
waterbased products, what were the major issues that you had to resolve in order to assess
the feasibility of making the conversion?
COST
1. How did you project the cost of completing the conversion when examining the economic
feasibility of the project?
2. How did you track the cost of effecting the conversion of your process?
3. What cost records do you have available for the materials used both before and after the
conversion?
4. What cost records do you have available for the engineering costs of planning and
executing the conversion?
5. What capital costs were incurred as a result of the conversion?
A-2
-------
6. What other operating costs, besides inventory, changed as a result of the conversion?
PRODUCT PERFORMANCE AND QUALITY
1. What product characteristics are you required to control to meet customer specifications?
2. Of the product characteristics specified by your customers, which are most difficult to
achieve using solvent-based coatings?
3. Which specified product characteristics are most difficult to achieve using waterbased
coatings?
4. What difficulty, if any, did you experience in identifying satisfactory waterbased coating
formulations to use as replacements for your solvent-based formulations?
5. How do you test a new coating to determine its conformance to specification (i.e., what
characteristics are commonly tested and what test methods are used)?
6. What assurances did your customers require before accepting any changed formulations?
7. What are the major causes of rejected product in your waterbased coating process?
8. What rejection rates did you experience when manufacturing solvent-based products?
9. What rejection rates did you experience when you first made the conversion to waterbased
coatings?
10. What is your current rejection rate of waterbased product?
PROCESS
1. Do you coat waterbased and solvent-based coatings on the same equipment?
2. What type of coating apparatus do you use to coat waterbased products?
3. What type of coating apparatus do you use to coat solvent-based products?
4. Does the coating apparatus you use require special adjustment or modification to run
waterbased coatings?
5. What type of oven configuration (i.e., equipment, zone structure, and operating
temperatures) do you employ when coating waterbased products?
A-3
-------
6. How does this configuration differ from the one used when coating solvent-based
products?
7. How does the process speed differ between waterbased and solvent-based coatings?
8. What is the difference in set-up of a solvent-based job and a waterbased job (e.g.,
additional time, material, or requirements for machine adjustments)?
9. Is there a significant difference in the process robustness between waterbased and
solvent-based products?
ENVIRONMENTAL IMPACTS
1. Have you measured or estimated the environmental impact (impact on air emissions,
wastewater, solid waste, and hazardous waste generated) of the conversion from
solvent-based to waterbased coatings?
2. Did the conversion introduce any new waste products, or eliminate any waste products,
from your manufacturing process?
3. Did the conversion change your equipment and facility cleaning practices?
4. Has your use of water increased, and if so, is the increase greater than your expectations?
5. What control or disposal costs have you incurred or avoided as a result of the conversion?
LABOR
1. Did the conversion to waterbased products cause any changes in the composition of your
labor force?
2. Did your workers require any specialized training to use waterbased products?
3. Were health and safety issues considered in evaluating the opportunity to convert to
waterbased products?
4. Has the use of waterbased coatings caused any change in your measurements of labor
efficiency?
A-4
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APPENDIX B
COST COMPARISON FOR WATERBASED VERSUS SOLVENT-BASED
ADHESIVE COATING SYSTEMS
B-l
-------
B.l INTRODUCTION
This appendix compares the capital and annual costs associated with using waterbased and
solvent-based adhesive coating systems based on approximate costs provided by facility contacts
and other industry sources. Section B.2 describes the costs associated with the purchase of a new
waterbased and a new solvent-based adhesive coating system. Section B.3 provides the capital
cost estimates for retrofitting an existing solvent-based coating line to operate with waterbased
adhesives. Section B.4 compares the annual costs of operating solvent-based and waterbased
adhesive coating lines.
In making these cost comparisons, certain industry segment and operational parameters
were assumed. For each of the comparisons, the costs were derived for one adhesive coating line
dedicated to producing a low performance masking tape. In addition, the following operational
parameters were assumed to be the same for waterbased and solvent-based coating:
• Coating line designed to manufacture 239,000 yd2 (200,000 m2) of product per day
• Line speed of approximately 600 feet (180 meters) per minute
• Coating line operates 350 days per year
• An adhesive density of 69 lb/ft3 (1,100 kg/m3) of backing material
• Dry coating thickness of 0.001 inches (0.025 millimeters) on the backing
The capital and annual costs derived in this appendix for the example masking tape coating line
should not be used to estimate the costs for other end product conversions.
