EPA-600/R-96-026
March 1996
EVALUATION OF BARRIERS TO THE USE OF RADIATION-CURED
AND HOT MELT COATINGS IN COATED AND LAMINATED SUBSTRATE
MANUFACTURING
By:
Jill B. Vitas, Geary D. McMinn, and William L. Blake, Jr.
TRC Environmental Corporation
6340 Quadrangle Drive, Suite 200
Chapel Hill, North Carolina 27514
EPA Contract No. 68-D2-0181
Work Assignment Nos. 1/005 and 1/015
EPA Project Officer: Carlos M. Nunez
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
Prepared for:
U.S. Environmental Protection Agency
Office of Research and Development
Washington, D.C. 20460
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before eomplei
1. RtPOHT NO.
EPA-600/R-96-026
4. TITLE AND SUBTITLt
Evaluation of Barriers to the Use of Radiation-cured
and Hot Melt Coatings in Coated and Laminated Sub-
strate Manufacturing
7. AUTHOHIS)
Jill B. Vitas, Geary D. McMinn, and William
Blake, Jr.
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADOBESS
TRC Environmental Corporation
100 Europa Drive, Suite 150
Chapel Hill, North Carolina 27514
b. REPORT DATE
March 1996
6. PERFORMING ORGANIZATION CODE
CII-94-56
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D2-0181, Tasks 1/005 and
1/015
12. SPONSORING AGENCY NAME ANU AODRtSS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory*
Research Triangle Park, NC 27711
13. TYPE OF- REPORT AND PERIOD COVERED
Final; 6/93 - 4/94
14. SPONSORING AGENCY CODE
EPA/600/13
15. supplemfntary NOTES AEEKT, project officer is Carlos M. Nunez, Mail Drop 61. 919/
541-1756. (*) Now known as the National Risk Management Research Laboratory.
16. ABSTRACT
The report gives results of a study to investigate and identify the technical,
educational, and economic barriers to the use and implementation of radiation-cured
and hot melt coatings in coated and laminated substrate manufacturing. (NOTE: In
support of EPA's Source Reduction Review Project (SRRP), maximum achievable
control technology (MACT) standards development, and the Pollution Prevention Act,
EPA's Air and Energy Engineering Research Laboratory (AEERL) is investigating
the current industrial use of and barriers to the extended use of radiation-cured coa-
tings in SRRP and MACT categories.) Important barriers include: capital cost, ad-
hesive cost, lack of data on physical properties of adhesives, and aesthetics of the
end product. The report identifies work areas that could help overcome identi-
fied technical, educational, and economic barriers. The discussed opportunities in-
clude: (1) convening a focus group to discuss identified barriers, identify other bar-
riers, and begin the process to overcome these carriers; (2) investigating the use of
radiation-curable systems in Europe; (3) researching the marketing difficulties asso-
ciated with nonsolvent-based products; and (4) investigating state economic incentive
programs to determine if financial assistance can be given to manufacturing facilities
to help encourage the testing of radiation-curable adhesives.
17.
2.
KFY WORDS AND DOCUVFNT ANALYSIS
Pollution
Substrates
Manufacturing
.Laminates
Coatings
Curing
DESCRIPTORS
Radiation
Adhesives
b. I DENT I F I ERS/OPEN ENDED TbHMS
Pollution Prevention
Stationary Sources
Hot Melt Coatings
Radiation Curing
c. cosaii Field/Croup
13B 14G
UD 11A
05 C
11C
13 H
V-i. D'STR.3UI ION STATEMENT
Release to Public
19. SF CURITY CLASS (This Reporr,
Unclassified
20. SECURITY CLASS (This p.ifc)
Unclassified
21 NO. PAGES
108
P R: C F
EPA For:r> 2220-1 (9-73)
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NOT]CL
This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
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ABSTRACT
In support of the Source Reduction Review Project (SRRP), maximum achievable control technology
(MACT) standards development, and the Pollution Prevention Act, EPA's Air and Energy
Engineering Research Laboratory (AEERL) is investigating the current industrial use of and barriers
to the extended use of radiation-cured coatings in SRRP and MACT categories. This report presents
the results of a study to investigate and identify the technical, educational, and economic barriers to
the use and implementation of radiation-cured and hot melt coatings in coated and laminated substrate
manufacturing. Some of the important barriers were the following: (1) capital cost; (2) adhesive
cost; (3) lack of data on physical properties of adhesives; and (4) aesthetics of the end product. This
report identifies work areas that could help overcome the technical, educational, and economic
barriers identified. Some of the opportunities discussed include the following: (1) convene a focus
group to discuss identified barriers, identify other barriers, and begin the process to overcome these
barriers; (2) investigate the use of radiation-curable systems in Europe; (3) research the marketing
difficulties associated with non-solvent-based products, (4) investigate state economic incentive
programs to determine if financial assistance can be given to manufacturing facilities to help
encourage the testing of radiation-curable adhesives; and (5) develop a software system that will
provide physical property data and other important information on alternative adhesive formulations
to assist facilities in identifying alternatives to their current solvent-based adhesives.
i i i
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TABLE OF CONTENTS
Chapter Page
Abstract i i j
List of Figures viii
List of Tables ix
Conversion Factors x
Executive Summary x i
1 INTRODUCTION AND PROJECT BACKGROUND 1-1
1.1 PROJECT BACKGROUND 1-1
1.2 PROJECT OBJECTIVES 1-3
1.3 INDUSTRY SEGMENT DESCRIPTION 1-4
1.4 REPORT ORGANIZATION 1-5
15 REFERENCES 1-5
2 CONVENTIONAL PROCESS DESCRIPTION 2-1
2.1 GENERAL 2-1
2.2 MATERIAL INPUTS 2-1
2.2.1 Substrates 2-1
2 2.2 Coatings 2-3
2.3 EQUIPMENT 2-3
2 4 CONVENTIONAL PROCESS DESCRIPTION 2-3
2.4.1 Adhesive Mixing 2-4
2.4.2 Adhesive Tape Manufacturing 2-5
2 5 PRODUCTS 2-9
2.6 EMISSIONS AND WASTE 2-11
2.6.1 Air Emissions 2-11
2.6.2 Liquid Waste Streams 2-12
2.6.3 Solid Waste 2-12
2.7 REFERENCES 2-13
3 DESCRIPTION OF RADIATION-CURING 3-1
3.1 PROCESSES 3-1
3.1.1 Introduction 3-1
3.1.2 Raw Materials 3-1
3.1.3 Equipment 3-2
3.1.4 Physical Processes 3-4
3.1.5 Product Performance 3-7
3.1.6 Emissions and Wastes 3-7
3.2 COSTS 3-9
3.2.1 General 3-9
3.2.2 Materials 3-9
3.2.3 Equipment 3-10
v
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TABLE OF CONTENTS (Continued)
Chapter Page
3.2.4 Operating and Maintenance Costs 3-11
3.2.5 Energy 3-13
3.3 REFERENCES 3-13
4 TECHNICAL BARRIERS TO RADIATION-CURING 4-1
4.1 GENERAL 4-1
4.2 EQUIPMENT SUITABILITY 4-1
4.3 MATERIALS AVAILABILITY 4-2
4.4 PRODUCT AND ADHESIVE PERFORMANCE CHARACTERISTICS 4-3
4.5 HEALTH AND SAFETY ISSUES 4-4
4.6 REFERENCES 4-4
5 ECONOMIC BARRIERS TO RADIATION-CURING 5-1
5.1 GENERAL 5-1
5.2 CAPITAL INVESTMENT FOR NEW SYSTEMS 5-1
5.3 PRICING PRESSURE 5-2
5 4 PAYBACK PERIOD FOR RETROFIT SYSTEMS 5-2
5.5 OPERATING COSTS 5-5
5.6 REFERENCES 5-5
6 EDUCATIONAL BARRIERS TO RADIATION CURING 6-1
6.1 GENERAL 6-1
6.2 MANAGEMENT AWARENESS 6-1
6.3 EMPLOYEE TRAINING 6-1
7 DESCRIPTION OF ALTERNATIVE TECHNOLOGIES 7-1
7.1 GENERAL 7-1
7 2 PROCESSES 7-1
7.2.1 Raw Materials 7-1
7.2.2 Equipment 7-3
7.2.3 Physical Process 7-4
7.2.4 Product Outputs 7-5
7.2.5 Emissions and Wastes 7-5
7.3 COSTS 7-6
7.3.1 Materials 7-6
7 3.2 Equipment 7-7
7 3.3 Operating and Maintenance Costs 7-7
7.3.4 Energy 7-10
7.4 TECHNICAL BARRIERS TO ALTERNATIVE TECHNOLOGY 7-12
7 4.1 Equipment Suitability 7-12
vi
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TABLE OF CONTENTS (Continued)
Chapter Page
7.4.2 Materials Availability 7-12
7.4 3 Product Performance Characteristics 7-12
7.4.4 Process Limitations 7-13
7.4.5 Health and Safety Issues 7-13
7.5 ECONOMIC BARRIERS TO ALTERNATIVE TECHNOLOGY 7-14
7.5.1 Capital Investment 7-14
7.5.2 Pricing and Potential Lost Market Pressure 7-14
7.5.3 Payback Period 7-15
7.6 EDUCATIONAL BARRIERS TO ALTERNATIVE TECHNOLOGY 7-16
7.6 1 Management Awareness 7-16
7.6.2 Employee Training 7-16
7.7 POLLUTION PREVENTION/SOURCE REDUCTION RESEARCH
OPPORTUNITIES 7-16
7.8 REFERENCES 7-17
8 POLLUTION PREVENTION/SOURCE REDUCTION RESEARCH
OPPORTUNITIES 8-1
APPENDIX A PRELIMINARY MARKET ANALYSIS A-l
APPENDIX B TRIP REPORTS B-l
v i l
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LIST OF FIGURES
Number Page
2-1 Combined Saturant Release Coat Line 2-6
2-2 Adhesive Coating Line 2-7
3-1 UV-Curable System - Continuous Web Configuration 3-3
3-2 Coater-Laminator with Curtain Electron Curing 3-5
3-3 Curtain Type Electron Processor 3-6
viii
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LIST OF TABLES
Number Page
2-1 Raw Materials Consumed in 1987 2-2
2-2 Equipment for Conventional Tape and Label Manufacturing 2-4
3-1 Comparison of UV/EB Laminating Adhesives With Other Systems 3-8
3-2 Equipment Cost Summary 3-11
3-3 Summary of Printing Costs 3-12
3-4 Summary of Printing Study Energy Costs 3-13
7-1 Commonly Used Raw Materials in Hot Melt Adhesives 7-2
7-2 Adhesive Prices 7-6
7-3 Equipment Costs 7-8
7-4 Annualized Operating Costs 7-10
7-5 Energy Costs 7-11
7-6 Annualized Costs 7-15
i x
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CONVERSION FACTORS
To Convert From
To
Multiply by
LENGTH
feel (ft)
meters (m)
0.3048
meters (m)
feet (ft)
3.281
inches (in)
centimeters (cm)
2.54
MASS OR WEIGHT
ounces (oz)
kilograms (kg)
0.02835
pounds (lb)
kilograms (kg)
0.454
pounds (lb)
tons
0.0005
toas
pounds (lb)
2,000
tons
kilograms (kg)
907.2
kilograms (kg)
pounds (lb)
2.205
kilograms (kg)
toas
0.001102
VOLUME
gallons (gal)
liters (1)
3.785
gallons (gal)
cubic inches (in3)
231
gallons (gal)
fluid ounces (oz)
128
gallons (gal)
cubic meters (m3)
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 (oz)
milliliters (ml)
29.57
CONCENTRATION
pounds/gallon (lb/gal)
grams/liter (g/1)
119.8
grams/liter (g/1)
pounds/gallon (lb/gal)
0.008345
DENSITY
pounds/gallon (lb/gal)
grams/milliliter (g/m!)
0.1198
grams/milliliter (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 (°C) subtract 32,
then multiply by 0.5556
Celsius (°C) Fahrenheit (°F) multiply by 1.8,
then add 32
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EXECUTIVE SUMMARY
Section 4(b) of the Pollution Prevention Act of 1990 requires the United States
Environmental Protection Agency (EPA) to "review regulations of the Agency prior and subsequent
to their proposal to determine their effect on source reduction." In support of the Pollution
Prevention Act, EPA established the Source Reduction Review Project (SRRP) to focus this review
on the regulations (and anticipated regulated industries) that may be promulgated under the Clean Air
Act Amendments of 1990 (CAAA), the Clean Water Act (CWA), or the Resource Conservation and
Recovery Act (RCRA). One of the goals of SRRP tasks is to ensure that source reduction and
multimedia issues are considered during the development of upcoming air, water, and hazardous
waste standards.
Maximum achievable control technology (MACT) standards to reduce hazardous air
pollutants (I-IAPs) from major source categories are regulations under the CAAA and a focus of
SRRP. Promulgation of these regulations began in 1992 and will continue throughout the decade and
into the next century. The MACT standards offer EPA an excellent opportunity to use SRRP to
incorporate pollution prevention measures into the upcoming standards for specific source categories.
Pollution prevention efforts can, may, or sometimes offer economic and reduced health and ecological
risk benefits to many sectors of society that are not available through traditional pollution control
methods.
In support of the SRRP Program, MACT standards development, and the Pollution
Prevention Act, EPA's Air and Energy Engineering Research Laboratory (AEERL) is investigating
pollution prevention opportunities for product and material substitutions that help industry to reduce
air emissions and waste. The specific objective of this project was to investigate the current industrial
use and barriers to the extended use of radiation-curable coatings. Adhesive-Coated and Laminated
Substrates (SIC 2671 and 2672), (typical products include: masking and duct tape, adhesive labels,
and adhesive coated foam products), an industry facing upcoming MACT standards, was selected as
an industrial segment to be the subject for this study. Thus, when the MACT standards are
developed, EPA will have a better understanding of what coating technologies are feasible pollution
prevention alternatives for this industry
xi
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This report presents the results of a study to investigate and identify the technical, educational,
and economic barriers to the use and implementation of radiation-curable coatings within the coated
and laminated substrate industry. This project involved preparing category analyses, identifying and
classifying the barriers to the use and implementation of the technology, evaluating and assessing the
environmental impacts, and identifying pollution prevention and source reduction research
opportunities. Information was collected for this project from a review of current technical literature
through cooperation with industry leaders and the leading trade organizations and through visits to
coated and laminated substrate facilities, radiation-curable coating and equipment suppliers, and an
international trade show.
Radiation-curable processes for the coated and laminated substrate industry involve either
electron beam (EB) or ultraviolet (UV) curing mechanisms to penetrate and cure the radiation-curable
coating to the substrate. These two methods of curing provide many technical, economical, and
environmental benefits to traditional solvent-based systems including increased bonding strength,
resistance to chemical and thermal elements, increased throughput, reduced cost per unit area, and
substantially lower environmental emissions. In addition, both EB- and UV-curing systems can use
most available substrates, present coating application systems, and a reduced amount of floor space.
This report divides the barriers to implementing EB- and UV-curable systems into three
categories: technical, economic, and educational barriers. Separate chapters examine each of the
three barrier categories.
Technical barriers include: the lack of industry knowledge of these systems since no
production line for coated and laminated substrate manufacturers is operating in the United States,
equipment suitability, materials availability (coatings are manufactured and sold by few companies),
product and adhesive performance characteristics (appearance, odor, and tack differences with
solvent-based products); and health and safety issues (radiation as a means of curing).
Economic barriers provide a challenge to implementing either an EB- or UV-curing system.
Economic concerns involve the capital investment of the system, pricing pressure from customers and
competitors, the payback period of the machinery, and operating costs of the radiation-curing
(specifically, EB-curing) mechanism.
The primary education barriers to implementing either an EB- or UV-curing system are
divided into the viewpoints of management and employees. IVlanagement expressed concern about
xi i
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the cost, performance, and productivity of the radiation-curing technology, where employees
expressed concerns regarding handling radiation-curable coatings and radiation safety.
Hot melt adhesives, another alternative to solvent-based systems, is also discussed in this
report. Hot melt adhesives are solids which are heated to their melting point and applied to the
substrate in their liquid state. Hot melt adhesives are currently used in many applications and provide
an alternative to the solvent-based systems. Certain hot melt adhesives can be reformulated and used
as the EB system's adhesive Technical, economic, and educational factors of hot melt adhesives are
also examined.
This document identifies work areas for EPA that could help overcome the technical,
educational, and economic barriers identified. Some of the opportunities discussed include the
following:
• Convening a focus group containing representatives from industry, trade associations,
environmental agencies, radiation-curable coating and equipment suppliers, and other
interested parties to discuss identified barriers and identify others and begin the process to
overcome these barriers.
• Investigating the use of radiation-curable systems within European markets to determine the
problems or opportunities they have discovered as a result of actual production using these
alterative adhesives.
• Researching the marketing difficulties associated with non-solvent-based products. A study
of specific characteristics of a product which improve its marketability (e.g., aesthetics) would
be beneficial.
• Reviewing State economic incentive programs (ETP) which assist facilities in developing low-
volatile organic compound (VOC) surface coatings. This information could be transmitted
to coated and laminated substrate manufacturers to assist them in meeting the applicable
requirements to receive the financial benefits.
• Developing a publicly available computer-based information system which would contain the
performance characteristics of various adhesive formulations to assist coated and laminated
substrate manufacturers in finding alternatives to solvent-based adhesives.
x i i i
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CHAPTER 1
INTRODUCTION AND PROJECT BACKGROUND
1.1 PROJECT BACKGROUND
Section 4(b) of the Pollution Prevention Act of 1990 requires the U.S. Environmental
Protection Agency (EPA) to "review regulations of the Agency prior and subsequent to their proposal
to determine their effect on source reduction."1 In support of the Pollution Prevention Act, EPA
established the Source Reduction Review Project (SRRP) to focus this review on the regulations (and
anticipated regulated industries) mandated under the Clean Air Act Amendments of 1990 (CAAA),
the Clean Water Act (CWA). or the Resource Conservation and Recovery Act (RCRA). One of the
goals of SRRP tasks is to ensure that source reduction and multimedia issues are considered during
the development of upcoming air, water, and hazardous waste standards. The following seventeen
industrial categories are affected by the SRRP:2
• Acrylic Fibers/Modacrylic Fibers
• Degreasing Operations
• Integrated Iron and Steel Manufacturing
• Machinery Manufacturing and Rebuilding
• Paints, Coatings, and Adhesives Manufacturing
• Paint Stripper Users
• Paper and Other Webs Coating
• Pesticide Formulating
• Pharmaceuticals Production
• Plywood/Particle Board Manufacturing
• Polystyrene Production
• Printing and Publishing
• Pulp and Paper Production
• Reinforced Plastic Composites Production
• Rubber Chemicals Manufacturing
• Styrene Butadiene Latex and Rubber Production
• Wood Furniture Manufacturing
Maximum achievable control technology (MACT) standards to reduce hazardous air
pollutants (HAPs) from major source categories are regulations under the CAAA and a focus of
SRRP. Promulgation of these regulations began in 1992 and will continue throughout the decade and
1-1
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into the next century The MACT standards offer EPA an excellent opportunity to use SRRP to
incorporate pollution prevention measures into the upcoming standards for specific source categories.
The Pollution Prevention Act of 1990 defines pollution prevention as "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."1 Pollution prevention efforts offer economic and reduced
health and ecological risk benefits to many sectors of society that are not available through traditional
pollution control methods.
In support of the SRRP Program, MACT standards development, and the Pollution
Prevention Act, EPA's Air and Energy Engineering Research Laboratory (AEERL) is investigating
pollution prevention opportunities for product and material substitutions that help industry to reduce
air emissions and waste. The specific objective of this project was to investigate the current industrial
use and barriers to the extended use of waterbased, hotmelt, and radiation-curable coatings.
Radiation-curable, hot melt, and waterbased coatings have been demonstrated to reduce pollution in
several specific end-use categories.
