&EPA
                          United States
                          Environmental Protection
                          Agency
                          Research and Development
                                    National Risk Management
                                    Research Laboratory
                                    Cincinnati, OH 45268
                                    EPA/600/S-95/024   September 1995
ENVIRONMENTAL
RESEARCH   BRIEF
                Pollution Prevention Assessment for a Manufacturer of
                                       Wooden Cabinets

                               Harry W. Edwards*, Michael F. Kostrzewa*,
                                        and Gwen P. Looby**
 Abstract
 The U.S. Environmental Protection Agency (EPA) has funded
 a pilot project to assist small and medium-size manufacturers
 who want to minimize their generation of waste but who lack
 the expertise to do so. In an effort to assist these manufactur-
 ers Waste Minimization Assessment Centers (WMACs) were
 established at  selected universities and  procedures were
 adapted from the EPA Waste Minimization Opportunity As-
 sessment Manual (EPA/625/7-88/003, July  1988). That docu-
 ment has been superseded by the Facility Pollution Prevention
 Guide (EPA/600/R-92/088, May 1992). The WMAC team at
 Colorado State University performed an assessment at a plant
 that manufactures wooden kitchen  and bathroom cabinets.
 Components purchased from vendors are prepared for produc-
 tion through cutting, sanding, and routing  operations. Stain,
 sealer, and top-coat are applied in separate spray booths. After
 the final coating, the components are dried and assembled.
 The assessment team's report, detailing findings and recom-
 mendations, indicated that paint sludge from the spray booth
 water curtains is generated in a large amount and that signifi-
 cant cost savings could be achieved by dewatering the sludge
 before it is shipped offsite for disposal and reusing the water.

 This Research Brief was developed by the principal investiga-
 tors and EPA's National Risk Management Research Labora-
 tory, Cincinnati,  OH, to  announce key findings of an ongoing
 research project that is fully documented in  a separate report
 of the same title available from University City Science Center.
* Colorado State University, Department of Mechanical Engineering
** University City Science Center, Philadelphia, PA.
                        Introduction
                        The amount of waste generated by industrial plants has be-
                        come an increasingly costly problem for manufacturers and an
                        additional stress  on the environment.  One solution to the
                        problem of waste generation is to reduce or eliminate the
                        waste at its source.

                        University City Science Center (Philadelphia, PA) has begun a
                        pilot project to assist small  and medium-size manufacturers
                        who want to minimize their generation of waste but who lack
                        the in-house expertise to do so.  Under agreement with EPA's
                        National Risk  Management Research Laboratory, the Science
                        Center has established three WMACs. This assessment was
                        done by engineering faculty and students  at Colorado State
                        University's (Fort Collins) WMAC. The assessment teams have
                        considerable direct experience with process operations in manu-
                        facturing plants and also have the knowledge and skills needed
                        to minimize waste generation.

                        The pollution prevention opportunity assessments are done for
                        small and medium-size manufacturers at no out-of-pocket cost
                        to the client. To qualify for the assessment, each client must
                        fall within Standard Industrial Classification  Code 20-39, have
                        gross annual sales not exceeding $75 million, employ no more
                        than 500 persons, and lack in-house expertise in pollution
                        prevention.

                        The potential benefits of the  pilot project include minimization
                        of the amount of waste  generated by  manufacturers,  and
                        reduction of waste treatment  and disposal costs for  participat-
                        ing plants. In  addition, the project  provides valuable experi-
                        ence for graduate and undergraduate students who participate
                        in the program, and a cleaner environment without more regu-
                        lations and higher costs for manufacturers.
                                                                              Printed on Recycled Paper

-------
Methodology of Assessments
The pollution prevention opportunity assessments require sev-
eral site visits to each client served. In general, the WMACs
follow the procedures outlined in the EPA Waste Minimization
Opportunity Assessment Manual (EPA/625/7-88/003, July 1988).
The WMAC staff locate the sources of waste in the plant and
Identify the current disposal  or treatment methods and their
associated  costs. They then  identify and analyze a variety of
ways to reduce or eliminate  the waste. Specific measures to
achieve that goal are recommended and the essential support-
ing technological  and economic information  is developed. Fi-
nally, a confidential report that details the WMAC's  findings
and recommendations (including cost savings, implementation
costs, and payback times) is prepared for each client.


Plant Background
This plant manufactures wooden kitchen and bathroom cabi-
nets. It operates 2,200 hr/yr to produce about 150,000 cabinets
annually.


 Manufacturing Process
 Most of the cabinet doors and components used in producing
 the cabinets are received  pre-cut from outside vendors. Other
 components are sent to a preparation area where they are cut,
 sanded, and edged. Components are then stored until needed
 on the painting line.

 Employees use a printout of the day's scheduled production to
 send the correct components to the painting area in the proper
 order and  quantity. First, the parts are sent by conveyor to a
 staining booth that uses  air-assisted  airless spray guns that
 rotate and coat the components  on one  side as they are
 passed through the booth. After exiting the booth the parts are
 flipped over and sent through a second staining booth where
 they are stained on the other side. Overspray is captured by a
 water curtain, and solvents are allowed to evaporate.

 Next the components travel to another spray booth for sealer
 application. The sealer booth uses air-assisted airless guns to
 spray one side of the components. Again, overspray is cap-
 tured by a  water curtain.  The parts then travel to  a final
 painting booth for top-coat application. Overspray is collected
 in the same manner as in the other booths.

