United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-97/083 September 1997
&EPA Project Summary
Utilizing Low Volatile Organic
Content Exterior Coatings for
Wood Furniture
Paul B. Kranz, James E. Stadelmaier and Thomas F. Stanczyk
Abstract
This report provides an evaluation of
commercially viable source reduction
techniques implemented by a manu-
facturer of wood chairs, bar stools and
settees in various styles ranging from
classic American to European contem-
porary.
As federal EPA regulations became
more stringent for volatile organic com-
pound (VOC) emissions in the wood-
working industry, the Dinaire Corpora-
tion began testing alternative formula-
tions employed as waterborne finishes,
sealers and topcoats. In an effort to
minimize costly investments in air emis-
sion control equipment, the company
examined and implemented a number
of source reduction techniques that dic-
tated modifications to raw material for-
mulations as well as equipment needed
to appiy and cure surface finishes.
By phasing in low VOC, water-based
formulations in conjunction with high-
volume low-pressure spray systems, an
ultraviolet curing system and proce-
dural modifications, Dinaire was able
to show reductions in the quantities of
hazardous waste as well as the overall
loadings of volatile organic compounds
released as hazardous air pollutants.
The reductions in air emission load-
ings negated the need for costly im-
provements in air emission control
equipment.
The Project Summary was developed
by the National Risk Management Re-
search Laboratory's Sustainable Tech-
nology Division, Cincinnati, OH to an-
nounce the key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
introduction
The process of finishing wood house-
hold furniture generally employs a num-
ber of operations, such as; glue sizing or
bleaching, cleaning/stripping, coating, dry-
ing, sanding, rubbing/buffing, equipment
cleaning and repair touch-up. These op-
erations will provide household furniture
with a pleasing appearance, a feeling of
smoothness and the protection of the
wood.
The finishing process typically yields:
• volatile organic compound (VOC)
emissions, including hazardous air
pollutants such as xylene and tolu-
ene
• liquid waste comprising of spent
stains, wash coats, fillers, various
sealers, discarded solvent and waste-
water generated from paint overspray
abatement systems
• solid wastes including overspray sol-
ids, solvent-laden residues, rags and
wood dust and scrap
The Dinaire Corporation is a manufac-
turer of wood furniture products, primarily
dinette sets. In an effort to minimize vola-
tile organic compound emissions as well
as hazardous waste, the company under-
took a program to identify and test alter-
native low-VOC waterborne finishing for-
mulations that would be economically ad-
vantageous in terms of minimizing expen-
ditures associated with the proper man-
agement of hazardous waste and the con-
trol of hazardous air pollutants.
Printed on Recycled Paper
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Taking into account the variable prod-
uct line and quality specifications, Dinaire
was challenged in its quest to identify and
implement alternative stains and coating
formulations containing reduced loadings
of volatile organic compounds character-
ized as hazardous air pollutants. The
company's operations complicated the
evaluations since two facilities were in-
volved in the manufacturing operations and
ihe equipment needed to apply the sur-
face finishes was not uniform at each fa-
cility. Quality issues did pose some barri-
ers to implementing, on a company-wide
scale, alternative low VOC, waterborne
coatings.
Low-VOC, waterborne sealants and
coatings were identified for wood furni-
ture, however, the conversion dictated in-
vestments in new equipment for applying
the formulations and curing the finished
products. The purpose of this project was
to analyze and document the applicability,
adequacy and advantages of finishing the
surfaces of wood furniture with low-VOC,
waterborne coatings. The analysis factor
in the findings, observations and recom-
mendations of the Pollution Prevention Op-
portunity Assessments published by Sci-
ence Applications International Corpora-
tion under EPA contract 68D0068, Pollu-
tion Prevention Initiative within the Great
Lakes Basin. The technical and economic
analysis also summarized some of the
findings of Dinaire's alternative formula-
tion evaluations.
This project was completed under the
terms of the Erie County WRITE Program
as a joint effort by Dinaire Corporation
located in Buffalo, NY; Erie County De-
partment of Environment and Planning,
Buffalo, NY, Recra Environmental, Inc.,
Amherst, New York; and the USEPA Of-
fice of Research and Development, Cin-
cinnati, OH.
Procedure
The Dinaire Corporation employs a sys-
tematic approach to manufacturing and
assembling wood furniture at its two facili-
ties located at Gruner Rd. and Ohio St.
