EPA/600/A-97/073
Evaluation of Waterborne Contact Adhesives for the Store Fixture Industry
S. L. Turner, D. R. Cornstubble, and C. M. Northeirn
Research Triangle Institute, P.O. Box 12194, Research Triangle Park, NC 27709
C. A. Vogel
U.S. Environmental Protection Agency, Air Pollution Prevention and Control Division,
Research Triangle Park, NC 27711
ABSTRACT
This paper presents the results of an evaluation of waterborne contact adhesives for
attaching laminates to 45-lb-density particleboard. The evaluation site, like many similar
manufacturing sites, currently uses solvent-borne contact adhesives for its lamination
applications. Replacement of solvent-borne products could significantly reduce volatile organic
compound (VOC) emissions and result in achieving environmental compliance while
maintaining the production of a high-quality end product for laminating manufacturers. Three
waterborne contact adhesives and one solvent-borne contact adhesive, serving as the control,
were tested during a full-scale onsite evaluation at a store fixture manufacturing facility.
Subjective evaluations of adhesive performance were made for each waterborne adhesive and
compared to the performance of the currently used control adhesive. The quantity of adhesive
used during application was measured, and samples of each adhesive will be analyzed for VOC
content. From preliminary information, VOC emissions and cost estimates were made. In
addition, a temperature-exposure test and a peel strength evaluation will be conducted to predict
the performance and longevity of the waterborne adhesives as compared to the control adhesive.
Results from the peel strength evaluation are not yet complete. Preliminary results show that
selected waterborne contact adhesives evaluated performed as well as the control. All of the
alternative adhesives had substantially lower applied VOC emissions as compared to the control
adhesive.
INTRODUCTION
Solvent emissions to the atmosphere are the most common waste streams from contact
adhesive applications, specifically those operations involving lamination. Solvents can represent
more than 80 weight percent of these adhesives. Some solvents commonly used in formulating
contact adhesives are hexane, methyl ethyl ketone (MEK), methylene chloride, and toluene, all of
which are both VOCs and hazardous air pollutants (HAPs),1
Contact adhesives are generally defined as adhesives that are dry-to the touch in a
relatively short period of time and that instantaneously adhere to themselves upon contact.2
These adhesives are used for laminating high-pressure laminates and low-pressure laminates to
various substrates. They are fast-bonding adhesives used to manufacture kitchen cabinets,
household and office furniture, and store fixtures. During assembly, both the laminate and
substrate surfaces are coated with a contact adhesive and allowed to cure by air-drying, forced
air-drying, or applying heat through an external source. The laminate and substrate are then
pressed together manually or mechanically using a rotary press or nip roller to form a final bond.3
Many facilities in the laminating industry are looking for alternatives to replace currently
used high-solvent-containing contact adhesives that can meet local, State, and Federal
regulations. These facilities are interested in identifying alternative contact adhesives that not
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only meet regulations but also perform as well as, or better than, the currently used contact
adhesives,
Project Objectives
This research project evaluated the performance, economics, and emission reduction
potential of low-VOC waterborne contact adhesive formulations for manual laminating
operations in assembling store fixtures. The evaluation was designed to show whether these
waterborne contact adhesives perform as well as, or better than, a currently used solvent-borne
contact adhesive and to show whether these products emit lower quantities of VOCs and/or
HAPs in laminating operations. Participants in this evaluation include representatives from the
U.S. Environmental Protection Agency's (EPA's) Air Pollution Prevention and Control Division
(APPCD), Research Triangle Institute (RTI), a store fixture manufacturing facility, four contact
adhesive suppliers, and one independent testing laboratory.
The primary objective of this evaluation project was to determine if three waterborne
contact adhesives could achieve performance levels equivalent to, or exceeding that of, a
currently used solvent-borne contact adhesive while emitting lower VOCs and/or HAPs. Two
secondary objectives of this research project were to (1) determine the relative cost of using each
alternative contact adhesive as compared to the currently used control, and (2) estimate the
emission reduction potential from the use of each alternative contact adhesive. Required data for
these secondary objectives included measurement of the quantity of adhesive used per unit area
and the VOC content of each adhesive.
RTI evaluated commercially available contact adhesives during a full-scale simulated
laminating operation. Each adhesive was applied to several pairs of test boards and finishes, or
laminates, before laminating the two pieces to each other. Adhesive performance was evaluated
based on application parameters, such as the total time it took to apply and drying time of each
adhesive; temperature and percent relative humidity were recorded during adhesive application.
