1

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 Centers (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That document has been superseded by the Facility Pollution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 manufacturing cylinders for rotogravure printing.

Rotogravure printing cylinders are produced from new stock

and used cylinders that require reworking. Cylinders undergo

cleaning, plating, lathing, polishing, and grinding. Then the

surfaces of the cylinders are engraved, cleaned, polished, and

chrome-plated. The assessment team’s report, detailing findings and recommendations, indicated that significant cost savings could be achieved by melting and reusing copper scrap as

anodes in the plating bath.

This Research Brief was developed by the principal investigators and EPA’s Risk Reduction Engineering Laboratory, 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 become 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 experience with process operations in manufacturing plants

and also have the knowledge and skills needed to minimize

waste generation.

The waste minimization 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 waste minimization.

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 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 waste minimization assessments require several site visits

to each client served. In general, the WMACs follow the procedures outlined in the EPA Waste Minimization Opportunity

Waste Minimization Assessment for a Manufacturer of New

and Reworked Rotogravure Printing Cylinders

United States

Environmental Protection

Agency

Risk Reduction

Engineering Laboratory

Cincinnati, OH 45268

ENVIRONMENTAL

RESEARCH BRIEF

Research and Development EPA/600/S-95/005 April 1995

Marvin Fleischman*, Clay Hansen*, and

Gwen P. Looby**

* University of Louisville, Department of Chemical Engineering.

** University City Science Center, Philadelphia, PA.

E AP
2

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 supporting technological and economic information is developed. Finally, 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 produces chrome-plated engraved copper-plated steel

and aluminum cylinders for rotogravure printing from new stock

and customer returns. It operates 6,240 hr/yr to produce over

7,000 cylinders annually.

Manufacturing Process

Rotogravure printing cylinders are produced from new stock

(primarily steel or aluminum) and used cylinders requiring reworking.

New cylinders are cleaned and degreased before processing.

Then the aluminum cylinders are passivated in a wash tank

containing an acid mixture, and zincated in a zinc oxide solution. Next, all aluminum and steel cylinders are nickel-plated

and then copper-plated. Used cylinders undergo cleaning, acid

stripping, and lathing and are then copper-plated. The plated

cylinders then undergo lathing, polishing, and grinding.

Customer-provided artwork is used to create plating images

which are then mechanically engraved on the surfaces of the

cylinders. The engraved cylinders are cleaned, polished, and

chrome-plated.

Cylinders are then tested in the proofing department. Those

cylinders that pass inspection are packaged and shipped. The

cylinders that fail inspection are stripped of chrome (using acid)

and are either replated with chrome or lathed and returned to

the copper-plating baths for reprocessing.

An abbreviated process flow diagram is shown in Figure 1.

Existing Waste Management Practices

This plant already has taken the following steps to manage and

minimize its wastes:

• Metal shavings (primarily copper) from turning, polishing,

and electronic engraving are recovered and sold for reclamation.

• Cylinders are rinsed with deionized water directly above the

tanks after nickel and copper plating in order to eliminate

drag-out of plating solution.

• Film with a very low silver content is used in image processing

in order to reduce the amount of waste silver generated.

• Silver is recovered onsite by electrolytic deposition.

• Recovered silver and waste film are sold to a recycler.

• Electronic engraving is used for etching cylinders in order to

eliminate the wastes that would be generated using chemical

etching.

• Cylinders are rinsed over the plating tanks and fume scrubber water is reused as plating bath make-up in order to

eliminate the need for chromium removal from wastewater.

• Chromic acid fume and evaporative losses are reduced

through the use of tank covers and floating plastic balls.

Plant personnel are currently evaluating the following options

for managing and minimizing plant wastes:

• The plant plans to switch to computer-generated imagemaking as a replacement for photographic image processing.

• Ceramic coating of the cylinders to replace nickel-,

copper, and chrome-plating is being investigated.

• An alternative to the ink solvent that contains methylene

chloride is being sought.

Waste Minimization 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 waste minimization that the

WMAC team recommended for the plant. The minimization

opportunity, the type of waste, the possible waste reduction

and associated savings, and the implementation cost along

with the 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 economic savings of the minimization opportunity, in most cases, results from the need for less

raw material and from reduced present and future 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 the savings achievable when

implementing each waste minimization opportunity independently 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 considered. These measures were not completely analyzed because

of insufficient data, minimal savings, implementation difficulty,

or a projected lengthy payback. Since one or more of these

approaches to waste reduction may, however, increase in

attractiveness with changing conditions in the plant, they were

brought to the plant’s attention for future consideration.

• Reduce or eliminate spillover from the nickel- and copperplating tanks by installing plastic guards around the tank

edges.

• Evaluate the necessity for and standardize the use of solvents in cleaning cylinders.

• Recover chromium or hydrochloric acid from the spent acid

stripper solution.

• Replace disposable filters used for filtering nickel- and copper-plating solutions with reusable stainless steel filters.