B.2 CAPITAL COST COMPARISON OF NEW ADHESIVE COATING SYSTEMS
Table B-l lists the capital costs associated with the purchase of a new waterbased and new
solvent-based masking tape coating line. These costs were derived from an equipment suppliers'
estimates and industry contacts. The results show that for a new system, the capital costs of both
B-2
-------
TABLE B-l. CAPITAL COSTS FOR NEW WATERBASED AND SOLVENT-BASED
COATING LINES3
Waterbased System
Solvent-based
System
Release Coater
Release Cure/Dryer System
Adhesive Coater
5235,000
5600,000
$400,000
$1,000,000
$235,000
$700,000
$400,000
Adhesive Cure/Dryer System
$1,100,000"
Installation (22% of purchase
cost)
TOTAL CAPITAL COSTS
TOTAL
$2,235,000
$492,00
$2,435,000
$536,000
$2,727,000
$2,971,000
2 Costs are in 1993 dollars.
h Dryer system for solvent-based adhesive coater is 120 feet long, with five
temperature
zones and a heat exchanger.
solvent-based and waterbased coating lines are approximately the same. However, the costs in
Table B-l do not include the purchase of an emissions control system for the solvent-based coating
line, which would be required for coating solvent-based adhesives. The additional costs of an
emissions control system would make the solvent-based system a much more expensive option.
B.3 RETROFIT CAPITAL COST OF WATERBASED SYSTEM
Table B-2 lists the capital costs associated with retrofitting an existing solvent-based
masking tape line to a waterbased system. Since the solvent-based system exists, the table
indicates where new equipment for waterbased adhesive coating are not required in operating the
solvent-based system. One major assumption for this example is that the coating head would
require alteration or changeout to maintain a waterbased coating line speed similar to the solvent-
based system. Table B-2 indicates that it costs approximately $660,000 to retrofit an existing
B-3
-------
solvent-based masking tape line to operate with waterbased adhesives. These costs do not include
research and development efforts or production losses during the retrofit.
TABLE B-2. CAPITAL COSTS TO RETROFIT A SOLVENT-BASED COATING LINE
TO WATERBASED3
Waterbased System
Solvent-based
System
Adhesive Transfer
Storage Tanks (2)b
Mix Tanks (3)b
Piping (500 feet)
Air Pumps (3)
Heat Exchangers (2)h
Coating Application
Coating Head
Drying/Curing Oven
IR Heaters (2)
TOTAL RETROFIT COSTS
$90,000
$90,000
$250
$3,600
$15,000
$400,000
$60,000
Existing
Existing
Existing
Existing
Not Required
Existing
Not Required
$658,850
a Costs are in 1993 dollars.
b Price includes installation.
B.4 ANNUAL COST COMPARISON OF WATERBASED AND SOLVENT-BASED
ADHESIVE COATING SYSTEMS
Table B-3 lists the annual operating costs for a solvent-based and waterbased system
coating masking tape. In order to assess the operating costs, assumptions were made to simplify
the calculations and are discussed in this section. As stated previously, this cost comparison is
only for a dedicated masking tape line and should not be used to compare these costs with other
industry segments or end products.
B-4
-------
TABLE B-3. ANNUAL COSTS FOR WATERBASED AND SOLVENT-BASED
ADHESIVE COATING LINES3
Waterbased Svstem
Solvent-based
System
Environmental - Air
Permitting Fees
($25/ton of HAP)
Environmental - Liquid
Wastewaterh
Hazardous Waste
($450/55-gallon dram)
Environmental - Solid
Start-up Wastes
($39.50/ton tipping
fee)
Operating Costs
Drying/Curing Ovenc
Emissions Control
Adhesive Coating
Cost/Wet Pound
Dry Pounds Used
Adhesive Coating Cost
TOTAL ANNUAL COSTS
ANNUAL COSTS SAVED WITH
WATERBASED
no permit required
$18,200
$5,400
(12 drums/yr)
$17,500
$343,000
$0
$1.00
8.657,775
$8,657,775
$9,041,875
$4,448,988
$12,500
(assuming 500 tons
emitted after
control)
minimal
$162,000
(360 drums/yr)
$3,500
$228,700
$97,500
$1.50
8,657,775
$12,986,663
$13,490,863
a Costs are in 1993 dollars.
l> Wastewater costs for the waterbased system represent the increased amount of
wastewater
generated relative to the solvent-based system.
c For estimating purposes, the oven energy costs for the waterbased system were
assumed
to be 1.5 times the cost for the solvent-based system.
B-5
-------
To calculate the air permitting fees for a solvent-based system, the air emissions after
carbon adsorption control were assumed to be 1,000,000 pounds (500 tons) [450,000 kilograms
(450 Megagrams)] of solvent. A permitting cost of $25 per ton ($22.70 per Megagram) of HAP
was used, based on CAAA Title V guidelines. The waterbased system was assumed to be solvent-
free.
Wastewater generation and disposal costs were assumed to be minimal for the
solvent-based system. The waterbased system was assumed to generate wastewater costing S350
per week for disposal.