The Gruner Rd. facility manufacturers table
tops, whereas the Ohio St. facility manu-
facturers chairs. The surface finishes on
the tables and chairs must conform to
required quality specifications, including
color.
Wood used in the manufacture of
Dinaire's products is cut into desired
shapes and sizes either by automatic ma-
chinery or manually with hand held power
tools. To produce wood materials of the
desired size and physical properties, lami-
nated wood is designed and produced at
Dinaire's facilities. The laminates are made
by taking strips of wood and gluing them
together. The adhesive bonding of the
laminated wood is cured at room tem-
perature yielding emissions comprising of
fumes from the glue and dust particulates
from the wood cutting operations.
The goals established by the Gruner
Rd. facility dealt with the identification of
low-VOC, waterborne coats for table tops
that would assist Dinaire in complying with
federal and state regulations governing
hazardous air pollutants emitted from wood
furniture operations. To achieve this goal,
the company defined the following equip-
ment specifications:
• Venjakob double head spray system
• Denibber-180 grit
• Venjakob surface cleaner
• Venjakob dual eight-gun carousel
spray machine equipped with 1.8
Kremlin air-assisted, airless spray gun
• Venjakob triple head, brush wiping
machine
• the Superfici dual 200-watt lamp ul-
traviolet (UV) modular curing unit
During the course of Dinaire's evalua-
tions, table tops were finished using the
Venjakob automatic spray equipment.
This equipment utilizes high-volume,
low-pressure spray guns. All of the table
tops are UV cured. In their assessment of
equipment modifications, Dinaire was able
to confirm commercial applications for UV
cured coatings on wood substrates. The
expanded use of UV curing was accom-
plished as a result of technological ad-
vances involving the development of
high- molecular weight, low-viscosity res-
ins.
The goals established by the Ohio St.
facility dealt with the identification and use
of a low-VOC, waterborne self-sealing top-
coat for the final coat and a low-VOC,
waterborne self-sealing topcoat for the sec-
ond coat of sealer. To'"achieve this goal,
the following equipment specifications were
identified.
• Accuspray HVLP Stain Guns #10 air
cap, #51 tip
• Enviro-Sealer Guns, Binks BBR
HVLP, #95-P air cap, #91, top 12 oz.
fluid delivery (45 sec.), 8 to 10 Ibs.
atomizing air, 9/16( minimum air hose,
2.5 wet mil thickness
• Accuspray HVLP waterborne lacquer
gun
• Devilbiss JGA 501 spray gun and
Binks BBR HVLP 95-P air cap, #94
tip for acrylic basecoat.
Results and Discussions
The evaluations that were undertaken
by Dinaire took into account a number of
environmental as well as economic and
productivity interests. In comparison to fin-
ishing processes employing solvent-based
formulations, Dinaire was able to show
a number of advantages to low-VOC,
waterborne formulations as long as qual-
ity specifications were adequately ad-
dressed. Based on the diverse operating
requirements, the company's evaluations
generated positive results summarized
herein.
Procedural and Equipment
Modifications
With the alternatives that were speci-
fied and tested, the table top operations
utilize a low-VOC, waterbased finish that
is UV cured. These operations also utilize
a solventbased, high-solids formulation that
is utilized as a top coat. The equipment
supplied by Venjakob applies coatings to
exact wet mil thickness (2.5-3.0). Any
overspray is recovered and reused as a
sealant. Between each application step,
table tops are UV cured.
In selecting UV-curing equipment,
Dinaire had to weigh the following factors:
• The process does not lend itself well
to simple hand-spray applications; as
such the UV equipment necessitates
investments in automated systems.
• The selected UV system requires "line
of sight" radiation; as such three-di-
mensional pieces will be difficult to
finish and applications by design will
generally involve flat-top components.
• Since most wood finishing is done for
aesthetic and design functions, fin-
ishing adjustments may have to be
made often to address changes in
custom specifications.
• The cost of the UV processor is com-
paratively high, however; investments
appear justified based on predefined
improvements in productivity.
• Extra care must be used when utiliz-
ing UV to ensure workplace safety as
a result of ozone formation. Constant
ventilation will be required to remove
the ozone and heat formed, and main-
tain the ideal operating temperatures
on the terminals, the neck and the
radiation surface.
• While the dry film thickness applied
with high-solids UV-cured coatings
does improve the utilization of top
coatings, improvements in transfer
application efficiency must be consid-
ered.