Then, after allowing an approximately 24-h dry time, samples were cut from the laminated
boards and evaluated using the following tests/factors:
• Onsite subjective peel test
• Offsite cyclic temperature-exposure test
• Offsite peel strength evaluation (not yet completed).
In addition, VOC content of each adhesive will be measured offsite, and the results will be used
with adhesive usage data to calculate applied VOC emissions. Product density, weight percent
solids, quantity of applied adhesive, and cost data, provided by technical data sheets from each
adhesive manufacturer, were used to estimate relative cost data for each adhesive product. RTI
will analyze, in triplicate, samples of each adhesive to confirm the product density, weight
percent solids, and VOC content; however, at the time this paper was written, these results Were
not available.
Facility Operations
The evaluation facility has been operating as a custom manufacturer of retail store
fixtures since October 1992. Their manufacturing space is approximately 22,000 ft2 (2,044 m2).
The facility operates 8 hours per day, 5 days per week, 260 days per year with 27 employees.
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Manufacture of retail store fixtures involves the forming and attachment of several types of
finishes, or laminates, to particleboard or medium-density fiberboard substrates. Examples of
finish materials used to make store fixtures include vinyl, top-coated papers, melamine-
impregnated papers, and high-pressure laminates. The primary raw materials used at this facility
consist of industrial-grade particleboard, medium-density fiberboard, and various finishes.
Examples of retail store fixtures include refund counters, layaway department counters, and
fitting rooms and stands for sunglass rollers. Approximately 98 percent of the laminating
activities performed at the evaluation site are done in-house. Their manufacturing process has
five main operations: substrate/laminate cutting, machining, edgebanding, laminating, and
custom building. Two of these processes, edgebanding and laminating, require the use of
adhesives and are described below.
Adhesive Applications
Edgebanding of boards is conducted on a machine operated by two persons: one person
feeds cut boards into the machine, and the other person unloads and stacks the boards after they
have been edgebanded. Rolls of edgeband made of polyvinyl chloride, or high-pressure laminate,
mostly noncontoured, are placed on the automatic band feeder. The edgeband is then attached to
the edge of cut boards with a hot melt polyvinyl acetate (PVAc) glue. After the boards are
removed from the edgebander, one to four operators hand-file the edges of the board until they
are smooth.
Currently, both PVAc glues and solvent-borne contact adhesives are used to attach
edgebanding to contoured surfaces manually. The facility is in the process of converting their
manual edgebanding operation to an automated system using PVAc adhesives in place of the
currently used solvent-borne contact adhesive. Because they expect to make this conversion
within the year, edgebanding adhesive applications were not a part of this evaluation.
The focus of this evaluation was on the application of laminates to 45-lb-density
particleboard of relatively large surface area (4 ft2 [0.186 m2]). This process typically requires
two operators. One operator cleans the surfaces of the substrate and laminate and applies two
coats of contact adhesive to one side of the substrate and to the opposing side of the laminate.
This operator uses a conventional air spray gun to spray apply a solvent-borne contact adhesive
pumped from a 55-gal (208L) drum. (English units are typically used to describe commonly used
materials and supplies in the lamination industry and will be used throughout the rest of this
paper.) The two coats of contact adhesive are allowed to air-dry after each application. Then,
the second operator attaches the laminate to the substrate by pressing the two surfaces firmly
together and using a hand-held, 2-in. (5.08 cm)-diameter roller as a final press. The formed piece
is allowed to air-dry for about 24 hours.
EXPERIMENTAL
This section describes materials and methods used to evaluate the waterborne contact
adhesives as compared to the control adhesive.
Products Tested
Raw Materials - Adhesives. Three alternative contact adhesives and the currently used
control adhesive were evaluated. Selection of alternative contact adhesives was based on the
ability of each to meet the following criteria:
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• Contain less than 540 g/L VOC
• Applicable to Formica topping or laminating
• Commercially available
* Vendor willingness to provide samples of, and technical information on, adhesives.
Two of the three contact adhesives were single-component, waterborne adhesives, and one was a
two-component, waterborne adhesive. The control was a solvent-borne adhesive (see Table 1).
