United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S2-87/007 May 1987
SEPA Project Summary
Evaluation of the Problems
Associated with Application of
Low Solvent Coatings to
Wood Furniture
Carl Uhrmacher
The coatings manufacturing industry
has advanced the state-of-the-art for
producing low volatile organic com-
pound (VOC) based finishes for wood
furniture. These improved coatings have
the potential to overcome earlier objec-
tions of the furniture industry to at-
tempts to regulate lower VOC emissions
in this industry. The objective of this
project was to evaluate a low-VOC
finishing system for the manufacture of
wood furniture and to compare its per-
formance in the manufacturing process
to an equivalent conventional solvent
based system. The production of furni-
ture finished with a conventional sol-
vent-based system and several days
production of wood furniture finished
with a low-VOC system were observed
and evaluated. All furniture was pro-
duced under a single contract with the
General Services Administration (GSA),
and was to be similar in color and style.
In the low-VOC system, a waterborne
combined toner and washcoat, a cata-
lyzed sealer, and a catalyzed topcoat
were used in place of part of the normal
coatings used in the conventional finish-
ing system. All problems, processing
changes, personnel comments, and pro-
duction figures were noted and analyzed.
The reduction in VOC emissions was
estimated from consumption data ob-
tained during the observation period.
The manufacturing economics, process
changes, impacts on the environment,
potential effects on worker health, and
changes in energy requirements were
evaluated for these low-VOC coatings.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that Is fully docu-
mented In a separate report of the same
title (see Protect Report ordering In-
formation at back).
Introduction
In 1979, the U.S. Environmental Pro-
tection Agency (EPA) issued draft control
technique guidelines for volatile organic
emissions (VOCs) resulting from the
application of coatings in the manufacture
of wood furniture. The industry, as repre-
sented by several trade associations, and
several individual companies objected to
the suggested use of new furniture coat-
ing technology based on the use of water-
borne coatings in lieu of the conventional
solvent-borne coatings.
Since 1979, the coatings manufacturing
industry has advanced the state-of-the-
art for the production of low-VOC coat-
ings. Their efforts have improved low-
VOC coatings, including high solids, cata-
lyzed high solids, and waterborne coatings.
These improved coatings could help to
overcome the earlier objections of the
furniture industry to the use of low-VOC
coatings.
The General Services Administration
(GSA), in cooperation with EPA and the
U.S. Army, awarded a contract to United
Globe Corporation, a division of Turner
Furniture Industries, for the manufacture
of traditional style household wood furni-
ture for use by Army personnel stationed
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overseas. A special clause in this contract
required that 1000 buffets be finished
with a low-polluting coating system,
defined by GSA and EPA to be one that
contains less than 100 Ib VOC/1000 ft2
of surface area finished (45.4 kg/92.9
m2).
Objective
The objective of this project was to
determine the effects of using a low-VOC
coating system in lieu of a conventional
solvent system in the manufacture of
comparable or equivalent wood furniture.
The major elements in the manufacturing
process to be evaluated in this study
included:
• Variances in equipment require-
ments, to accommodate the low pol-
luting system.
• Variances in the number or sequence
of processing steps.
• Manufacturing problems associated
with the low polluting systems.
• Variations in labor and energy re-
quirements.
• Finishing system effects on process
economics.
• Reduction in pollution achieved by
use of the low-VOC coating system
compared with use of conventional
coating systems.
This report does not present opinions
about the aesthetic quality or commercial
acceptability of the low-VOC finishes
since the primary objective of this project
was to determine the effect of low-VOC
coatings on the manufacturing and fin-
ishing processes. The furniture produced
during this program was required to meet
minimum GSA standards for quality and
color.
Materials and Procedures
Coating Material
All of the coating materials used in the
low-VOC trials and in the conventional
GSA finishes are listed, along with their
density and VOC content, in Table 1.
The Furniture
The finishing of GSA contract furniture
that was coated with conventional sol-
vent-borne coatings was observed. This
furniture was a mix of the bedroom and
dining room suites produced with the
same finish. Buffets were chosen by GSA
to be used in the trials. One thousand
buffets were produced with the new finish
and were to blend in with the non-test
dining room furniture.
Procedures
No air samples were collected for this
project because of the plant configuration.
It was assumed that all volatile material
eventually was released to the atmo-
sphere, that total emissions could be
calculated from density, and that VOC
content data could be determined by
laboratory analysis.
