United States National Risk Management

Environmental Protection Research Laboratory

Agency Cincinnati, OH 45268

Project Summary

Research and Development EPA/600/SR-97/083 September 1997

Abstract

This report provides an evaluation of

commercially viable source reduction

techniques implemented by a manufacturer of wood chairs, bar stools and

settees in various styles ranging from

classic American to European contemporary.

As federal EPA regulations became

more stringent for volatile organic compound (VOC) emissions in the woodworking industry, the Dinaire Corporation began testing alternative formulations employed as waterborne finishes,

sealers and topcoats. In an effort to

minimize costly investments in air emission control equipment, the company

examined and implemented a number

of source reduction techniques that dictated modifications to raw material formulations as well as equipment needed

to apply and cure surface finishes.

By phasing in low VOC, water-based

formulations in conjunction with highvolume low-pressure spray systems, an

ultraviolet curing system and procedural 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 loadings negated the need for costly improvements in air emission control

equipment.

The Project Summary was developed

by the National Risk Management Research Laboratory’s Sustainable Technology Division, Cincinnati, OH to announce the key findings of the research

project that is fully documented in a

Utilizing Low Volatile Organic

Content Exterior Coatings for

Wood Furniture

Paul B. Kranz, James E. Stadelmaier and Thomas F. Stanczyk

separate report of the same title (see

Project Report ordering information at

back).

Introduction

The process of finishing wood household furniture generally employs a number of operations, such as; glue sizing or

bleaching, cleaning/stripping, coating, drying, sanding, rubbing/buffing, equipment

cleaning and repair touch-up. These operations 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 toluene

• liquid waste comprising of spent

stains, wash coats, fillers, various

sealers, discarded solvent and wastewater generated from paint overspray

abatement systems

• solid wastes including overspray solids, solvent-laden residues, rags and

wood dust and scrap

The Dinaire Corporation is a manufacturer of wood furniture products, primarily

dinette sets. In an effort to minimize volatile organic compound emissions as well

as hazardous waste, the company undertook a program to identify and test alternative low-VOC waterborne finishing formulations that would be economically advantageous in terms of minimizing expenditures associated with the proper management of hazardous waste and the control of hazardous air pollutants.
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Taking into account the variable product 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 characterized as hazardous air pollutants. The

company’s operations complicated the

evaluations since two facilities were involved in the manufacturing operations and

the equipment needed to apply the surface finishes was not uniform at each facility. Quality issues did pose some barriers to implementing, on a company-wide

scale, alternative low VOC, waterborne

coatings.

Low-VOC, waterborne sealants and

coatings were identified for wood furniture, however, the conversion dictated investments 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 recommendations of the Pollution Prevention Opportunity Assessments published by Science Applications International Corporation under EPA contract 68D0068, Pollution Prevention Initiative within the Great

Lakes Basin. The technical and economic

analysis also summarized some of the

findings of Dinaire’s alternative formulation 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 Department of Environment and Planning,

Buffalo, NY, Recra Environmental, Inc.,

Amherst, New York; and the USEPA Office of Research and Development, Cincinnati, OH.

Procedure

The Dinaire Corporation employs a systematic approach to manufacturing and

assembling wood furniture at its two facilities located at Gruner Rd. and Ohio St.

The Gruner Rd. facility manufacturers table

tops, whereas the Ohio St. facility manufacturers 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 machinery or manually with hand held power

tools. To produce wood materials of the

desired size and physical properties, laminated 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 temperature 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 equipment 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 ultraviolet (UV) modular curing unit

During the course of Dinaire’s evaluations, 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 accomplished as a result of technological advances involving the development of

high- molecular weight, low-viscosity resins.

The goals established by the Ohio St.

facility dealt with the identification and use

of a low-VOC, waterborne self-sealing topcoat for the final coat and a low-VOC,

waterborne self-sealing topcoat for the second 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 lbs.

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 finishing processes employing solvent-based

formulations, Dinaire was able to show

a number of advantages to low-VOC,

waterborne formulations as long as quality specifications were adequately addressed. Based on the diverse operating

requirements, the company’s evaluations

generated positive results summarized

herein.

Procedural and Equipment

Modifications

With the alternatives that were specified 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-dimensional 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, finishing adjustments may have to be

made often to address changes in

custom specifications.

