A Cooperative Project
between the
U.S. Environmental
Protection Agency
and the
Printing Trade
Associations
Nationwide
FOR
THE
OtWNT
SCREEN PRINTING PROJECT CASE STUDY2
US. ERA
SCREEN PRINTING
Changing Equipment
and Reducing
Solvent Use In
Screen Reclamation
The Design for the Environment (DfE)
Screen Printing Project is a unique,
cooperative effort between the screen
printing industry and the U.S. Environmental
Protection Agency (EPA). The voluntary
project helps screen printers improve their
efforts to reduce risks to their workers and
the environment in cost-effective ways.
EPA and the screen printing industry are
developing a series of case studies to illus-
trate how screen printers can improve their
environmental performance. This case study
describes a successful pollution prevention
program at Action Graphics, a commercial
printer in Louisville, Kentucky, that took the
initiative to minimize risks to workers and
the environment. In doing so, the company
purchased equipment that re-duced solvent
use and chose safer alternatives for the sol-
vents it could not eliminate.
Specifically, this case study shows:
' How the need for ink remover can be elimi-
nated by:
• Reclaiming screens immediately after
a print run.
• Using a high-pressure water system.
• Switching to more effective, safer
emulsion and haze remover products.
• How the quantity of solvent used during
the printing process can be greatly
reduced by finding more efficient sol-
vents and reusing rags.
Background
Action Graphics produces point-of-pur-
chase display products, such as shelving
signs, banners, and window signs used in
retail stores and fast-food restaurants.
Traditional solvent-based inks are used in
about 60 percent of the company's printing.
and ultraviolet (UV) curable inks are used
in 40 percent. Action Graphics opened for
business in 1979 and currently has 30
employees, half of which are directly
involved in printing processes.
Over the past five years, Action Graphics
has developed a creative and comprehensive
approach to pollution prevention. Although
a small shop with limited resources, it has
greatly reduced solvent use through many
innovative changes. The primary change
was the introduction of a high-pressure
water system, which eliminated the need
for ink remover solvent. In addition, the
company substituted safer screen recla-
mation chemicals, purchased a distiller,
switched to a slower-evaporating solvent
for screen cleaning during press runs,
changed to a safer ink thinner, and devel-
oped a rag reuse policy. These changes
lowered the company's level of volatile
organic compounds (VOCs) and decreased
its generation of hazardous waste.
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A Change in Screen
Reclamation Equipment
and Chemicals
Action Graphics' owner, Joe Miller,
began thinking about the unintended
effects of the solvents the company
used when representatives from the
Occupational Safety and Health
Administration (OSHA) visited the
shop in 1991. While the company
was not exceeding OSHA levels for
contaminants in the air, the visit
made Miller more aware of the possi-
ble respiratory health issues associat-
ed with solvents used in the screen
reclamation process.
At that time, Action Graphics was
using a traditional three-step screen
reclamation process: first, workers
applied an ink remover; second, they
applied an emulsion remover; and third,
they applied a haze remover to eliminate
any remaining ink and emulsion. Each
chemical product was washed off the
screen with a low-pressure water sprayer
at 400 to 500 pounds per square inch
(psi). When needed, a degreaser also
was used.
The ink remover consisted of diace-
tonealcohol (75 percent), methylchloro-
form (10 percent), and 2-butoxyethanol
(15 percent). Exposure to these ingredi-
ents can cause adverse health effects.
Methylchloroform exposure, for exam-
ple, can cause dizziness, lightheaded-
ness, and mild eye and skin irritation,
and may have more serious effects with
long-term exposure. The emulsion
remover's ingredients included phos-
phoric acid, which can cause burns after
prolonged exposure. The haze remover
contained sodium hydroxide, which can
also cause burns, and cyclohexanol,
which can irritate the eyes, nose, and
throat and possibly cause more serious
effects at high concentrations. The
degreaser did not present health con-
cerns.
Indeed, some workers found vapors
from the solvents to be overpowering at
times, making breathing difficult in cer-
tain areas of the plant and causing eye
irritation. In addition, operators occa-
sionally received burns when they used
some of the cleaning chemicals improp-
erly.
To reduce these health risks, Action
Graphics completely overhauled its
screen reclamation process at the end of
1991. The key component of the new
process was a high-pressure water sys-
tem that met Miller's need to improve
worker health and the environment by
reducing solvent use. The system also
promised to pay for itself in a reason-
able amount of time. Miller also con-
sidered but ruled out enclosed booths in
which solvents are reused. These were
economically infeasible for the relative-
ly low volume of screens reclaimed at
Action Graphics.
With the new
high-pressure
water system,
workers transfer
screens to the
reclamation area
immediately after
a press run.
Speed is essential
because it pre-
vents the ink from
drying on the
screens. Operators
apply the emulsion
remover with a
brush, then rinse
the screens by
shooting water
through them at a pressure of 3,000 psi.
The combination of not allowing the ink
to dry and using the high-pressure water
stream allows workers to flush out both
ink and emulsion without the use of ink
remover. Eliminating the need for ink
remover decreased
the company's
annual solvent
use by approxi-
mately 770 gal-
lons, reduced
worker exposure
to potentially
harmful chemicals,
and saved over
$13,000 per year in purchasing costs.
