&EPA
United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/M-91 /047 Oct. 1991
ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for a
Manufacturer of Printed Labels
F. William Kirsch and J. Clifford Maginn*
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 hazardous waste but
lack the expertise to do so. Waste Minimization Assessment
Centers (WMACs) were established at selected universities
and procedures were adapted from the EPA Waste Minimiza-
tion Opportunity Assessment Afenua/(EPA/625/7-88/003, July
1988). The WMAC team at the University of Tennessee per-
formed an assessment at a plant producing printed labels —
approximately 14 billion labels/yr. Steel printing cylinders are
nickel and copper plated, etched with the label patterns to be
printed, chromium plated, and then used with ink applied to print
the labels. About 75% of the cylinders are chemically etched,
and the remainder are mechanically etched. Solvents used with
ink concentrate and for cleaning press parts are recoverad and
sold to reclaimers. Spent reagents, filters, cleaning rags, and
sludge are shipped offsite for disposal. Process wastewater
and rinse water are treated by ion exchange and distillation.
The team's report, detailing findings and recommendations,
indicated that most waste other than water and paper consists
of spent solvents, and that the greatest savings could be
obtained by using recovered solvent instead of virgin solvents
for cleaning at press side.
'University City Science Center, Philadelphia, PA 19104.
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 a separate report of the same
title available from the authors.
Introduction
The amount of hazardous 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 hazardous waste 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 formation of hazardous waste but
lack the inhouse 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 (Knoxville) WMAC. The assessmentteams have
considerable direct experience with process operations in
manufacturing plants and also have the knowledge and skills
needed to minimize hazardous 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
{gy Printed on Recycled Paper
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annual sales not exceeding $50 million, employ no more than
500 persons, and lackinhouse expertise in waste minimization.
The potential benefits of the pilot project include minimization
of the amount of waste generated by manufacturers, reduced
waste treatment and disposal costs for participating plants,
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 Opportu-
nity Assessment Manual(EPA/625/7-88/003, July 1988). The
WMAC staff locates the sources of hazardous waste in the plant
and identifies 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.
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 printed labels. It operates 6,120 hr/yr to
print approximately 14 billion labels.
Manufacturing Process
This plant prints label patterns on wide paper roll stock. About
80% of the labels are rolled onto cardboard cores, which are
slit Into narrow rolls. The remainder are cut into sheets, which
are counted into stacks. Raw materials include reagents for
nickel-, copper-, and chromium-plating and etching of print-
ing cylinders, light-sensitive film, blue dye, printing ink con-
centrates, solvents, fitter media, cleaning rags, cotton, and
paper stock.
Plating and etching of the steel printing cylinders used to print
the labels involve the following steps:
• The cylinders are degreased and washed. (Used cylinders
are first dechromed in an acid bath containing a dechrome
salt and then machined to remove previously etched label
patterns).
• The cylinders are nickel plated in a tank containing a
solution of nickel sulfate, nickel chloride, and boric acid.
After rinsing, the cylinders are copper plated in a tank
containing copper nuggets in a solution of sulf uric acid and
a hardness additive.
• After rinsing, the plated cylinders are polished with pumice
and washed with detergent.
• About 75% of the cylinders are chemically etched. Using
pattern negatives, a base film is developed by a photo-
graphic process. (Silver is recovered for sale.) After a
photoresist coating is applied to the printing cylinders, the
patterned film is applied and the cylinders are exposed to
high-intensity light. A blue dye is then applied for develop-
ment, and the photoresist and dye coatings are hardened
in isopropyl alcohol.
• The cylinders are etched in ferricchloride solution contain-
ing copper sulf ate, and then rinsed in water. About 90% of
the cylinders are sent to the printing process at this stage;
the remaining 10% are chrome plated first in a solution of
chromic acid and sulfuric acid.
The following steps are carried out in printing the labels:
• Ink concentrates are mixed with solvents for desired color
and drying times and applied to the paper using an impres-
sion type of press.
• After each color is applied the ink is dried on the line in an
electric or gas-fired oven. Up to 6 colors can be applied to
the paper in one line.
• After each run, press parts are cleaned using solvents and
rags.
• About 80% of the printed paper is slit into narrow rolls and
packaged. The remainder is cut into sheets.
Existing Waste Management Practices
Solvent vapors from the printing-line drying ovens are recov-
ered in three parallel carbon adsorption beds and regenerated
with steam. The effluent steam is condensed producing a
solvent layerthat is decanted, neutralized with hydrogen perox-
ide and caustic soda, and sold to reclaimers. Sodium acetate
produced in the neutralization is shipped offsite for disposal.
Spent reagents, lathe waste, and spent dye are shipped offsite
for disposal. Solvent-laden rags and cotton from cleaning press
parts are also shipped offsite for disposal. Spent filters, scrap
paper, and obsolete label patterns are discarded with municipal
trash.
Water from plant operations is treated in an ion exchange unit
and discharged to public water facilities.
Waste Minimization Opportunities
The type of waste currently generated by the plant, the source
of the waste, the quantity of the waste, and the annual waste
management costs are given in Table 1.