• Unlike most other industrial finishing
applications, wood finishes almost al-
ways require a multi-step system ap-
plied over a natural variable substrate.
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As such variable colors, glosses and
open-pore finishes may be difficult to
achieve with a UV system.
• The UV-curable coatings are not com-
patible with oil-based stains, such as
linseed oil. As such, a UV coating
would prevent complete curing.
• The conversion to UV-curable coat-
ings would not eliminate the use of
formulations with minimal solvent con-
tent. The formulations applied to the
table tops would still need to be prop-
erly managed.
The company's investment in the UV-
curing system factored in the following
advantages:
• High solid coatings formulations can
be effectively applied with variable
product specifications, reducing the
VOC loadings of the applied coat-
ings.
• Because of the high-solids content
of coatings, the company can
achieve high-film thicknesses with
significantly fewer coats and pro-
cess steps that are comparatively
attained with low-solids, conven-
tional coatings.
• Because the polymer is completely
cross-linked, the film's properties, in
terms of surface scratch resistance
and chemical resistance, are as high
or higher than films that have been
chemically cross-linked with external
catalysts.
• UV coatings generally cure within as
little as one to two seconds of expo-
sure to UV light yielding the benefit of
high production throughput as a re-
sult of the fast cure cycle.
• The extremely fast cure rates allow
for short ovens and conveyor sys-
tems; as such the facility does not
have to allocate valuaBfe pfaht "space
for coatings to cure in storage.
• Although a detailed energy conserva-
tion analysis had not been completed,
the company noted that the UV sys-
tem consumes less energy than gas-
fired curing ovens.
The installation of HVLP spray guns
improved the transfer efficiencies of
high-solids, water based formulations re-
ducing the wet film thickness for ulti-
mate coating.
In addition to reducing overspray emis-
sions, the improvements in transfer effi-
ciency have resulted in as much as a
50% reduction in the use of coating mate-
rials. To optimize the benefits of HVLP
spray equipment, the company continues
to investigate productivity gains attributed
to improvements in transfer efficiency. For
example, Dinaire is able to stain 12 chairs
with each gallon of stain using automated
HVLP spray guns, whereas 5-7 chairs
were stained with each gallon of stain
prior to the transfer efficiency improve-
ments.
As the facility has converted to high-
volume, low-pressure HVLP spray
guns, procedural changes and up-
grades have been made with the chair
finishing operations resulting in a re-
duction in the number of solvent based
coatings, as well as fugitive air emis-
sions from the spray booths. With em-
ployee training, excessive overspray has
also been minimized. In addition, the con-
sumption of solvents in the various formu-
lations has been reduced.
"Prior to implementing'a spray system,
the compan/s operations involved dip-
ping and hand-wiping coatings. This
change reduced the generation of waste
rags containing solvents, thus reducing
employee exposure to fumes while allow-
ing for higher production rates.
Quality Issues
Quality issues did pose some major bar-
riers to implementing an alternative finish-
ing system utilizing a low-VOC water-borne
formulation. During the evaluation phase,
the company documented problems, such
as raising of wood grains, yellowing of
stains after prolinged sunlight, inconsis-
tencies in stain quality, and quantities of
select formulations contained unaccept-
able concentrations of formaldehyde.
These problems were eventually dealt
with; however, the company ultimately had
to change suppliers and impose proce-
dural modifications for operators and in-
ventory managment to ensure adherence
to plant quality controls.
Environmental ,
The changes implemented by the com-
pany resulted in a number of environmen-
tal benefits. These improvements assisted
the company in their efforts to minimize
capital investments dictated by regulatory
standards governing the control of haz-
ardous air pollutants from the wood furni-
ture finishing operations.
The combined changes in operations
and formulations showed:
• 80-90% reduction in the costs associ-
ated with managing hazardous waste
• significant reductions in the VOC con-
tent of materials used as sealants
and topcoats
• reduction in waste overspray attrib-
uted to both the use of low-VOC,
waterborne formulations and improve-
ments in transfer efficiency attain-
able with HVLP spray applications
of high-solids coatings
• reduction in energy consumed with
UV-cured formulations
In comparison to the old operations,
reliant on low-solid content solvent-based
coatings, the topcoat overspray can be
recovered and reused as sealant. The
company is attempting to recover stain
overspray; however, reuse opportunities
are limited due to inconsistencies in the
recovered stain quality.