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. Environmental Protection Agency. The EPA Project Officer was Emma

Lou George.
3

New cylinders (aluminum, steel) Used cylinders

Cleaning, degreasing Cleaning, acid stripping, lathing

Passivation

zincating

Nickel

plating

Copper

plating

Lathing,

polishing Grinding Artwork

Proofing Chrome

plating Finishing Electronic

engraving

Image

processing

Inspection Acceptable

yes

Shipping

no

no

yes

Correctable

Acid

stripping Re-etching

Steel

Al cylinders cylinders

Figure 1. Abbreviated process flow diagram for rotogravure printing cylinders.
4

Table 1. Summary of Current Waste Generation

Annual Quantity Annual Waste

Waste Generated Source of Waste Waste Management Method Generated (lb/yr) Management Cost 1

Butyl acetate, acid stripping solution, Preparation of used cylinders Drained to storage tank; shipped offsite for 144,600 10,530

and rinse water disposal as hazardous waste

Wastewater Preparation of used cylinders Drained to holding tank; neutralized; sewered 607,900 —-2

Passivating and zincating solutions Preparation of new cylinders Drained to storage tank; shipped offsite for 21,520 1,460

disposal as hazardous waste

Wastewater Preparation of new cylinders Drained to holding tank; neutralized; sewered 349,780 —-2

Cleaning water Cleaning of copper-plating tanks Drained to storage tank; shipped offsite for 160,130 11,520

disposal as hazardous waste

Copper- and nickel-plating sludge Copper- and nickel-plating tanks Shipped offsite for disposal as hazardous waste 1,320 gal 7,320

Copper anode nuggets Copper plating Sold to recycler/reclaimer 1,440 -1,330

Chromium sludge Chrome-plating tank Shipped offsite for disposal as hazardous waste 550 gal 2,540

Wastewater Chrome plating Drained to holding tank; neutralized; sewered 3,002,400 —-2

Copper sludge Grinding Shipped offsite for disposal as hazardous waste 26,000 gal 15,600

Scrap metal Cutting, lathing, and polishing Sold to recycler/reclaimer 93,700 -79,580

Wastewater Cleaning of film processors Drained to storage tank; shipped offsite for 15,000 1,080

disposal as hazardous waste

Water overflow Film processors Drained to holding tank; neutralized; sewered 676,540 —-2

Silver Onsite electrolytic silver recovery Shipped offsite for further recovery 100 -3,780

Waste film Image processing Sold to reclaimer 750 -7,560

Copper dust Engraving Sold to recycler/reclaimer 120 -110

Solvent-based ink Proofing of cylinders Shipped offsite for fuels blending 8,700 1,540

Water-based ink Proofing of cylinders Shipped offsite for ink reblending 900 160

Spent etch bath and rinse water Re-etching of cylinders Drained to storage tank; shipped offsite for 3,000 640

disposal as hazardous waste

Ethanol Re-etching of cylinders Drained to holding tank; neutralized; sewered 4,300 —-2

Wastewater Re-etching of cylinders Drained to holding tank; neutralized; sewered 16,010 —-2Rags Various plant operations Laundered offsite; returned for reuse 15,000 units not available

Paper towels Various plant operations Shipped to landfill 300,000 units —-3

1 Includes waste treatment, disposal, and handling costs.

2 Included in total POTW and onsite treatment costs of $32,750/yr.3 Included in total landfill disposal costs of $34,200/yr.
5

Table 2. Summary of Recommended Waste Minimization Opportunities

Annual Waste Reduction

Net Annual Implementation Simple Payback

Minimization Opportunity Waste Reduced Quantity (lb/yr) Per cent Savings Cost (yr)

Melt copper scrap resulting from turning Copper shavings, particles, and 43,200 45 $35,890 57,100 1.6

and cutting cylinders, polishing, en- spent anode nuggets

graving, and plating in a furnace and

reuse as anodes in the plating bath.

A degreasing system may be required

for cleaning of the copper scrap prior

to melting.

Install a drip board on the chrome plating Chromic acid 1,530 n/a 1,760 40 0.1

bath so that dragout can be captured

and returned to the plating bath.

Currently trapped dragout in the core

tape used on the cylinders is lost on

the floor and in the rinse tank and

eventually is sewered.

Install a filter press in order to recover Copper sludge 26,000 gal1 100 47,460 16,820 0.4

copper from the grinding sludge.

Sell the recovered copper to a reclaimer and sewer the removed water.

Reuse spent butyl acetate once for Butyl acetate 5,150 50 2,960 640 0.2

subsequent cleaning.

Use a small distillation unit to reclaim Butyl acetate 7,210 70 3,740 3,700 1.0

spent butyl acetate for reuse.

Remove metal from the spent cleaning Cleaning water 160,1301 100 17,450 35,520 2.0

water from copper-plating tank clean-out

using electrolytic metal recovery.

Sell recovered copper to a reclaimer

and sewer the water.

Install high pressure spray rinses and Nonhazardous rinse water 1,200,960 50 4,120 1,150 0.3

automatic shut-offs in certain process Hazardous rinse water 6,765 50

areas in order to reduce water

consumption.

Replace the ethanol rinse with a Ethanol 4,3002 100 2,740 290 0.1

hot deionized water rinse followed

by hot air blowing. This measure

will also reduce BOD (Biological

Oxygen Demand) and BOD

surcharges.

Install a distillation unit to recover Ethanol 3,000 70 1,670 3,700 2.2

ethanol for reuse. This measure

will also reduce BOD and BOD

surcharges.

Install an in-line evaporator to Hazardous liquid waste 384,360 62 24,040 37,700 1.6

remove water from the waste going

to the waste disposal tank for later

disposal as hazardous waste.

Base sewer charges on actual Not applicable —- —- 7,600 4,140 0.5

wastewater effluent rather than on

water consumption.

1 Waste has been changed in form to one that is less costly for plant to manage.2 A wastewater stream of the same quantity will be generated if this opportunity is implemented.
6

United States

Environmental Protection Agency

Center for Environmental Research Information

Cincinnati, OH 45268

Official Business

Penalty for Private Use

$300

EPA/600/S-95/005

BULK RATE

POSTAGE & FEES PAID

EPA

PERMIT No. G-35