During the first task of this project, the 52 SIC categories (under the 17 SRRP categories)
were identified as having the possible potential to use radiation-curable, and waterbased coatings as
pollution prevention alternatives. During this phase, contacts were made with representatives from
coating suppliers and trade associations and limited literature searches were completed. From this
list of 52 potential industries, 10 were selected for further study. Preliminary market analyses were
prepared for each of these 10 categories Following the completion of the 10 analyses, 3 industry
segments were selected for investigation: adhesive-coated and laminated substrate manufacturing
(SIC 2671 and 2672), metal can coating (SIC 3411), and commercial printing, not elsewhere
classified (SIC 2759). This report focuses on the coated and laminated substrate manufacturing
industry. A separate project has been initiated by AEERL to investigate waterbased coatings. In
addition, another pollution prevention alternative for the coated and laminated substrate
manufacturing industry is the use of hot melt adhesives. Therefore, waterbased coatings were
eliminated and the focus of the project became the barriers to the use of radiation-curable and hot
melt coatings, in coated and laminated substrate manufacturing
1-2
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1.2
PROJECT OBJECTIVES
This report presents the results of a study to investigate and identify the technical, educational,
and economic barriers to the use and implementation of radiation-curable and hot melt coatings within
the coated and laminated substrate manufacturing industry. This project involved preparing category
analyses, identifying and classifying the use and implementation barriers, evaluating and assessing the
environmental impacts, and identifying pollution prevention and source reduction research
opportunities within the coated and laminated substrate manufacturing industry. In order to
successfully accomplish these objectives, information was collected from several sources including
literature searches, plant visits, pollution prevention experts, and industry and trade association
personnel.
Literature searches of the EPA on-line databases, local university library databases, and
Dialog* were conducted. The Pollution Prevention Information Clearinghouse (PPIC) and the
Pollution Prevention Information Exchange System (PIES) were also accessed. 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 within the Pressure Sensitive Tape Council (PSTC), RadTech International, the
Tag and Label Manufacturers Institute (TI.MI), and equipment and coating manufacturing firms.
The final source of project and industry information was compiled during a total of two site
visits. Copies of the site visit reports are included in Appendix B of this report. Together, these
information gathering efforts provided the background needed to identify the barriers and source
reduction research opportunities within the coated and laminated substrate manufacturing industry.
1-3
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1.3 INDUSTRY SEGMENT DESCRIPTION
The focus of this report is the manufacturing of coated and laminated substrates, including
tapes, labels, and decals. The industry spans two 4-digit standard industrial classification (SIC)
codes; SIC 2671 (Paper and Plastic Films Coated and Laminated for Packaging), and SIC 2672
(Paper and Plastic Films Coated and Laminated, Not Elsewhere Classified). The industry can be
divided into two segments: coated webs for packaging uses; and adhesives-coated products.
The coated and laminated substrate manufacturing industry was selected for investigation for
three reasons. First, the industry is the largest source of methyl ethyl ketone (MEK) and the third
largest source of toluene releases as accounted for in EPA's Toxic Release Inventory (TRI).
According to the TRI, the industry emitted approximately 16.1 million pounds per year (7 3 million
kilograms) of MEK and 26 million pounds per year (12 million kilograms) of toluene in 1990.3 A
reduction in these emissions may also produce a corresponding reduction in ozone formation and help
some areas of the country reach attainment levels for the national ambient air quality standard
(NAAQS) for ozone
The second reason for selection of this industry is the potential for research and development
opportunities. At the completion of this study, no facilities in this industry were using radiation-
curable adhesives in a production environment. All work is being done on a pilot-scale basis
Although hot melt adhesives are used, the potential for further market penetration is substantial. The
AEERL has been charged with providing technical assistance to industry in the area of research and
development. By preparing this report, AEERL will further the dialogue between the coated and
laminated substrate manufacturers and the adhesive manufacturers.
The final reason for the selection of coated and laminated substrate manufacturing is the
timing of this industry's MACT standard. The EPA has scheduled its promulgation of this industry's
standard in the year 19974 This schedule gives the agency over two years to develop a standard that
will properly implement the SRRP approach to regulatory development. Using this report as a source
of background information, EPA will have the time to consider several pollution prevention
alternatives for the coated and laminated substrate manufacturing industry. Based on the assessment
of alternatives, the EPA will be able to develop a MACT standard that is efficient, effective, and
flexible for the coated and laminated substrate manufacturing industry to implement.
1-4
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1.4 REPORT ORGAMIZATION
This report is divided into eight chapters and two appendices. Chapter 2 describes the
conventional manufacturing processes and includes a discussion of the material inputs, manufacturing
equipment, physical processes, product outputs, and emissions and wastes. Chapter 3 includes a basic
discussion of the alternative technology under investigation. This chapter evaluates the process, cost,
and emissions and waste differentials between the conventional and alternative processes. Chapter
4 identifies the technical barriers to the extended use of radiation-curable coatings. It includes a
description of the difficulties with, and available information on, solutions currently under
consideration. Chapter 5 discusses educational barriers, and Chapter 6 identifies educational barriers.
Chapter 7 describes hot melt adhesives which either are, or could be, used to replace conventional
processes. The last chapter, Chapter 8, presents additional source reduction and pollution prevention
research opportunities Appendix A contains a copy of the preliminary market analysis that was
developed during the early stages of this project. Appendix B contains copies of the trip reports
prepared as part of the data gathering effort.
1.5 REFERENCES
1. Pollution Prevention Act of 1990, 42 U.S.C. §13101, et seq.
2 U.S. Environmental Protection Agency. Source Reduction Review Project. EPA-100/R-92-
002. Office of the Administrator, Pollution Prevention Policy Staff. Washington, DC. March
1992.
3. Toxic Chemical Release Inventory Database. U.S. Department of Health and Human
Services, National Institutes of Health, National Library of Medicine. Bethesda, MD.
Toxicology Information Program Online Services TOXXET® Files. 1990.
4. The Air Pollutant Consultant, Volume 3, Issue 1, McCoy and Associates, Inc., Lakewood,
CO January/February 1993.
1-5
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CHAPTER 2
CONVENTIONAL PROCESS DESCRIPTION
2.1 GENERAL
This chapter provides an overview of the coated and laminated substrate manufacturing
industries. The chapter is divided into five sections: (1) Material Inputs, (2) Equipment,
(3) Conventional Process Description, (4) Product Outputs and (5) Emissions and Waste. The
material inputs and equipment sections address the raw materials and equipment necessary to
manufacture coated and laminated products. The conventional process description section
describes the various elements of the manufacturing process with specific product examples. The
last section characterizes the air emissions and liquid and solid waste streams that result from
current industry manufacturing practices.
2.2 MATERIAL INPUTS
The raw materials used in the coated and laminated substrate manufacturing process
consist of substrates, adhesives and other coatings, and cleaning materials. Commonly used raw
materials for both SIC 2671 and SIC 2672 facilities are listed in Table 2-1.
2.2.1 Substrates
A substrate (backing) is the material to which an adhesive is applied to make the desired
product. Substrates are supplied on large, continuous rolls called webs. Substrates provide
strength, protection, and/or a colored surface for the adhesive. Substrate categories include paper,
polymer film, fabric, foil, and foam. Paper and film are the two most frequently used substrate
materials.1-2
2-1
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TABLE 2-1. RAW MATERIALS CONSUMED IN 1987
Material Quantity
million pounds million kilograms
INDUSTRY 2671, PAPER COATED AND LAMINATED, PACKAGING
Primary Materials, parts, containers, and supplies
Paper 926 420
Glues and adhesives NA NA
Plastics resins consumed in the form of granules, pellets, 520.9 236
powders, liquids, etc.
Plastics, products consumed in the form of sheets, rods, tubes, NA NA
and other shapes
Printing ink (complete formulations) NA NA
Petroleum wax 30.1 13.7
Paperboard containers, boxes, and corrugated paperboard NA NA
Aluminum foil:
Plain 25.9 11.7
Converted NA NA
INDUSTRY 2672, PAPER COATED AND LAMINATED, N.E.C.
Primary Materials, parts, containers, and supplies
Paper NA NA
Glues and adhesives NA NA
Plastics resins consumed in the form of granules, pellets, NA NA
powders, liquids, etc.
Plastics, products consumed in the form of sheets, rods, tubes, and other NA NA
shapes
Printing ink (complete formulations) NA NA
Petroleum wax NA NA
Paperboard containers, boxes, and corrugated paperboard NA NA
Aluminum foil:
Plain NA NA
Converted NA NA
Source: Reference 1
NA = Not Available
N.E.C. = Not Elsewhere Classified
2-2
-------
2.2.2 Coatings
The various coatings applied, along with the type of substrate, define the end-use of a
coated and laminated product. Coatings typically consist of solvents, resins, and additives, with
the composition varying depending on the desired characteristics. Some commonly used coatings
include saturants, release coats, tie coats, and adhesives. Not all coated and laminated products
incorporate all of these coatings. For example, saturants are used primarily with paper substrates,
while tie coats are used mainly with film products. A brief discussion of each type of coating
follows.
Saturants are mixtures applied to raw paper to improve the paper's internal strength and
resistance to various environments.3 Release or backsize coatings are applied to the substrate
on the side opposite of the adhesive. The release coat allows rolled adhesive products to be
unwound, prevents tearing, and provides resistance to fluids.3 Tie coats or primers are coatings
applied between natural rubber adhesives and film substrates to improve the bond between the
adhesive and the Film.2,4 Adhesive is applied to the saturated and/or release-coated substrate. The
adhesive product may contain petroleum resins, solvents, natural and synthetic rubber,
antioxidant, and filler.3 Adhesives are required to have three main properties: peel adhesion,
cohesive holding power, and surface tack.
2.3 EQUIPMENT
Table 2-2 lists the equipment used to manufacture tapes and labels on a conventional line.
The process description provides more detail on the function of each piece of equipment.
2.4 CONVENTIONAL PROCESS DESCRIPTION
The manufacturing process consists of three basic steps: adhesive mixing, tape or label
stock manufacturing, and roll converting. Adhesive components are brought into the plant in
bulk, stored in inventory, and mixed as operations require. Mixed coatings are stored in process
holding tanks until they are needed at the coating line. Master rolls {i.e., webs) of substrate {e.g.,
paper, foil, film), each approximately 3,000 yards (2,743 m) long, are loaded on the machinery.
2-3
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TABLE 2-2. EQUIPMENT FOR CONVENTIONAL TAPE AND
LABEL MANUFACTURING
Equipment Function
Banburys Used to mix rubber stock and mill/extrude rubber sheets
Mixing tanks Mixes rubber many times in the form of sheets, thinning
solvents, and other additives to make liquid adhesive
Wind/Unwind rollers Loading and unloading rollers that supply web to the
coating area
Maintain tension on web to allow for even application of
the coatings
Supplies coating to the dam
Hold the coating for application to the web
Receive coating from dam or trough and applies to web
Meter thickness of coating on web
Capture overflow of coating from the dams
The web is fed through rollers, which maintain tension on the material to allow even coating.
After the coating is applied, the web is led through the dryer to a rewind station. The
conventional solvent-based system is also referred to as a thermal system due to the thermal
drying. The application of each coating {e.g., saturants, release coats, tie coats, and adhesives)
is performed in the same manner. The coatings can be applied on a single line or on separate
lines. Once the product has been coated with the necessary materials, it is sent to the slitter area
for conversion to smaller rolls. The finished product is packaged and sent to a holding area for
movement to the warehouse for shipment.
2.4.1 Adhesive Mixing
Adhesives provide a bond between the substrate and the object to which the substrate is
applied. A variety of adhesives can be used in the manufacturing process. The formulation of
solvent-based adhesives involves combining adhesive stock, petroleum resins, natural and/or
synthetic rubber, antioxidants, and/or filler in banburys (rubber mix tanks) which are used to mix
Idler rollers
Coating head
Dams and ears
Application rollers
Metering rollers
Troughs
2-4
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the rubber substrate and mill/extrude the rubber sheeting. The adhesive is placed in a mixing
tank along with a dissolving solvent and other ingredients to make the liquid adhesive. The
solvent used in most solvent-based adhesives is toluene (virgin and reclaimed). After mixing,
the adhesives are pumped through cloth filters, which remove large particles, to process troughs
on the production lines or to storage tanks.
2.4.2 Adhesive Tape Manufacturing
The process description contained in this section is specific to paper tape (e.g., masking
tape) production. However, by either eliminating the saturation step or by replacing it with
another coating step (i.e., tie coating) and by substituting the paper web with another substrate,
the product output is virtually limitless.
The first step in adhesive tape manufacturing is to create a saturated substrate. This is
done by passing the raw substrate, paper, through a saturant bath. The saturation process gives
the paper extra strength to prevent tearing. The paper then travels through a drying oven which
evaporates the carrier. If the saturant is waterbased, the evaporated water is emitted to the
atmosphere. If the carrier is a solvent, some type of control device is normally used. The
saturated paper is then roll-coated with a release coating. The amount of coating is regulated by
a metering device, often a doctor blade. The substrate is then fed through another dryer and
rewound. In applying the release coat on a single-sided tape, only one side of the paper is
coated. This is the side opposite where the adhesive will be applied. The release coat's purpose
is to allow the tape to be unrolled without tearing or breaking. Figure 2-1 shows a diagram of
a combined saturant and release coat line.
The saturated/release-coated substrate is then fed on an adhesive-coating line, illustrated
in Figure 2-2. There are several methods by which adhesive can be applied. The most
commonly used application methods are reverse-roll, direct-roll, and gravure. The method
described in this section is reverse-roll. The adhesive is applied to the side opposite the release
coat by a reverse application roller, that is, the application roller rotates counter to the direction
that the web is moving. The amount of adhesive applied is regulated by a metering roller which
restricts the feed to the application roller. Adhesive spills are captured in a catch basin located
below the adhesive/paper contact point. Once the adhesive is applied, the paper is fed into a
2-5
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FOIL COVERED
to
I
ON
COATING HEAD
FEED
DAW
PAPER LINED
CATCH BASIN
ADJUSTABLE
DAMS
(EARS)
Figure 2-1. Combined saturant release coat line.
-------
UNWIND
LATEX
SATURANT
S>
FROM OVEN
Figure 2-2. Adhesive coating line.
-------
dryer which volatilizes the vehicle solvent, in most cases, the organic vapors are routed to some
type of abatement or control device. However, many small plants route their oven exhaust
directly to the atmosphere. The paper is then wound and sent to the storage area or directly to
the slitting department for further processing.
The slitting department performs cutting and sizing operations. Excess edge portions of
the product roll, known as slitter-ends, are removed from the web and either placed in a dumpster
to be transported to a municipal landfill or sold to a converter. The end result of a slitting
operation might be converting a 60 inch (152.4 cm) wide by 3,000 yard (2,743 m) long roll of
product into thousands of rolls of 0.25 inch (0.64 cm) wide tape. These cut rolls are then moved
to the pressroom for custom orders or the finish room for packaging before warehousing and
shipment as a finished product. The warehouse holds custom orders and stock products awaiting
shipment. Off-specification product is often boxed and sold to a distributor/converter or disposed
of in a municipal landfill.
On each line there are rollers that serve specific purposes. For example, tension rollers
help maintain tension on the paper so the coating can be applied evenly (see Figure 2-1). Bowed
wooden rollers help to remove any wrinkles prior to product rewind. The coating application
area or coater head also has two types of rollers. An application roller receives the coating from
a trough or another roller and applies it to the substrate. A metering roller helps control the
amount of coating applied to the application roller or the substrate. Additionally, a doctor blade
is used to remove any excess coating applied to the substrate.
There are several additional devices on the coaters which are important to the application
process. Dams are devices which hold the coating for application. The coatings are pumped
from holding tanks or drums through filtered pipes/hoses to the dam. The dams have adjustable
"ears" which are placed in position in relation to the width of the substrate. The coating is
applied within a fraction of an inch of the edge of the substrate, leaving an uncoated margin to
avoid contamination of rollers and machinery. Troughs are located beneath dams to capture any
overflow. Pneumatic edge guides are often used at the exit of the dryer to sense the edge of the
web, keeping it straight and allowing for smooth and even rewinding. Many of the rollers on
the lines are coated with silicone, tape, or plasma coatings to prevent adhesive or other coatings
from drying on the rollers and sticking to the web as it passes. These coatings also facilitate
cleaning.
2-8
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Many larger companies also use a dual rewind pivot (See Figure 2-1). At the start of a
production run, the web is placed on one arm of the pivot. When the operators determine the
process is running within the control limits, the device pivots and the operator breaks the
substrate, attaching it to the second roller. The set-up material is either disposed of as waste or
sold as substandard product at reduced prices. The rewind pivot is also used at the end of a
production run when one web has run out and the next web is beginning.
2.5 PRODUCTS
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 web materials mentioned previously are used in combination
with glass, rayon, nylon, polyester, or acetate fibers to produce reinforced substrates. Films such
as polyethylene, polyester, or polypropylene are often combined with these fibers to produce
tapes used in heavy-duty packing and bundling applications. The type and number of reinforcing
strands per area, the thickness of the coating applied, and the type of film used differentiate the
grades and types of film tape.2,4 Two-faced tapes are substrates with an adhesive coating applied
on both sides of the substrate (usually foam or film). Two-faced tapes have both heavy-duty uses
in carpet tapes and light-duty uses in business forms and nametag applications.
Tape end-use categories include the following:2-4"5
• Medical and first aid tapes. These tapes were the first application of pressure-sensitive
products. These products are used by doctor's offices, and at home for first aid purposes,
foot care, and athletic protection wraps.
• Office and graphic art tapes. These tapes were first produced as clear cellophane film
tapes, but now include many other substrate varieties.
Packing and surface protection. Film tapes are the most frequently used tapes for
packaging. Saturated paper tape is still dominant in surface protection tape applications
and sheet products.
• Building industry products. These include tapes used for paint masking, temporary
attachment of wood products, weather sealing a building, bridging narrow cracks to
2-9
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overpaint, electrical wrapping, coverings for doors and walls, floor tile installation, and
glass treatments.
• Electrical tapes. These tapes include two classes: tapes intended for original equipment
manufacturers (OEM) and tape for electrical insulation during installation. Current OEM
tape may have cloth, film, paper, aluminum foil, nonwoven fabrics, or laminated
substrates depending upon the desired qualities in the backing. Electrical installation
tapes often have either a plasticized vinyl or polyethylene film backing.
• Automotive industry products. These are used in the electrical system of automobiles.
These products are similar to the OEM tapes discussed above. Other automotive tape
products include tape strips used to mount interior moldings and trim.
• Shoe industry tapes. These are used to cover the backseam to reduce pressure spots.
Fabric, paper, and film tapes may be used in this application. Tapes are also used in
binding and reinforcing areas in the construction of shoes.
• Appliance industry products. These products include decorative strips, nameplates, foam
gasketing, and foam pads for sound insulation for attachment to appliances.
Splicing tapes. These are used to splice various webs during manufacturing operations.
Paper tapes, two-faced tapes, and film tapes are used for this purpose.
• Corrosion protective tapes. These tapes help to prevent the breakdown of materials
covered by the tape. Consumption of polyethylene film tapes for corrosion protection is
very large.
Label manufacturing is similar to pressure sensitive tape manufacturing, with priority
properties being printability, flatness, ease of die cutting, and release paper components. A label
manufacturer may sell his product either in rolls or sheets as a final product, or as a raw product
for a printing and die cutting operation.2,4
Other adhesive-coated and laminated product lines include adhesive-coated floor tiles, wall
coverings, automotive and furniture woodgrain films, and decorative sheets.
2-10
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2.6 EMISSIONS AND WASTE
2.6.1 Air Emissions
In 1990, the total of all MEK releases to the air by facilities operating under SIC 2671
was 1.1 million pounds (0.5 million kilograms).6 Toluene air releases totalled 8 million pounds
(3.6 million kilograms).6 SIC 2672 facilities emitted nearly 15 million pounds (6.8 million
kilograms) of MEK and 18 million pounds (8.2 million kilograms) of toluene.6 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 reductions are dependent on the facility location. In heavily
industrialized areas, the reduction of VOC emissions may produce a corresponding reduction in
ambient hydrocarbon levels, and a corresponding reduction in ozone formation. In rural areas,
lower VOC emissions will result in lower overall ambient hydrocarbon levels, helping to reduce
the transport of ozone precursors to urban areas. In addition, the reduction of air toxics 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 groundwater. Reducing
the quantities of these materials used for cleaning will reduce the number of contaminated
aquifers, drinking water wells, and soils.