• The cost of the UV processor is comparatively high, however; investments

appear justified based on predefined

improvements in productivity.

• Extra care must be used when utilizing UV to ensure workplace safety as

a result of ozone formation. Constant

ventilation will be required to remove

the ozone and heat formed, and maintain 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 considered.

• Unlike most other industrial finishing

applications, wood finishes almost always require a multi-step system applied 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 compatible with oil-based stains, such as

linseed oil. As such, a UV coating

would prevent complete curing.

• The conversion to UV-curable coatings would not eliminate the use of

formulations with minimal solvent content. The formulations applied to the

table tops would still need to be properly managed.

The company’s investment in the UVcuring 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 coatings.

• Because of the high-solids content

of coatings, the company can

achieve high-film thicknesses with

significantly fewer coats and process steps that are comparatively

attained with low-solids, conventional 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 exposure to UV light yielding the benefit of

high production throughput as a result of the fast cure cycle.

• The extremely fast cure rates allow

for short ovens and conveyor systems; as such the facility does not

have to allocate valuable plant space

for coatings to cure in storage.

• Although a detailed energy conservation analysis had not been completed,

the company noted that the UV system consumes less energy than gasfired curing ovens.

The installation of HVLP spray guns

improved the transfer efficiencies of

high-solids, water based formulations reducing the wet film thickness for ultimate coating.

In addition to reducing overspray emissions, the improvements in transfer efficiency have resulted in as much as a

50% reduction in the use of coating materials. 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 improvements.

As the facility has converted to highvolume, low-pressure HVLP spray

guns, procedural changes and upgrades have been made with the chair

finishing operations resulting in a reduction in the number of solvent based

coatings, as well as fugitive air emissions from the spray booths. With employee training, excessive overspray has

also been minimized. In addition, the consumption of solvents in the various formulations has been reduced.

Prior to implementing a spray system,

the company’s operations involved dipping and hand-wiping coatings. This

change reduced the generation of waste

rags containing solvents, thus reducing

employee exposure to fumes while allowing for higher production rates.

Quality Issues

Quality issues did pose some major barriers to implementing an alternative finishing 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, inconsistencies in stain quality, and quantities of

select formulations contained unacceptable concentrations of formaldehyde.

These problems were eventually dealt

with; however, the company ultimately had

to change suppliers and impose procedural modifications for operators and inventory managment to ensure adherence

to plant quality controls.

Environmental

The changes implemented by the company resulted in a number of environmental benefits. These improvements assisted

the company in their efforts to minimize

capital investments dictated by regulatory

standards governing the control of hazardous air pollutants from the wood furniture finishing operations.

The combined changes in operations

and formulations showed:

• 80-90% reduction in the costs associated with managing hazardous waste

• significant reductions in the VOC content of materials used as sealants

and topcoats

• reduction in waste overspray attributed to both the use of low-VOC,

waterborne formulations and improvements in transfer efficiency attainable 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 evaluation, the operations were able to phase

in low-VOC waterborne stains and highsolids 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 3.0mil finish at each application, in comparison to the old operations 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 contribute to the reduction in the generated quantities of hazardous waste. During the evaluation 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 operation 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 variable costs NPV. Since the substitution of

low-VOC coatings for solvent coatings was

only partially implemented by Dinaire, assumptions 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 economics of the project.

Some of miscellaneous savings attributed 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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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. Paul Kranz

is with Erie County Department of Environment and Planning, Buffalo, NY 14202.

James E. Stadelmaier and Thomas F. Stanczyk is 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, 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:

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

EPA/600/SR-97/083

Official Business

Penalty for Private Use $300

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35

• total cost of disposing of hazardous

waste generated by the Ohio St. facility reduced from $17,925 in 1990

to $765 in 1994

• total cost of disposing of hazardous

waste generated at Gruner Rd. reduced 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 specifications; 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 translates 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 improved 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 solvent based formulations have been minimized to a level that can be better controlled. The reduced reliance on hazardous air pollutants has also minimized discarded 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 potential to improve with full implementation of

the low VOC strategy. With implementation of these changes, economic savings

were recognized in terms of better resource 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 controlling emissions of hazardous air pollutants

in relation to applicable regulations.