United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/003 April 1995
&EPA ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for a Manufacturer of Paper Rolls,
Ink Rolls, Ink Ribbons, and Magnetic and Thermal Transfer Ribbon
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. Waste Minimization Assessment Cen-
ters (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That document has been superseded by the Facility Pollution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 Tennessee performed an assessment
at a plant that manufactures paper rolls, ink rolls, ink ribbons,
and magnetic and thermal transfer ribbon. The raw materials
required and the process operations used are specific to the
product being produced. Production of ink ribbons requires
application of ink to fabric ribbon and winding the ribbon into a
plastic cassette or onto a reel-to-reel assembly. To produce
rubber ink rolls, rubber sheets are kneaded until porous by a
series of operations and extruded into rubber cylinders which
are then filled with ink. Paper rolls are converted from bolt
paper through a series of cutting operations. The remaining
products, magnetic and thermal transfer ribbons, are produced
by applying proprietary coating mixtures to mylar film. The
assessment team's report, detailing findings and recommenda-
tions, indicated that the plant generates a great deal of hazard-
ous waste in the coating operations of the magnetic and thermal
transfer ribbon production and in the clean-up of production
equipment. The greatest cost saving opportunity recommended
to the plant involved the reuse of tracer ribbon in the ink ribbon
production line in order to reduce raw material purchase costs.
* University of Tennessee, Department of Engineering Science and Mechanics
"University City Science Center, Philadelphia, PA
This Research Brief was developed by the principal investiga-
tors and EPA's Risk Reduction Engineering Laboratory, Cin-
cinnati, 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
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
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.
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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 proce-
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
The plant manufactures small paper rolls for calculators and
cash registers, ink ribbon assemblies, rubber ink rolls, and
magnetic and thermal transfer ribbons. Total production for all
products is approximately 14 billion units/yr for this plant, which
operates 6,240 hr/yr.
Fabric
ribbon
Oil-based
ink
Plastic ,
components
White
tracer
ribbon
Manufacturing Process
The manufacturing processes used to produce each type of
product are described below.
Ink Ribbon Assemblies
Raw materials for the process include oil-based ink, fabric
ribbons, plastic cassette components, plastic and metal spool
cores, and white fabric tracer ribbon.
Pre-mixed oil-based ink is applied to the fabric ribbon which is
wound onto a spool and stored until needed for product as-
sembly. The majority of the inked ribbon is used in the produc-
tion of cassette containment units, and a small portion of the
ribbon is used in reel-to-reel ribbon assembly.
The first step in cassette containment unit manufacturing is the
manual assembly of cassette components into one-half of a
housing. A white fabric tracer ribbon is then wound through the
internal system of rollers to designate the path that the inked
ribbon is to follow. The second half of the housing is then
bonded to the assembled cassette. Then, the inked ribbon is
inserted into the cassette; as the tracer ribbon is removed, it is
replaced with the inked ribbon.
In reel-to-reel ribbon assembly, the inked ribbon is cut to
length, inserted into a pair of metal or plastic spool cores, and
wound onto the cores.
An abbreviated process flow diagram for this process is shown
in Figure 1.
Rubber Ink Rolls
Raw materials used in the manufacture of rubber ink rolls
include synthetic rubber sheets, oil-based ink, toluene, plastic
Figure 1. Abbreviated process flow diagram for ink ribbon assemblies.
and metal cores, and sodium nitrate. The rubber, toluene, and
sodium nitrate are placed into a rubber mill where the sodium
nitrate is kneaded into the rubber. (Toluene renders the rubber
more receptive to the sodium nitrate which makes the rubber
more porous, thereby facilitating ink absorption.) The resulting
rubber ball is formed into a rubber sheet.
The rubber sheets are allowed to air dry for several weeks.
Dried sheets are then cut to size and fed through an extrusion
molder which forms hard rubber cylinders. Next, the cylinders
are placed into a warm water wash to remove sodium nitrate
from the rubber. Following electric drying for one day, the
rubber rolls are soft and porous and able to absorb ink.
In order to introduce the ink into the rolls, they are placed in a
vat containing pre-mixed ink. A vacuum is placed on the vat to
remove air from voids, and when the vacuum is removed, the
ink is driven into the pores.
The flow diagram for this process is shown in Figure 2.
Paper Roll Conversion
Bolt paper, red powdered ink dye, rubber cement, and plastic
cones are among the raw materials used in paper roll conver-
sion. The bolt paper is placed on a machine which slits the roll
for the production of smaller rolls.
The paper is marked with red ink along the first few feet of
each roll to serve as an end-of-roll warning to the eventual
user. The desired length of paper is wound onto a plastic core,
the end of the paper is cut free from the slitting machine, and a
light strip of rubber cement is applied to the paper end to
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Sodium nitrate
toluene
Ink dye
solvent
Paper rolls
Plastic cores
Rubber cement
Plastic or
metal cores
Figure 2. Abbreviated process flow diagram for rubber ink roll pro-
duction.
prevent the roll from unwinding. Groups of smaller rolls are
conveyed to a hydraulic press which separates the individual
rolls along score lines.
An abbreviated process flow diagram for paper roll conversion
is shown in Figure 3.
Magnetic and Thermal Transfer Ribbon
Raw materials used in the production of magnetic and thermal
transfer ribbon include mylar film and a variety of proprietary
materials.
Initially, the mylar to be coated is passed through a gauge to
determine material thickness. Then coating solution is applied
in a coater. The specific make-up of the coating solution is
determined by the type of transfer ribbon produced. The solu-
tion is applied to the moving mylar film in a thickness which is
measured with a gauge to ensure uniform product quality.
From the gauge the coated film goes through a drying tunnel.
After drying, the ribbon is wound onto a core and aged as
needed. Then the rolls are placed on a slitter and cut into
smaller rolls as determined by specifications.
Magnetic and thermal transfer ribbon production is shown in
Figure 4.
Figure 3. Abbreviated process flow diagram for paper roll conver-
sion.
Existing Waste Management Practices
This plant already had implemented the following techniques to
manage and minimize its wastes.
• A paper compactor bales the trim waste from paper roll
conversion for recycle by an outside firm.
• Water used to cool the braking system on the paper conver-
sion slitters is reused in the warm water wash tanks for the
rubber ink roll production line.
• Shrink-wrap trim waste from the paper roll conversion line is
baled for recycle by an outside firm.
• Aqueous-based cleaner is used instead of alcohol hand
cleaner in order to reduce the amount of hazardous waste
shipped offsite.
• Separate ball attrition mills are used for magnetic and thermal
transfer ribbon production to reduce the amount of clean-up
waste generated.
• Plant personnel, with the assistance of outside agencies, are
evaluating the composition of solid waste generated in order
to develop measures to reduce landfilled quantities.
Waste Minimization Opportunities
The type of waste generated by the plant, the source of the
waste, the waste management method, the quantity of 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 recommended for the plant. The minimization opportu-
nity, 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.
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Proprietary
materials
Mylar
Figure 4. Abbreviated process flow diagam for magnetic and thermal
transfer ribbon production.
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, one additional measure was considered. This
measure was not analyzed completely because of its techno-
logical complexity and anticipated lengthy payback period. Since
this approach to waste reduction may, however, increase in
attractiveness with changing conditions in the plant, it was
brought to the plant's attention for future consideration.
• Install an onsite wastewater treatment system to permit
removal of nitrate from washwater so that the water and the
nitrate can be reused.
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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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-95/003
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