Action Graphics also changed its
emulsion remover to sodium metaperio-
date, which, unlike the company's origi-
nal emulsion remover, does not cause
burns. Although the new emulsion
remover is slightly more expensive, it is
also more highly concentrated, so
Action Graphics uses less (see chart for
cost savings). Workers complete the
process by applying a new, less corro-
sive haze remover and rinsing it out
with water at 3,000 psi.
Another advantage to the new high-
pressure water system is that it includes
filtration equipment that reduces the
amount of waste from the reclamation
process discharged into the sewer sys-
tem. The filtration system removes all
particles 5 microns or larger and keeps
the wastewater in compliance with local
sewer district requirements.
Besides the environmental and
health benefits, the new equipment
and chemicals actually do a better job
of keeping the screens clean. In addi-
tion, the old caustic chemicals tended to
slowly eat away at the screens. The new
system causes less wear and tear on the
screens, so they need to be replaced less
often.
One of the benefits of solvent reduc-
tion is that it almost always saves
money. All told, Action Graphics' new
system saves $9,400 a year in operating
costs. Since the one-time capital cost
for the system was only $13,300, it paid
for itself in less than 16 months.
Screen reclamation with a high-pressure water system
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>JS EM
Comparison of Yearly
Operating Costs*
Old System New System
Ink Remover $13,100 $0
Emulsion Remover $5,000 $2,600
Haze Remover $7,800 $10,900
Filter Media $0 $3,000
Total $25,900 $16,500
Yearly Operating Cost Savings: $9,400
""Although Action Graphics believes labor costs also were
reduced under the new system, specific data are not available.
A Change in Solvents
Used During Press
Operation
About a year after Action Graphics
overhauled its screen reclamation system.
another one of its solvents surfaced as a
problem. Like many printers, Action
Graphics used a solvent during the print-
ing process to remove dried ink left on
screens overnight or during lunch breaks.
The quickly evaporating solvent, called a
press wash, consisted of n-butyl acetate.
toluene, n-butanol, and isopropanol.
In 1989, Action Graphics purchased a
distiller to reclaim its press wash solvent
and consequently reduce its hazardous
waste disposal and solvent costs. As a
result, the company was able to reuse
roughly 100 gallons of solvent over the
course of a year, for a savings of about
$500 annually. Although this early
change was a step in the right direction.
when Action Graphics' management
applied for a permit with the local Air
Pollution Control Board in 1992, they
realized that more had to be done.
During the application process, the shop
discovered that much of its VOC emis-
sions were coming from the quickly
evaporating press solvent. The board
found that the level of VOCs on the
application triggered ordinances that
required Action Graphics to perform a
best achievable control technology test to
find ways to decrease its VOC emissions.
These ordinances help protect both the
environment and worker health, since
VOCs can contribute to air pollution and
exposure to VOCs can lead to adverse
health effects.
Some of the
changes Action
Graphics explored
to reduce these
environmental and
health effects
included using
thermal incinera-
tion, catalytic
incineration, or car-
bon absorption.
Thermal and cat-
alytic incineration
involve burning
VOCs that are cap-
tured in a dryer.
Carbon absorption
removes VOCs
through activated
carbon, which peri-
odically must be sent out for reactivation.
Through a cost-benefit analysis, Action
Graphics found that these processes
required a large capital investment.
Since Action Graphics is a small shop, a
large financial investment was out of the
question. The company decided that
chemical reformulation of its press wash
was a more affordable alternative. In
addition, chemical reformulation
promised to stop VOCs from being gen-
erated in the first place, a true pollution
prevention alternative, instead of trying
to capture the VOCs after generation.
Finding a new solvent was no easy
task, however. The company spoke with
other screen printers, distributors of
national brands that are marketed as
environmentally friendly, and local chem-
ical suppliers. Action Graphics found
that formulations from local chemical
suppliers were much less expensive than
national brands and through trial and
error found one that met its needs.
Action Graphics switched to a solvent
that contains aromatic solvent naphtha
(60 percent), l-methoxy-2-propanol (30
percent), and oxybispropanolmethylether
(10 percent). This mixture evaporates
much more slowly than the company's
traditional solvent, thereby decreasing
Action Graphics' total VOC emissions.
Workers did not like switching to this
new solvent, however. Since it evapo-
rates more slowly, press operators were
concerned that they would have to check
more carefully to see if it was completely
Screen cleaning with a slowly evaporating press wash
evaporated before continuing a press run.
To address this issue, company manage-
ment wrote a letter to the press operators.
The letter explained that the new solvent
really did not require any additional
effort and that the switch was not only
necessary to comply with regulations, but
also helped create a healthier work envi-
ronment. Employees gradually adjusted
to the new procedure.
The company not only reduced its
VOCs by using the new solvent, but also
reduced the total quantity of solvent used.
since press operators needed less of the
slower-evaporating sol-
vent to do the same
job. This switch
cut solvent usage
from approxi-
mately 1,200
gallons per year
to 300 gallons.