For the evaluation, project engineers estimated that approximately 1 to 2 gal (3.79 to
7.57 L) of adhesive would be used. Therefore, one 5-gal (18.95L) container of each adhesive
was requested from each vendor. Each adhesive was assigned an identification (DD) number and
labeled to simplify compilation of test data into a database for future analysis. This ensured data
quality control and protected the identities of participating suppliers.
Table 1. Contact Adhesives Evaluated *
Adhesive identification
Property
Generic description
Volatiles
Volatile content, g/L
Solids, weight percent
Resin base
Density, Ib/gal (g/mL)
Dry time, min
Adhesive 1
Waterborne,
two-component
Toluene,
methanol
<60
47-51
Polychloroprene
8.9-9.3 (t.07-1.12)
0.25-60
Adhesive 2
Waterborne,
single-component
Toluene
70-75
45
NA
9.2 (1.10)
30
Adhesive 3
Waterborne,
single-component
Toluene
43
45
NA
8.98 (1.08)
15-30
-Control
Solvent-borne,
single-component
Acetone, n-hexane,
hexane isomers,
toluene
623
17.5
Polychloroprene
and phenol
6.3 (0.76)
15
NA = Not available.
* Properties taken from material safety data sheets (MSDSs) and/or technical data sheets for each adhesive. Each
adhesive was supplied by a different adhesive manufacturer.
Raw Materials - Substrate and Laminate Type. The substrate used in this evaluation
was a 45-lb-density particleboard. Typically, the facility receives substrates in units, each
containing 35 sheets 4 ft wide by 10 ft long by % in. thick (1.22 m x 3.04 m x 1.9 cm). Four
sheets were taken from one unit and cut into ten 4 ft by 1 ft (0.76m) by 3A in. sheets. This
provided 40 test boards for the evaluation.
The laminate applied to each 4 ft by 1 ft by % in. board was Formica, taken from a
common lot and cut to dimensions slightly larger than the substrate. Laminate is always cut
larger than the substrate to which it is applied so that an even edge can be achieved after cutting
away excess laminate. Each test board and laminate were labeled before adhesive application.
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Measurements and Evaluations
The evaluation facility selected an operator for this evaluation. The operator had 5 years
of experience using conventional air spray technology to spray solvent-borne adhesives and no
experience using high-volume, low-pressure (HVLP) technology to spray adhesives. Efforts
were made to meet manufacturer recommendations for spray equipment settings and handling for
each adhesive.
Subjective evaluation of test samples was conducted at the facility shortly after adhesive
application. Test samples for exposure testing were packaged and shipped to RTFs Analytical
and Chemical Sciences (ACS) research laboratory and placed in an incubator for cyclic,
temperature-exposure testing. The remaining test samples were packaged and shipped to SGS
US Test Corporation, in Fairfield, New Jersey, for peel strength evaluation of adhesive bonds.
Subjective Evaluation. Approximately 24 hours after air-drying, a facility representative
in charge of quality assurance (QA) performed a subjective peel test on test boards from each
adhesive set. This test is normally conducted at the facility as part of their routine QA check of
assembled products and consists of manually peeling back the laminate from the substrate to
observe how easily it can be pulled back and to count the number of strands or legs of adhesive
that remained on the substrate. This evaluation is unconventional but is a required pass/fail test
for the facility. During and after this test, RTI used a simple questionnaire to evaluate the
representative's response for the pass/fail of each test board.
Temperature-Exposure Testing at RTI. A temperature-exposure test for sample
boards was conducted at RTFs ACS research laboratory. Upon its arrival at RTI, each sealed can
containing four board samples each was inspected. These cans contained either control samples
or test samples and were preconditioned for 7 days at 50 ± 2 percent relative humidity and 73.4 ±
1.8 °F (23 ± 1°C) immediately before testing. The control samples remained in the control
environment throughout the test.
The preconditioned samples were subjected to two 24-h exposure cycles, cold then hot, at
conditions specified in Table 2. At the end of the cold cycle, the exposed samples were
photographed. At the end of the entire exposure period, the exposed test samples were allowed
to reach room temperature. After the exposed test samples reached room temperature, the
evaluation facility's QA representative performed a subjective peel test and compared their
performance with the performance of the matched controlled samples. Although this test has
been completed, data were not available in time for inclusion in this paper.
