vvEPA
United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/012 August 1995
ENVIRONMENTAL
RESEARCH BRIEF
Pollution Prevention Assessment for a Manufacturer of Automotive
Lighting Equipment and Accessories
Marvin Fleischman*, Brian Couch*, Alan Handmaker*,
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. Waste Minimization Assessment Cen-
ters (WMACs) were established at selected universities and
procedures were adapted from the EPA Waste Minimization
Opportunity Assessment Manual (EPA/625/7-88/003, July 1988).
That document has been superseded by the Facility Pollution
Prevention Guide (EPA/600/R-92/088, May 1992). The WMAC
team at the University of Louisville performed an assessment
at a plant that manufactures automotive lighting equipment and
accessories. Plastic, metal, glass, and composite-component
products are assembled by the plant. Raw materials include
coils of metal, paint, solvents, oils, coolants, light bulbs, glass
and mirrors, plastic resins, wiring, and wire terminals. Plant
operations include plastic injection molding, metal pressing and
punching, painting, and assembly. The team's report, detailing
findings and recommendations, indicated that a significant
amount of waste is generated through the stripping of paint
hooks and parts and that the greatest cost savings could be
achieved by installing a plastic media blasting paint stripper.
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.
Introduction
University of Louisville, Department of Chemical Engineering
** University City Science Center, Philadelphia, PA
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
Risk Reduction Engineering Laboratory, the Science Center
has established three WMACs. This assessment was done by
engineering faculty and students at the University of Louisville's
WMAC. The assessment teams have considerable direct ex-
perience with process operations in manufacturing 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 re-
duction of waste treatment and disposal costs for participating
plants. In addition, the project provides valuable experience for
graduate and undergraduate students who participate in the
program, and a cleaner environment without more regulations
and higher costs for manufacturers.
u5§ 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 produces automotive products, including lamps, mir-
rors, flashers and switches, wiring systems, and emergency
warning equipment.
Manufacturing Process
Numerous plastic, metal, glass, and composite-component prod-
ucts are assembled by the plant. Operations include plastic
injection molding, metal pressing and punching, painting, and
assembly. Raw materials used by the plant include coils of
metal, paint, solvents, oils, coolants, light bulbs, glass and
mirrors, plastic resins, wiring, and wire terminals. The various
production operations used by the plant are described in the
following sections.
Metal Working Operations
In the metal working area, several single-station and two multi-
station metal presses perform blanking, drawing, bending,
punching, or breaking of metal sheets or tub ng. A small amount
of tapping of pressed and cast metals is also done. Drawing
oils, cutting lubricant, and rust-proofing compounds may be
applied automatically or manually prior to metal working. As a
result of the necessary lubrication, parts must be washed
before they are painted, used in assembly, or packaged and
sold.
Wire Harness Fabrication
Wiring is cut to appropriate lengths and the plastic insulation
surrounding the wires is stripped off at each end of the wiring
prior to terminating or molding. Workers attach terminals to the
wires for assembly. In the shuttle molding process, some of the
wires are bundled together and the terminals are placed in a
mold into which PVC is injected. A junction block that provides
sealed, plug-in connection ports for other wires is thus formed.
Plastic Injection Molding
Various thermoplastics, including nylons, acrylics, polycarbon-
ates, polypropylenes, and acrylic-butadiene-styrene, are pro-
cessed according to customer specifications. Plastic pellets are
transferred pneumatically from storage boxes to heated driers
above the injection-molding presses. The pellets are melted in
a screw injection molder and injected intc the mold. Sprues
and runners from the finished parts are reground and returned
to the hopper above the press, when possible.
Metal Painting
Several different solvent-based paints are used for painting
metal parts. In general, the painting campaigns for metal parts
last between a half-hour and several days.
Metal parts that are to be painted are first placed on an
overhead conveying system that carries them through a six-
stage pretreatment system to remove oils from metal working
and to undergo surface preparation by chemical treatment. The
six stages are an aqueous alkaline cleaner, a rinse, an iron
phosphate-phosphoric acid chemical conversion coating for
rust prevention and paint adhesion enhancement, another rinse,
a chromating seal, and a final rinse.
After the six-stage treatment, the parts pass through a com-
pressed air blow-off and air-knife, and then enter a drying
oven. The parts are allowed to cool and then are sent to the
first paint booth and then through a second booth where the
other side is painted. The majority of the paint overspray in
these two booths is collected in a waterfall. The parts are
allowed to air dry for a short time and then enter a hand-spray
touch-up booth.
The painted metal parts then go through the direct-fired oven,
are allowed to air cool, and are removed from the hangers.
Parts are placed in boxes and stored for later use in assembly
operations. Some painted parts are put in final packaging for
shipment from the warehouse.