During the company's period of evalu-
ation, the operations were able to phase
in low-VOC waterborne stains and high-
solids coatings. These new formulations
assisted the company in reducing the
loadings of volatile organic compounds
emitted as air emissions. Operations can
yield a finished product in 2 to 3 steps
ensuring 2.5 to S.Omil finish at each appli-
cation, in comparison to the old opera-
tions which required as many as 4 to 5
procedural steps resulting in 1.4 to 2.1 mil
finish.
A number of the modifications selected
by the company can be categorized as
source control techniques, which contrib-
ute to the reduction in the generated quan-
tities of hazardous waste. During the evalu-
ation period, the quantities of ignitable
waste (D001) were reduced by greater
than 95%.
Economic
The fixed cost for the project including
the purchase and installation of the HVLP
guns and Superfici UV curing unit was
calculated to be $50,740. Annual opera-
tion and maintenance costs were assumed
to be $1,000 for the economic analysis
supplementing this project.
The Net Present Value (NPV) for the
project was determined by factoring in the
equipment purchase NPV, tax savings on
depreciation NPV, and savings on vari-
able costs NPV. Since the substitution of
low-VOC coatings for solvent coatings was
only partially implemented by Dinaire, as-
sumptions on the economic impact from a
complete substitution had to be made.
Based on these assumptions, the project
provided a positive net present value and
a payback period of 2.68 years. Once
fully implemented, the low-VOC coating
alternatives will improve the overall eco-
nomics of the project.
Some of miscellaneous savings attrib-
uted to the changes:
• average cost per gallon of low-VOC
stains approximately 5.5% lower than
the cost per gallon of solvent stain
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• total cost of disposing of hazardous
waste generated by the Ohio St. fa-
cility reduced from $17,925 in 1990
to $765 in 1994
• total cost of disposing of hazardous
waste generated at Gruner Rd. re-
duced from $15,785 in 1990, to $8,050
in 1994
Conclusion
The decision by Dinaire Corporation to
phase in lowVOC water based stains and
high-solid content topcoats has provided
a number of benefits justifying ongoing
investment in the company's strategy to
minimize reliance on all solvent-based
stains and topcoats associated with wood
furniture finishing operations.
Despite various quality issues, Dinaire
was able to achieve customer specifica-
tions; however, inventory management,
proper equipment controls, and operator
training were all important elements to
sustaining the changes.
Investments in a modular ultraviolet (UV)
curing system resulted in significant gains
in productivity. The fast curing cycle trans-
lates into greater product throughput and
control over product quality.
The improvements in spray transfer
efficiency as well as the conversion to
high-solids coatings resulted in better
utilization of resources, including costly
finishes, energy, and labor. With HVLP
spray guns, the stain utilization was im-
proved 40-70%, significantly reducing air
emissions attributed to overspray and
solvent use.
In addition to improving productivity and
resource utilization, the investments in the
new finishing operations helped Dinaire
comply with air regulations and, in doing
so, avoided capital-intensive air abatement
control equipment.
By reducing exposure to solvent-laden
stains and topcoats, work place safety
and environment was improved. The risks
posed by the company's reliance on sol-
vent based formulations have been mini-
mized to a level that can be better con-
trolled. The reduced reliance on hazard-
ous air pollutants has also minimized dis-
carded oversprays posing environmental
compliance issues.
In terms of positive economic impact,
the changes provided a good net present
value and a payback that has the poten-
tial to improve with full implementation of
the low VOC strategy. With implementa-
tion of these changes, economic savings
were recognized in terms of better re-
source utilization, including, energy, labor
and raw materials, reduced disposal
charges for hazardous waste, reduced
charges for stains and coatings used in
operations, reduced costs for controlling
overspray, and reduced costs for control-
ling emissions of hazardous air pollutants
in relation to applicable regulations.
The full report was submitted in fulfillment of CR-816762 Erie County Department
of Environment and Planning under the sponsorship of the U.S. EPA. PaulKranz
is with Erie County Department of Environment and Planning, Buffalo, NY 14202.
James E. Stadelmaierand Thomas F. Stanczykis with Recra Environmental, Inc.,
Amherst, NY 14228. Paul R
Paul Randall is the EPA Project Officer (see below).
The complete report, entitled "Utilizing Low Volatile Organic Content Exterior
Coatings for Wood Furniture," (Order No. PB98-100415; Cost: $21.50, subjectto
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:
Sustainable Technology Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use $300
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EPA/600/SR-97/083
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