Emissions from the application of solvent-based coatings are often directed to a control
device (e.g. carbon adsorption, catalytic or thermal incinerators). While such control devices
reduce VOC emissions, the use of incineration will actually increase ambient levels of carbon
dioxide (C02) and nitrogen oxides (NOx) in the area and potentially offset VOC reductions. A
facility must be aware of the reductions of a particular pollutant and increases in emissions of
other pollutants associated with a particular control device.
2-11
-------
2.6.2 Liquid Waste Streams
Spent cleaning solvents are the largest liquid waste produced by coated and laminated
substrate manufacturers. Many of these solvents are recoverable through distillation and can be
incorporated in a future coating formulation, however they may also be sent off-site for disposal.
A second liquid waste stream consists of excess or off-specification coating.
Facilities are responsible for the environmental impacts that their water may have on a
sewer or water system. A facility must always consider the effects of a new liquid waste stream
on plant wastewater treatment (WWT) operations or on the Publicly Owned Treatment Works
(POTW). Some cleaners may reduce toxicity, hazardous waste, and air emissions, but create
excursions in effluent limitations.
2.6.3 Solid Waste
Solid waste in the form of drums of coatings and solvent waste from the manufacturing
operations may be classified into three areas: cleaning waste, waste substrate, and solidified
coating waste. Solid waste from cleaning includes items such as rags, floor coverings, machinery
coverings, and coating filters. Waste substrate (from the edge of substrate rolls, at the beginning
and end of a run, and from cutting and packaging operations) disposal is dependent on local/state
regulations but it can generally be disposed of as nonhazardous waste. The characteristics of the
solvent remaining on the substrate also affect its classification as solid waste. Solidified coating
waste is coating which has dried.
In addition, solid waste may be created by emissions control equipment. Activated carbon
from carbon adsorption systems must be replaced periodically, presenting a solid waste disposal
problem. The remains of ash and sludge from incineration or ash, sludge, and spent catalyst from
catalytic oxidation must be disposed of properly, usually as solid waste (however, testing should
be conducted periodically to determine if the waste should be treated as a hazardous material).
Waste from incineration or oxidation may also have alternative uses.
2-12
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2.7
REFERENCES
1. U.S. Department of Commerce. 1987 Census of Manufactures, Industry Series: Converted
Paper and Paper board Products, Except Containers and Boxes, MC87-1-26C. Bureau of
the Census. Washington, D.C. 1990.
2. Satas, Donatas. Handbook of Pressure-Sensitive Adhesive Technology. Van Nostrand
Reinhold Company. New York, NY. 1982.
3. "Shurtape®. What is pressure-sensitive tape?" Shuford Mills, Inc., Hickory, NC. Provided
in Memorandum from W.H. Little. Jr. to Radian Corporation, Research Triangle Park, NC.
June 12, 1992.
4. McMinn, B.W. and Vitas, J.B. Improved Equipment Cleaning in Coated and Laminated
Substrate Manufacturing Facilities (Phase I). F.PA-600/R-94-007. (NTIS PB94-141157).
U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory,
Research Triangle Park, NC. January 1994.
5. Goodwin, Don R. Pressure Sensitive Tape and Label Surface Coating Industry -
Background Information for Proposed Standards: Draft EIS. EPA-450/3-80-003a. (NTIS
PB81-105942). U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Research Triangle Park, NC. August 1980.
6. Toxic Chemical Release Inventory Database. U.S. Department of Health and Human
Services, National Institutes of Health, National Library of Medicine. Bethesda, MD.
Toxicology Information Program Online Services TOXNET® Files. 1990.
2-13
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CHAPTER3
DESCRIPTION OF RADIATION-CURING
3.1 PROCESSES
3.1.1 Introduction
This section gives an overview of radiation-curing in the coated and laminated substrate
manufacturing industry and includes a discussion of raw materials, equipment, physical processes,
product performance, and emissions and wastes. Radiation-curing systems use either ultraviolet
(UV) light or electron beam (EB) curing mechanisms to penetrate and cure a radiation-curable
coating to a substrate. The use of radiation-curing/laminating systems has been increasing in recent
years in markets such as food packaging, printing, graphic arts, and roll converting. Radiation-
curing technology is currently being used with a wide variety of web substrates including paper,
films, and foils.
3.1.2 Raw Materials
In general, the raw materials used in a radiation-curing process for coated and laminated
substrates are the same as those used with conventional thermal systems. These materials consist
of substrates, adhesives, and other coatings. The UV-curable and EB-curable adhesives have been
applied to paper, film, and foil webs as have their solvent-based adhesive counterparts. They have
been used to laminate polyester, polycarbonate, polyethylene, and cellulose acetate films. At this
time, the only web substrate to which UV-curable and EB-curable coatings have not been
successfully applied are those that are porous in nature, such as the fabric which may be used in
medical tapes.1 Because the substrates used in both radiation-curable and thermal coating and
laminating systems are very similar, this section will focus on the coatings.
A coating must perform in a specific manner to meet customer demands. Whether these
coatings are solvent-based or radiation-curable is irrelevant as long as customer specifications are
met. Release coats manufactured for compatibility with EB-curable and UV-curable adhesives are
3-1
-------
often 100 percent solvent-free silicone acrylate. One manufacturer of EB-curable release coatings
has received approval from the Food and Drug Administration (FDA) to use their coatings in food
containers and other related applications. Specially formulated release coatings arc critical in the
EB-curing adhesive process because of the increase in tack associated with EB-curable adhesives.
Currently available release coatings used with thermal systems will not perform properly with
radiation-curable adhesives and will need to be reformulated or replaced.
Radiation-curable adhesives include both UV-curable and EB-curable varieties. UV-curable
coatings consist of monomers, which reduce the coating's viscosity and provide application
characteristics; oligomers, which give the coating its physical and performance characteristics;
pigments: fillers; inhibitors, which improve shelf life; and photoinitiators, which speed the curing
process. The UV-curable adhesives contain a photoinitiator which initiates the polymerization of
the adhesive to the substrate when exposed to a UV light. EB-curable hot melt pressure sensitive
adhesives contain 100 percent solids with polymers, monomers, additives, but no photoinitiator. EB-
curable low-melt adhesives which require less heating than hot melts and are developed to perform
like solvent-based acrylic adhesives are currently being introduced in Europe. In the EB system, the
electrons that are generated react directly with the monomers and polymers, eliminating the need for
a photoinitiator.2
3.1.3 Equipment
Radiation-cured coating and application equipment differs from conventional equipment in
one area: the curing mechanism. Both thermal and radiation-curable systems operate unwind,
coating, curing, and drying/rewind stations. In conventional adhesive curing, a thermal dryer is used
to heat and dry or cure the coating. The thermal dryer system relies on electricity or natural gas to
heat the air which then dries/cures the coating. In a radiation-curing system, energy beams are used
to cure the coating. UV-curing equipment consists of a UV lamp suspended above the coated
substrate, a light reflector, a radiation shield, and a cooling system. Mercury lamps are frequently-
used to provide the UV-curing mechanism. The substrate with the wet coating passes under the light
and is exposed to the UV wavelengths which crosslink the polymers and monomers, creating a
uniform adhesive layer. Production line speeds for UV-curing equipment range from 100 to 800 feet
3-2
-------
Coating
Reservoir
Roll Coating
Station
Unwind Roll
Station
Ultraviolet
Lamps
Rewind Roll
Station
Figure 3-1. UV-curable system - continuous web configuration.5
-------
per minute (fpm) (30.5 to 245 meter/minute). Figure 3-1 is a schematic of the UV-curing equipment.
EB-curing equipment consists of a control panel to regulate the amount of energy, a
transformer to control line voltage, an electron accelerator to deliver the EB energy, and a nitrogen-
inerting system to prevent ozone formation.3 Figures 3-2 and 3-3 are diagrams of an EB production
line and a cross section of the EB curing processor, respectively. Production line speeds for EB-
curing equipment can exceed 1.600 fpm (488 meter/minute). Operations in excess of 1600 fpm will
need a specialized nitrogen-inerting system to prevent unacceptable ozone emissions.'1 The curing
method for EB is similar to the UV process.
3.1.4 Physical Processes
UV-curing and EB-curing represent the two most widely used radiation-curing methods.
Each has process advantages and disadvantages which are discussed in detail below.
IJV polymerization occurs when a specially formulated coating comes into contact with a
UV light source, primarily a mercury lamp. The characteristics of the coating and substrate effect
the UV energy being absorbed by the photoinitiator. The curing of the coating is also dependent on
both of these factors.3 If the UV energy does not penetrate the coating effectively, much of the
coating will not be cured. UV energy does not penetrate thick, dark, or colored coatings or
substrates very well.4
EB-curing occurs when a specially formulated coating is exposed to electrons. The proper
curing of an EB adhesive is dependent on the mixture of raw materials and the level of energy used
to power the electrons. One advantage that EB has over UV is that the electrons can cure the layers
of 100 percent solid adhesives. This ability allows EB-curing to be used on a variety of substrates.3
However, if the ratio of energy to raw materials is not properly determined, a substrate can be
damaged (e.g., paper can become brittle).4 EB-curing is similar to UV-curing with one notable
exception: the UV-curing requires a photoinitiator to generate the free radicals. Both systems cure
the coating in approximately one second.3
3-4
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UNWIND FOR UNWIND FOR
LAMINATION LAMINATION
Figure 3-2. Coater-laminator with curtain electron curing.'
(Reprinted with permission from Nablo, Sam V. and E.P. Tripp III. "Electron Curing of Coatings and Adhesives,"
Hot Melts-An Overview for Management. 1979.)
-------
LINEAR FILAMENT
Figure 3-3. Curtain type electron processor.
(Reprinted with permission from Nablo, Sam V. and E.P. Tripp III. "Electron Curing of Coatings and Adhesives,"
Hot Melts-An Overview for Management. 1979.)
-------
Radiation-curable hot melts arc hot melts which crosslink when exposed to radiation such
as l"V light and electron beams. Radiation-curable hot melts have been developed with acrylics,
SIS, and SBS resins. These adhesives exhibit properties of high solvent resistance and high shear
strength at elevated temperatures comparable to those of solvent-based adhesives.
3.1.5 Product Performance
The use of radiation-curable laminating adhesives has allowed the coating of substrates
which have previously been unusable. Substrates such as plastics can now be coated with EB-
curable and IJV-curable adhesives which provide high bond strengths at low adhesive weights.
Although no EB-curable adhesive lines are in commercial operation in the United States, tests have
been conducted to evaluate and compare the performance of EB-laminating adhesives with those of
solvent and standard hot-melt adhesives. Laboratory tests were conducted comparing peel and shear
properties of radiation-curable, solvent-based, hot melt, and silicone-based adhesives. Table 3-1
presents a summary of one study.3
3.1.6 Emissions and Wastes
In general, UV-curable and EB-curable coatings do not contain solvents. The absence of
solvents completely alleviates VOC emissions to the air from the application and curing process.
The EB systems use nitrogen (N2) to inert the curing area and prevent ozone emissions. In addition,
the EB- and UV-curing processes do not create any hazardous waste.
Both U V-curable and EB-curable coatings are considered solid waste before and after curing
since the ingredients are 100 percent solids. Due to the size of the UV and EB machinery, less solid
waste is created since less make ready substrate, used to thread through the lines prior to beginning
the coating process, is needed. Also, both UV and EB systems can coat the substrate to the edge,
thus creating less slitter waste from the edges. Recycled paper can also be used in the radiation-
curing process but not in traditional solvent systems.4
3-7
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TABLE 3-1. COMPARISON OF UV/EB LAMINATING ADHESIVES WITH OTHER SYSTEMS
Type/
Polyurethane
Silicone
Rubber
Characteristics
UV/EB
Epoxy Based
Based
Based
Based
Hot Melt
Curing Method
Radiation,
Acid-based
Moisture/
Heat/
Heat/
Heat, one-
One-
Catalyst,
Amine,
Catalyst,
Pressure
component
Component
Two-parts
Two-parts
One or two
Parts
Solvent-
based
Curing
RT, fast
RT-350°F (177°C),
RT-200°F (93°C),
RT-300°F
RT-250°F
Exceed melt
Condition
slow, need post cure
slow,
(149°C),
(121°C),
point of
for ultimate
post cure
slow,
slow,
the base
performance, need
occurs
post cure occurs
post cure
polymer,
thorough mixing
slow
Adhesion
Good/
Good/
Good/
Fair/
Fair/
Good;
Properties and
Excellent
Excellent;
Excellent
Good;
Good
Loss of strength
Comment
Peel strength
low; adhesion
to plastics
weak
Peel and shear
strengths low,
adhesion to
organic substrates
weak
at elevated
temperatures,
tend to be brittle
at
low
temperatures
Chemical
Excellent
Excellent
Excellent
Excellent
Poor
Poor
Resistance
Heat
Good
Excellent
Good
Excellent
Fair
Poor
Resistance
RT - residence time & temperature
Source: Reference 3
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Another source of emissions and waste is from equipment cleaning. Solvent-based coating
spills are usually cleaned with a solvent-type cleaner. Radiation-cured coatings can be removed with
less polluting methods.
Spills and overflows of the radiation-curable coatings from the dam can be cleaned with a
dry rag, industrial strength soap, or isopropyl alcohol (IPA). a minimally toxic solvent. The solvents
used in the coating and cleanup of conventional solvent-based adhesives present a toxicity threat
which the radiation-curing process does not pose.3 The radiation-curable coatings do have the
potential to cause skin irritation, which can be prevented by wearing the proper protective safety
equipment.
3.2 COSTS
3.2.1 General
One of the many aspects of investigating alternative technologies is the cost difference
between the conventional and alternative technologies. Four primary areas were evaluated as part
of this study: materials, equipment, operations and maintenance, and energy costs. The information
provided was received from several sources and, thus, should be used only as a guide.
3.2.2 Materials
In order to compare the raw material costs for both solvent-based and radialion-curable
processes, several factors must remain constant. The substrate (i.e., paper, foil, film) cost remains
the same because no new substrates are required to be developed. Line speeds and coating thickness
(i.e., a 1 mil thick coating after curing) also must be considered constant for this comparison. The
cost for the coatings applied to the substrate is the variable examined. All PSA products have both
a release and adhesive coating. Pressure-sensitive release coatings for the three (i.e., UV-curable,
EB-curable, and solvent-based) types of coalings vary according to formulation. Solvent-based
release coatings (30 to 50 percent solids, 50 to 70 percent solvent) and adhesives (30 to 60 percent
solids, 40 to 70 percent solvent) were reported to sell for approximately $1.50 to $1.90 per wet
3-9
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pound.7 Liquid UV-curable release coatings and adhesives (100 percent solids) were reported to sell
for approximately $3.00 to $5.00 per pound and $4.00 to $6.00 per pound respectively. Of that
$3.00 to $5.00, it was estimated that approximately 25 to 50 percent of the UV-curable adhesive
costs are for the photoinitiator.8 The EB-curable release and hot-melt adhesive (100 percent solids)
coatings were reported to sell for approximately $10.00 per pound and $1.50 to $2.00 per pound
respectively.1910
Another study provided a comparison of costs for thermal and EB-curable adhesives in
Europe. Some European companies are currently using EB technology in commercial adhesives
applications. The study compared a 60 percent solids, 40 percent solvent adhesive to a 100 percent
solids hot melt and 100 percent solids low-melt EB-curable adhesive. During the manufacturing of
the product, a 0.008 lb/ft2 [41 gram per square meter (gsm)J wet coating of the 60/40 adhesive was
applied to obtain a 0.005 lb/ft2 (25 gsm) dry coating. The adhesive costs approximately SI.50 per
pound. The study estimated the cost to be approximately $0.13 per square yard to use the 60/40
solvent-based adhesive. The 100 percent solids EB-curable rubber hot melt adhesive cost
approximately $2.30 per pound. This corresponds to a cost of $0.12 per square yard with a 0.005
lb/ft2 (25 gsm) coating. The EB-curable low-melt costs approximately $3.00 per pound, making a
square yard of product cost approximately $0.22 to produce at 0.005 lb/ft2 (25 gsm).10
3.2.3 Equipment
Pressure-sensitive coating application equipment can range in performance, price, and size.
No data have been established for costs associated with a manufacturer of EB-curcd adhesive coated
and laminated substrates because no company in the United States uses EB technology for
commercial production. The equipment costs discussed below represent a comparison between the
types of coated and laminated adhesive curing mechanisms. These figures compared systems which
cure a 60 inch wide substrate at lines speeds of 600 fprn. A solvent-based thermal adhesive dryer
was estimated to cost approximately $1.1 million while an EB adhesive curing "turn-key" system
was quoted at $750.000.4 Waterbased adhesive system dryer costs were estimated at $600,000 while
a hot melt chill roller with the chiller system costs approximately $30,000.1213
3-10
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TABLE 3-2. EQUIPMENT COST SUMMARY (in 1993 $)
Silicone Coater Adhesive Coater Silicone Coat P.S. Coat
& Drive & Drive Dry/Cure Dry/Cure
Waterbased silicones
Solvent-based silicones
100% solids -
Thermal cure
Five-roll coater
Offset-gravure coater
100% solids -
EB-curable
Five-roll coater
Offset-gravure
coater
Solvent-based adhesives
Hot melt for ED
EB-curable system for
hot melt adhesive
Dryer system for
solvent-based adhesives
-120 feet (36.6 m) and
5 zone, with
incinerator
235,000
235,000
350,000
300,000
350,000
300,000
600,000
700,000
475,000
750,000
400,000
360.000
750.000
1,100,000
Source: Reference 4
A supplier of coating machinery was contacted regarding the cost associated with PSA lines.
Table 3-2 summarizes the costs provided for different methods and machinery of PSA equipment.4
The equipment costs are based on machinery which will coat a 60 inch (152.4 cm) wide substrate,
running approximately 600 feet (182.9 m) per minute (fpm).'2
3-11
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3.2.4 Operating and Maintenance Costs
Operating and maintenance (O&M) costs occur for all types of coating lines. The thermal
system's maintenance cost was estimated to be approximately S2.500 per year for approximately
6,000 hours of operation. For the thermal lines, dryer conveyors and heating mechanisms are the
primary operating and maintenance cost items. EB and UV systems were estimated to cost
approximately $2,000 and between $6,000 to $8,000 per year respectively for operating and
maintenance. EB machinery maintenance primarily involves replacing the windows which expose
the substrate to electrons. The UV system's maintenance costs consist predominantly of replacing
the lamp system. These estimates are based on the opinions of EB-curing, UV-curing, and thermal
equipment manufacturers.4 The printing study showed amortized (i.e., 7 years, 6,000 hours of
operation per year) maintenance costs for thermal, EB-curing, and UV-curing of $0.16. $0.45, and
$7.00 per hour respectively."
The operating costs data comparison for thermal, EB, and UV PSA lines were not available
at this time. However, the offset printing line study will be used to show a comparison of coating
equipment factor costs for the three curing methods, fable 3-3 provides a short summary of raw
material, waste, and operating costs."
TABLE 3-3. SUMMARY OF PRINTING COSTS
Tnk Cost
Varnish Cost
4% Thermal
Total Hourly
Drying Type
S/lb
S/lb
Waste
Costs
Thermal
$2.50
$3.33
$283
$1,148
Electron Beam
$7.50
$2.40
$0
$1,104
Ultraviolet
$7.85
$3.25
$0
$1,189
Source: Reference 3
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3.2.5 Energy
Because there is not a commercial PSA EB-curing production line in operation, the results
of the printing study will also be used as a comparison of energy cost for thermal, EB. and UV
operations. The energy costs were amortized over several years at 6,000 hours of operation per year.
Table 3-4 summarizes the energy cost for the print line.