Table 2. Exposure Test Conditions
Exposure cycle Temperature, °F * Moisture conditions
Cold 32 Freezer, uncontrolled humidity
Hot 120 Open, uncontrolled humidity
1 °C = (°F - 32 °F)/(1,8 °F/°C).
Peel Testing at SGS US Test Corporation. The SGS US Test Corporation in Fairfield,
New Jersey, is conducting a peel test on each of the five test samples from test board 10 of each
adhesive. The laboratory uses American Society for Testing and Materials (ASTM) standard test
method D 903-93. The facility is modifying the test slightly. Test method D 903-93 is designed
for a flexible laminate that can be pulled back at a 180 ° angle. However, because the Formica
5
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laminate used in this test is not that flexible, SOS US Test Corporation is making the necessary
adjustments and conducting this test by pulling the flexible laminate back at a 90 ° angle.
Physical Properties of Each Adhesive. The physical properties of each adhesive are
essential in calculating the VOC emissions and relative cost estimates. To determine these
properties, samples were taken from each adhesive and will be analyzed in RTFs laboratory
using standard test methods.
Samples of each adhesive were obtained before the evaluation began. Before adhesive
application, an operator thoroughly mixed each 5-gal (18,75 L) container of adhesive. After the
containers were opened, the operator took three grab samples from the center of each container
using 500-mL (17-fl-oz) amber sample jars with sealing lids from VWR Scientific. These
samples were packaged and shipped to RTFs analytical laboratory and will be analyzed in
triplicate for total volatiles, water content, and density of each adhesive. The analyses will be
conducted according to the standard test methods:
• VOC content EPA Method 24, Determination of volatile matter content, water
content, density, volume solids, and weight solids of surface
coatings
» Nonvolatile ASTM D 1489-93, Standard test method for nonvolatile content of
content aqueous adhesives
• Water content ASTM D 3792-79, Standard test method for water content of
water-reducible paints by direct injection into a gas chromatograph
• Density ASTM D 1875-90, Standard test method for density of adhesives
in fluid form
RESULTS
This evaluation took place at a store fixture manufacturing facility over a 3-day period.
The ambient air temperature and percent relative humidity were monitored and measured during
adhesive application. The average temperature was 24°C (75°F), and the average relative
humidity was 47 percent. These conditions fell within the application specifications of each
adhesive manufacturer.
Adhesive Performance and Usage
The primary objective of this evaluation was to evaluate the performance of the
alternative waterborne contact adhesives. To help meet this objective, the actual dry time of each
adhesive and the total application time, or process time, for adhesive application to each
assembly were calculated. The time it takes for an applied adhesive to dry affects not only the
performance of the laminated assembly but also the time it takes an operator to put together that
assembly.
The actual dry times for the control and Adhesive 2 were similar at 24 and 28 minutes,
respectively. The dry time for Adhesive 1,5 minutes, was less than the dry time for the control.
Adhesive 3 had the longest dry time of 47 minutes. All of the other adhesives dried more slowly
than the manufacturers' recommended values. Table 3 lists the actual dry time, recommended
dry time, and total application time for each adhesive.
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Table 3. Average Dry Times and Total Application Time, in Minutes
Adhesive 1
Adhesive 2
Adhesive 3
Control
Actual dry time
5
28
47
24
Recommended dry time '
<1 to 120
15
30
15
Total application time
6
31
48
26
a Assumes acceptable temperature and percent relative humidity during application.
This facility defines total application time as the sum of the total time it takes an operator
to apply adhesive to both substrates, allow each substrate to dry, and laminate the substrates
together for further processing. The total application time for Adhesive 1 was approximately
four times better than the control (see Table 3). Total application times for Adhesives 2 and 3
were greater than the control. This information is useful in predicting the effect on the
production rate at the facility. Since application time is short (approximately 1 to 2 minutes per
assembly), dry time has the greatest effect on a facility's capability to increase its production rate.
Accordingly, Adhesive 1 had a superior dry time compared with the other alternative waterborne
adhesives and to the solvent-borne control. The dry time for Adhesive 2 was considered
acceptable by the facility.
The secondary objective of this evaluation was to estimate VOC emissions and relative
costs of each adhesive, as applied. To make these estimates, the average quantity of each
adhesive used to cover laminate assemblies was recorded, and the quantity of dry solids, both
actual and theoretical, was calculated from vendor information (see Table 4). Although an
attempt was made to apply each adhesive per its manufacturer's instructions, the resulting actual
dry grams for each waterborne adhesive applied was two to three times greater than the
theoretical value.