The solvent-based system was assumed to generate 30 55-gallon (208-liter) drums per
month at an average cost of $450/55-gallon (208-liter) drum for disposal. The waterbased system
was assumed to generate one 55-gallon (208-liter) drum per month of hazardous waste from spent
fluids such as hydraulic oil.
Solid waste disposal costs were assumed to increase in proportion to the increased amount
of siart-up substrate required for a waterbased adhesive coating system. For a masking tape
production line, the amount of start-up waste was assumed to be five times that for a solvent-based
system. The solvent-based system was assumed to generate 6,000 yd2 (5,000 m2) of solid waste
per day at a cost of $3,500 per year for landfill disposal.
The operating costs for both oven systems were assumed to be the energy costs required
to evaporate the adhesive vehicle. The following assumptions were made to calculate the oven
energy costs:
• Natural gas oven
• Energy requirements of 83,000 Btu/1,000 ft2 of 0.0015 inch (260 kW-hrs/1,000 m of
0.038 millimeter) adhesive-coated substrate
• Natural gas cost of $5.49/MMBtu ($0.55/therm)
Using these parameters and the assumptions stated in section B.l, the energy costs for a
solvent-based oven were calculated by:
B-6
-------
(Energy required!unit of product) x (Amount of product generated
annually)*.(Cost of energy) = Annual energy cost
[(83,OOOBta/1,000/r2) X (0.001 inch/0.0015 inch) x (9ft 2/yd2)]
x [(239,000yd21 day) x (350^/yr)] x [(MMBtu/ltfBtu)
x($5A9/MMBtu)\ =$228,700
Therefore, the energy costs of operating a solvent-based oven are $228,700 per year. The energy
costs for operating a waterbased oven were assumed to be 1.5 times the operating cost of a
solvent-based oven. This factor takes into account the higher heat capacity of water versus
solvents and the energy required to operate any IR heaters used in the waterbased oven.
The costs for operating a carbon adsorber used with the solvent-based system were derived
from the following assumptions:
• Cost of $75,000 per carbon bed replacement
• Carbon bed replacement occurs every two years
• Electrical energy costs of $60,000 per year
These costs yield an annual operating cost of approximately $97,500 for the carbon adsorber. No
emissions control system is required with a solvent-free waterbased adhesive system, therefore,
the operating costs for emissions control are zero.
The annual costs for waterbased and solvent-based adhesive coatings were calculated using
several assumptions:
• Solvent-based adhesive cost of $1.50 per wet pound ($0.68 per wet kilogram)
• Waterbased adhesive cost of $1.00 per wet pound ($0.45 per wet kilogram)
• 50 percent solids content for both solvent-based and waterbased adhesives
B-7
-------
Using these adhesive parameters and the assumptions stated in section B.l, the waterbased
adhesive costs were calculated from:
(Amount of product generated annually) x (Adhesive coating density)
x(Cost of adhesive) = Annual cost of adhesive coating
[(239,000yd2/day) x (350days/yr) x (9ft2/yd2)] X [(69 lbadhesive/ftJ)
x (0.001 inch) x (I ft/12 inch)] x [($ 1.00/lb coating)
x (2 lb coating /I Ibadhesive)] = $8,657,775/_vr
Therefore, the waterbased adhesive costs approximately $8,657,775 per year. By substituting the
cost of solvent-based adhesive [$1.50 per wet pound ($0.68 per wet kilogram)] into the above
equation, the cost of solvent-based adhesive amounts to approximately $12,986,663 per year.
Summing the costs in Table B-3 results in an annual savings of $4,448,988 using a
waterbased masking tape line.