Table 2 shows the opportunities for waste minimization that the
WMACteam recommended forthe plant. The type of waste, the
minimization opportunity, the possible waste reduction and
associated savings, and the implementation cost along with the
paybacktime are given in the table. The quantities of hazardous
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.
ft should be noted that, in most cases, the economic savings of
the minimization opportunities result from the need for less raw
material and from reduced present and future costs associated
with waste treatment and disposal. Other savings not quantifi-
able by this study include a wide variety of possible future costs
related to changing emissions standards, liability, and em-
ployee health. It should also be noted that the savings given for
each opportunity reflect the savings achievable when imple-
menting 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 by the WMAC
team, two other measures were considered. These measures
were not analyzed completely because of insufficient data or
minimal savings as indicated below. They were brought to the
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plant's attention, however, because these approaches to waste
reduction may increase in attractiveness with changing plant
conditions.
• Water from the plant's solvent recovery system is sprayed
into the firebox of an incineration boiler for disposal. An
option to use this slightly contaminated water as boiler
feedwater was not recommended because of a lack of
information on the possible effect of the contained solvent
on the heat transfer surface of the boiler and on the rest of
the steam system.
• Advance preparation of solvent-laden rags used to clean
press parts would reduce the quantity of solvent lost by
evaporation. This measure was not analyzed further be-
cause minimal savings would be expected.
This Research Brief summarizes a part of the work done under
Cooperative Agreement No. CR-814903 by the University City
Science Center underthe sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma Lou
George.
Table 1. Summary of Current Waste Generation
Waste Generated
Source of Waste
Annual Quantity Annual Waste
Generated Management Cost
Solvent vapors
Drying oven exhaust.
Solvent vapors in drying oven exhaust are adsorbed in carbon
beds, desorbed by a steam purge, condensed, decanted from
the steam condensate, and shipped to a reclaimer.
300,000 gal
$1,028,869'
Spent ink/solvent mixture
Spent blue dye mixture
Solvent vapors
Spent reagent solutions
(Sodium acetate, ferric
chloride, hydrochloric acid,
and chromium, nickel and
copper salts)
Spent rinse water
Spent cotton, rags and
polishing cloths
Sludge from water
treatment
Paper waste
Ink solids
Lathe waste (turnings,
pumice, copper fines)
Condensed inks, mixed with blended solvents, are used in 34,540 gal
printing. The spent mixtures are shipped offsite for disposal.
Blue dye solution, used in preparing printing cylinders, is 1,100 gal
recycled to the process. When spent, it is shipped offsite
for disposal.
Solvents used in etching and printing evaporate to the plant 189,055 gal
atmosphere.
Spent reagents from plating, etching, and solvent recovery 22,118 gal
operations are shipped offsite for disposal.
Rinse water from plating and etching operations, and fume 252,910 gal
scrubber effluent, are passed through an ion exchange resin
bed and discharged to POTW
Solvent-laden cotton and rags from cleaning, and pigment- 1,760 gal2
laden polishing cloths, are shipped offsite for disposal.
Sludge generated on regeneration of ion exchange resin used 2,090 gal
for water treatment is shipped offsite for disposal.
About 4,200,000 Ib/yr of scrap paper is sold. The remainder, 5,600,000 Ib
5,600,000 Ib/yr, is disposed of as landfill.
Waste ink solids from printing operations are shipped offsite 1,650 gal
to be burned as fuel.
Waste from machining and polishing printing cylinders is 495 gal
shipped offsite for disposal.
49,482
5,314
541,868'
35,388
5,000
12,800
5,700
39,600
13,500
900
Spent ink filters
Used ink filters from printing operations are shipped offsite
for disposal.
550 gaP
4,000
'Includes savings on raw materials.
232 ban-els of spent cotton, rags, and polishing cloths.
310 barrels of spent ink filters.
•feV.S. GOVERNMENT POINTING OFFICE: 1991 - 548-028/40073
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Tabla 2. Summary of Recommended Waste Minimization Opportunities
Waste Generated
Annual Waste Reduction Net Implementation Payback
Minimization Opportunity Quantity Percent Annual Savings Cost Years
Spent Solvent
Used recovered solvent
instead of virgin solvent
for cleaning press parts.
None
$284,294'
$0
Spont safety solvent
Ink/solvent mixture
Safety solvent vapors
Spont ink filters
Used recovered solvent None - 59,443'
instead of safety solvent
for cleaning.
Automate mixing of ink, 5,225 gal 75 47,085'
extender, and solvent to
reduce oyermixing and
evaporative loss.
Replace a cleaning tank 2,833 gal 50 9,604'
lid to reduce solvent
evaporation loss.
Rinse spent ink filters 363 gal2 66 5,016'
with solvent and reuse
288,800
500
6.1
0.1
'Includes savings on raw materials.
=6.6 barrels per year of spent ink filters.
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA PERMIT NO. G-35
Official Business
Penalty for Private Use $300
EPA/600/M-91/047
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