The reasons for the actual dry solids applied for the alternative waterborne adhesives'
being greater than the manufacturer's recommendations resulted from two factors: (1) the
unfamiliarity of the operator with HVLP spray gun equipment, and (2) the application of
adhesive onto a larger area of laminate than the area of substrate. (The laminate area was about
10 percent larger than the substrate area; the overhang that was cut away was included in the
weight measurements.)
For the control, the operator applied the adhesive as it is normally applied at this facility.
The resulting quantity of actual dry solids applied for the control was 60 percent less than the
theoretical quantity as recommended in the technical data sheet. This was due primarily to the
operator's unfamiliarity with the use of the HVLP spray gun equipment with the control
adhesive.
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Table 4. Average Adhesive Usage Estimates for Laminate Assembly
Adhesive 1
Adhesive 2
Adhesive 3
Control
Adhesive used, g
105
83
168
64
Dry solids, g
48.3
44.0
74.3
5.6
Dry solids per side, (g/ft2) "
Actual
6
5.5
9.3
0.7
Theoretical
3
3
3
2
* Usage is expressed as grams per square foot for a constant assembly area of 8 ft2 (0.743 m2).
b 1 g/ft2 =10.765 g/m2.
Facility Evaluation of Each Adhesive
On occasion, 24 hours after adhesive application, the plant manager will conduct a
subjective peel test on a few assembled parts to determine if the assemblies pass or fail the peel
test. This test involves manually peeling back the laminate from the substrate to observe how
easily the laminate pulls back and to count the number of adhesive strands that remain on the
substrate. Each of the alternative waterborne adhesives passed the subjective peel test at the
facility, except Adhesive 3. For Adhesive 3, each laminate fully delaminated from each
assembly as it was pulled from the substrate. The plant manager performed the test on panels
labeled A#S#5O through A#S#9O approximately 18 to 22 hours after application. Table 5
shows which adhesives passed and which failed for each set of tested panels.
Table 5. Subjective Evaluation Results
A#S#5O
A#S#60
A#S#70
A#S#80
A#S#9O
Adhesive 1
Pass
Pass
Pass
Pass
Pass
Adhesive 2
Pass
Pass
Pass
Pass
Pass
Adhesive 3
Fail
Fail
Fail
Fail
Fail
Control
Pass
Pass
Pass
Pass
Pass
Based on dry time, total application time, and subjective peel test, Adhesive 1 performed
as well as or better than the control. Adhesive 2 also performed acceptably, although its dry time
and application time exceeded those of the control by several minutes. However, Adhesive 3
performed poorly in all three categories. To compare the usage of alternative adhesives with the
control is difficult because the actual adhesive application per unit area was higher than the
recommendations of each adhesive manufacturer. While the overapplication of the alternative
adhesives would be expected to increase their application and dry times, it is not clear how this
affected their performance in the subjective peel test.
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Applied VOC Emissions
The other secondary objective of this evaluation was to compare estimates of total applied
VOC emissions of each adhesive. This type of assessment would help manufacturers in the store
fixture industry to identify the impact alternative waterbome adhesives would have on emissions
per square foot of area sprayed, VOC emissions per unit of area for each adhesive were
estimated using vendor-supplied physical data, the average quantity of wet adhesive actually
applied to each substrate, and the surface area of the assembly. Equation 1 was used to estimate
the average actual VOC emissions:
"Act
x V
*• v
Adh
(1)
-Act
-VOC
Adh
= average actual VOC emissions, g/ft2
= VOC content, g/L
= wet adhesive used, L
= assembly surface area, ft2.
Estimates of theoretical VOC emissions for each adhesive were also made, using vendor-
supplied physical data and recommended dry application coverage quantities (see Table 6),
Table 6. Applied VOC Emissions for Each Adhesive
Actual VOC emissions a (g/ft2) b
Theoretical VOC emissions (g/ft2)
Adhesive 1
0.72
0.34
Adhesive 2
0.69
0.44
Adhesive 3
0.84
0.27
Control
6.65
9.43
1 Emissions are expressed as grams per square foot for a constant assembly area of 8 ft2 (0.743 m2).
blg/ft2 = 10.765 g/m2.
