United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-93/149 October 1993
EPA Project Summary
Replacement of Hazardous
Material in Wide Web
Flexographic Printing Process
Paul B. Kranz, Thomas R. Williamson III, and Paul M. Randall
The study summarized here evaluated,
on a technical and economic basis, the
effect of substituting water-based inks for
solvent-based inks in a flexographic print-
ing process.
To reduce volatile organic compound
(VOC) emissions by switching from the
use of solvent-based inks to water-based
inks, several equipment modifications and
a feedstock substitution were completed:
dryer capacity enhancement, press roller
modification, ink handling equipment up-
grade and installation of an in-line corona
treatment system. Water-based inks con-
taining 72.5% less VOC were used in lieu
of, and in conjunction with, traditional sol-
vent-based inks.
The ink substitution reduced the emis-
sions generated from the printing pro-
cess. For each percent increase in water-
based ink use, VOC emissions were re-
duced 14 Ib. This was based on usage of
about 2250 Ib of solvent-based ink/wk,
which caused a VOC emission of about
1570 Ib. Typically, the substitution did not
adversely affect product quality or non-
hazardous scrap waste generation. The
average reduction of 95% of liquid F003
waste from waste ink and cleaning sol-
vents recorded during the study period
resulted from operational practice changes
and employee training.
To complete the economic evaluation,
the costs of press modifications, ancillary
equipment, waste disposal, inks, and sol-
vent were obtained. A payback period and
project net present value were calculated.
The project has a positive net present
value of $39,165 and a payback period of
2.5 yr, based on 21 % utilization of water-
based ink. If full conversion to water-based
inks is implemented, the payback period
is theoretically reduced to 0.54 yr.
Additional benefits from reduced VOC
emissions and liquid hazardous waste
have been an improved working environ-
ment: reduced indoor air pollutants, re-
duced handling of hazardous solvents by
employees, and the appreciation by com-
pany employees of the need to make a
conscious effort to further reduce waste
generation.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the research project that is
fully documented in a separate report of
the same title (see Project Report order-
ing information at back).
Introduction
A wide web flexographic printing firm sub-
stituted water-based inks for solvent-based
inks when manufacturing flexible packaging
using plastic sheet substrates (e.g., plastic
bags for bread). The project objectives were
to evaluate the technical feasibility (particu-
larly as related to process implementation
and performance), the economic effect, and
the resulting change in VOC emissions
achieved by the substitution. The technical
evaluation was to quantify the reduction in
both volatile and liquid-phase solid hazardous
wastes.
This is a study of the effectiveness and
applicability of ink substitutions to reduce waste
in a wide web (greater than 16 in. wide)
flexographic printing process. This Project was
completed under the Erie County/EPA Waste
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Reduction Innovative Technology Evaluation
(WRITE) Program as a joint effort by
Lustreprint Company; Erie County Environ-
mental Compliance Services, Buffalo, New
York; Recra Environmental, Inc., Amherst,
New York; and the U.S. Environmental Pro-
tection Agency's (EPA) Office of Research
and Development, Cincinnati, Ohio.
Procedure
The industrial participant (Lustreprint Com-
pany) prints flexible packaging whose prod-
ucts are used in the food and snack industry
and in medical, industrial and consumer ap-
plications. Printing is completed on a number
of different web materials, (commonly polypro-
pylene (acrylic coated, Saran coated, and
uncoated corona pretreated), cellophane (Sa-
ran coated), polyester (both metallized and
unmetallized), polyethylene, and nylon (both
Saran coated and uncoated)). At the time of
this study, Lustreprint used one Hudson/Sharp
48 in., central impression, six-oobr, flexo press
and one Heinrich (W&H) five-color, flexo, stack
press.
In 1974, the New York State Department
of Environmental Conservation (NYSDEC)
approved a permit for air emissions from
Lustreprint's two printing presses. When a
three-shift, 7 day-a-week work schedule was
implemented in 1989, the total plant emis-
sions exceeded the baseline criteria of 100
tons/yr. of VOC's.
New York's regulations require that a facil-
ity reduce overall plant emissions to within
the compliance level of 100 tons/yr. As an
option, Lustreprint chose to reduce the use of
solvent-based inks and adhesives. The first
step eliminated solvent-based adhesives used
in laminating. This was followed by a phase-
in of water-based inks to replace the existing
solvent-based inks in the printing operation.
The company goals are to reduce all volatile
organic air emissions to an extent that would
eliminate the need for costly air abatement
and permitting and to eliminate all liquid-phase
solid waste, characterized as hazardous
waste, at the facility.