TABLE 3-4. SUMMARY OF PRINTING STUDY ENERGY COSTS
Cost Factors
Thermal Line
EB-Curing System
UV-Curing System
Electricity
$25.39
$6.46
$36.75
Natural gas
$18.16
Nitrogen
$15.20
Total Hourly Costs
$43.55
$21.66
S3 6.75
Full operating time
5,500
4,000
4,000
(hrs)
Standby (hrs)
300
500
500
Warm-up (hrs)
200
Not operating (hrs)*
1.500
1,500
Total Hours
6,000
6,000
6,000
Source: Reference 11
*Not operating (hrs) - The curing mechanisms can be started and shut-down in a matter of minutes therefore less hours
of full operation and none for warm-up.
3.3 REFERENCES
1. Presentation by Thomas Hohenwater, Jr., Goldschmidt Chemical Corporation, Hopewell,
VA. Energy Sciences Inc. Group Presentation. Wilmington, MA. November 17, 1993.
2. Presentation by Bert Blackwood, Swift Adhesives, Franklin Lakes, NJ. Energy Sciences Inc.
Group Presentation. Wilmington, MA. November 17, 1993.
3. 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 (TAPP1). 1987.
3-13
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4. Presentation by Frederic S. Mclntyre, Energy Sciences Incorporated, Wilmington, MA.
Energy Sciences Inc. Group Presentation. Wilmington, MA. November 17, 1993.
5. Walata, Stephen A. and C.R. Newman. Radiation-Curable Coalings. EPA-600/2-91-035.
(NTIS PB91-219550). U.S. Environmental Protection Agency, Control Technology Center,
Research Triangle Park, NC. July 1991.
6. Nablo, Sam V. and E.P. Tripp 111. "Electron Curing of Coatings and Adhesives," Hot Melts-
An Overview for Management. 1979.
7. Telecon. Bennett, Lisa, Environmental Inks and Coatings, Morganton, NC, with Geary
McMinn, TRC Environmental Corporation, Chapel Hill, NC. October 14, 1993.
8. Telecon. Or I off. John, National Starch & Chemical, Bridgewater, NJ, with Jill Vitas, TRC
Environmental Corporation, Chapel Hill.NC. October 19, 1993.
9. Telecon. Tripp, Ted, Ted Tripp Consulting. Wilmington, MA, with Jill Vitas, TRC
Environmental Corporation, Chapel Hill, NC. October 6, 1993.
10. Mclntyre, Frederic S. "Environmental Imperatives: Hot Melt Coating & EB Curing," Energy
Sciences, Inc. Wilmington, MA. 1993.
11. Newcomb, W.T., and T.J. Menezes. "A Comparison of E-Beam, UV and Thermal Drying
for Web Offset Printing," RPC Industries I lay ward, CA. No date available.
12. Guenther, Donald C. "Equipment cost estimate," Faustel, Inc. Germantown, WI. 1993.
13. Telecon. Hubbard, Chuck, Black Clawson, Fulton, NY, with William Blake, Jr., TRC
Environmental Corporation, Chapel Hill, NC. Cost of Hot Melt Chiller System. January 20,
1994.
3-14
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CHAPTER 4
TECHNICAL BARRIERS TO RADIATION-CURING
4.1 GENERAL
Reviewing alternative technologies for the coated and laminated substrate manufacturing
industry reveals several technical barriers, the greatest of which is the lack of practical, commercial
production experience in using UV- or EB-curing systems. Currently, no known large tape and label
manufacturers are using radiation-curing for production purposes however, many large facilities are
experimenting with radiation curable adhesives. Only proprietary, pilot-scale systems have been
tested. This has made it difficult to identify all technical barriers to radiation-curing in the coated and
laminated substrate manufacturing industry. However, in discussions with equipment and raw
material vendors, some general technical barriers have been identified. These technical barriers can
be categorized as follows: equipment suitability, materials availability, product and adhesive
performance characteristics, and health and safety issues. Each of these barrier categories will be
discussed in this chapter.
4.2 EQUIPMENT SUITABILITY
For this discussion, the important equipment for the coated and laminated substrate
manufacturing industry are be broken down into two segments: coating application equipment and
curing equipment. All other auxiliary equipment, such as the wind and unwind stations, remain the
same regardless of the type of application and curing equipment used.
The application equipment for liquid UV-curable adhesives should be the same as a solvent-
based coating system. UV-curable adhesives can be applied by a reverse roll coater, a metering rod
coater, or gravure roll coater.1 Therefore, most tape and label manufacturers would not need to
retrofit or replace existing equipment in order to use UV-curable adhesives.
The application equipment for EB-curable adhesives would be a hot melt coating system.
Many tape and label manufacturers have a hot melt line at their facility and therefore the addition of
4-1
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the EB-curing system could be easily accomplished. However, for those facilities that do not have
a hot melt line, the equipment necessary to liquify the adhesive would need to be purchased.
The radiation-curing equipment can be easily installed onto an existing thermal system with
minimal downtime if enough horizontal (i.e., floor space) is available between the application
equipment and the dryers. Several radiation-curing equipment manufacturers have suggested that the
equipment can be installed under the thermal dryers if the dryers are elevated approximately 10 feet
(3 m) off the ground. If insufficient room exists between the application equipment and the thermal
dryer or if the dryer is at ground level, the installation of the radiation-curing equipment will be much
more difficult and time consuming, and will require either removing the thermal dryer completely or
moving the application equipment to another area.
4.3 MATERIALS AVAILABILITY
At the time of this study, no known facility was commercially producing radiation-cured tapes
or labels. This is due in part to the lack of available radiation-curable pressure sensitive adhesives.
A few smaller adhesive manufacturing companies have developed potentially applicable adhesives,
but have had limited success in presenting these new formulations to the tape and label manufacturers.
Several large adhesive manufacturers state that radiation-cured technology is not yet available that
will provide the tape and label manufacturers with a radiation-curable adhesive that has the same
physical properties as the solvent-based adhesives. However, these same large adhesive coating
manufacturers stated that their research and development teams are working on the radiation-curable
alternatives, and that the technology will be available within the next two years.
The development of solventless adhesives is a very time consuming process. With each new
adhesive developed, the manufacturer must ensure that each hazardous component of the adhesive
is registered under the Toxic Substances Control Act (TSCA). The TSCA registration process can
be very time consuming and costly2 In some cases, the registration process can take up to three
years.
In addition to the need for development of radiation-curable adhesives with the same physical
properties as the solvent-based adhesives, the release coatings will need to be reformulated to be
compatible with the new adhesives. As with adhesives, each new release coat component must be
4-2
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TSCA registered. The increased tack associated with EB-curable adhesives makes the release coating
a very important part of the tape and label manufacturing process. It is critical that the release coat
allow for a smooth release of the tape or label, or consumer satisfaction may be affected. A further
discussion of physical properties is included in the following section.
4.4 PRODUCT AND ADHESIVE PERFORMANCE CHARACTERISTICS
As discussed in Section 3.1.5 of this report, the physical properties of the radiation-curable
adhesives are some of the most difficult barriers to overcome. The solvent-based adhesives have very
specific properties that have been established as "standard" properties (i.e., color, lack of clarity) that
consumers believe are critical to the tape or label and its end-use. Until recently, radiation-curable
adhesives did not have those standard properties.
Liquid UV-curable adhesives, while less costly than solvent-based adhesives, lack many of
the physical properties of solvent-based adhesives. One such property is the cure window or the time
period during which the adhesive can be properly cured. The cure window for liquid UV-curable
adhesives is short, therefore, the adhesive can be undercured or overcured very easily. This curing
problem can lead to poor tack and increased creep (wrinkling). Other properties that have prevented
liquid UV-curable adhesives from being considered as alternatives to the solvent-based adhesives
include: increased viscosity, making the adhesive difficult to apply with conventional application
equipment; residual odors from the undercured adhesive; and appearance problems.3 The problems
associated with the UV-curable adhesives led to the creation of the EB-curable products. Hot
melt/EB-curable adhesives do not possess many of the problems that UV-curables exhibit and offer
some advantages over solvent-based formulations such as increased temperature and chemical
resistance. This makes them attractive for some high performance applications.
Due to the lack of known commercial application of either of these radiation-curable
technologies, it is difficult to discuss aesthetic properties of these products However, it is important
to mention that in discussions with marketing representatives from the tape and label companies,
aesthetics are very important to their customers. Poor perception of a low-VOC product which does
not look or feel like a solvent-based product, even though the low-VOC product may actually
perform better, may lead to lack of market acceptability. This could be a considerable barrier.
4-3
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4.5
HEALTH AND SAFETY ISSUES
In general, health and safety concerns are evident when using radiation technologies. Even
though radiation-curable adhesives would be handled in the same manner as solvent-based adhesives,
with the use of gloves and eye protection at all times, facilities still question effects on workers'
health. There is the potential for skin to become sensitized to the adhesives, if the coating is not
washed off quickly.
In addition, through recent advances in monomer chemistry, the health and safety hazards
associated with radiation-curable coatings have decreased significantly. The monomers have a high
molecular weight which reduces the volatility and removes almost any danger associated with vapor
inhalation. There continues to be concerns with skin becoming sensitized when in direct contact with
the radiation-curable coatings, and workers are still required to wear appropriate personal protective
equipment when handling these materials.4
There is a concern with the use of a radiation-cured product that residual monomers may
remain in the product. Several tape and label manufacturers have expressed a concern that consumers
may attempt to tile a law suit against the manufacturers for being exposed to these residual
monomers. The manufacturers would like to minimize the risk to their companies by having EPA
establish a level of residual monomer that can remain in the product and the product can be
considered "safe."5
4.6 REFERENCES
1 Presentation by Richard Greer, Faustel CMM International, Chicago, IL Coating
Technologies/Methods. August 31, 1993.
2. Memorandum. Ilohenwater, Tom, Goldschmidt Chemical Corporation, Hopewell, VA, to
Beth McMinn, TRC Environmental Corporation, Chapel Hill, NC. Toxic Substances Control
Act Review. November 22, 1993.
3. Telecon. Ted Tripp, Ted Tripp Consulting, Wilmington, MA, with Jill Vitas, TRC
Environmental Corporation, Chapel Ilill, NC. Discussion of barriers to radiation-curable
adhesives. October 6, 1993.
4-4
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4. Memorandum. Ross, Alexander, Rad Tech International North America, Falls Church, VA
to Beth McMinn, TRC Environmental Corporation, Chapel Hill, NC. Comments on Health
and Safety Issues Associated with Radiation-curable Coatings. March 4, 1994.
5. Presentation by Jill Vitas, TRC Environmental Corporation. RadTech International, Orlando,
FL. Barriers to Radiation-Curable Coatings in the Coated and Laminated Substrate
Manufacturing Industry. Comment made during presentation by George Moses, Avery
Dennison, Pasedena, CA May 2, 1994
4-5
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CHAPTER 5
ECONOMIC BARRIERS TO RADIATION-CURING
5.1 GENERAL
In addition to the technical barriers described in Chapter 4, coated and laminated substrate
manufacturers must evaluate the economics associated with making significant raw material and
process changes. This section discusses the economic harriers to using radiation-curable adhesives
including capital investment, pricing pressure, payback periods, and operating costs. Due to the lack
of known production facilities using liquid UV-curable adhesives, this chapter focuses on the EB-
curable adhesive systems.
5.2 CAPITAL INVESTMENT FOR NEW SYSTEMS
A comparison of thermal (solvent-based) and EB-curing teclmology must examine the capital
investment costs for new equipment. The costs reported below were provided by a supplier of both
EB-curing and thermal machinery. For a 60-inch (152.4 cm) wide substrate and lines speeds of 600
fpm (182.9 meters per minute), the EB machinery plus a hot melt chill roller with the chiller system
is less expensive than the new thermal equipment without control equipment. In terms of retrofit, a
facility would need to add an EB-curing mechanism, listed at approximately $750,000 each for each
coating line. Assuming the facility already has a hot melt adhesive system and release coating
equipment in place, additional add-on costs for a retrofit would be minimal.1
Cost in dollars for a new solvent-based system:
Solvent-based silicone release coater and drive - 235,000
Solvent-based silicone adhesive coater and drive - 400,000
Solvent-based silicone release coat dry/curc system - 700,000
Dryer system for solvent-based silicone adhesives;
120 ft. (36.6 m) 5 zone - 1.100.000
Subtotal 2,435,000
Installation (22 percent of subtotal) 535.700
Grand Total for installed solvent based system 2,970,700
5-1
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Cost in dollars for a new ED-cured system:
KB - 100 percent solids five-roll release coater -
EB - hot melt adhesive coater (drum unloader/melter)
EB - release curing system -
EB - curing system for hot melt adhesive -
350,000
360,000
750,000
750.000
Subtotal
Installation (22 percent of subtotal)
2,210,000
486.200
Grand Total for EB-curing system with installation
2,696,200
5.3 PRICING PRESSURE
The profit margin for many FSA products is very low, pennies per square foot Because of the
low profit margins, facilities must consider the effect of environmental regulations on product costs.
Upcoming environmental regulations may effect a facility's emission requirements, requiring them
to reduce, control, or eliminate many of their solvent emissions, pay large fines, or close the facility.
Additionally, the cost for maintaining and operating emission control devices and following
recordkeeping requirements may be substantial. These costs will cause the price of PSA products
to increase. These costs could be avoided if reasonable alternative technologies could be obtained.
Alternative technologies must not only address the production issue and be affordably priced, but
provide fewer emission problems than a solvent-based system.
5.4 PAYBACK PERIOD FOR RETROFIT SYSTEMS
In order to compare the costs for a single-line solvent-based system and an EB-curing system,
several assumptions must be made: the coating head/area will not be significantly altered, substrate
types will not change, the dryer will not be used with the EB-curing system, and the radiation-curing
equipment will be retrofitted to the present coater. EB-curable and solvent-based facilities will also
incur environmental compliance costs to dispose of their solid and hazardous waste. Assuming an
industrial tipping fee of $39.50/ton of waste, total waste production of 6,000 square yards (5,016
square meters) per day, average thickness of mixed coated and uncoated waste equal to 1.8 mil, and
a density of waste equal to 62.4 lbs per cubic foot (1,000 kg/m3), a total of $3,500 is spent annually
5-2
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on solid waste at a solvent-based facility while the EB-curable facility would spend approximately five
percent of this amount totaling $ 170.3 The solvent-based line generates approximately 25 drums of
waste annually. Assuming a hazardous waste disposal fee of $450 per drum, a total of SI 1,250 is
spent on hazardous waste annually at the solvent-based facility. EB-curable coatings are considered
solids after curing therefore no hazardous waste is generated from production. However, both
facilities may have liquid hazardous waste from cleaning the coatings from machinery, etc. The cost
to retrofit one solvent-based line to an EB-curing line, and the possible savings, are itemized below.
EB equipment costs:
EB-curable release and adhesive coater curing equipment -
(See Section 5.2 of this chapter)
Solvent-based coating system costs:2
1 Energy costs per year -
(natural gas fired oven, 6,000 hours of operation)
2. Solid waste (e.£.,makeready, raw material) costs per year
6'(i0() >,ds2 x x (!M x 0.0018 to x JL. = 2,835 £
day yr yds2 12 iii yr
62.4 lbs ^ ton $39.50 $1.23
ft* 2,000 lbs ton tl3
ft* SI 23
2,835 — x = S3,500
vt ft3
3. Hazardous waste costs per year - SI 1,250
25 drums $450 $11,250
x - (5.4)
year dntm year
4. Air emission costs per year - $44,000
(Solvent lost from: Process - 290,000 lbs * 7.25 lbs/gal=40,000 gal)
(Toluene - $1.10/gal.4)
290,000 lbs x ¦ 1 gal x S-14,000 fS
7.25 lbs gal K '
5. Engineer/environmental regulatory savings - $15,000
(One-half of one environmental person's time saved5)
$1,500,000
$170,000
$3,500
(5.1)
(5.2)
(5.3)
5-3
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0.5 employees x $29,300 $15,000 (5 6)
employee
EB-curable coating system costs.
1. Energy costs per year - $87,000
(Electricity - $25,840; Nitrogen - $60,800)
2. Solid waste per year - $170
8K tons waste x qqj x S39.50
year ton fee
3. Hazardous waste costs per year - $0
4. Additional costs incurred - $35,000
(N2 system - 28,000 scf tank, $25,000,
installation, $5,000; piping, $5,000)
Dollars saved bv using EB-curing
svstem per vear:
Previous
Current
Savings
1. Energy
$170,000
$87,000
$83,000
2. Solid waste
$3,500
$170
o
o
3. Hazardous waste
$11,000
$0
11,000
4. Air emissions (lost solvent)
$44,000
$0
44,000
5. Other costs/savings (1 st yr)
$15,000
$30,000
-15,000
(5.7)
Savings per year to switch to EB-curing - $126,000
Using the savings per year from switching to the EB-curing equipment, and the cost for the solvent-
based release and adhesive coating lines, at a discount rate of 2.1 percent, the net present value theory
estimates that approximately 11 years would be required to recover the capital costs of the EB
investment. This assumes the cost per coated area for both coatings is equal.
Additional savings such as reduced maintenance, floor space saved for other uses, lower shipping
costs for solid materials, and less clean-up time for EB-curable coatings should also be considered
in the examination of EB-curing system implementation costs and savings.
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5.5 OPERATING COSTS
Actual operating costs for radiation-curable PSA applications are not available as no known
facility in the United States is using this technology commercially. However, as described in Section
3 .2.4, operating and maintenance costs for an EB-curing system are lower than conventional thermal
systems.
5.6 REFERENCES
1. Guenther, Donald C. "Equipment cost estimate," Faustel, Inc, Germantown, Wl. 1993.
2. Newcomb, W.T., and T.J. Menezes. "A Comparison of E-Beam, UV and Thermal Drying for
Web Offset Printing," RPC Industries, Hayward, CA. No date available.
3. Telecon. Representative of Durham County Landfill, Durham, NC with William L. Blake, Jr.,
TRC Environmental Corporation, Chapel Hill, NC. December 1993.
4. "The Markets," American Paint and Coatings Journal. 78(17): pp. 23,24. 1994
5. Statistical Abstracts of the U.S. 1993. U.S. Department of Commerce, Bureau of the Census,
pp. 575, 742.
5-5
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CHAPTER 6
EDUCATIONAL BARRIERS TO RADIATION CURING
6.1 GENERAL
The final category of barriers considered was educational barriers. This chapter divides
educational barriers into two broad categories: management barriers and employee training
barriers.
6.2 MANAGEMENT AWARENESS
Management at PSA facilities expressed concern about radiation-curing technology cost,
performance, and productivity. Significantly high initial costs are a major issue for PSA
facilities. However, the cost and pricing information provided in this document illustrates that
the newly installed cost of radiation-curing equipment should approximate those of new thermal-
curing machinery without control equipment. The productivity of the radiation equipment
exceeds that of the present thermal system due to the speed of cure available for most substrates,
allowing faster line speeds. This increased productivity leads to lower cost which equates to
higher profits. It is important that industrial managers be aware of the current technology
advances in radiation curing and that they are aware of the associated long term costs and
benefits.
6.3 EMPLOYEE TRAINING
The two main concerns expressed by employees regarding handling radiation-curable
systems were coating and radiation safety. Employees must be trained to properly handle these
coatings. Radiation-curable coatings are non-hazardous, however, they can cause allergic
responses if allowed to contact a person's skin for a prolonged period of time. The coating
manufacturers contacted for this project provide customers with employee training (i.e., safe
handling practices, protective equipment, cleaning) concerning radiation-curable coatings. The
most significant fear employees expressed was association with the word "radiation." The
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alternative technologies are cured by radiation beams. Both UV and EB equipment suppliers
have created methods to harness the radiation energy and safely apply it to a coating. The EB
equipment, as shown in Figure 3-1, has shielding, control windows to direct the electron beams,
and radiation leak detection equipment to guard against problems with the system and protect
employees against possible radiation exposure. Nitrogen inerting is used to avoid creating ozone
from the process, when the system operates above 1,600 feet per minute, and prevents ozone
from escaping to the atmosphere. Employees who use the radiation-curing equipment must be
instructed on its proper use.