Equation 2 was used to estimate theoretical VOC emissions:
X
"Theo
(2)
= theoretical VOC emissions, g/ft2
= manufacturer's recommended dry adhesive coverage, g/ft2
= VOC content, g/L
= weight fraction solids, g/g
= density, g/L.
Table 6 shows that the estimates of average actual VOC emissions of the waterbome adhesives
were lower than the control; this coincides with theoretical emission estimates. The emission
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estimates depend on the solids content of each adhesive, VOC content of each adhesive, and the
quantity of adhesive applied to each assembly. Theoretical VOC emission rates based on vendor
recommendations for adhesive quantity per unit area were substantially lower. Factors for
deviations between actual and theoretical VOC emission estimates are adhesive overspray and
the use of more adhesive than recommended by adhesive manufacturers (see Table 4).
Estimated Costs of Alternative Adhesives
Product density, weight percent solids, quantity applied (coverage), and cost data were
used to calculate cost estimates for each waterborne contact adhesive. The cost per gallon, the
theoretical coverage and cost, and the actual coverage and cost are listed in Table 7 for each
adhesive. Cost estimates show that all of the waterborne products are more costly to use than the
control for the same coverage area. Theoretically, only Adhesive 2 is less costly than the control
at twice the coverage area. The cost estimate for each alternative waterborne contact adhesive
was based solely on the cost of the adhesive and does not include equipment costs.
Table 7. Adhesive Coverage and Cost Information
Theoretical coverage, frugal
Actual coverage, fiVgal
Cost, US dollars/gar
Theoretical cost, US dollars/ft20
Actual cost, US dollars/ft26
Adhesive
1
674°
337
32.4
0.048
0.010
Adhesive
2
626 a
341
14.7
0.023
0.043
Adhesive -
3
611"
197
18.5
0.030
0.094
Control
250 b
714
7.4
0.030
0.010
8 At 3 g/ft2 dry adhesive solids applied per side. c Cost based on use of 55 gal (208 L) drum.
b At 2 g/ft2 dry adhesive solids applied per side.
CONCLUSIONS
This evaluation suggests that selected waterborne contact adhesives can perform as well
as a solvent-borne contact adhesive that is currently being used in the store fixture assembly
industry. In fact, one of the better performing waterborne adhesives evaluated (Adhesive 1) had
actual dry times that were approximately five times lower than the control. Adhesive 1 passed
the onsite subjective peel test, and Adhesive 3 failed.
The actual and theoretical VOC emissions resulting from the use of the waterborne
adhesives were significantly lower than the emissions resulting from the use of the control.
Actual VOC emissions from this evaluation averaged about 0.75 g/ft2 (8.07 g/m2) for the
waterborne products and 6.7 g/ft2 (72.13 g/m2) for the solvent-borne control. If the adhesives
were applied at the generic application rates recommended by the manufacturers, then the
theoretical VOC emissions from the application of the waterborne products would have averaged
approximately 0.36 g/ft2 (3.88 g/m2). The theoretical application values were taken directly from
the manufacturer's technical data sheets for each adhesive. These values are generic and cover a
range of laminating applications for various industries. They do not apply specifically to
laminating applications for the store fixture industry, nor specifically to this facility. Discussions
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with adhesive vendors indicated that wide variations in the amount of dry solids applied would
not have an appreciable effect on performance; for Adhesive 3, the vendor stated that no
appreciable performance effects would be noticed up to 15 g/ft2 (161.5 g/m2) of dry solids
applied.
Based on the quantity of adhesive used during the evaluation, all waterborne products
were more costly to use than the control. Again, if the adhesives were applied at the generic
application rates recommended by the manufacturers, then the cost of using the waterborne
products would have ranged from approximately $0.023 to 0.048/ft2 ($0.25/m2 to 0.52/m2) for
adhesive cost only.
The quantity of applied dry solids has a direct impact on the cost and VOC emissions
resulting from the use of each adhesive. For this evaluation, the control was applied at a rate that
is consistent with the manufacturers' recommendations. Therefore, the emissions shown in
Table 6 and the cost estimates in Table 7 are reasonable approximations for the control adhesive.
During the evaluation, due to the operator's lack of experience using HVLP equipment; the dry
solids application rate, as shown in Table 6 for the waterborne adhesives exceeded the
manufacturers' recommended quantities. The VOC emissions and cost of adhesive used would
be substantially lower if these adhesives were applied as recommended by the manufacturers.