Although the new
solvent costs a little
more per gallon, the com-
pany saves about $2,300 a year in pur-
chasing costs because it uses so much
less of the new product.
At the same time that the Air Pollution
Control Board suggested that Action
Graphics reduce its VOC emissions from
its press wash solvent, the board also
noted that the company was close to the
emissions limit for ethylene-based glycol
ether compounds. If the company
exceeded the limit, it would move to a
higher emissions category under Title V
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FOR
THE
of the Clean Air Act and be subjected to
a costly permit application process.
Many of the company's inks and thin-
ners contained these compounds.
Action Graphics followed the same steps
it took to locate a new press wash and
found a new ink thinner that consisted of
safer chemicals, l-methoxy-2 propanol
(85 percent) and oxybispropanolmethyl-
ether (15 percent), which are not listed
as hazardous air pollutants. Although
the company saw no reduction in solvent
usage, these safer chemicals cost less
than the glycol ether ink thinner, saving
the company approximately $900 a year.
Continued Improvements For More Information
Rag Reuse
Another proposed solution for reduc-
ing solvents from Action Graphics' best
achievable control technology test was
to purchase a centrifuge to reclaim sol-
vent from used rags. The company
found in its cost-benefit analysis, how-
ever, that for its low volume of rags, a
centrifuge was not the best option.
Instead, the company instituted a policy
to reuse the rags as many times as possi-
ble before disposal. Now, instead of
press operators always reaching for a
new rag each time they clean a screen,
they are asked to reuse a rag as long as
they are running the same color ink.
When they change inks, they also
change their rags.
Eventually the heavily soiled rags are
sent to an industrial laundry. Action
Graphics does not reuse rags from the
laundry, however, because the laundry
washes rags that are used for many pur-
poses, including rags from metal shops.
These rags often retain minute metal
pieces, which would destroy Action
Graphics' screens. Instead, the laundry
provides the rags to other companies
that do not need to use them on fragile
equipment.
The participation rate for rag reuse
has not been as high as the company's
management would like, because clean
rags do a better job cleaning screens.
Action Graphics hopes increased educa-
tion will help employees understand the
benefit of generating fewer solvent-
soaked rags.
While your print shop may use differ-
ent inks or create different products than
Action Graphics, you may still be able
to learn from Action Graphics' deci-
sions. When problems were identified,
the company actively sought out creative
solutions.
Company management weighed all
their options carefully, spoke to other
printers, and when appropriate con-
ducted cost-benefit analyses before
making changes.
Purchasing the high-pressure water
system, switching press wash solvents
and ink thinner, and instituting a rag
reuse policy resulted in win-win situa-
tions. These changes enhanced screen
reclamation performance, benefitted
worker health and the environment, and
saved the company money. If you are
interested in these improvements, you
can learn from Action Graphics' suc-
cess.
Action Graphics' progress probably
will not stop there, however. One of the
key factors behind Action Graphics'
success has been the company's contin-
ued self-evaluation and openness to new
ideas. Action Graphics' management is
always on the lookout for new ways to
improve working conditions and mini-
mize the company's impact on the envi-
ronment. One future improvement the
company is considering is switching
over completely to UV curable inks,
eliminating its use of solvent-based inks.
For more information on the tech-
nologies in this case study, contact your
equipment suppliers. For more informa-
tion on other technological and chemical
alternatives, refer to the summary book-
let Designing Solutions for Screen
Printers—An Evaluation of Screen
Reclamation Systems. For more infor-
mation on EPA's DIE Program or to
obtain additional case studies, bulletins,
and other related materials, contact:
Pollution Prevention Information
Clearinghouse (PPIC)
U.S. EPA
401 M Street, SW (7409)
Washington, DC 20460
Phone: 202-260-1023
Fax: 202-260-4659
For more information on this case
study and trade association information,
contact:
Screenprinting and Graphic Imaging
Association International (SGIA)
10015 Main Street
Fairfax, VA 22031
Phone: 703-385-1335
Alternatively, you can visit the DIE
home page on the World Wide Web at
http://www.epa.gov/dfe or the SGIA
home page at http://www.sgia.org
Also be sure to investigate your local
health and environmental regulations.
Local agencies are familiar with priority
issues in your area and can help you find
the best ways to prevent pollution in
your community.
What Is the Design for the Environment
Screen Printing Project?
The U.S. Environmental Protection Agency's (EPA) Design for the
Environment (DfE) Screen Printing Project is a voluntary project that
encourages printers to consider environmental concerns along with cost
and performance when purchasing products to use in their facilities.
Replacing hazardous chemicals with environmentally safer substitutes
is one way to reduce the impact of printing on the environment while
maintaining product quality. Many printers, however, have limited time
and resources and therefore need help identifying and testing environmentally safer substi-
tutes.
DfE fills this information gap. EPA has teamed up with screen printing industry represen-
tatives (including trade associations, printers, and suppliers) in the DfE Screen Printing
Project. The project's goal is to evaluate and publicize pollution prevention opportunities in
screen printing, particularly in the screen reclamation process.
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