Plastic Painting
The plastic parts painting operation consists of five separate
paint lines which are usually cleaned out daily.
Solvent-based acrylics, lacquers, and two-component urethanes
and epoxies are used in plastic painting. Preparation of plastic
parts for painting is not needed because the parts are clean
when received for painting.
Assembly
A variety of assembly operations, including fastening, crimping,
terminating, boring, drilling, reaming, and stapling, are per-
formed in the assembly lines for a variety of products. Assem-
bly operations may be automated or manual.
In a typical assembly operation, parts are unpacked from
various storage containers and placed on a conveyor belt.
Smaller parts are attached to the main housing as the part
moves down the line. Assembly may consist of attaching a wire
harness or other subassembly to the main housing. Bonding is
done using various techniques such as hot melting, sonic
welding, hot-knife welding, and mechanical bonding. Lamps
are soldered to wires or conductors. Brazing is used for bond-
ing terminals to a lamp in a specific product assembly line.
Next, the assembly is tested by plugging it into an electric
outlet prior to final bonding and sealing. The part then under-
goes final bonding with glue, is sealed with grease, and is
submerged in water for testing. In the mirror assembly opera-
-------
tions, glass is placed inside a painted rubber ring and is
crimped using a press or glued into housings.
An abbreviated process flow diagram depicting the manufac-
ture of automotive lighting equipment is shown in Figure 1.
Existing Waste Management Practices
This plant already has taken the following steps to manage and
minimize its wastes:
• Some waste cardboard is baled and recycled.
• Scrap metal and plastic are collected and sold.
• A portion of the rejected plastic parts is reused.
• Shipping containers and packaging is reused, when pos-
sible.
• Unwanted pallets and skids are given away to a shelter
workhouse for rebuilding.
Plant personnel are currently evaluating the following options
for managing and minimizing plant wastes:
• Alternatives to caustic and methylerie chloride paint strip-
ping, such as plastic media blasting are being considered.
• The plant is considering participating in a local pallet and
packaging waste exchange.
• A central chiller is to be installed to replace portable chillers
that tend to generate waste oil emulsions from ethylene
glycol losses from connection and disconnection.
• The purchase of a softwood denailing/chipping machine is
being considered to provide materials from waste pallets
which may be useful elsewhere.
• The use of a laundry service forthe cleaning and subsequent
reuse of rags is being considered.
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 payback
Incoming
Materials
Finished Parts to
Packaging and Shipping
Figure 1. Abbreviated process flow diagram for manufacture of automotive lighting equipment.
-------
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 the economic savings of the opportu-
nity, in most cases, results from the reduction in raw material
and costs associated with waste treatment and disposal. Other
savings not quantifiable by this study include a wide variety of
possible future costs related to changing emissions standards,
liability, and employee health. It also should be noted that the
savings given for each opportunity reflect that pollution preven-
tion opportunity only and do not reflect duplication of savings
that would result when the opportunities are implemented in a
package.
Additional Recommendations
In addition to the opportunities recommended and analyzed by
the WMAC team, several additional measures were consid-
ered. These measures were not analyzec completely because
of insufficient data, minimal savings, implementation difficulty,
or a projected lengthy payback. Since one or more of these
approaches to pollution prevention may, however, increase in
attractiveness with changing conditions in the plant, they were
brought to the plant's attention for future consideration.
• Recover solvent from the cleaning of paint lines and guns
instead of spraying it into the water curtains and emitting it to
the atmosphere. Reuse the solvent if it is sufficiently clean or
dispose of the waste through the waste fuels program. This
opportunity would lead to reduced discharges to the POTW
and reduced fugitive emissions, stack emissions, and worker
exposure.
• Instead of landf illing waste pallets, grind the waste into wood
chips and mulch in cooperation with the local recycling
roundtable.
• Use dedicated dispensers for oil changeouts and dedicated
buckets for leaks from oil drums in the metal working area
instead of using unsegregated waste oil drums and buckets.
• Reuse packaging in cooperation with customers and suppli-
ers to reduce the amount of packaging waste generated.
• Minimize the number of waste paint drums that must be
disposed of by purchasing paint in 330-gallon returnable
totes.
• Reduce evaporative losses from metal part painting pretreat-
ment tanks by keeping lids closed.
• Use permanent washable filters in the paint booths instead of
disposable filters.
• Replace the current painting system for metal parts with one
that would generate less solvent-containing waste and fewer
air emissions. (The plant is in the process of implementing
this change.) Consider replacing the painting system for
plastic parts also.
• Investigate further opportunities for waste recycling.
• Replace hot caustic and methylene chloride with a nonhaz-
ardous solvent for stripping.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-814903 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.