The performance effect of the application rate of dry solids for each waterborne adhesive
is uncertain. It can be assumed that, if the adhesive is applied at a rate significantly lower than
recommended by the manufacturer, then the performance will be poor. However, when the
quantity of applied dry solids significantly exceeds the manufacturers' recommended application
rates, as in this evaluation, the effect on performance is less intuitive. The greater-than-
recommended quantity of dry solids could serve to reduce the performance of the adhesive by
interfering in the drying and substrate bonding process. Therefore, although Adhesive 3
performed poorly in the subjective peel test, it cannot be concluded with certainty that this
adhesive would have also performed poorly if the recommended amount had been applied.
Conversely, because Adhesives 1 and 2 performed well in the subjective peel test, we cannot be
certain that the performance would have been the same if the recommended quantity of adhesive
had been applied.
The reader should note that the operator who applied the adhesive was unfamiliar with
the use of waterborne adhesives and the HVLP spray system used to apply the waterborne
adhesives. Although attempts were made to follow the spray equipment manufacturers'
recommendations, this research suggests that the operator's familiarity with the waterborne
adhesive products and application equipment can substantially affect the cost and VOC
emissions associated with the adoption of a new product.
REFERENCES
1. Paul Grumpier. Analysis of Pollution Prevention Opportunities and Impediments in the Wood
Products Manufacturing Sector in Georgia. Georgia Department of Natural Resources, Atlanta,
Georgia. April 1,1996.
2. D.H. Mcllrath. A new approach to formulating waterborne contact adhesives. Adhesive Age
36(12): 38-41, November 1993.
3. Choosing the right laminating adhesives. Furniture Design and Manufacturing (60): 160-166,
December 1988.
11
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NRMRL-RTP-P-167
TECHNICAL REPORT DATA
(Please read Iniintctions on the reverse before completin.
1. REPORT NO,
EPA/600/A-97/073
2,
3. Rl
4. TITLE AND SUBTITLE
Evaluation of Waterborne Contact Adhesives for the
Store Fixture Industry
5. RhKOKI UAI t
6. PERFORMING ORGANIZATION CODE
7.AUTHOR(s) s.Turner, D. Cornstubble, and C. Northeim
(RTI), and C. Vogel (EPA)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Research Triangle Park
P.O. Box 12194
Research Triangle Park, North Carolina 27709
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
CR 824152
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Published paper; 4-10/96
14. SPONSORING AGENCY CODE
EPA/600/13
is. SUPPLEMENTARY NOTES APPCD project officer is Chester A. Vogel, Mail-Drop 61, 919/
541-2827. For presentation at World Environmental Congress (WORLD '96), Cin-
cinnati, OH, 10/27-29/96.
16. ABSTRACT
paper gives results of an evaluation of waterborne contact adhesives
for attaching laminates. The evaluation site, like many similar manufacturing sites,
currently uses solvent-borne contact adhesives for its lamination applications. Re-
placement of solvent-borne products could significantly reduce volatile organic com-
pound (VOC) emissions and result in achieving environmental compliance while main-
taining the production of a high-quality end product for laminating manufacturers.
Three waterborne contact adhesives and one solvent-borne contact adhesive (the con-
trol) were tested during a full-scale onsite evaluation at a store fixture manufactur-
ing facility. Adhesive performance was subjectively evaluated for each waterborne
adhesive and compared to the performance of the currently used control adhesive.
The quantity of adhesive used during applications was measured, and each adhesive
will be analyzed for VOC content. VOC emissions and costs were estimated from
preliminary information. In addition, temperature- exposure will be tested and peel
strength will be evaluated to predict the performance and longevity of the waterborne
adhesive compared with the control solvent-borne adhesive. Results from the peel
strength evaluation are not yet available. Preliminary results show that selected
waterborne contact adhesives evaluated performed as well as the control.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
tMDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Pollution
Solvents
Adhesives
Commercial Buildings
Evaluation
Laminates
Volatility
Organic Compounds
Pollution Prevention
Stationary Sources
Contact Adhesives
Store Fixtures
Volatile Organic Com-
pounds
13 B
11K
HA
13 M
14G
11D
20M
07D
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 222O-1 (9-73J
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