6-2
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CHAPTER 7
DESCRIPTION OF ALTERNATIVE TECHNOLOGIES
7.1 GENERAL
An alternative to solvent-based adhesives is hot melt adhesives. Currently, hot melt adhesives
are estimated to account for 22 percent of the total adhesive consumption in the United States as
measured by dry adhesive weight.1 Hot melt adhesives arc different from solvent-based adhesives in
that hot melt adhesives are not dissolved in solvents. Instead, hot melt adhesives are solids which are
heated to their melting point and applied to the substrate in their liquid state. Hot melt adhesives have
been used in a variety of different applications which include bookbinding, product assembly, box and
carton sealing, and pressure sensitive tapes.
Some manufacturers estimate that hot melt adhesives account for almost 100 percent of the
adhesives used by the bookbinding and the box and carton sealing industries, which have been
dominated by hot melt adhesives because these adhesives are capable of quick line speeds and cure.
7.2 PROCESSES
7.2.1 Raw Materials
Unlike the solvent-based adhesives which are formed primarily from natural rubbers, hot melt
adhesives are composed of high molecular weight polymers which are thermoplastic in nature. The
most commonly used polymers for hot melt pressure sensitive adhesive applications include ethylene
vinyl acetate (EVA), styrene-isoprene-styrene (SIS), and styrene-butadiene-styrene (SBS). By
themselves, these polymers do not exhibit the full range of performance characteristics required for
the product's end use. As a result, a variety of tackifying resins, waxes, antioxidants, plasticizers, and
other materials are added to the adhesive formulation in order to enhance the polymer performance.
Table 7-1 lists some of the commonly used hot melt adhesive ingredients.2
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TABLE 7-1. COMMONLY USED RAW MATERIALS IN HOT MELT ADHESIVES
Base Material
Reactive
Hot Melt
Adhesives
Tackifiers
Waxes
Misc.
acid copolymers
amorphous
polyolefins
epoxy
polyester
styrene resins
styrene
copolymer resins
paraffins antioxidants
microcrystallines plasticizers
olefin/butyl rubber polyurethane a-pinene resins
ethylene/acrylic
copolymers
ethylene/vinyl
acetate copolymers
ethylene
terpolymers
polyacrylic
polyamide
polyisobutylene
polyester
polystyrene
polyvinyl acetate
polyvinyl butyryl
polyethylene
styrene block
copolymers
oxidized
microcrystallines
P-pinene resins synthetics
dipentene resins
hydrogenated
rosins
oxidized
synthetics
ester waxes
fillers
foaming
agents
stabilizers
esterified rosins polyethylene wax
C-5 hydrocarbon
resins
C-9 hydrocarbon
resins
phenolic resins
aromatic (coal
tar) resins
terpene phenolic
resins
paraffinic oils
naphthenic oils
courmarone
indene resins
polybutenes
Source: Reference 2
7-2
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The standard hot melt formulations suffer from poor solvent resistance, poor shear
strength at elevated temperatures, and lack of clarity. As a result, new formulations have been
developed to overcome these deficiencies. These new hot melt technologies include acrylic hot
melts, radiation-curable hot melts, reactive hot melts, and epoxies.
Acrylic hot melts are being developed through a technique called grafting. In this
process, catalysts are used to create polymer combinations that would not otherwise form.
Grafted acrylic hot melts have excellent clarity and stability but poor shear resistance at elevated
temperatures. This difficulty, however, has been overcome with radiation-curable hot melt
technology.
Other new technologies are reactive hot melts and epoxies. Both reactive hot melts and
epoxies have high solvent resistance and high shear strength comparable to those of solvent-based
adhesives. The main components in reactive hot melts and epoxies are polyesters and
polyurethanes. These compounds form bonds when they are combined and react with one
another. In the case of some polyurethane formulations, the polyurethane will undergo a
chemical reaction when exposed to moisture, often called a moisture-curing hot melt. The
resulting compound has high shear strength at elevated temperature and high solvent resistance.
7.2.2 Equipment
The four main pieces of equipment used in the hot melt coating process include the
following:
1. Heated Mixing Tank
2. Heated Storage Tank
3. Hot Melt Coater
4. Slitter
Mixers used in the hot melt application are identical to those used in solvent-based systems
except that they have jackets which provide heat to melt the adhesive materials. The storage tank
for hot melt is identical to the solvent-based adhesive storage tanks except that heat has been
added to keep the hot melt in its molten state. The hot melt coater consists of an unwind station,
a release coating station, an adhesive coating station, a chilled roller, and a rewind station. The
coating stations are typically slot die or roll coater. The slot die coaters have heated lips, while
7-3
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the roll coaters have heated metering and applicator rollers. In the case of reactive hot melts, the
slot die coater is usually used because it is enclosed and better protects the adhesive from
elements (e.g., moisture) which might cause the adhesive to degrade or cure prematurely. In
some instances, the reactive hot melt requires an inerted coating head because the coating is
extremely sensitive to environmental exposure during application. The final piece of equipment
is the slitter, which is identical to those used with solvent systems.
7.2.3 Physical Process
As with the solvent-based coating facilities, many hot melt coaters formulate their own
adhesives. However, in the hot melt line, the mixers must be heated to melt the compounds to
be blended. The storage tanks in the hot melt line must also be heated to keep the adhesive in
its molten state.
Unlike the solvent-based storage tanks, the hot melt tanks must be carefully sized to
prevent charring. Charring occurs when the adhesive has been heated too long and begins to
decompose and turn to carbon. If the tank is too large, the hot melt holding time will be too
long, and the hot melt will begin to char. If the tank is too small, the hot melt material that
clings to the sides of the tank will char. To compensate for charring and other contaminants
(e.g., dirt or metal shavings) which may contaminate the storage tank, a filter is placed in the
delivery system between the tank and the coating head.
Manufacturers who do not formulate their own adhesive do not require the heated storage
tank and heated mix tanks. Instead, they can feed the adhesive directly into the coater. If the
hot melt is in pellet form, it is fed into a hopper which regulates the flow of adhesive to the
coating head. In other configurations, the hot melt is placed in a drum, which is attached to the
coating head. A heated plate is placed on top of the drum or a heated rod is placed in the drum,
melting the adhesive and allowing it to flow into the coating head.
Once the hot melt is molten, the substrate is unwound and coated at speeds of 50 to 2,500
fpm (15 - 760 m per minute). The typical hot melt line operates at a speed of 1800 fpm (550 m
per minute). The hot melt coater is usually a roll coater or a slot die coater capable of handling
viscosities in the range of 5 to 200 centipoise. The substrate is then rewound and sent to the
slitter. No drying ovens are needed in the hot melt process because hot melts are 100 percent
7-4
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solids which cure upon cooling. Solvent-based adhesives average 40 percent solids and 60
percent solvent Before the product can be rewound, the solvent vehicle must be removed via
drying. Moreover, the hot melt system does not need a solvent recovery system because solvents
are not used.
7.2.4 Product Outputs
Hot melt adhesives have been restricted to some of the lower performance commodity
areas such as labels, carpet tapes, and some lower performance masking and duct tapes.
Expanded use of hot melts has been limited by the coatings' low solvent resistance, low shear
strength at elevated temperatures, and darker color. The development of acrylic and reactive hot
melt adhesives is eliminating these performance deficiencies and is allowing hot melt to penetrate
more markets.
7.2.5 Emissions and Wastes
Unlike the solvent-based coating lines, hot melt adhesive coating lines do not generate any
VOC emissions during the coating process because hot melt adhesives do not require solvents
or any other vehicle to transfer the adhesive to the substrate. Both hot melt and solvent systems
will generate several tons of solid waste, such as slitting ends and defective product, which are
considered non-hazardous and can be disposed of in a municipal landfill. In addition, hot melt
facilities may generate some hazardous waste because mineral spirits, toluene, or another solvent
may be used to clean and remove adhesive from the equipment. On average, however, the
quantity of solvent generated from cleaning operations for hot melts is small [e.g., less than 200
gallons (0.757 m3) per year] when compared with the quantity of waste solvent generated by
solvent-based coating lines [e.g., 8,000 gallons (30 m3) per year].
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7.3 COSTS
7.3.1 Materials
T he cost per pound of solvent-based adhesive is about three quarters as much as hot melt
adhesives. However, most solvent-based adhesives average 40 percent solids, whereas hot melt
adhesives are 100 percent solids. Therefore, more solvent-based adhesive must be applied to achieve
equal coating thickness. A more accurate price comparison is the applied cost or the dry cost of the
adhesive. When comparing the diy adhesive costs, hot melt adhesives are less expensive than solvent-
based adhesives. Table 7-2 presents some typical hot melt and solvent-based adhesive prices.
TABLE 7-2. ADHESIVE PRICES
Adhesive Type
Price ($/wet pound)
Price ($/dry pound)
Solvent-based
1.50-1.90
3.75-4.75
Conventional Hot Melt
N/A
1.25-2.00
Source: References 3 and 4
The cost of adliesives greatly influences the annual profits of a coater. Assuming a production
rate of 239,000 square yards (200,000 square meters) per day, 350 operating days per year, an
adhesive density of 69 lbs per cubic foot (1,105 kg per cubic meter), and a 1 mil dry coating
thickness, a hot melt coating at a price of $2.00 per pound will cost the coater $8.7 million annually
(Equation 7.3). A 40 percent solids solvent-based adhesive priced at $1.50 per pound will cost the
coater $16.2 million annually (Equation 7.6).
Hot Melt Adhesive Cost:
239,000yds2 350day (3ft)2 0.001 in . .. ft 752,850 ft3
- — x i x -—x x 1 mil x = : (7 n
day yr yd7 1 mil 12 in yr
69 lb x $2.00 1 lb coating _ SI38
ft * lb coating 1 lb adhesive ft3
(7.2)
752,850 ftJ $138 eQ~nnnnni
x S8,700,000/yr (7 3)
yr ft3
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Solvent-Based Adhesive Cost:
day yr yd2 1 mil
12 in yr
ft _ 752,850 ft}
(7.4)
69 lb $1.50 1 lb coating
69 lb
ft3
= $258.75/yr
(7.5)
ft3 lb coating 0.4 lb adhesive
(tM 752'8S0 ft' x S2S8 75 = 516,200,000
7.3.2 Equipment
Equipment costs of hot melt systems are substantially less than solvent-based systems.
Hot melt adhesive coaters are approximately the same price as the solvent-based coaters, but the
hot melt systems do not require the additional expensive of operating dryers or the solvent
recovery/incineration equipment As a result, the hot melt systems cost about 50 to 70 percent
less than the solvent-based systems. A typical hot melt coating line, capable of operating at
speeds of 600 fpm (183 m per minute) to 1,800 fpm (550 m per minute), costs about $600,000-
The solvent-based coating equipment, including the dryer and solvent recovery system,
costs about $2.4 million. A breakdown of these expenses is presented in Table 7-3. In addition,
much less floor space is needed in a hot melt system because the main contributor to the length
of the solvent system, the dryer, has been eliminated.
7.3.3 Operating and Maintenance Costs
The operating cost of hot melt coaters is less than the operating cost for solvent coaters
for the following five reasons:
1. Fewer employees needed per line
2. Lower freight costs of shipping hot melt coatings
3. Lower inventory costs from ease of storage of hot melt coatings
4. Fewer environmental compliance costs
5. Lower insurance costs
Hot melt lines require fewer employees because the coating equipment requires less floor
space. An entire hot melt coating line is about 40 feet (12 m) long, while the solvent coating
$700,000.59
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TABLE 7-3. EQUIPMENT COSTS
Equipment Cost (Dollars)
Hot Melt Equipment
Hot Melt Coater (includes release coater) 600,000-700,000
Total Hot Melt Cost 600,000-700,000
Solvent-Based Equipment
Release Coater 235,000
Adhesive Coater 400,000
Release Coating Dryer 700,000
Adhesive Coating Dryer with Incinerator 1,100,000
Total Solvent-Based Cost 2,435,000
Source: Reference 9
system is about 150 feet (45 m) long. As a result, hot melt coaters only require one to two
people to monitor and maintain them, while a solvent line requires 3 to 4 people because of the
length. Assuming an annual income, excluding benefits, for a production operator of $23,100,
a hot melt line with two employees has labor costs of $46,200 per year associated with that
operation (Equation 7.7). A solvent line requiring four employees has $92,400 in labor costs
associated with it (Equation 7.8).10
Hot Melt System Labor Costs:
2 employees x $23.100 _ $46,200 (7.7)
employee
Solvent-Based System Labor Costs:
4 employees x $23,100 = $92,400 (7.8)
employee
Another cost differential is freight. Freight costs are much less for hot melt systems
because of the reduced volume of adhesive that is purchased and shipped. A hot melt facility
also has lower inventory costs because short curing times enable the coater to ship product almost
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immediately after coating. At a solvent-based adhesive-coating facility, the product is typically
kept for several days before it reaches a final cure, increasing the product inventory that must
be kept at any one time.
In addition, a hot melt facility has fewer environmental compliance costs because it has
minimal environmental concerns. Less money will be spent on permitting fees and disposal fees
due to the absence of hazardous materials. Also, less time needs to be spent on environmental
compliance at a hot melt facility, reducing an employee's time and possibly eliminating the need
for one employee. Based on the average salary, excluding benefits, of $29,300 year at
manufacturing facilities, a hot melt coater requires $15,000 per year to have one person working
half time on environmental compliance (Equation 7.9). A solvent-based coater spends $29,300
annually to have one person working full time on environmental compliance (Equation 7.10).10
Hot melt and solvent-based facilities will also incur environmental compliance costs to
dispose of their solid and hazardous waste. Assuming an industrial tipping fee of $39.50/ton of
waste, total waste production of 6,000 square yards (5,016 square meters) per day, average
thickness of waste is 1.8 mil, and a density of waste substrate equal to 62.4 lbs per cubic feet
(1,000 kg/m3), a total of $3,500 is spent annually on solid waste at both hot melt and solvent-
based facilities (Equation 7.11).11 As discussed earlier (Section 7.2.5), hot melts average two
drums of hazardous waste annually, while solvent-based systems generate 25 drums of waste
annually. Assuming a hazardous waste disposal fee of $450 per drum, a total of $900 are spent
on hazardous waste annually at hot melt facilities (Equation 7.12) and $11,250 are spent at
solvent-based facilities (Equation 7.13).
Hot Melt System Environmental Compliance Labor Cost:
0.5 employee x ^29,300 _ jjj qqq (7,9)
employee
Solvent-Based System Environmental Compliance Labor Cost:
1 employee x $29;3(X) = $29,300 (7.10)
employee
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Hot Melt System and Solvent-Based System Landfill Cost:
6,(XX) yds2 350 day (3 ft)1 ft 62.4 lt« ton $39.50 53,500 n n\
i x i * L x 0.0018 m x x _ x _____ x = (7.11)
day yr yds2 12 in ft5 2000 lbs ton yr
Hot Melt System Hazardous Waste Disposal Cost:
2 drums ^ $450 _ $900 ^ 12)
year drum year
Solvent-Based System Hazardous Waste Disposal Cost:
25 drums T S450 _ $11,250 (7 13)
year drum year
Finally, the insurance costs of the hot melt process are much less than the solvent-based
process because the risk associated with solvents has been eliminated in the hot melt process.
In the solvent-based system, the insurance underwriter must account for the highly flammable
nature of the products being used in the facility, raising the annual premium. No insurance costs
were available at the time of this report preparation. Annualized operating costs are summarized
in Table 7-4, using the outputs of equations 7.3 through 7.9.
TABLE 1-4. ANNUALIZED OPERATING COSTS
Annual Costs
Labor Cost
Environmental Compliance Labor
Landfill Costs
Hazardous Waste Disposal Costs
Solvent System Hot Melt System
$92,400 $46,200
$29,300 $15,000
$3,500 $3,500
$11,250 $900
7.3.4 Energy
The energy cost of a hot melt system is also less than a solvent-based system because hot
melts do not require drying or solvent recovery. A solvent-based system requires 83,000 BTU
to dry 1,000 square feet (93 square meters) of substrate with a 1.5 mil coating thickness of a 40
percent solids solvent-based adhesive.52 A hot melt system requires only 2,000 BTU to coat and
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cure 1,000 square feet (93 square meters) of substrate to a 1.5 mil coating thickness.12 Table 7-5
lists the energy requirements for both hot melt and solvent-based adhesive coating systems.
TABLE 7-5. ENERGY COSTS
Hot Melt System
Solvent-Based System
Energy Requirement
83,000
2,000
(BTU/Thousand ft2)
Price/MMBTU
5.49
5.49
Total MMBTU Usage
41,000
1,000
Annual Energy Cost
$230,000
$5,500
Assuming that 239,000 square yards (200,000 square meters) of tape are produced per day
with a coating thickness of one mil at a facility that operates 350 days per year, a total of 41,000
MMBTUs are used in a solvent-based system annually and 1,000 MMBTUs are used in a hot
melt system. In 1990, the average cost of energy for industrial users was $5.49 per MMBTU.
Using this as the price of energy, a total of $230,000 is spent on energy in a solvent system
annually (Equation 7.14) and $5,500 is spent on energy in a hot melt system annually
(Equation 7.15).
Solvent-Based System Energy Cost:
83,000 BTU 0.001 in (3 ft)2 239,000 yd2 350 day MMBTU $5.49 $230,000 (? 14)
1000 ft 2 * 0.06l* in X X X ^ X 10* BTU * MM6TU ~ yr
Hot Melt System Energy Cost:
2,000 BTU t 0.001 in t (3 ft)2 t 239,000 yd2 t 350 day Y MMBTU t S5.49 = S5.500 f715>
1000 ft2 0.0015 in yd1 day yr 106 BTU MMBTU yr
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7.4
TECHNICAL BARRIERS TO ALTERNATIVE TECHNOLOGY
Although hot melt adhesives provide several advantages over solvent-based adhesives,
such as faster line speeds, lower energy requirements, lower freight costs, and no emissions of
VOCs, hot melt adhesives are not widely used in pressure sensitive tapes. The reasons for the
low consumption of hot melt adhesives vary depending upon product type, but the most
significant reason has been due to product performance limitations.
7.4.1 Equipment Suitability
Even though hot melt coaters are very similar to solvent coaters, converting from solvent-
based coatings to hot melt coatings typically requires new equipment because hot melt adhesives
have greater viscosities which solvent-based coating application equipment cannot handle. Roll
coater configurations could be a problem for hot melt adhesives, especially in the case of reactive
hot melts, because in a roll coating system, the hot melt is exposed to the environment for longer
periods of time. Reactive hot melts may cure too quickly if exposed to moisture prematurely.
7.4.2 Materials Availability
Low performance hot melt adhesives are readily available. However, the higher
performance hot melts are fairly expensive due, in part, to the limited number of suppliers.
Coaters often will not buy the adhesive until the price is reduced, and adhesive manufacturers
cannot lower the price until they have sufficient demand to warrant mass production. Even if
hot melt is more economical, coaters are hesitant to purchase a product when there are only a
few suppliers. Coaters fear that the price might increase when demand increases due to the
limited availability of the product
7.4J Product Performance Characteristics
The primary difficulty with hot melt technology is that it cannot meet many product
performance demands. For example, some products require high corrosion resistance and/or heat
7-12
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resistance. Hot melts are currently unable to provide these characteristics without using
expensive reactive hot melts or without additional curing with electron beams or UV lights.
Other products require the use of heat sensitive substrates (i.e., some films) which may be
damaged by the hot melt adhesives. Adhesive manufacturers are currently working to overcome
these product performance deficiencies by developing new formulations.
7.4.4 Process Limitations
The hot melt process is limited by the performance of its raw materials. As the raw
materials improve, so will the product performance. In addition, the hot melt system's ability
to coat with more viscous materials may open the market for new products. For example, the
hot melt process has made it possible for Hardcast, Inc. in Wylie, Texas, to produce a duct
sealant on polyester and foil rolls. This product is not available in solvent form because it
requires a coating thickness of 33 mil. Solvent systems cannot be coated at this thickness
because of the low viscosity of the solvent adhesive. Traditionally, duct sealants were solvent-
based and had to be applied manually to the duct with a brush, a very labor intensive process.
