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ment has been superseded by the Facility Pollution Prevention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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