Results
Re/eases to the Atmosphere
The use of the low-VOC system in this
study reduced the amount of VOCs re-
leased to the atmosphere. There was a
40% reduction based on the EPA labora-
tory analysis of the coating system. Of
the 50.8 Ib (23 kg) reduction: 59% was
produced by using the waterborne coating
in place of the washcoat and toner; 12%,
by using the catalyzed sealer; and 23%,
by using the catalyzed topcoat.
The goal of 100 Ib VOC emitted/1000
ft2 coated was met with this system. The
total was estimated to be 75.7 lb/1000
ft2 (34.3 kg/93 m2), a reduction of 50.8
Ib/1000 ft2 (23 kg/93 m2). The use of the
waterborne coating accounted for 29.9 Ib
(13.6 kg) of this reduction, the catalyzed
sealer for 6.1 Ib (2.8 kg), and the catalyzi
topcoat for 11.6 Ib (5.2 kg). The resul
are summarized in Table 2.
So//d Waste
There was an increase in the amou
of solid waste generated as sludge trapp
in the water pan booths after the sprayi
of the high solids catalyzed coatings. TF
was estimated by plant personnel to be
30% increase over the normal conve
tional coatings. This is not a major e
vironmental problem for this plar
because these sludges, which are meti
free, can be burned in a state-approv
incinerator.
Analysis
Waterborne Toner/Washcoat
The major problem with the waterbon
coating was grain raising caused by tl
water in the formulation. This caused tl
surface to be rough and required ext
sanding. This also opened the grain ai
allowed the wipe stain (filler) to penetra
too deeply and produce too dark a cole
Extra retarder had to be added to tt
filler, and the furniture had to be wipe
Table 1.
Coating
Density and VOC Content of Coatings
Coating Manufacturer's Lab
EPA Lab
Density
Ib/gal. kg/I
%VOC
(wt)
Density
Ib/gal. kg/I
%VOC
(wt)
Waterborne
Catalyzed Sealer
with Catalyst'
Catalyzed Lacquer
with Catalysf
Low-VOC GSA Coating System
7.54 0.9035 43
7.75 0.9287 73
7.88 0.9443
7.65
0.9167
64
7.77
7.76
7.65
7.63
0.9308
0.9298
0.9164
0.9148
42.3
71.0
73.9
64.5
68.0
Conventional GSA Coatings
Sap Stair?
Toner
Washcoat
Wipe Stairf
Shade*
Sealer
Lacquer
6.74
6.63
7.00
7.44
6.65
7.10
7.55
0.8076
0.7945
0.8388
0.8915
0.7969
0.8508
0.9047
97
99
92.1
79
98
81
82
6.73
6.63
6.96
7.11
6.70
7.22
7.53
0.8068
0.7942
0.8342
0.8526
0.8034
0.8652
0.9025
97.8
97.6
92.5
83.4
99.0
82.9
78.9
8 Based on laboratory analysis of freshly catalyzed material.
b Same coating used in both systems.
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Table 2.
VOC Reduction
Coating
GSA Sap Stain"
Toner
Washcoat
GSA Wipe Stain"
GSA Shade Stain"
Sealer
Catalyzed Topcoat
GSA Lacquer
Total VOC used
for conventional
system'
Ib/IOOO ft2
13.4
17.3
17.6
26.7
1.6
22.3
N/A
27.6
Total VOC used
for low-VOC
system'
lb/10OO ft2
10.6 c
j „
27.2
0.7
16.2
16.0
NA
VOC Reduction"
lb/1000 ft2
-2.8
\ -29.9
+O.5
-0.9
-6.1
+16.0
-27.6
Emitted per 1000 ft2
Net VOC reduction
126.5
75.7
-50.8
"Metric conversion: 1 lb/1000 ft2 = 0.0049 kg/m2.
* Coating used by both systems.
with naphtha to remove the excess stain.
The resultant problem with the filler could
be solved, but the grain-raising problem
remained throughout the trial, and proce-
dural changes during the manufacturing
process did not mitigate the problem.
Catalyzed Sealer
Three problems occurred with this
coating: "setting-up," "orange peel," and
worker complaints about eye irritation
and smell. Setting-up refers to thickening
of the catalyzed material when stored.
The coating used had a 1 -day pot life, and
the attempt to extend its pot life failed
during the evaluation.