The hot melt "sealant-on-a-roll" requires less labor because coating is preapplied to the correct
thickness and curing is immediate.13
7.4.5 Health and Safety Issues
A hot melt system is much safer than a solvent system because the highly flammable and
potentially explosive solvents have been eliminated. The main safety issue that remains is
protecting employees from the heated equipment used to melt the adhesive. Also, precautions
must be taken to keep the employee from contacting the heated adhesive during the mixing or
coating process.
When using polyurethane reactive hot melts which contain isocyanates, other
precautionary measures should be taken. Although the diisocyantes in the polyurethane
formulation should not volatilize during the coating process because application temperatures are
below volatilization temperatures, precautionary measures should be taken to prevent the operator
from inhaling any fumes. This may require ensuring a positive air flow in the facility. In
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addition, operators should wear protective gloves when handling the adhesive. Moreover, due
to the presence of isocyanates in the adhesive, polyurethane hot melts cannot be used to package
food due to the possibility of migration.
Epoxies also have worker safety issues. If the temperature exceeds 250°F (121 °C), a
chain reaction will occur, followed by release of gases and, possibly, an explosion. Therefore,
epoxy systems require special controls to regulate temperature.
7.5 ECONOMIC BARRIERS TO ALTERNATIVE TECHNOLOGY
7.5.1 Capita! Investment
In many instances economics is the factor limiting the use of hot melts. Switching to hot
melt coatings requires capital outlays to convert an existing line to a hot melt line. In addition,
hot melt adhesives which have the desired performance characteristics may not be readily
available. This means that manufacturers will have to invest capital in research and development
efforts to formulate a new adhesive with the desired properties.
7.5.2 Pricing and Potential Lost Market Pressure
The current market structure also discourages manufacturers from changing product lines.
Customers require the products they purchase to meet certain performance characteristics. This
is typically done by testing, or product certification through a laboratory such as Underwriters
Laboratory. Each time the product is modified, the customer may ask for the product to be re-
certified. The recertification process allows other companies to submit their products for
certification as well. Therefore, switching adhesives provides a manufacturer's competitors an
opportunity to capture a portion of their business. As a result, manufacturers often resist making
product changes.
Hot melt adhesives are capable of performing most adhesive functions, however, they are
not used because the tape market is very competitive. Profits average one cent per roll of tape
sold to wholesalers. Therefore, the only way to make a profit is to sell large quantities. With
such competitive pricing, manufacturers must assure their customers that they have the best
7-14
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product. If switching to hot melt adhesives causes a loss in functionality of the product,
customers will seek other vendors.
7.5.3 Payback Period
Approximately one year is required to recover the capital costs associated with converting
a solvent-based line to a hot melt line when considering the change in adhesive costs, energy
costs, labor costs, and environmental costs. Table 7-6 presents a cost itemization for conversion.
These costs are based on the cost estimates outlined in Section 7.3. In addition, the payback
period was based upon a 2.1 percent real discount rate, which is equal to the 1992 real growth
in the gross domestic product (GDP).10
TABLE 7-6. ANNUALIZED COSTS
Annual Costs Solvent System Hot Melt System
Adhesive Cost
$16,200,000
$8,700,000
Labor Cost
$92,400
$46,200
Energy Cost
$230,000
$5,500
Environmental Compliance Labor
$29,300
$15,000
Landfill Costs
$3,500
$3,500
Hazardous Waste Disposal Costs
$11,250
$900
Due to the variability in adhesive costs, and labor costs among facilities, the payback
period was also calculated considering only disposal costs and energy costs. Under this scenario,
the payback period was three years.
In addition, the hot melt systems can be operated at line speeds up to three times greater
than solvent-based systems. In facilities that need extra capacity to meet market demand,
converting to hot melt will allow them to increase the capacity of each line and therefore increase
the revenues per line.
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7.6
EDUCATIONAL BARRIERS TO ALTERNATIVE TECHNOLOGY
7.6.1 Management Awareness
Most coaters formulate their adhesives in house due to concerns about trade secrets. Only
17 percent of all adhesives are purchased.1 In many cases, the hot melt adhesive formulation is
beyond the in-house capabilities of coaters. Therefore, management needs to establish closer ties
with adhesive suppliers and manufacturers to help them understand the hot melt formulation
process so that new hot melt products can be developed for the coater's end use.
7.6.2 Employee Training
A company's research and development employees may or may not need additional
training in the polymer sciences to assist them in developing new hot melt formulations. In many
cases, research and development employees have been trained in rubber chemistry rather than
polymer chemistry because rubbers have been the traditional adhesive base.
Employees in the materials purchasing department may need to be trained to identify new
hot melt products capable of performing the same function as a solvent-based product. In
addition, they may need training to help evaluate the economic benefits of hot melt adhesives so
that they do not merely look at raw material prices.
Finally, line managers and production employees will need to be trained in the proper
handling and disposal procedures for hot melt adhesives.
7.7 POLLUTION PREVENTION/SOURCE REDUCTION RESEARCH
OPPORTUNITIES
As discussed earlier, one of the barriers to the use of hot melt adhesives is that a large
number of adhesive formulations are currently used, and many facilities do not have experience
with hot melt chemistry. One method to alleviate this problem is to develop a publicly available
database which would contain the performance parameters of various adhesive formulations.
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Ideally, the converter would be able to input the performance parameters desired. The program
would then identify several compounds which could be modified to meet these requirements.
The U.S. Army Armament Research Development and Engineering Center (ARDEC),
under the sponsorship of the U.S. Army Materiel Command (AMC), has developed similar
databases which contain information regarding the properties of various adhesives, adherents, and
application techniques. The databases were designed to assist Department of Defense contractors
in designing and repairing military equipment. One difficulty with the military databases is thai
much of the information is considered classified.14 A publicly available version could be
developed from the declassified sections of the databases and other available information. This
database could also be developed with the assistance of adhesive manufacturers. Although many
adhesive manufacturers will not provide the specific formulation of their products, they often will
provide detailed descriptions of product performance as an inexpensive marketing method. The
database will serve as a method of disseminating information on the adhesive products available
and the coating methods available.
7.8 REFERENCES
1. Satas, Donatas. Handbook of Pressure Sensitive Adhesive Technology. Second Edition.
Van Nostrand Reinhold. New York, NY. 1989.
2. Buccigross, Henry and Jay Cheney. "Hot Melt Adhesive Development and the
Proliferation of Raw Materials," 199J Hot Melt Symposium. TAPPI. 1991.
3. Presentation by Thomas Hohenwater, Jr., Goldschmidt Chemical Corporation, Hopewell,
VA. Energy Sciences Inc. Group Presentation. Wilmington, MA. November 17, 1993.
4. Telecon. Bert Blackwood, Swift Adhesives, Franklin Lakes, NJ, with Scott Snow, TRC
Environmental Corporation, Chapel Hill, NC. December 3, 1993.
5. Meeting. Chuck Hubbard of Black Clawson, Fulton, NY, with William L. Blake, Jr., and
Jill Vitas, TRC Environmental Corporation, Chapel Hill, NC. Discussion on hot melt
application equipment. November 12, 1993.
6. Telecon. Ted Loranz, May Coating Technologies, Inc. Acumeter Division, Hopkinton,
MA, with William L. Blake, Jr., TRC Environmental Corporation, Chapel Hill, NC.
December 2, 1993.
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7. Telecon. Glen Urquhart, Bolton-Emerson America, Lawrence, MA, with William L.
Blake, Jr., TRC Environmental Corporation, Chapel Hill, NC. December 2, 1993.
8. Telecon. Guido Verini, Rotomec America, Atlanta, GA with William L. Blake, Jr., TRC
Environmental Corporation, Chapel Hill, NC. December 2, 1993.
9. Guenther, Donald C. "Equipment Cost Estimate," Faustel, Inc., Germantown, WI.
November 24, 1993.
10. Statistical Abstracts of the U.S. 1993. U.S. Department of Commerce, Bureau of the
Census, pp 575, 742.
11. Telecon. Representative of Durham County Landfill, Durham, NC, with William L.
Blake, Jr., TRC Environmental Corporation, Chapel Hill, NC. December 1993.
12. Nelson, Ken. "Hot Melts Grow in Popularity and Face New Challenges," Adhesives Age.
May 31, 1993. pp 6-9.
13. Memorandum. Blake, William L., Jr. and Beth W. McMinn, TRC Environmental
Corporation, to Carlos M. Nunez, U.S. Environmental Protection Agency. Site Visit-
Hardcast, Inc. Wylie, TX. December 20, 1993.
14. Desmond, Anthony T., Joseph A. Brescia, and Kathleen A. Chabot. "Database Helps
Engineers Choose Proper Bonding Method," Adhesives Age. May 31, 1992. pp.11-14.
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CHAPTER 8
POLLUTION PREVENTION/
SOURCE REDUCTION RESEARCH OPPORTUNITIES
In spite of the identified barriers to radiation-curable adhesives, several opportunities exist
which could help in reducing or removing these barriers. As stated throughout this document,
the lack of practical, commercial use of radiation-curable adhesives in the coated and laminated
substrate manufacturing industry is the greatest barrier to overcome.
In order to facilitate the transfer of information on this alternative technology to the
industry, a focus group could be convened containing representatives from industry, trade
associations, environmental agencies, radiation-curable coating and equipment suppliers, hot melt
coating and equipment suppliers, waterbased coating and equipment suppliers, and other
interested parties. The charter of the focus group would be to identify all barriers including those
not discussed in this document, exchange information on alternative technologies (including
research and development opportunities), and develop good working relationships between
adhesive manufacturers and coated and laminated substrate manufacturers. By forming the focus
group, technical, economic, and educational barriers could be discussed and eliminated. To
further the information exchange, the focus group could encourage demonstrations at host
facilities using the alternative adhesives, host educational seminars on alternative technologies,
and provide guidance to EPA on the focus of their research efforts.
In addition to the information exchange within the focus group, another area of further
study is to investigate the European market. It has been suggested that actual production
facilities in Europe are using radiation-curable adhesives. It would be valuable to pursue the
European market to determine what problems or opportunities they have discovered as a result
of actual production using these alternative adhesives.
Additional opportunities for research into the marketing problems associated with
alternative technologies would be beneficial. Many companies state that their customers are
hesitant to purchase non-solvent-based products because of aesthetics. Surveys could be
developed to better determine the specific characteristics that are lacking in the alternative
adhesives. As a result of the information gathered in the marketing analysis, coated and
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laminated substrate manufacturers could encourage radiation-curable adhesive manufacturers to
develop products that overcome the aesthetic problems that have been identified. As part of the
marketing study, purchasing personnel from retail outlets could be included in the technology
transfer. This would allow customers to learn about the new technologies; their physical
properties, and their environmental benefits. By providing these people with the appropriate
information, better purchasing practices can be implemented that will help prevent pollution.
Economic incentives for the use of low-VOC emitting adhesives is another area that could
be studied. Under the interpretation of section 182(g)(4) of the CAAA, States are encouraged
to adopt economic incentive programs (EIP) to encourage the development of low-VOC surface
coatings. The study would include a review of applicable State EIPs to determine which areas
of the country aTe eligible for these incentives. Information could be transferred to coated and
laminated substrate manufacturing facilities in those areas of the country where financial
incentives would be available to assist them in meeting the applicable requirements to receive
these benefits.
8-2
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APPENDIX A
PRELIMINARY MARKET ANALYSIS
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COATED AND LAMINATED SUBSTRATES FOR PACKAGING AND OTHER USES
(SICs 2671 - 2672)
1. INDUSTRY DESCRIPTION
Coated and laminated paper and plastic films (webs) have a wide variety of uses,
including packaging, labelling, adhesive tapes, and decals. The industry spans two 4-digit
standard industrial classification (SIC) codes; SIC 2671 (Paper and Plastic Films Coated and
Laminated for Packaging), and SIC 2672 (Paper and Plastic Films Coated and Laminated, Not
Elsewhere Classified). Both of these SICs comprise the same industrial processes and consume
many of the same materials. The primary differences are in the strict definition of the end uses
of the products manufactured. The web coating industry is fragmented, with over 100 coating
companies reporting annual sales greater than $1 million to Ward's Business Directory, a
marketing information service (see Table l).1 Numerous other firms perform some coating as
a secondary function. American Business Lists, of Omaha, Nebraska, records over 500 facilities
operating under SIC 2671, and nearly 3,000 under SIC 2672.2
TABLE 1. DISTRIBUTION OF WEB COATING COMPANIES BY ANNUAL SALES
(Annual Sales Over $1 Million, SICs 2671 - 2672)
Sales ( $ million)
Number of Companies
> $1,000
3
SI,000 - $500
4
$500 - $100
10
$100 - $50
17
$1 - $50
89
Total Number of Companies
123
Source: Ward's Business Directory of US. Private and Public Companies 1993, Vol. 5
In addition to the coating of paper that occurs under SICs 2671 and 2672, paper is coated
for printing and publishing uses by primary paper mills (SIC 2621). This coating process is
almost entirely a water-based process, with kaolin clays as the primary pigment used to mask the
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paper fibers. The pigments are coated onto the paper surface using binders, or adhesives, such
as starch, casein, protein, or synthetic compounds.3 Because it occurs at facilities not considered
in the scope of this work assignment, this process is not addressed in the remainder of this report
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2. INDUSTRY ECONOMICS
The web coating industry has experienced significant growth over recent years. The
industry can be broadly divided into coated webs for packaging uses and adhesive-coated
products. The economic value of coated webs for packaging uses, including laminations such
as those used for aseptic packaging, has steadily increased through the late 1980s and early
1990s. The economic value of adhesive-coated webs, including tapes, labels, and decals, has also
increased in recent years as new applications for pressure sensitive adhesives have been
developed. Table 2 shows the value of materials used, the value added by coating operations,
and the combined economic value of shipments for SICs 2671 and 2672 from 1987 to 1991.4,5
TABLE 2. COMBINED ECONOMIC VALUE OF SICS 2671 AND 2672
Year
Cost Of Materials
(Millions)
Value Added By Manufacture
(Millions)
Value of Shipments*
(Millions)
1987
4,054.4
3,317.1
7,333.9
1988
5,139.3
4380.6
9,461.3
1989
5,577.0
4313.9
10,083.9
1990
5,635.5
4.454.4
10,104.5
1991
5,858.5
4,662.2
10,526.9
* Value of shipment* equates to the net selling value of all primary and secondary products and supporting services. It is a measure of the total
economic value of transactions in this industry.
Source: Census of Manufactures 1987 and Annual Surveys of Manufacturing 1988 - 1991
The coated web industry is dominated by several large manufacturers, the most well
known of which is Minnesota Mining and Manufacturing Company (3M).1 Table 3 shows the
sales (including sales of products other than those classified under SICs 2671 and 2672) of the
five largest web coaters. With over 75 percent of total sales among the companies involved in
these SICs, these five companies are overwhelmingly influential in the course of technology
development in this industry. 3M, in particular, is widely acknowledged to conduct strong
research and development efforts, and uses a variety of technologies in its many operations. The
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remainder of the industry includes many small companies. Table 4 shows the distribution of
plants and density of employment by workforce size.
TABLE 3. FIVE LARGEST PAPER COATERS (BY SALES IN SICS 2671 -2672)
Company
Sales (millions)
Minnesota Mining and Manufacturing Company
13,503
Boise Cascade Corp., White Paper Division
2,610*
Bemis Company Inc.
1,142
Consolidated Papers Inc.
912
Appleton Papers Inc.
770*
Total Sales Of Top Five
18,937*
Percentage Of Total Industry Sales
76.8*
Estimated
Source: Ward's Business Directory of U.S. Private and Public Companies 1993, Vol. 5
TABLE 4. NUMBER OF FACILITIES AND EMPLOYEES (SICS 2671 - 2672)
Work Force Size
SIC 2671
SIC 2672
Facilities
Employees
Facilities
Employees
1 -49
42
W
284
4,600
50 - 99
23
1,700
56
3,800
100 - 499
50
9,100
61
11,800
500 - 999
5
3,000
8
10,700
1,000 - 2,499
0
0
3
W
Total
120
13,800 +
412
30,900 +
W = information withheld by Census Bureau
+ = employment is in excess of figure shown
Source: 1987 Census of Manufactures
The States with the largest number of plants are California, Illinois, New York,
Massachusetts, New Jersey, and Ohio. The Great Lakes region (EPA Region 5) has more plants
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than any other area, followed by the Northeastern States (EPA Regions 1 and 2) and Southeastern
States (EPA Regions 3 and 4). California (59 plants), Texas (25 plants), and Minnesota (14
plants) are the only States West of the Mississippi River with more than 10 facilities.6
Although sales in SICs 2671 and 2672 have been rising, employment has declined
significantly in recent years.'1'5 Table 5 shows employment and compensation data for the paper
coating industry between 1987 and 1991. The decline in total employment is only partly
explained by a reduction in production labor, indicating that the industry is not only achieving
manufacturing efficiencies, but is also beginning to focus on leaner support staffing as a means
of controlling costs.
TABLE 5. EMPLOYMENT AND COMPENSATION (SICS 2671 - 2672)
Year
Total Employees
Production Employees
Number
(000)
Payroll
($ Million)
Average
Employee
Compensation
($)
Number
(000)
Wages
(S Million)
Average
Production
Worker
Compensation
($)
A
B
C
D
E
F
1987
42.1
1,134.6
26,950
29.1
692.5
23,797
1988
48.0
1.342.9
27.977
33.4
833.1
24,943
1989
52.1
1,431.3
27,472
35.8
882.9
24,662
1990
51.4
1,473.9
28,675
34.9
877.1
25,418
1991
49.6
1,483.6
29,911
34.1
886.2
25.988
Source: Census of Manufactures 1987 and Annual Surveys of Manufactures 1988 - 1991
While sales have been increasing in the web coating industry, profits have lessened. Both
SIC 2671 and SIC 2672 have experienced declining returns on sales over the years 1989 to 1992.
This trend is evidence of a buyer's market in which firms have been forced to sacrifice margins
to remain competitive, and is not unusual given general economic conditions over recent years.
Return on assets and assets to sales ratios have both weakened in SIC 2671, while both have
improved in SIC 2672. These trends would seem to indicate that coaters in SIC 2671 have not
been able to fully utilize their capacity, while coaters in SIC 2672 have. However, without
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further analysis, no conclusions can be drawn. Additional factors that might explain these trends
include equipment age and depreciation practices. Current ratios, or the ratio of current assets
to current liabilities, appear to show that the industry is managing liquidity well in a difficult
environment.7
TABLE 6. KEY INDUSTRY RATIOS (SICs 2672 - 2673)
I Year
Return On Sales
Return On
Assets
Assets To Sales
(Percentage)
Current Ratio
2671
2672
2671
2672
2671
2672
2671
2672
1989
3.7
3.2
7.1
3.4
42.1
41.1
1.9
1.8
1990
4.1
3.6
6.1
5.6
44.5
41.9
1.7
1.9
1991
3.3
3.1
5.0
6.6
58.3
37.7
2.4
1.7
1992
2.5
2.3
6.3
6.3
46.5
40.1
2.7
1.8
Source: Duns Analytical Services, Industry Norms & Key Business Ratios (1989 - 1992)
The coated web market is broadly segmented among commercial markets, with a small
percentage of expenditures attributable to government sales (see Table 7). Consumer products
such as adhesive and masking tapes that are manufactured in this industry are sold either directly
to retailers, or through wholesale distribution channels. A large segment of the market is
comprised of products sold to manufacturers for incorporation as components of larger end
products. Labels, decals, and decorative panels fit into this segment. Finally, there is a large
segment of the market that is not clearly defined. Coated web products that are consumed as
supplies by service operations such as automobile paint and body shops may fit into this
category.4
The cost of entry into this industry is relatively high when compared to the average of
all industries, with the cost of an establishment ranging between two and three times as high as
that of an average manufacturing facility.6 Web coating is a very capital intensive operation,
requiring large amounts of floor space for both materials storage and process equipment. Energy
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costs are relatively high as well, due to the need for drying ovens. Equipment costs are
significant, with a process line representing an average investment of more than $500,000.