To achieve these goals, ink use was moni-
tored over four 1-wk-long study periods: 3-
wks when both water-based and solvent-
based inks were used and 1-wk when only
solvent-based inks were used. Historical data
for emissions and waste generation were ex-
trapolated for comparison with the weekly
experimental data. From the 4-wk ink use
and waste analysis data, the VOCs, released
as emissions from the printing process, could
be calculated. A material accounting approach
was used for these calculations. All liquid
wastes generated during the test periods were
segregated and analyzed for percent volatile
constituents.
Substituting water-based inks required press
modifications. The most significant retrofit was
the installation of an Enercon corona dis-
charge treater. Modifications to the Hudson/
Sharp 48 in., central impression, six-color,
flexographic printing press included upgrad-
ing drying capacities and using enlarged ex-
haust and supply fans. Additional ductwork
and noise abatement equipment were needed.
Ink metering rolls were replaced to facilitate
drying. Pumps were also replaced to accom-
modate the new printing inks. Because of
prohibitive costs, the Heinrich (W&H) press
was not modified or retrofitted and was not
used in the water-based ink tests. Future
plans would include replacing this press with
one that could accommodate the ancillary
equipment required for water-based ink use.
The four 1 -wk-bng study periods were com-
pleted to acquire the information on ink use.
Routinely, during the course of each week,
several printing jobs were completed accord-
ing to customer demand and work sched-
ules. The type and amount of ink used for
each printing job was recorded on a Job Ink
Use Work Sheet and a Daily Operations Re-
port Form. These forms were completed at
the end of a print run by the press operator.
Both ink use and make-up solvent added
were recorded. This information was pro-
cessed by a computer billing system to pro-
vide a total picture of the printing job with
respect to material use. Information on the
forms was transferred to the WRITE Ink Us-
age Report identifying ink stock number, ink
type (water versus solvent and color), pounds
of ink to press, pounds of make-up added,
pounds returned to inventory, and weight per-
cent VOC in the ink. VOCs were then calcu-
lated on a material balance basis.
Results and Discussion
Historical Background
Lustreprint is required to submit to
NYSDEC, a monthly report describing VOC
emissions from the plant as a result of opera-
tions. This information includes the amount of
ink used with the necessary calculations to
determine total VOC for the month. NYSDEC
uses the information to determine regulatory
compliance.
Historical data for the period April through
August of 1990 was chosen for comparison
with WRITE data for several reasons. Be-
cause three-shift work schedule adopted at
this time provided comparable ink usage and
the corona treater and other equipment had
not yet been installed for the changeover to
water-based inks, the informatbn represented
a period of exclusive solvent ink use. The
data also represented a period with no signifi-
cant plant operation upsets, which may have
affected ink and solvent use. The historical
data, in its raw form, represents total VOCs
from ink and makeup solvent use for each
month from the two presses, with half the ink
use attributed to each press. Therefore, the
data were adjusted to represent VOC emis-
sions from a single press (total VOC/2) for a
1-wk period (total monthly VOC per press/4)
for comparison with the study period data.
The data in Table 1 shows the VOC emis-
sions, as a functbn of ink use, based on
historical data.
Table 1. VOC Emissions Based on Ink Use,
1990
Ink used VOCs calculated
Month (Ib/wk) (Ib/wk)
April
May
June
July
August
3,038
1,681
2,686
2,109
2,945
2,111
1,700*
2,289
1,731
2,345
* This value is derived from the historical operational
data and attributed to high makeup solvent use
during the event.
Table 2 provides information on the total
pounds and percent of ink used, calculated
VOC emissions, and VOC emissions as a
percentage of ink used for each of the four 1 -
wk-long evaluation periods.
During Weeks 2 and 3 of the study,
Lustreprint's quality assurance check sheets
for each printing job were collected. The press
operator checks the printing quality for sev-
eral parameters at the start and during the
press run.
Ink color, print position, and register are
checked to ensure a satisfactory product that
meets customer criteria. The ink adhesion
check includes the industry standard 610 Tape
Test. A tear sheet sample is collected and the
print itself is checked for various printing im-
perfections such as pin-holes, halo, fish eyes,
and roll marks.
A review of the quality assurance sheets
indicates that the use of water-based inks
typically did not change product quality al-
though some problems arose after customer
use, depending upon the ultimate use of the
packaging, what the package contained, and
the means by which the packages were
sealed. Heat and stress of the printed pack-
age material caused by the package folding
and sealing process at times resulted in a
loss of ink adhesion.