-------
te Generation
<0
i
c
0)
t
Table 1. Summary of Cu
0)
8
1
c
c
'*
3
"TO
3
C
C
»nf Method
Waste Manage me
Source of Waste
Waste Generated
„
^0
o
CO
*-
1
0>
TO
TO
5
^0
^T
?5
w
1
o
%
K."
CM
<*
o
o
o
8"
-S
TO
*
!
P
Segregated; sold i
Metal working operations, rejected parts
and customer returns, other operations
Scrap metal
o
K
t-T
O
CM"
-33
c
-3
C
9>
i^
0)
o
o
o
o"
CM
-33
Ground; sold to re
Bonding operations
In'
& TO
Plastic waste (contaminal
and rejected composite p
^
^
§
TO
O
8
-
S
jo
o
"S
-3:
1
c
cycler or la,
Ground; sold to re
Customer returns
Plastic waste
o
R
o
CO
Landfilled offsite
in
to
0)
TO .
-c -e*
Stripping and terminating operations, wire
operations, injection molding, and assemb
Plastic waste (insulation,
cable scrap, foam)
o
CM
^
»~
o
S
£
,^
1
be used as
Shipped offsite to
c
E
Q-
Paint line and paint gun cleaning, paint eq>
and fixture cleaning, paint stripping
Solvent waste
o
o
o
K"
cE
Evaporates to atm
Fugitive and stack emissions
Evaporated solvent
o
§
0"
CM
o
R!
co
•recovery
Shipped offsite for
Paint stripping and parts washing
Solvent waste
0
CO
NT
CO
CM
K
10
.
3
be used as
Shipped offsite to
Metal and plastics paint spray booths
c
Paint waste (obsolete pa/'
overspray, plastic sheet,
paint solids, filters)
o
^r
•>—
O
Oi
co
-
Incinerated offsite
Plastics paint spray booth
Paint waste (water/paint)
-------
-2 *-
(o "5
rn O
^
H §
c C
^ 1
CO
5
^ io
t\J ^_
O Q
"co co
c *
o
^S
§
c
£
CO
s
(/)
1
•33
!
Q
8
o
CO
Table 1. (continued)
Waste Generated
o o o o o
10 o CM to co
CM o K
$ *"" S2
o o o 10 o
O O M' IV Co
o CM TJ- CD »-
>— CM ^~-" CM"
R!
'C
-S
"co
o
CX
"6
•S
0> w -~
.£ co ^
•^ S 5
o to w
^3 CO
CO -S T3
^ C CD
•S N §
^ *» CO
q) -C _Q
§- ^ CO ^ CO
S .« | .§ |
s ^ 1 g 'g
^ ° x> ° -o
c co S CD -5
rco -C co "^ co
tc CO ^-J Co ^j
Oj
1 .e? .1 g
§. | 2 -g
1 ! I f !
a j= ^. .5 Q-
.§ 1- ^ 5- §
^ CO CO CO .O
•S ! 8 3 §
•X § 't -J >-
Paint waste (paint overstocks)
Paint waste (stripper solids)
Grease
Ink waste
Miscellaneous solid waste
6>
a
CO
CD
•^c.
-5
0
O
CO
-Q
c
CO
.0 C
m '*=
•S CD
t ^c
•o CD
,- ^
>~ CO
o ^
— - To
(fl 3
*" s
-c 5
U ^v
W)
m
o
o
CO
1 i
ct; -g
§ .2
E o
co Q.
w fi-
m vj
i c
1 1
CD CO
o_ ^->
(/) Cl.
(/) c:
'c; .0
Q> 3
o "o
0 Q.
•>- cu
Includes waste disposal costs.
It is estimated that an additional $1
Table 2. Summary of Recommendi
1~^
co s —
|1
c/3 sL
cx-
..§
a
is
1°
f
"co
3 W
£ ^^
^'S
CD CO
0 0 ° S
0
co 10 S
o" *\ ° CM
'r~' ^J" O
^~ a -^. o> 01 CM
000° ° o
CM o c-, o ° o \j-
CD o ^ CM ^ ^ o
T— Co C\J Q
T- >-.
.« .§ -, .§ a
^ !^ "C3 ^ 5
00^0 0
CO CO c. CD CD
O. ci. »~ co ex ex
.ci. .Q c: ex .9- .5 (n
* "^ 5 -^ £ "§ "5 ^
!i!iii il Is !
co-ScoSUjQ. co£ co5 ^
ili-i^ „ . i=, i ilfg ill
^-S!Si§ 1. i.^l fl-sts HI
lilt
III! lit!
litii ill!
Ititili Mtlillii Hill 11
-------
Q--5
t 5
3 £
it
2*
0) CO
o
m
I o 5-9J? o
i -O s Q. s w
-------
United States
Environmental Protection Agency
Technology Transfer and Support Division (CERI)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-95/012
------- |