United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/007 July 1995
&EPA ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for
Rotogravure Printing Cylinder Manufacturing
Marvin Fleischman*, LaTres Jarrett*,
Clay Hansen*, 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ment has been superseded by the Facility Pollution Prevention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 the
University of Louisville performed an assessment at a plant
that manufactures rotogravure printing cylinders from new stock
and customer returns. Used cylinders and new cylinders un-
dergo surface preparation, plating, and image transfer opera-
tions. The team's report, detailing findings and
recommendations, indicated that process wastewater and waste-
water treatment sludge are generated in large quantities and
that significant cost savings could be realized by recovering
plating chemicals from wastewater.
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
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 prob-
* University of Louisville, Department of Chemical Engineering
"University City Science Center, Philadelphia, PA
lem 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 the University of
Louisville's WMAC. The assessment teams have considerable
direct experience 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.
Methodology of Assessments
The pollution prevention assessments require several site vis-
its to each client served. In general, the WMACs follow the
procedures outlined in the EPA Waste Minimization Opportu-
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nity 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
The plant manufactures rotogravure printing cylinders from
new stock and customer returns. It operates approximately
7,500 hr/yrto produce over 5,000 engraved cylinders annually.
Manufacturing Process
Chrome-plated engraved copper-plated steel cylinders for roto-
gravure printing are produced by the plant. The principal raw
materials used are new and used steel cylinders and various
chemicals for stripping and plating. The processes involved are
cylinder preparation by nickel and copper plating, image pro-
cessing, engraving or etching, and chrome plating.
Used Cylinders
Used cylinders requiring only re-chroming (approximately 10%
of the returned cylinders) are stripped of their existing chrome
layer using an acid stripping-solution. Then they are top-etched
with ferric chloride and/or re-chromed.
Used cylinders that are returned for a new design or are
otherwise uncorrectable are lathed to remove both the chrome
and the copper layers and are designated as "cutoffs". The
cutoffs are then processed in the same manner as new cylin-
ders.
New cylinders
Rejected
cylinders
New Cylinders
New steel bases and cutoffs are first degreased in a caustic
bath and rinsed. Following cleaning, the cylinders are nickel
plated and then copper plated. (Initial nickel plating enhances
the bond between copper and steel during subsequent copper
plating). After copper plating, the cylinders are polished using a
water-cooled grinding wheel.
While the cylinders are being plated, customer provided art-
work is prepared for image processing in another area. Black
and white artwork is photographed and then scanned electroni-
cally. Negatives are produced for each color to be printed.
Further processing is determined by the manner in which the
image will be transferred to the cylinder.
If mechanical engraving is the transfer method to be used, the
negatives are developed onto bromide films which are at-
tached to an optical scanning drum in tandem to the cylinder to
be engraved. The other method used is direct transfer etching
which requires photoresist application followed by acid etching.
After engraving or etching, the cylinders are inspected for
defects. Then a complete ink proof is made from the finished
cylinder. The cylinders that are deemed acceptable after proof-
ing are chrome plated and then shipped. If the cylinders are
deemed unacceptable, they may be top-etched to add neces-
sary depth for proper image transfer, proofed again, and, if
acceptable, chrome plated. Otherwise, the rejected cylinders
are lathed and the entire process is repeated.
An abbreviated process flow diagram for new cylinders is
shown in Figure 1.
Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes:
Direct transfer
or
electronic engraving
Artwork
Figure 1. Abbreviated process flow diagram for new cylinders.
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• An effort is made to collect copper scrap and send it offsite for
recycling.
• High-speed copper electroplating tanks are used to prevent
process and plating chemicals from clinging to the cylinders,
thereby extending bath life.
• Deionized water is used in all of the plating line rinses. Its use
eliminates the presence of calcium and magnesium ions and
thus reduces sludge formation.
• Diversion tanks are used to segregate the plating baths from
the rinse watersto prevent dilution and maintain bath compo-
sition.
• Silver is reclaimed from solution overflow in the developers
through a vendor-sponsored ion-exchange program. Silver
is also reclaimed from waste film by an offsite recycler.
• Dry-film photoresist is used in the directtransfer process thus
eliminating the chlorinated solvents frequently used in pho-
toresist applications.
• Direct transfer is being completely replaced by electronic
engraving for image transferring. The directtransfer process
generates hazardous wastes such as xylene and ferric
chloride but electronic engraving generates only copper
dust, waste sandpaper, and towels.
• Fumes and mist from the chrome-plating tank are scrubbed
and recirculated to the plating bath.
• Raw materials are purchased in returnable containers and
finished products are shipped in customer-provided return-
able boxes.
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 the financial savings of the opportunities
result from the need for less raw material and from reduced
present and future costs associated with waste management.
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 the
savings achievable when implementing each pollution preven-
tion opportunity independently and do not reflect duplication of
savings that would result when the opportunities are imple-
mented 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 analyzed 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.
• Install a sewer meter to measure the actual volume of
wastewater discharged from the plant.
• Extend the life of the acid-stripping solution by using an acid
purification unit.