TABLE 7. COATED AND LAMINATED WEB SHIPMENTS BY MARKET
SEGMENTS
Market Segment
SIC 2671
SIC 2672
Value
% of
Value
% of
($ million)
Total
(S million)
Total
Wholesalers
466.2
19
1,041.8
19
Retailers
59.2
2
132.4
2
Manufacturers
1,014.1
41
2,266.2
41
Government
15.5
1
34.7
1
All Other
905.0
37
2,022.6
37
Total
2,460.0
100
5,497.7
100
Source: Census of Manufactures 1987
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3. PROCESS
The web coating industry uses a variety of coating processes but the most common is roll
coating. Alternative processes include knife coating, curtain coating, and various printing
methods such as gravure, lithography, and screen printing. In addition to the actual coating
process, the industry uses (1) mixing and blending equipment to prepare the coating materials,
(2) ovens and other curing equipment to dry or cure coated materials, and (3) converting
equipment to slit, sheet, and cut the coated product. Larger manufacturers also use automated
packaging equipment to prepare their products for shipment.8
3.1 Process Flow Description
The web coating process involves four distinct sub-processes: (1) preparation of materials,
including the blending of coatings; (2) coating of the substrate; (3) curing or drying of the
coating; and (4) finishing the coated web by such processes as slitting, die-cutting, and
rewinding.8 Each of these processes is connected by material handling steps to preceding and
subsequent processes. Material handling, while not a value-added process, is a significant activity
representing both a large capital investment and a continuing expense.
Blending of coating materials is a relatively simple operation, but is very capital intensive.
Coatings materials are delivered in drums, by tank-truck, or by rail car, and are blended in large
vessels (up to 20,000 gallons in some cases). The coatings are then pumped into bulk storage
tanks through dedicated piping. The coatings are delivered from storage to the coating lines
through permanently installed lines and manifolds. Smaller facilities handling less volume
frequently purchase their coatings in a ready-to-use form, or in a concentrated form that requires
simple dilution. Such facilities generally pump their coatings directly from drums or totes, rather
than from bulk storage tanks to the coating lines.
The coating process itself is a combination of three functions: (1) web transport; (2)
coating delivery; and (3) application to the substrate.8 Transport of the web is accomplished
under tension using rollers and either optical or pneumatic guiding equipment. The coating,
having been pumped from either a storage tank or portable vessel, is distributed at the point of
coating application {i.e., the coating head) either manually (by the operator using a putty knife
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or other spreading device), or by rotating rollers. The coating must be uniformly distributed
across the coating head, and is usually contained by dams or troughs. Application to the
substrate occurs as the web is transported past the coating head. The transfer mechanism can be
either direct, with the coating supply coming into contact with the web, or indirect, with a
transfer mechanism such as a coating roller removing coating from the supply and transporting
it to the web. The amount of coating applied is metered, usually mechanically by a knife, rod,
or roller, but sometimes pneumatically, by an air curtain that blows excess coating back towards
the coating supply.8
After a uniform layer of coating has been applied to the substrate, the web is transported
through a drying or curing mechanism. With solventborne or waterbome coatings, this
mechanism is an oven that evaporates the vehicle solvent, and removes the vapors, leaving the
polymer solids on the web surface. With radiation-curable coatings, the mechanism is an energy
source such as an ultraviolet lamp or electron-beam. The energy excites the coating molecules,
causing them to crosslink into a solid film.8
Once a product is coated, it is slit into narrower widths according to its end use. Typical
processing widths are 30 to 60 inches (0.76 to 1.5 meters). End product widths range as low as
0.0625 inches (0.16 cm), and as high as the full processing width of the web. Other converting
capabilities that are typically found in a finishing department include die-cutting to shape (for
labels or decals) and some printing. Rolls are wound to length when all finishing is complete,
packaged, and shipped.8
3.2 Equipment
The equipment used to coat paper for uses other than printing is manufactured by a wide
variety of general and specialty machine companies. Thomas Register, a standard reference used
by industrial purchasing agents to identify vendors, lists over 100 vendors of coating machinery.9
Not all of these vendors manufacture full coating lines. Some specialize in metering devices,
curing mechanisms, or other components. However, there is clearly a competitive market for the
manufacture of coating equipment, and a company trying to modify its current processes or install
new ones has a wide array of options. Table 12 shows the name and location of coating
machinery vendors reporting annual sales in excess of $50 million to the Thomas Register.
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TABLE 12. VENDORS OF COATING MACHINERY REPORTING ANNUAL SALES
GREATER THAN $50 MILLION
Equipment Vendor
City, State
FAG Industrial
Stamford, Connecticut
| BTG Incorporated
Decatur, Georgia
Ball Metal Incorporated
Chicago, Illinois
George Koch and Sons Incorporated
Evansville, Indiana
Rutherford Machinery Division, Sequa Coiporation
East Rutherford, New Jersey
Black Clawson Co., Conversion Machinery Division
Fulton, New York
Cincinnati Industrial Machinery Division of Eagle-
Picher Industries
Cincinnati, Ohio
Gougler Industries, Division of Furukawa
Kent, Ohio
DeVilbiss Ransburg
Toledo, Ohio
Source: Thomas Register, Products and Services Series, 199?
In some cases, a coating company may require the products of more than one vendor to
assemble a process line that will meet all of its production requirements. This complexity is
itself a barrier to the introduction of alternative coating systems. Turnkey manufacturing systems
are an inducement to an organization considering the installation of a new process. In those
instances where a company is considering the modification of existing equipment, their options
may be reduced to smaller vendors that specialize in the engineering of process lines. Larger
vendors are likely to be less eager to pursue the retrofit of existing equipment, preferring instead
to dedicate their efforts to sales of new units.
3.3 Raw Materials
The basic materials used in web coating include flexible substrates, such as paper and
light gauge plastic films, and liquid coatings. The combined SICs use in excess of $1.5 billion
of paper annually, while consuming nearly $250 million of glues and adhesives. Additional raw
materials include plastic resins, foils, inks, and petroleum wax. The industry uses a significant
All
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amount of packaging materials, with purchases of paperboard containers, boxes, and corrugated
paperboard exceeding $140 million annually.6
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4. EMISSIONS
The paper coating process has both air emissions, and liquid and solid waste streams. The
primary points of air emissions are the mixing operations, the coating head, and the oven exhaust.
Sources of fugitive air emissions include the delivery and transfer of coating materials (loading
dock), bulk storage tanks, coating transfer lines and vessels (both permanently installed and
mobile), and cleaning operations (including dip tanks, cleaning solvent storage cans, and the
actual wiping of equipment).
Common process liquid waste streams (including liquid hazardous wastes) are spent
cleaning solvents, wastewater from cleaning of vessels and tanks, and contaminated coating
materials. The potential for accidental releases exists both on the loading dock and in storage
and transport of coating materials. The Toxic Release Inventory (TRI) database does not indicate
significant liquid wastes from SICs 2671 and 2672.10 It is not known at this time whether this
is an accurate reflection of the process waste, or an anomaly of the reporting requirements.
Solid wastes include the solvent soaked rags that are used for cleaning of equipment,
waste substrate material from the web transport and coating process, and discarded packaging
materials. Of these solid wastes, the rags and some waste substrate material are likely to be
classified as hazardous wastes, although some facilities allow their solvent soaked rags to dry by
evaporation before discarding them as a solid waste.
All emissions and waste stream data were taken from the 1991 TRI database. The
combined emissions and wastes of the two SICs are shown in Table 12. In SIC 2761, 150
sources of an estimated 200 facilities nationwide reported to the database in 1991. In SIC 2672,
309 of an estimated 400 facilities reported to the database.
TABLE 12. TRI DATABASE EMISSIONS AND WASTE STREAMS
(SICS 2671 - 2672)
| Waste Type
1991 Releases (lbs)
1 Air Emissions
45,996,431
Waste Water
717,232
Solid Wastes
19,014
Source: Toxic Chemical Release Inventory Database, National Libra/y of Medicine, U.S. Department of Health and Human Services
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5. CONCLUSION
No direct information on the penetration of the web coating industry by waterborne and
radiation-curable coatings was found during the preparation of this report However, numerous
contacts throughout the industry and with materials suppliers indicate that there are a variety of
coating applications that are currently being satisfied by waterborne technologies, and that
radiation-curable technology is also gaining greater favor among coaters. Steady progress is
being made by research and development departments at both resin manufacturers and coating
suppliers in formulating radiation-curable adhesives. This industry can be categorized as having
good potential for further penetration of these low-emissions coating technologies.
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6. REFERENCES
1. Ward's Business Directory of U.S. Private and Public Companies, Gail Research Inc., 1993,
Volume 5.
2. American Business Lists, Omaha, NE, Mailer #01-003, January 1993.
3. Ducey, Michael J. "What is Paper Coating?" Graphics Arts Monthly Vol. 64, No. 3 (March
1992) pp. 118-121.
4. United States, Department of Commerce, Bureau of the Census. Census of Manufactures.
1987. GPO, 1988.
5. United States, Department of Commerce, Bureau of the Census. Annual Surveys of
Manufacturing, 1988-1991. GPO.
6. Editorial Code and Data, Inc., Manufacturing USA: Industry Analyses, Statistics, and
Leading Companies, Gail Research Inc., 1992.
7. Duns Analytical Services, Industry Norms & Key Business Ratios, 1989-1992.
8. McMinn, Beth and Vitas, J. B., Improved Equipment Cleaning in Coated and Laminated
Substrate Manufacturing (Phase I). EPA-600/R-94-007 (NTIS PB94-141157). U.S.
Environmental Protection Agency, Air and Energy Engineering Research Laboratory,
Research Triangle Park. NC. January 1994.
9. Thomas Publishing Co., Thomas Register of American Manufacturers, 83rd Edition. New
York. 1993.
10. United States, Department of Health and Human Services, National Library of Medicine.
Toxic Chemicals Release Inventory Database, 1991. TOXNETK.
A-15
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APPENDIX B
TRIP REPORTS
From
Hardcast, Inc.
Energy Sciences, Inc.
Location
Wylie. TX
Wilmington, MA
Date Page
11/22/93 B-2
11/17/93 B-7
B-l
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6340 Quadrangle Drive, Suite 200
Chape! Hill, NC 27514
0(919)419-7500 Fax (919) 419-7501
TRC Environmental Corporation
Date:
December 30, 1993
To:
Carlos Nunez
Organics Control Branch
Aii and Energy Engineering Research Laboratory (MD-61)
U.S. Environmental Protection Agency
Research Triangle Park. NC 27711
From:
William L. Blake, Jr.
Beth W. McMinn
TRC Environmental Company
Subject:
Site Visit - Hardcast, Inc.
Manufacturer of Duct Sealant
EPA Contract 68-D2-0181, Work Assignment Number 1/005
TRC Reference Number 1645005
I. Purpose
As part of its emphasis on pollution prevention, the U.S. Environmental Protection
Agency (EPA) is identifying the barriers to the extended use of hot melt, radiation-cured, and
waterbased coatings in Source Reduction Review Project (SRRP) categories and Maximum
Achievable Control Technology (MACT) categories. TRC Environmental Corporation (TRC) is
supporting EPA in this effort by evaluating the current use of these coatings in the coated and
laminated substrate industry (SICs 2671 and 2672) under Work Assignment Number 1/005, EPA
Contract Number 68-D2-0181.
The primary type of air emissions in the coated and laminated substrate industry is
volatile organic compounds (VOCs) and Hazardous Air Pollutants (HAPs) used in adhesive and
other coating formulations. VOCs and HAPs are emitted during the drying process as the coated
substrate is heated to evaporate the solvent in the coating. Hot melt coatings are considered a
pollution prevention alternative for the industry because they are 100 percent solid formulations
which remain on the substrate during the curing process. As a result, no solvents are emitted
during the coating and drying process.
The purpose of the visit to Hardcast in Wylie, Texas, was to review the hot melt coating
process. Hardcast uses hot melt technology to make a duct sealant in the form of a high
performance pressure sensitive tape.
This trip report includes four sections. Section II identifies the location of the Hardcast
facility. Section III presents the individuals who participated in the site visit, and Section IV
includes the technical information compiled during the site visit.
Offices in California, Colorado, Connecticut, Illinois, Louisiana, Massachusetts, Minnesota, New Jersey, New York, North Carolina,
Ohio, Oregon, Texas and Utah Z a TRC Comoany
Pnr.lcfl on Recycled faxt An Ecljal Ooporfcr > Empicr»-
-------
II.
Place and Date
Hardcast, Inc.
P.O. Box 1239
903 West Kirby
Wylie, TX 75098
(800) 527-7092
November 22, 1993
III. Attendees
Hardcast, Inc.
Harris Armstrong, General Manager
TRC Environmental Corporation
William L. Blake, Jr., Environmental Engineer
Beth W. McMinn, Environmental Engineer
IV. Discussion
The visit to the plant included an opening conference and a tour of the production lines.
During the visit, the following topics were discussed:
• Company Profile
• Market Segments
• Manufacturing Process
• Environmental Impacts
Each topic is discussed in detail below.
Company Profile
Hardcast is a manufacturer of duct sealing systems. They began operations 25 years ago
with the development of a two-component waterbased duct sealant. Through the years, they have
expanded their product lines to include one-component waterbased duct sealants, and, as of 10
years ago, hot melt duct sealing tapes.
Carlisle Syntec Systems, which specializes in roofing membranes, acquired Hardcast six
years ago because they wanted to add the hot melt and waterbased sealant systems to their
product line. Carlisle Syntec is a subsidiary of Carlisle Companies, Inc.
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Market Segments
Hardcast's primary market segment is the HVAC industry. Hardcast has three main
products including: a brush-on one-component waterbased duct sealing system, a brush-on two-
component waterbased duct sealing system, and a hot melt "sealant-on-a-roll."
The one-component waterbased duct sealing system is simply a sealant which is applied
to the duct with a brush. A seal is formed as the water in the sealant is evaporated and the
remaining solid sealant bonds to the duct. The two-component waterbased duct sealing system
consists of a fiber impregnated cheese cloth component and a sealing component. The end-user
will dip the fiber impregnated cloth into the sealant. Then, he/she will wrap the dipped cloth
around the duct. A seal is formed as the water evaporates and the remaining solid sealant bonds
with the cloth and the duct. The hot melt duct sealing system consists of a foil coated with
sealant in the form of a pressure sensitive tape. The end-user simply unwinds the tape and
presses it in place. The system forms an immediate bond and reaches a final cure after 24 hours.
Hardcast sells these products as alternatives to traditional, solvent-based systems which
come in cans and must be applied to the duct with a brush. The Hardcast duct sealing products
also offer a means of overcoming some of the deficiencies associated with solvent-based systems.
For example, waterbased and hot melt coatings do not emit VOCs during duct sealing. As a
result, ducts can be sealed while a building is occupied, unlike solvent-based sealants which
require the area being sealed to be vacant. The hot melt system has the added feature of
immediate bonding, allowing the HVAC system to become operational sooner. In addition, the
hot melt coating thickness is controlled, so the end-user does not have to worry whether too
much or too little coating is applied. If too much coating is applied, the cost of sealing the duct
work rises. If too little coating is applied, the seal will not last and the duct will need to be
recoated. Moreover, hot melt coatings require less labor to apply than the solvent-based coating
systems. Even though the tape is more expensive for the same amount of coating, the applied
costs are less due to the labor savings and the consistent coating thickness.
Due to customer requests over the years, Hardcast has also developed some specialty
products. For example, the duct sealing tape is often used as a temporary patch for holes in
trailers of roadway trucks. As a result, Hardcast developed a permanent patch for these trailers.
The permanent patch consists of applying a piece of metal coated with hot melt sealant to a
thickness of 33 millimeters. The patch is then positioned over the holes, and held in place by
the pressure sensitive sealant backing. However, these specialty products are only a small
portion, less than 10 percent, of Hardcast's overall revenue.
Manufacturing Process
Hardcast has three different manufacturing processes, waterbased sealant production, fiber
impregnated substrate production, and hot melt sealant-on-a-roll production. The waterbased
sealant production process is used to make the one-component waterbased duct sealants and the
sealant component of the two-component waterbased duct sealants. Each of these sealants is
blended using banbury-type mixers. The blended sealant is pumped to a temporary holding tank
from which the product can be dispensed into containers for shipment and sale.
B-4
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The manufacturing process for the fiber impregnated substrate component of the two-
component waterbased sealants begins with banbury mixers. These mixers are used to create a
gypsum slurry which is pumped into a coating application pan on the coating line. The slurry
is applied to the cheese cloth using a knife-over-roll coater. After coating application, the
substrate passes through a 15 to 20 feet dryer to remove excess water. The evaporated water
goes to the atmosphere. The entire system operates at a speed of 50 fpm.
The hot melt duct sealant production process also begins with mixing operations, in the
first phase, butyl rubber and modifiers are blended in a heated banbury mixer. The blended
rubber is then dumped onto the talc-covered floor and allowed to cool. After sufficient cooling,
the modified rubber solidifies. Next, the modified rubber is manually chopped into small pieces
and added to another heated mixer, where tackifiers are added to create the final hot melt coating
formulation. After mixing, the hot melt coating is pumped to a heated holding tank, where it will
remain until it is needed in the coating operation. The tank is heated to keep the coating in its
molten state.
The hot melt coating line operates at 20 to 60 fpm and consists of a 4 feet wide slot die
which is heated to temperatures of 300° to 375°F, a laminating station, a chilled roller, and wind
and unwind stations. First the substrate is unwound and coated with 15 to 33 millimeters of
sealant. The hot melt is pumped from the heated storage tank through a filter into the slot die
as needed. Next the release liner, usually polyester, is unwound and laminated to the sealant.
In instances when the substrate is heat sensitive, the release liner is coated with sealant, and the
substrate is laminated to the sealant after it has cooled. The coated and laminated product passes
over a chilled roller to speed the curing process. Finally, the coated and laminated substrate is
rewound and moved by crane to a slitting machine where it is converted to the desired width.
Environmental Impacts
The hot melt production process has fewer waste streams than a solvent-based system.
The hot melt production process at Hardcast does not emit any VOCs during the coating process
since hot melt adhesives are 100 percent solid and do not require any vehicle solvents. In
addition, the hot melt production process does not have any emissions from the fossil-fuel fired
dryers because drying is not needed to cure the sealant. Some particulate matter, in the form of
talc, is emitted during the hot melt sealant formulation process. The talc used during the
blending process is collected and reused.
The solid waste from a hot melt process is comparable to a solvent-based production
process. Both processes generate waste slitter ends and defective product which are considered
non-hazardous and can be landfilled.
Hot melt facilities may generate some hazardous waste during equipment cleanup.
Hardcast uses mineral spirits to clean the equipment. However, they use only one or two 55-
gallon drums annually. Because much mineral spirits evaporates during cleaning, Hardcast
generates very little hazardous waste. The rags used to clean the equipment are considered a
non-hazardous solid waste and can be landfilled.
B-5
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The other emissions at the Hardcast facility are from the waterbased duct sealing systems.
Combustion products, primarily water and carbon dioxide, are emitted to the air from the dryer
used in making the fiber impregnated cloth. Some 1,1,1-trichloroethane (TCA) is currently used
in the waterbased products. TCA can be emitted in the form of a vapor or a liquid waste
discharged to the sanitary sewer. However, the TCA should not be part of the formulation by
February 1994 due to an effort by Hardcast to eliminate hazardous materials from their products.
In addition there are small amounts of ethylene glycol in the waterbased formulations which can
be emitted during formulation in the form of vapor or as a discharge to the sanitary sewer.
Moreover, some hazardous waste is generated from the waterbased lines because the sludge from
the gypsum slurry is considered hazardous.