Some combinations of water ink and sol-
vent ink were incompatible. Water inks did
not provide a consistent opaque white for
laminations to cover metallized films and re-
sulted in "blocking" (or transfer of print) when
printing on Saran-coated materials, especially
cellophane. In most cases, however, depend-
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Table 2. Ink and VOC Emission Data for 4-Week Study Period
Measured Parameter Week 1 Week 2 Week 3
Week 4
No. of inks
Solvent ink (Ib)
Water ink (Ib)
Total ink (Ib)
Solvent ink (%)
Water ink(%)
VOC emissions (Ib)
(calculated)
VOC emissions (%)
(% of ink total)
Waste (Ib)
Waste VOC content (Ib)
23
1,112
1,251
2,363
47.1
52.9
827.5
35.0
55.6
54.3
32
1,746
508
2,254
77.5
22.5
1,251.7
55.5
20.0
4.7
ing on the surface printed, no difference was
noted with the use of water-based inks.
Normal propyl alcohol added in small
amounts (less than 1%) to prevent water ink
foaming at the ink pan and to assist in ink
wetting was beneficial. Variatbns of the pres-
sure sensitive "stickyback" material used to
attach the printing plates to the plate cylinder
(solid versus cushioned stickyback) also en-
hanced printing solid plate backgrounds with-
out pin-holing. The plate material may also
have an effect. Photo polymer plates work
well with water but are more expensive than
rubber. Nylon plates are a possible compro-
mise with a longer life than rubber plates.
VOC Reduction
Substituting with water ink reduced the
emissions generated from the printing pro-
cess. For each percent increase in water-
based ink use, the calculated reductbn in
VOC emissions was 14 Ib (Table 3).
As can be seen from Table 3, for Weeks 1
and 2, the VOC generation decreased in
proportion to the percentage of water-based
ink used. A 52.9% water-based ink use re-
sulted in a 53.3% reduction in VOC emis-
sbns. Similarly, in Week 2, a water-ink use
rate of 22.5% resulted in a VOC emissbn
reduction of 23.4%.
For Week 4, the corresponding reduction
in VOC emissions was less significant: a
55.6% water-ink use rate reduced VOC emis;-
sbns only 43.3%. Total ink use for Week 4
was 1,237 Ib of combined water ink and
solvent ink. This amount is approximately half
that was used during the other 3 wks of the
study. The number of different inks used in
Week 4 is, however, comparable with that
used in Week 1. With the same number of
ink changes at the printing statbns and with
each change requiring a cleaning before add-
ing new ink, the amount of cleaning make-up
solvent relative to total ink use is expected to
increase. The contribution of VOC emissions
33
2,252
0
2,252
100
0
1,571.5
22
549
688
1,237
44.4
55.6
509.0
69.8
0.0
0.0
41.1
0.0
0.0
from clean-up solvents reduced the overall
effectiveness of VOC reduction by water inks.
Waste Reduction
Historically, 315 gal of solid waste was
generated each month. This translates to ap-
proximately 1.5-55 gal drums or 424 Ib/wk.
Printing operations during Week 1 generated
55.5 Ib of solvent-ink waste, and Week 2
generated 20.0 Ib of water-based ink waste.
Therefore, the net result in Week 1 was an
87% decrease from normal in solid waste
generation (from 424 Ib to 55.5 Ibs); a 95%
decrease in Week 2 (to 20.0 Ib); and 100%
elimination of solid waste generation in Weeks
3 and 4.
Note that much of this waste decrease can
be attributed to factors other than the type of
ink used. The WRITE Program evaluatbn
and the use of the waste generation form
increased awareness of press operators and
deterred waste generation. This induced press
operators to reuse solvent for additional clean-
ing or reuse in the solvent inks.
Economic Analysis
An economic analysis of the changeover
from solvent to water-based ink is included as
part of this project.
Fixed, variable, and overhead costs are
affected by this substitution and are consid-
ered. Fixed costs include the purchase and
installation of new equipment (primarily the
Enercon corona discharge treater) and costs
for replacing equipment ancillary to the cen-
tral impression cylinder press, such as pumps,
dryer upgrade, ink pans, etc.
Variable cost adjustments include the pre-
mium paid, or reduced cost, for water-based
inks. Calculating the costs for all inks used
during each of the 1-wk period produced an
average cost per gal. It was anticipated that,
with the premium paid for water-based inks,
the cost per gal would be higher for the
weeks when the greatest amount of water-
based inks was used. Disposal costs were
calculated by using the amount of waste sol-
vent ink generated in gals and the most re-
cent disposal cost figures provided by
Lustreprint. (The cost of scrap product waste
was, however, attributed to plant personnel
being unfamiliar with the operation of the
corona discharge treater. This waste was not
included in the economic determination and
should decrease over time.) Other variable
costs included variations in labor hours and
utilities.
Overhead costs also play a role in deter-
mining the cost savings. Items such as the
time previously expended for regulatory com-
pliance, insurance costs, employee equipment
and safety training, and OSHA compliance
were expected to be reduced as a result of
removing hazardous waste from the shop
floor. These potential cost savings were esti-
mated from existing figures where available.