Catalyzed Topcoat
Two major problems were observed
with the catalyzed topcoat: "bridging"
(i.e., the topcoat along the molding edge
remained wet or tacky after drying in the
oven); and worker complaints about
blowdown that made working conditions
sticky. Concern was voiced about "print-
ing" (i.e., the soft surface imprinting with
packing material), although there was no
evidence that this occurred. Concern was
also voiced about the ability to strip the
topcoat if reworking of the finish was
required. This could not be determined
during this evaluation because no pieces
required refinishing.
Economic Analysis
Coating Cost
The low-VOC coating system was less
expensive in material costs than conven-
tional systems. Using proprietary pricing
information, the cost of the low-VOC/
1000 ft2 coated was estimated to be
$101.03, or $4.59/buffet; the cost of the
conventional finish was $129.26/1000
ft2 coated, or $5.98/buffet. The resulting
material savings for 1000 buffets were
estimated to be $1280 in reduced coating
usage.
Personnel and Personnel
Assignments
No additional workers were assigned
to the finishing room floor for the low-
VOC coating trials. However, floor in-
spectors were used during the test for
wiping or sanding. If this system were to
be permanently introduced, additional
workers would be necessary. The labor
requirements were estimated to increase
by 6%.
Production Rates
Production rates for the low-VOC were
not changed from the conventional sys-
tem. Line speed was maintained once
the initial adjustments were made for
introduction of the new coatings.
Equipment
There was no increase in costs due to
new equipment requirements. All low-
VOC coatings were applied with in-house
equipment. The waterborne coating was
pumped from a local pressure pot and not
supplied from the pump house as a pre-
caution against possible corrosion.
Energy
There was no increase in the oven
temperature during the low-VOC trial.
The oven was maintained at approxi-
mately 110°F (43°C), and the heat
boosters were not used. There were no
increases in energy costs from using the
low-VOC coatings.
Based on estimates of costs given by
plant management, there would be no
overall net increase in cost to the manu-
facturer for this system because the
increase in labor would be offset by the
decrease in material costs.
Health and Worker Safety
The more toxic or hazardous system
cannot be determined on the basis of
information in the Material Safety Data
Sheets alone because there is no estima-
tion of worker exposure. However, the
low-VOC system releases less solvents
to the workplace because they are, by
definition, lower in VOC. Despite this,
there were worker complaints about eye
and throat irritation when the catalyzed
coatings were being used. The catalysts
were p-toluenesulfonic acids, which are
known to be mucous membrane irritants.
No heavy metals are listed in either
system.
Conclusions and
Recommendations
Summary Conclusions
The waterborne and catalyzed coatings
system used in this evaluation resulted
in a 40% reduction of VOC content from
the conventional coatings system. The
low-VOC system used approximately 34
kg/93 m2 of surface area coated (76
lb/1000 ft2), compared to approximately
57 kg VOC/93 m2 for the conventional
coatings system (127 lb/1000 ft2). The
contract goal of 100 Ib VOC emitted/1000
ft2 covered (45.4 kg/93 m2) was met.
• Catalyzed coatings can be used suc-
cessfully in the furniture manufac-
turing process. The problems noted
during the trial run can be eliminated
by providing additional worker train-
ing, improving ventilation, making
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minor adjustments to materials, and
using properly adjusted spray
equipment.
Catalyzed coatings did reduce VOCs
by 35% of the total reduction, but
their use alone would not have been
sufficient to meet the goal specified
in the GSA contract, less than 100
Ib VOC emitted/1000 ft2 covered
(45.4 kg/92.9 m2).
The major factor in achieving the
contract reduction goals for VOC
usage was the use of the waterborne
toner/washcoat which accounted for
59% of the total reduction.
Some process modifications from
conventional operations may be re-
quired to eliminate the problem of
grain raising, seeding, and bridging.
These problems were successfully
addressed during this project to meet
GSA specifications.
Carl Uhrmacher is with Carltech Associates, Inc., Columbia, MD 21045.
Charles Darvin is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of the Problems Associated with
Application of Low Solvent Coatings to Wood Furniture," (Order No. PB 87-
168 746/AS; Cost: $18.95. subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road .
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC27711
United States
Environmental Protection
Agency
Onter for Environmental Research
Information
Cincinnati OH 45268
/
Official Business
Penalty for Private Use $300
EPA/600/S2-87/007
0000329 PS
60604
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