 After the final coating, the components are dried in a large kiln
 and then sent to the assembly line. The parts are glued and
 stapled into finished cabinets, and drawers are assembled in a
 similar manner.  The face boards are added  as the cabinets
 move down the line. The cabinet doors are pre-hinged and
 then  fastened to the  cabinets. Assembled cabinets  are  in-
 spected and shipped.

 An abbreviated process flow diagram is shown in Figure 1.


  Existing Waste Management Practices
 This plant already has implemented the following techniques to
 manage and minimize its wastes.
  •  Soap is used instead of lacquer thinner for cleaning the steel
    conveyor bands on the painting lines. Prior to the change to
    soap cleaning, approximately one drum of lacquer thinner
    was used each day for cleaning the bands.

  •  Used wooden pallets are recycled offsite when possible.

Pollution Prevention Opportunities
The type of waste currently generated by the plant, the source
of the waste, the waste management method, the quantity of
the waste, and the annual waste management cost for each
waste stream identified are given in Table 1.

Table 2 shows the opportunities for pollution prevention that
the WMAC team recommended for the plant. The opportunity,
the type of waste, the possible waste reduction and associated
savings, and the implementation cost  along with the  simple
payback time are given in the table. The quantities of waste
currently generated by the plant and possible waste  reduction
depend on the  production level of the plant. All values should
be  considered in that context.

It should be noted that, in most cases, the economic savings of
the minimization  opportunities result from reductions  in  raw
material and costs associated with hazardous waste  treatment
and disposal.  Other savings not quantifiable by this study
include a wide variety of possible future costs related to chang-
ing emissions standards, liability, and employee health. It also
should be noted  that the savings given for each opportunity
reflect that pollution  prevention  opportunity alone and do not
reflect duplication of savings that would result when the oppor-
tunities are implemented in a package.


Additional Recommendations
 In  addition to the opportunities recommended and analyzed by
the WMAC team, two other measures were considered. These
 measures were not analyzed completely because  of insuffi-
 cient data, implementation difficulty, or a  projected  lengthy
 payback. Since one or more  of these approaches to pollution
 prevention may, however, increase in attractiveness with chang-
 ing conditions in  the plant, they were  brought to the plant's
 attention for future consideration.

    • Replace the water curtains in the paint booths with a dry filter
     bed for collection of overspray.

    • Install air-assisted airless fine finish paint guns and paint line
     heaters to reduce the amount of paint overspray generated.
 This research  brief summarizes a part of the work done under
 Cooperative Agreement No. CR-819557 by the University City
 Science Center under the sponsorship  of the U. S. Environ-
 mental Protection Agency. The EPA Project Officer was Emma
 Lou George.

-------
                       Pre-Cut Cabinet Doors
                       and Other Components
Preparation
- Cutting
•»
- Sanding
- Routing

1
Stain
Application
'
1
Sealer
Application
\
t
1 Top Coat
Application
\
r
Drying
1
r
Assembly
\

Inspection


	 ^—
                                                                                              Completed Cabinets
                                                                                                  to Customers
Figure 1. Abbreviated process flow diagram for wooden cabinet manufacturers.

-------
     . Summary of Current Waste Generation
Waste Generated
Paint sludge
Evaporated lacquer thinner
Evaporated paint solvents
Wasta lacquer thinner
Miscellaneous soKd waste
Source of Waste
Water curtain in sealer and top-coat
spray lines
Stain, sealer, and topcoat lines
Spray booths
Cleaning of equipment
Various operations
Waste Management Memoa
Shipped off site for disposal as
hazardous waste
Evaporates to plant air
Evaporate to plant air
Shipped offsite for disposal as
hazardous waste
Shipped offsite to municipal landfill
ueneraieo cu/y/
130,000
19,030
236,000
38,900
364,000

$101,000
10.0101
0
33,200r
23,600
11ncludes lost raw material value.
        Summary of Recommended Pollution Prevention Opportunities
                                                           Annual Waste Reduction
Pollution Prevention Opportunity
                                      Waste Reduced     Quantity (Ib/yr)
                                                                          Percent
                                                  Net Annual  Implementation     Simple
                                                   Savings         Cost      Payback (yr)
Install a purification system to reduce the
water content of the paint sludge gener-
ated through treatment of the wastewater
from the water curtains in the sealer and
topcoat spray booths. Implementation
of this opportunity will lead to a reduced
vokme of hazardous waste shipped
otfsite,

Capture the lacquer thinner used for line
cleaning In the paint spray booths and
reuse H. Current practice is to use the
thinner once and spray it into the water
curtain from which it evaporates.

Segregate waste cardboard from other
solid waste, bale it, and sell it to a card-
board recyeter.  The resulting reduction
in volume of solid waste will lead to
lower landfill costs. No waste reduction
will result from this opportunity.
Paint sludge
                                                           47,000
                                                                            36
                                                                                         $45,070
                                                                 $9,600
Evaporated lacquer
thinner
Miscellaneous
solid waste
9,520
                                       50
                              3,880
                                                    5,670
                                                                  500
                                           4,600
                                                                                0.1
                                                                                0.8
 United States
 Environmental Protection Agency
 National Risk Management Research Laboratory (G-72)
 Cincinnati, OH 45268

 Official Business
 Penalty for Private Use
 $300
                                                                      BULK RATE
                                                                POSTAGE & FEES PAID
                                                                           EPA
                                                                    PERMIT No. G-35
 EPAJBOO/S-95/024

-------