B-6
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TRC
TRC Environmental Corporation
6340 Quadrangle Drive, Suite 200
Chapel Hill, NC 27514
« {919)419-7500 Fax(919)419-7501
December 15, 1993
Carlos Nunez
Organics Control Branch
Air and Energy Engineering Research Laboratory (MD-61)
U.S. Environmental Protection Agency (EPA)
Research Triangle Park, NC 27711
Geary D. McMinn
TRC Environmental Corporation
Visit to Energy Sciences, Inc., a manufacturer of Electron Beam (EB) curing
equipment
Wilmington, Massachusetts, November 17, 1993
EPA Contract 68-D2-0181, Work Assignment 1/005
Technical, Economic, and Educational Barriers
TRC Reference Number 1645005
I. Purpose
As part of its emphasis on pollution prevention, the U.S. Environmental Protection
Agency (EPA) is identifying the barriers to the extended use of radiation-cured and waterbased
coatings in Source Reduction Review project (SRRP) Categories and Maximum Achievable
Control Technology (MACT) categories. TRC Environmental Corporation (TRC) is supporting
EPA in this effort by evaluating the current use of these coatings in the coated and laminated
substrate industries (SICs 2671 and 2672) under EPA Contract Number 68-D2-0181, Work
Assignment 1/005.
The primary sources of emissions in the coated and laminated substrate industry are
volatile organic compounds (VOC) and hazardous air pollutants (HAPs) used in pressure sensitive
adhesives (PSA) and other coatings, such as saturants and release coats. Electron Beam (EB)-
cured coatings, one type of radiation-cured coating, are recognized as a possible pollution
prevention alternative because they emit extremely small amounts of VOCs during the curing
process. The EB-curable coatings are 100 percent solids and therefore, have minimal emissions.
The primary benefit of the visit to Energy Sciences Incorporated (ESI) was to attend a
meeting and interact with manufacturers involved in supplying EB-related services to the coated
and laminated substrate industry. Some of the meeting attendees included EB-curing equipment,
release coating, adhesive coating, and application equipment manufacturers. This group of
suppliers provides a total package concept (TPC) to potential customers to help meet their needs.
The meeting followed the agenda below:
Date:
To:
From:
Subject:
B-7
Offices in California, Colorado, Connecticut, Illinois, Louisiana, Massachusetts, Minnesota, New Jersey, New York, North Carolina,
Ohio, Oregon, Texas and Utah A trc Company
Printed or Recycled Pope- An F<*«> Oppor-.nity Fmpbyrr
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Subject
Presenter
I.
Welcome and Introductions
ESI
11.
Pilot Line Tour
ESI
III.
Purpose of Meeting
TRC
IV.
EB-Curable Adhesive Coating Supplier
Swift Adhesives Corp.
V.
EB-Curable Release Coating Supplier
Goldschmidt Chemical Corp.
VI.
Coating Equipment Supplier
Faustel Equipment Corp.
VII.
EB-Curing Equipment Supplier
ESI
This trip report includes three sections and
one attachment. Section 11 identifies the
individuals who participated in the visit and Section III summarizes the information presented.
II. Location, Data, and Attendees
Location of Presentation and ESI contact
Energy Sciences Inc.
Fred Mclntyre
42 Industrial Way
Wilmington, MA 01887
November 17, 1993
Energy Sciences Inc.
Frederic Mclntyre
Todd Trucx
John Chrusciel
Greg Tully
42 Industrial Way
Wilmington, MA 01887
(508) 694-9000
Swift Adhesives Company
Bert Blackwood
795 Franklin Ave.
Franklin Lakes, NJ 07417
(201) 891-3355
Keith Bachmann
3100 Woodcreek Dr.
P.O. Box 1546
Downers Grove, IL 60515
(708) 971-6776
Goldschmidt
Tom Hohenwater 914 E. Randolph Road
P.O. Box 1299
Hopewell, VA 23860
(804) 541-8658
B-8
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Faustel
Donald Guenther
P.O. Box 1000
Germantown, WI 53022
(414) 253-3333
TRC Environmental Corporation
Beth McMinn
Geary McMinn
100 Europa Dr., Suite 150
Chapel Hill, NC 27514
(919) 968-9900
Mass. Office of Technical Assistance
John Fleen
Kenneth J. Soltys
100 Cambridge St., Suite 1904
Boston, MA 02202
(617) 727-3260
III. Discussion
The ESI meeting and technical presentations offered an opportunity to confer directly with
EB-curable coating and machinery manufacturers. Each of the presenters represents one
component of the total package concept of EB technology. Alone, the representative companies
would be unable to further the use of the EB technology, but by working together, they provide
a potential customer with equipment, coating, and application experience. The information below
summarizes each of the technical presentations.
Pilot Line Tour
ESI operates an EB-curing pilot coater at their Wilmington, Massachusetts, facility. The
coater is used for research and development, material scale-up, limited production samples, and
demonstration purposes. At the time of the ESI meeting, the pilot coater was applying an EB-
curable clearcoat to an 18 inch polyethylene web to be used as labels for two-liter soft drink
bottles. The 500 feet per minute application speed allowed the pilot coater to apply the clearcoat
at the rate of approximately 1 to 1.5 pounds per 3,000 ft2.
ESI's pilot line is capable of running approximately 900 feet per minute. The pilot coater
is equipped with a corona treater, a device which treats the substrate to help the coating adhesion.
The application rollers on the pilot coater can be offset gravure, direct, or knife-over-roll. The
clearcoat being applied on November 17 was 98 percent solids with a small amount of solvent
{i.e., isopropyl alcohol - IPA) added to improve clarity. The source of the curing mechanism is
the EB light which provides a high energy concentration which penetrates and solidifies the
coating. The accelerated electron beams bombard and penetrate the coated substrate. The
electrons loose their energy in the coating material where they interact with the prepolymer
B-9
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material forming the radical required to begin the polymerization process. The amount of energy
lost from the electrons is directly related to the cure level of the coating.1
When the EB-curing device is in operation, ozone is formed. The EB chamber is
equipped with a nitrogen blanket to prevent ozone from escaping to the atmosphere. The curing
system typically heats the substrate 4°C per megarad of radiation dosage above the ambient
temperature. The coating operator commented that for inks and PSAs, an increase in temperature
of 2°C and 6°C per megarad, respectively, was standard. Coatijng cleanup is performed with rags,
IPA, and acetone, which is used only when the cured coating attaches to machinery.
Swift Adhesives Corp. - EB Adhesive Coating Supplier
Swift Adhesives Corporation formulates EB-curable adhesives. Swift offers over 2,500
products worldwide. Some of the products for the coated and laminated substrate industry are
waterbased coatings, hot melt adhesives, and hot melt/EB-curable adhesives. The primary market
for these coatings has been labels and graphic arts applications for food product packaging. Swift
is a formulator, marketer, and seller of the hot melt EB PSAs.
Swift representatives discussed their basic hot melt/EB-curable PSA, 2C145, which offers
higher temperature resistance and lower viscosity than traditional solvent-based coatings. Swift's
one-component, 100 percent solids EB PSAs offer rapid cure (i.e., less than one second), and
have high cohesive strength, plasticizer resistance, good holding power, and excellent peel and
tack. Hot melt/EB-curable PSAs can be used with a facility's current hot melt machinery.
Goldschmidt Chemical Corp. - EB-Curable Release Coating Supplier
Goldschmidt Chemical has been formulating EB and ultraviolet (UV) silicone acrylates
since the early 1980s. They are currently the only producer of silicone acrylates. The primary
market for EB- and UV-curable coatings has been in Europe. Presently, all of Goldschmidts's
EB- and UV-curable coatings are manufactured in Germany. However, Goldschmidt will begin
producing the coatings in the United States in 1995. EB acrylates have no photoinitiator or
monomers and require no post-cure. Goldschmidt's EB/U V-curable coatings have been approved
by the Food and Drug Administration (FDA) for contact with food.
Goldschmidt's EB/UV-curable coatings are 100 percent solvent-free silicone acrylates
which can be applied to many substrates including paper, and a variety of films like polyethlene,
polyesters, and polypropylene. EB-curable coatings are considered non-hazardous waste both in
cured and uncured states. They offer little to no weight loss since they are 100 percent solids,
increase the tinsel strength of the substrate and can be applied to recycled paper. One paper tape
manufacturing facility in Europe uses approximately 1 gram of EB-curable coating per m2 at
2 megarads energy. This converts to approximately 0.6 lbs per ream of paper.
The EB-curable coatings do have some negative aspects. First, the coatings can discolor
polypropylene and other substrates if they are run with higher rads than necessary. Second, the
curing chamber must be inerted in nitrogen to prevent releases of ozone during the radiation
B-10
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curing process. Finally, the cost of the coating is approximately $10 per pound ($22.00 per Kg)
for 100 percent solids coating. If a solvent-based adhesive is approximately $2.50 per pound
($5.51 per Kg) for 40 percent solids, then a comparable 100 percent solid coating would cost
approximately $6.25 per pound ($3.77 per Kg).
Faustel Equipment Corp. - Coating Equipment Supplier
Faustel is a designer and manufacturer of machinery used in the production of coated,
laminated and printed flexible products. Faustel provides coating machinery for traditional
solvent-based coatings, waterbased PSAs, and UV/EB-curable reactives. The company provides
its customers with machinery and the process knowledge to determine the best coating methods,
machine compatibility, and materials availability for production. Faustel also offers a
"Technology Center" which provides customers with a pilot coater/laminator to test their
specialized designs prior to actual production.
Energy Sciences Incorporated - EB Curing System Supplier
ESI provides both UV- and EB-curing mechanisms. The EB-curing process energizes
electrons which are absorbed by molecules (free radicals) in the coating. The free radicals cause
the polymerization of the monomer and prepolymer which make up the liquid coating. Curing
occurs within approximately a few milliseconds after passing through the electron beams. Line
speeds can exceed 1,640 feet per minute (500 meters per minute) with the inerting system in
place. The inerting system controls the ozone created when the electrons contact the coating and
substrate. Presently, ESI's EB machinery can process 100 inch wide substrates. Substrates with
widths of 144 inches are possible with equipment modifications. The challenges for ESI are to
develop faster cure speeds, lower N2 requirements, and no ozone escaping from the use of the
specialized coatings.
In addition to the presentation summaries above, TRC and the meeting attendees discussed
questions developed prior to the meeting. The questions and resulting comments are included
below.
General
1. How long has ESI been making electron beam curing equipment?
Since J 970
2. What converting markets do you currently serve?
Food packaging, graphic arts, printing, converting
3. What percentage of your total business does each market represent?
Graphic arts is 40 to 50 percent, remainder is approximately equal
4. What markets do you feel will be important in the future?
Silicone release coatings, PSAs, flexible packaging, laminates
B-11
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Process Information
5. What types of PSA products have you successfully produced? What types of EB-cured
PSA products have been successfully produced commercially?
Two grades which are prototypes; None used commercially in U.S. but waiting for
customers
6. For each of those products, what were the benefits and short-falls of the EB-cured
adhesive?
High temperature resistance, sheer strength, plasticizer resistance; substrate discoloration
7. Are there any substrates to which EB-cured adhesives cannot be successfully applied?
Porous substrates (fabric) and substrates with prior solvent-based coatings
8. What equipment modifications are necessary to accommodate the EB-cured adhesive?
Can existing coating equipment be used?
So far all rollers will coat with EB-curable coatings, a new curing mechanism is needed
9. What other modifications, such as corona treatment of the substrate or reformulation of
the release coat are necessary?
Depending on the substrate and coating combination, corona treatment may be necessary;
EB adhesives can be used with waterbased release coats but not in combination with
solvent-based or UV-curable coatings
10. What line speeds are possible with this equipment? Compared to line speeds for a
thermal system and to a liquid UV system?
EB can presently run at 500 meters'minute; UV is about the same
11. What is the operating temperature of the EB-cured adhesive?
Curing increases the temperature of the substrate approximately 4°C per megarad of EB
dose. The application temperature of hot meltlEB-curable adhesive is approximated 300
to 325°F (163°C)
12. What variables may be manipulated to adjust the cure? (line speed, EB intensity, etc.)
Cure time, exposure, voltage, change coating reactivity
13. What is the expected life of the EB system?
20 years
14. How often do the filaments/window foil need to be changed?
Filaments - 10,000 hours, window foil - 2,000 hours of operation
15. What substrate widths is your equipment able to process?
Up to 100 inches (250 cm) standard but 144 (370 cm) is possible with some changes
B-12
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16. According to several sources, an EB/low melt combination is being developed in Europe.
What is pushing the European adhesive manufacturers to this new technology?
Low melt has properties similar lo acrylic adhesives and eliminates solvent emissions;
there is more interest in U.S. due to environmental push. However, there are more
facilities in U.S. using hot melt adhesives (50+ percent) compared to Europe (15 - 20
percent).
Costs
17. How do the capital costs of an EB system compare to a thermal system? To a liquid UV
system?
Thermal with control device is equal to EB system; UV systems are one-half the cost of
EB systems
18. How do the maintenance costs of an EB system compare to a thermal system? To a liquid
UV system?
EB is about $2,000, thermal is about $2,500; UV is about $6,000 to $8,000
19. How do the raw material costs of an EB system compare to a thermal system? To a liquid
UV system?
EB is about 2 to 3 times as much as thermal for adhesives; UV- and EB-curable
adhesives are approximately the same, UV-curable release coats cost more than EB-
curable release coats
20. How do the energy costs of an EB system compare to a thermal system? To a liquid UV
system?
EB system costs are about 10 percent of an electric thermal system, less than a gas
thermal system; EB cost are one-third of UV-curing system
21. In your presentation at the CMM conference, you stated that an EB system on a dollars
per square meter of product is about 6.3 percent less expensive that the equivalent thermal
system. What product was being manufactured and have any similar cost comparisons
been done for other FSA products?
A 38 inch (96.5 cm) graphic arts web offset printing process; Unknown at this time
22. What hidden benefits are there to using an EB system (i.e., reduction in floor space,
insurance, safety)?
No fire problems, chemicals are safer to handle, insurance costs may reflect these
changes
Marketing
23. What are the concerns expressed by the PSA tape and label manufacturers with regard
to this technology?
Three areas of concern; Cost, Performance, Productivity
B-13
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24. In our discussion with several PSA tape and label manufacturers, aesthetics is a major
concern. What are you as an equipment provider of the "total package concept" doing
to help alleviate this problem?
Working to make color and texture of coatings the same as with thermal!solvent-based
systems
Emissions and Waste
25. Is ozone generation a concern with EB curing units? Can this be overcome with modified
ventilation?
Negligible with inerting capabilities; no need to modify standard ventilation
26. What classification of waste is spent EB-cured adhesive: hazardous or solid?
Solid, non-hazardous waste
27. Axe there any emissions associated with the EB system (i.e., the adhesive itself, or during
the application and curing process)?
Negligible ozone emissions
28. What other wastes are associated with an EB system (water, hazardous waste, solid
waste)?
Water from cooling for shielding is recirculated, solid waste from make-ready scrap, and
any waste from cleaning (i.e., IP A, industrial soap)
Safety
29. What specific safety precautions must be taken with an EB system (i.e., personal
protective equipment, procedures, etc.)?
See the Safety Report (Attachment A) with Package for safe handling practices, lock-
out/tag-out, and standard safe operating procedures. Suppliers of coatings teach safe
handling of chemicals as with solvent-based coatings
REFERENCES
1. C.R. Newman and Stephen A. Walata. Radiation-Curable Coatings. EPA-600/2-91-035.
(NTIS PB91-219550). Control Technology Center, Research Triangle Park, NC. April
1991.
B-14
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ATTACHMENT A
RADIATION-CURABLE SAFETY REPORT
B-15
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ESI
Energy Sciences Inc.
£2 IrxSustria; Wcy. Wiimincion l/A S'c-S.7 US A
lei: (508)6W-5-COO Iv.v."?-02^£S27ves ro*.-(bZE)
»m • t i •
An open letter to customers who are installing ESI Electrocurtaint systems
From: ESI Customer Service
This letter includes several iteirs enclosed to assise you in understanding
those safety issues which relate to the ESI Electrocurtain system you have
purchased. Like all industrial equipment, electron beam systems should be
operated by trained individuals, but the level of training required is not
unusually stringent. Good manufacturing practices and the Electrocurtain
safety features combine to provide system safety for the typical industrial
environment.
Electron beam systems utilize high energy electrons to treat your product.
Therefore, the two most important safety concerns are high voltage and radiant
energy. By radiant energy, we mean the electrons themselves and also the
small amount of x-rays produced vithin the Selfshield® during production
operations.
The ESI representative vho supervises the installation of your system is your
primary employee "trainer". He will work closely vith your operator and
maintenance teams to familiarize then vith the complete system. For high
voltage, considerations, a brief explanation of the power train, its safety-
features, and the precautions required during operation or service will
suffice to ensure worker safety when properly understood and followed.
The radiant energy developed by the system can become more of an employee
concern and is usually dubbed "radiation". Not infrequently, people begin to
harbor totally inappropriate fears because they don't understand either
radiation or this kind of equipment. Therefore, putting this system's
"radiation" characteristics in proper perspective is crucial and, in fact, has
led to total worker-acceptance in hundreds of plants around the world. The
installation supervisor is your on-site resource for training your maintenance
people and line operators with regard to radiation safety features and
procedures. If it is requested, ESI can provide a more general safety-
presentation for your other employees. This would consist of a one hour
presentation (and discussion) of the kind of system this is (that it is
similar to a microwave oven) and how ESI ensures that the radiation inside
poses no threat to people.
In addition to these training and presentation provisions, the enclosed
materials are supplied to give you a single package of radiation-safety-
related information. There are items included for:
(1) All employees within the production facility.
(2) Maintenance and operators working vith the equipment.
(3) Management personnel.
Dear Sir:
An Iwoscki E lectric Gioup Coa>pa^\' £J- lg
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Those items are described as follows
(1) For all employees, there is a sheet entitled "Putting Radiation Doses in
Perspective" (Appendix 1) and a booklet entitled "P.adiation - A Fact of
Life" (Appendix 2). The sheet demonstrates that film badges on ESI
employees have shown radiation doses that are 500 times less than what
OSHA calls perfectly safe! That is important to communicate.
The booklet can help them understand what radiation is and how we live in
it all the time. (This can be ordered from the International Atomic
Energy Agency in Vienna, Austria.)
(2) For maintenance and operators, there is the safety section (*/2) of the
operator's manual (Appendix 3). These are discussed in detail by the
installation supervisor.
(3) For management, there is a technical report (TR-107) on safety
considerations for these systems (Appendix A). Such issues as x-ray
shielding, applicable federal regulations and the use of film badges are
discussed. (The badges are not required but can be used to monitor dose
received by workers.) Also the industrial experience is described for
several companies whose workers wore film badges around ESI Electrocurtain
systems. The data amply proves the equipment is well within the OSKA
"safe" limit.
There is a set of sheets summarizing what a company "Radiation Protection
File" should include (Appendix 5). Blank forms are included in this set
and should be filled out with data relating to your Electrocurtain system.
For management which wants to consider using film badges (if only for one
year, as has often been done), a pamphlet from Landauer is enclosed
(Appendix 6). This company provides monthly checks on whatever radiation
doses are received by the personnel film badges. They can provide full
instructions about the badges and how they can be used.
There is also a Service Bulletin which describes the kind of routine
checks that should be undertaken and recorded on a monthly basis (Appendix
7).
Finally, an example of procedures relating to radiation protection is
included (Appendix 8). Since each company must develop policies and
procedures to meet their own standards, the example is included to be used
as a guideline if your company wishes to officially document how workers
should deal with radiation protection.
If there are any further ways we can assist you in these matters or any safety
concern, please do not hesitate to call.
B-17
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PUTTING RADIATION DOSES IN PERSPECTIVE
In One (8 Hour) Day :
tc
H-*
C30
04 mrem .2 mrem 20 mrem
100 times
500 times
2000 mrem 10,000 mrem 100,000 mrem
ESI Film Average "SAFE"
Badge Avg. American (OSHA)
Spine
X-ray
Detectable Some
Blood Changes Injury
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