Based on these costs, payback period and
net present value (NPV) were calculated
(Tables 4 and 5).
The payback period could be further re-
duced by eliminating the solid waste disposal.
With the complete changeover to water inks
and the planned purchase of an ink splitter at
approximately $8,000, an additional savings
for solid waste disposal is possible. The
payback period would then be reduced 0.53
year.
Reduced material handling and regulatory
and training costs would lower this payback
period further. It was not possible to quantify
these during the study, and it is estimated
that their effect would be minimal unless full
conversion took place.
The positive NPV indicates the project
changeover will favorably affect cash flows
and will ultimately result in a cost savings.
This economic evaluatbn indicates that the
decision to substitute the water inks for sol-
vent inks was financially beneficial. To under-
score the selection, a brief discussion of the
alternative, installing an incineration unit to
control plant emissions, is necessary. The
estimated cost of a facility wide incineration
unit varied significantly — between $200,000
and $1,000,000. In addition, the VOC content
of the Lustreprint emissions would have been
insufficient for proper operation of the incin-
eratbn unit. A supplemental natural gas feed
for the unit would cost approximately $45,000
per year. Furthermore, the potential for fur-
ther regulatory restrictions in solvent use for
the printing industry could affect the cost/use
of this technology. (Note - the control technol-
ogy has nothing to do with further regulatory
restrictions.)
Conclusions
By installing an in-line corona treater, higher
surface tension water-based inks could be
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used. This, in turn, reduced VOC emissbns
approximately 72.5%, when compared with
those for solvent. The water-based ink formu-
las contain about 20% solvent. For a process
using a quantity of approximately 2250 Ib of
solvent-based ink (weekly), VOC emission
levels were about 1570 Ib. For every 1%
increase in water-based ink use, VOC emis-
sbns were reduced 14 Ib.
The substitution typically did not adversely
affect product quality or nonhazardous scrap
waste generatbn. Some changes in operat-
ing procedures were, however, necessary
because of the nature of water-based inks.
The average reductbn of 95% of liquid F003
waste from waste ink and cleaning solvents
recorded during the study period resulted from
operational practice changes.
The payback period for the corona treater
and equipment modificatbns is 2.56 years.
Additionally, through segregation of wastes
once full implementation of water-based inks
is achieved, the payback period could be
reduced to 0.54 years. NPV works out to a
positive cash flow of $39,165 for this project.
This project has resulted in a double ben-
efit to Lustreprint: they have reduced their
VOC emissions and reduced process costs.
This successful implementation of water-based
inks in flexographic wide web printing should
be considered as a VOC source reductbn
method for similar printing operatbns.
The full report was submitted in fulfillment
of CR-816762-02-0 by Erie County Depart-
ment of Environment and Planning under the
sponsorship of the U.S. Environmental Pro-
tection Agency.
Table 3. VOC Reduction
Week
1
2
3
4
Total
ink (Ib)
2,363
2,254
2,252
1,237
Factored*
VOC (Ib)
1,772
1,634
1,633
897
Water ink
(%)
52.9
22.5
0.0
55.6
Reduced
VOC (Ib)
827.5
1,251.7
1,571.5
509.0
Reduction (%)
53.3
23.4
0
43.3
'Calculated by taking 72.5% of the total ink quantity.
Table 4. Payback Period
Variable
Initial
Investment
Projected
Savings
Payback
Period, yr
Current process revisions
Adding an $8000 ink splitter
Full water-based ink conversion
$62,901
$70,901
$62,901
$24,587
$34,887
$117,078
2.56
2.03
0.54
TableS. Net Present Value'
Depreciation
Method
Straight line
Sum of years digits
Double declining
balance
Initial
Investment
$62,901
$62,901
$62,901
Operation &
Maintenance
$6, 145
$6, 145
$6, 145
Tax Savings on
Depreciation
$15,461
$17,634
$17,238
Savings on Ink
and Solvent
$90,577
$90,577
$90,577
NPV
$36,992
$39, 165
$38,769
'Assumptions: 10-year life span; no salvage value; 10% discount factor; 40% tax rate; $1,000 per year O&M cost.
•&U.8. GOVERNMENT PUNTING OFFICE: 19*3 - 7S047I/M071
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P. B. Kranz is with Erie County Department of Environment and Planning,
Buffalo, NY 14202; T. R. Williamson III is with Recra Environmental, Inc.,
Amherst, NY 14228; and the EPA author, Paul M. Randall (also the EPA
Project Officer, see below), is with the Risk Reduction Engineering Labora-
tory, Cincinnati, OH 45268.
The complete report, entitled "Replacement of Hazardous Material in Wide
Web Flexographic Printing Process," (OrderNo. PB93-228 128/AS; Cost:
$19.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
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POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-93/149
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