United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/004 April 1995
&EPA ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for a Manufacturer
of Labels and Flexible Packaging
Richard J. Jendrucko*, Brian T. Hurst*, 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ment has been superseded by the Facility Pollution Prevention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 Tennessee performed an assessment at a plant
that manufactures printed labels and flexible packaging. Op-
erations performed by this plant include printing cylinder
plating, printing cylinder etching, printing plate production, print-
ing, and extrusion-coating-laminating. The team's report, de-
tailing findings and recommendations, indicated that waste
solvents are generated in large quantities and that the greatest
cost savings could be realized by installing a second distillation
unit to recover solvents from ink solids.
This Research Brief was developed by the principal investiga-
tors and EPA's Risk Reduction Engineering Laboratory, Cincin-
nati, OH, to announce key findings of an ongoing research
project that is fully documented in 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 Tennessee, Department of Engineering Science and Mechanics
"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
Risk Reduction Engineering Laboratory, the Science Center
has established three WMACs. This assessment was done by
engineering faculty and students at the University of
Tennessee's WMAC. The assessment teams have consider-
able direct experience with process operations in manufactur-
ing 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 minimiza-
tion.
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.
Methodology of Assessments
The waste minimization assessments require several site visits
to each client served. In general, the WMACs follow the proce-
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dures 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 supporting tech-
nological and economic information is developed. Finally, a
confidential report that details the WMAC's findings and recom-
mendations (including cost savings, implementation costs, and
payback times) is prepared for each client.
Plant Background
This plant manufactures printed spiral wound labels for com-
mercial use and flexible packaging for foods. It operates 6,240
hr/yrto produce over 14 billion units of product annually.
Manufacturing Process
The operations used by this plant include printing cylinder
plating, cylinder etching, printing plate production, printing, and
extrusion-coating-laminating. Each process is described briefly
below.
Cylinder Plating and Etching
Chrome is removed from used cylinders in an electrolytic de-
chrome unit and then the cylinders are lathed to remove the
previous copper-plated pattern. New cylinders and used cylin-
ders accidently lathed beyond the nickel layer are then nickel
plated.
The cylinders are cleaned and copper plated. Next, the cylin-
ders are lathed, polished, and cleaned prior to etching. A thin
coating of photoresist chemical is sprayed onto the copper-
plated cylinders. A plastic positive pattern is manually wrapped
around the cylinder which is then exposed to high intensity
ultraviolet light.
To develop the design onto the cylinder surface, dye is poured
over the cylinder. Cylinders are rinsed and dried. The cylinders
are then inspected for irregularities and hand-coated with stag-
ing lacquer.
Patterns are etched into the cylinders by immersing them in a
chemical solution. Lastly the photoresist and dye solutions are
removed with solvent-laden rags. Photoresist stripper is ap-
plied as a final step to remove all remaining solvents and
etching solution.
Once the design has been etched into the cylinder, the cylinder
is inspected and chrome plated. A set of printed samples is
produced for approval before printing runs in the rotogravure
printing line.
An abbreviated process flow diagram for cylinder plating and
etching is shown in Figure 1.
Printing Plate Production
For flexographic printing, another type of cylinder is prepared.
Used cylinders are reprocessed by first removing the previous
pattern and adhesive backing from them.
Multiple positive patterns of the desired pattern supplied by the
customer are aligned on a grid to insure proper position on a
photopolymer sheet. The pattern/grid combination is cut and
trimmed to fit the photopolymer sheet. Then, the sheet is
exposed to ultraviolet light on both sides sequentially.
Each sheet is washed in solvent to remove the areas of the
sheet not exposed to the ultraviolet light. Then, each plate is
positioned onto a steel-based cylinder and attached using an
adhesive backing. Printing samples from each cylinder are
produced, and accepted cylinders are transferred to the
flexographic printing area.
An abbreviated process flow diagram for flexographic printing
plate production is shown in Figure 2.
Printing
Rotogravure printing and flexographic printing are similar ex-
cept for the type of ink and the printing cylinder used. Ink
concentrate is mixed in-house with various solvents (alcohol
for flexographic printing) by the supplier. The mixed ink is then
poured into a reservoir located on the press.
A printing cylinder is partially immersed in an ink-filled trough
and excess ink is removed. A continuous sheet of paper rolls
across the cylinder. After each ink application, the paper passes
through a heated tunnel to dry the ink prior to subsequent
printings. Varnish is applied to products that require it in a
similar manner.
The finished product is wound onto a core and removed from
the press. The roll of product is then rewound so that the
printed label will be on the outside. The roll is then placed onto
a slitter to cut large rolls that are several labels wide into
smaller rolls. The smaller rolls are reverse-wound again, pack-
aged, and stored.
An abbreviated process flow diagram for printing is shown in
Figure 3.
Extrusion-Coating-Laminating
In the extrusion-coating-laminating line a flexible packaging
composed of up to five layers of material is produced. Various
combinations of paper and foil are combined to form the multi-
layer product. Plastic pellets for laminating are melted in ex-
truders which are positioned over the paper in a laminating
machine. This process yields an outer lamination coating on
the other various layers. The paper is then cooled as it rolls
across a water-cooled cylinder. Once the product is removed
from the press, the roll is packaged and stored.
An abbreviated process flow diagram for this line is shown in
Figure 4.
Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes:
• Mixtures of ink solids and solvents are separated by distilla-
tion; recovered solvents are sold to an outside company.
• Plant personnel are evaluating a clean-up program utilizing
a water-based cleaner instead of alcohol for alcohol-based
ink printing runs.
• An onsite incinerator is used to oxidize volatilized ink solvents
so that evaporative emissions to the atmosphere meet fed-
eral guidelines.
• A computerized monitoring system for press set-up is used
to reduce paper waste.
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Used cylinders
Cylinders to
rotogravure printing
Figure 1. Abbreviated process flow diagram for cylinder plating and etching.
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 simple payback time are given in the table. The
quantities of waste currently generated by the plant and pos-
sible 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 minimization
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 in-
clude 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 the savings achievable when implementing each waste
minimization opportunity independently and do not reflect du-
plication 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 analyzed completely because
of insufficient data, 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.
• Clean solvent-laden rags onsite instead of shipping them
offsite for cleaning.
• Reuse treated wastewater in the preliminary stations of the
cylinder plating line prior to sewering.
• Minimize dragout from the plating bath by installing an array
of rinse spray nozzles above a "dead rinse" tank following the
plating bath. Install drag-out boards around the plating tank
to return dripping solution as cylinders are lifted out of and
moved away from the plating tank.
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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-Multiple positive patterns
Photopolymer sheet
Cylinders to Floxographic Printing
Figure 2. Abbreviated process flow diagram for flexographic printing plate production.
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Ink,
solvents
Varnish,
solvents
Printing
Ink
application
Drying
Varnish
application
Drying
Printed rolls
to storage
Figure 3. Abbreviated process flow diagram for printing.
Paper, foil
Plastic pellets
Extrusion - coating - laminating
Finished product to storage
Figure 4. Abbreviated process flow diagram for extrusion - coating - laminating.
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United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-95/004
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