B-8
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APPENDIX C
1992 TRI DATA FOR ADHESIVE COATING INDUSTRY
C-l
-------
TABLE C-l. 1992 TOXIC CHEMICALS RELEASE INVENTORY DATA FOR SICs 2641, 2671, AND 2672*
Pollutant
SIC 2641
SIC 2671
SIC 2672
Fugitive
Point
Total
Fugitive
Point
Total
Fugitive
Point
Total
Acetaldehyde
2,300
47,000
49,300
Acetone
5,360
1,004,043
1,009,403
60,695
204,105
264,800
697,496
1,356,320
2,053,816
Acrylamide
2
0
2
Acrylic acid
297
14,359
14,656
Acrylonitrile
6,300
22,500
28,800
Ammonia
250
500
750
52,000
0
52,000
1,683
123,082
124,765
Antimony
52
210
262
Benzene
14
4,800
4,814
Bis(2-ethylhexl) adipate
34
6,769
6,803
Butyl acrylate
218
56
274
4,300
207
4,507
Chlorine
1
0
1
250
31,000
31,250
Chlorine dioxide
5
0
5
Chloroform
3,300
3,700
7,000
Chromium compounds
0
10
10
Cobalt compounds
0
30
30
Cumene
340
1,500
1,840
Cyclohexane
5
21,000
21,005
6,244
157,732
163,976
23,805
865,472
889,277
Di(2-ethylhexyl) phthalate
0
1,485
1,485
Dichloromethane
0
680,000
680,000
21,000
57,000
78,000
Diethyl phthalate
5
5,700
5,705
0
25,000
25,000
(continued)
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TABLE C-l. 1992 TOXIC CHEMICALS RELEASE INVENTORY DATA FOR SICs 2641, 2671, AND 2672* (continued)
SIC 2641
SIC 2671
SIC 2672
Pollutant
Fugitive
Point
Total
Fugitive
Point
Total
Fugitive
Point
Total
Ethyl aery I ate
3,000
400
3,400
Ethylbenzene
880
28,870
29,750
Ethylene glycol
1,200
24.000
25,200
32,636
32,335
64,971
Formaldehyde
7,469
94,426
101,895
Freon 113
10,000
0
10,000
Glycol ethers
5
700
705
26,287
76,631
102,918
11,524
87,243
98,767
Hydrochloric acid
0
286,705
286,705
3
572,5S1
572,554
Isopropyl aJcohol
52,225
5,729
57,954
6,200
9,600
15,800
11,399
4,886
16,285
Lead compounds
0
20
20
Maleic anhydride
5
500
505
Methanol
525
337,027
337,552
66,832
220,408
287,240
464,115
2,030,159
2,494,275
Methyl acrylate
4,291
7,000
11,291
Methyl ethyl ketone
55,760
386,533
442,293
332,366
776,865
1,109,231
731,217
4,448,321
5,179,538
Methyl isobutyl ketone
147
29,272
29,419
7,500
89,620
97,120
16,225
318,169
334,394
Methyl roetbacrylate
3,600
20,200
23,800
Methylenebis(phenyliso
cyanate)
0
1
I
n-Butyl alcohol
500
23,667
24,167
7,079
62,087
69,166
Naphthalene
750
87,000
87,750
Nickel compounds
0
3
3
(continued)
-------
TABLE C-l. 1992 TOXIC CHEMICALS RELEASE INVENTORY DATA FOR SICs 2641, 2671, AND 2672' (continued)
Pollutant
SIC 2641
SIC 2671
SIC 2672
Fugitive
Point
Total
Fugitive
Point
Total
Fugitive
Point
Total
Nitric acid
500
0
500
Phenol
8,957
87,817
96,774
Phthalic anhydride
5
0
5
sec-Butyl alcohol
0
13,232
13,232
Styrene
8,714
2,260
10,974
6,800
37,597
44,397
Sulfuric acid
0
56,493
56,493
0
168,780
168,780
tert-Butyl alcohol
250
750
1,000
0
4,900
4,900
Tetrachloroethylene
4,260
0
4,260
0
3,000
3,000
Toluene
1,350,536
4,188,701
5,539,237
892,957
5,554,775
6,447,732
2,067,138
17,022,103
19,089,241
Toluene-2,4-diisocyanate
10
10
20
ToIuene-2,6-diisocyanate
10
10
20
Toluenediisocyanate
15
7
22
Trichloroethylene
7,065
0
7,065
Vinyl acetate
295
581
876
2
7,192
7,194
14,336
35,230
49,566
Vinylidene chloride
15,300
140,800
156,100
Xylenes
5,300
5,400
10,700
6,750
119,586
126,336
48,993
1,297,858
1,346,851
Zinc (fume or dust)
0
750
750
Zinc compounds
0
15,048
15,048
1,750
251
2,001
372
10
382
1,1,1-Trichloroethane
129,996
46,748
176,744
22,829
258,083
280,912
1,2,4-Triinethylbenzene
1,600
7,800
9,400
(continued)
-------
TABLE C-l. 1992 TOXIC CHEMICALS RELEASE INVENTORY DATA FOR SICs 2641, 2671, AND 2672' (continued)
Pollutant
SIC 2641
SIC 2671
SIC 2672
Fugitive
Point
Total
Fugitive
Point
Total
Fugitive
Point
Total
1,3-Butadiene
36
36
72
18,500
115,300
133,800
1,4-Dioxane
90
12,000
12,090
2-Ethoxyethanol
18,000
19,000
37,000
2-Methoxyethanol
2,917
16,630
19,547
4,4 -Isopropylidcne-diphcnol
0
2,000
2,000
GRAND TOTAL
1,479,392
6,345,787
7,825,179
1,602,888
8,011,931
9,614,819
4,291,700
29,577,528
33,869,228
"SIC 2641 was discontinued in the late 1980s and subdivided into SICs 2671 and 2672. However, many facilities still report under this SIC.
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