• Regenerate spent ferric chloride etchant onsite or offsite by
electrolysis of the copper.
• Reblend waste inks offsite into a black inkthat can be reused.
• Recycle containers in which copper anodes are received.
• Filter and reuse caustic cleaning solution.
• Reduce volume of trash discarded using a compactor.
• Recover spent butyl acetate used for cleaning in the proofing
process.
• Reduce drag-out losses to the onsite wastewater treatment
plant by using multistage countercurrent rinsing following
plating.
• Use an alternate reagentto complex the soluble metals in the
wastewater to obtain a reduced volume of sludge.
• Install a filmless electronic camera system that can transfer
images directly, eliminating the need for film developing and
finishing.
• Reduce drag-out losses by removing protective cones on the
cylinder ends directly over the plating tanks.
• Remove copper anodes from plating bath when not plating.
• Remove chromium (VI) from process waste streams using
granular activated carbon units.
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. Environmen-
tal Protection Agency. The EPA Project Officer was Emma
Lou George.
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Table 1. Summary of Current Waste Generation
Waste Generated
Scrap copper
Scrap copper
Recovered silver from ion
exchange unit and waste film
Waste ink, xylene, and dye
Ferric chloride sludge
Wastewater treatment sludge
Evaporated solvents
Used filters
Grinding sludge
Miscellaneous solid waste
Process wastewater
Process wastewater
Domestic wastewater
Source of Waste
Cutting and lathing of cylinders
Cutting and lathing of cylinders
Image processing
Proofing of cylinders and photo-
resist development
Etching tank
Onsite wastewater treatment plant
Cylinder cleaning
Plating baths
Grinding of cylinders
Various plant operations
Cylinder preparation and plating
Grinding, etching, image process-
ing, direct transfer, and polishing
Domestic uses
Waste Management Method
Bundled; sold to scrap recycler
Mixed with trash; shipped to
nonhazardous landfill
Sold to recycler
Shipped offsite for fuels blending
Shipped offsite for disposal as
hazardous waste
Shipped offsite for disposal as
hazardous waste
Evaporated to plant air
Shipped to nonhazardous landfill
Shipped to nonhazardous landfill
Shipped to nonhazardous landfill
Treated in onsite wastewater
treatment plant; sewered
Sewered
Sewered
Annual Quantity
Generated (Ib/yr)
16,000
16,000
140
7,150
1,420
33,150
18,490
4,220
filters/yr
470
2,592,000
1,003,000
8,689,000
9,765,000
Annual Waste
Management Cost'
-14,950
(revenue received)
170
-1,780
(revenue received)
7,700
1,100
8,500
0
included in waste manage-
ment cost for miscellaneous
solid waste
same as above
27,030
29,93d2
29,93d2
29,93d2
WMAC estimates total administration and record-keeping costs associated with waste management of$2,400/yr, excluding wages.
Includes operation of onsite waste water treatment plant, sewer costs, and water purchase cost.
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Table 2. Summary of Recommended Waste Minimization Opportunities
Pollution Prevention Opportunity
Waste Reduced
Annual Waste Reduction
Quantity Per cent
(Ib/yr)
Net Annual Saving Implementation Simple
($/yr) Cost Payback (yr)
Improve collection of copper scrap
for offsite recycling. Currently, half
of the copper scrap generated is
disposed of trash.
Install an electric furnace for
melting and ingoting of copper
scrap for reuse as anodes on-site.
(Degreasing of copper scrap may
be required.)
Scrap copper mixed with trash
Scrap copper recycled
Scrap copper mixed with trash
16,000
16,000
100
100
$12,370
47,150
49,300
Reuse the acid stripping solution
used for chrome removal before
treating it in the onsite
wastewater treatment system.
Use a hot deionized water rinse
followed by drying with an air
knife in place of alcohol for drying.
Replace cotton filters used in
conjunction with copper plating
with reusable ceramic cartridge
filters.
Collect, filter, and reuse cooling
water used for grinding.
Concentrate copper-plating rinse
water and reuse as plating bath
make-up. Recover and reuse
evaporated water.
Concentrate nickel-plating rinse
water and reuse as plating bath
make-up. Recover and reuse
evaporated water.
Recover nickel from plating rinse
water using reverse osmosis and
reuse as plating bath make-up.
Reuse water.
Process wastewater (cylinder
preparation) 5,860
Process wastewater (etching
and direct transfer) negligible
Used filters 1,900 filters
Process wastewater (grinding) 3,829,000
Process wastewater (cylinder
plating) Wastewater 144,470
treatment sludge 4,590
Process wastewater (cylinder plating) 165,110
Wastewater treatment sludge 1,100
Process wastewater (cylinder plating) 165,110
Wastewater treatment sludge 990
50
45
44
14
14
16
3
16
3
2,960
800
36,530
810
6,840
4,900
5,480
1,100
400
1,260
24,210
24,210
10,200
1.4
1.6
3.5
4.9
1.9
1
The same quantity of waste will be generated onsite.
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United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
EPA/600/S-95/007
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
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