United States
                Environmental Protection
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
  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).

  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
  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

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.
  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
  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
  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
   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,
            Ink used       VOCs calculated
Month       (Ib/wk)            (Ib/wk)
 * 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-

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)
VOC emissions (%)
(% of ink total)
Waste (Ib)
Waste VOC content (Ib)




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


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
  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
  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

  By installing an in-line corona treater, higher
surface tension water-based inks  could be

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
ink (Ib)
VOC (Ib)
Water ink
VOC (Ib)
Reduction (%)
 'Calculated by taking 72.5% of the total ink quantity.
 Table 4. Payback Period

Period, yr
 Current process revisions
 Adding an $8000 ink splitter
 Full water-based ink conversion
 TableS. Net Present Value'
Straight line
Sum of years digits
Double declining
Operation &
$6, 145
$6, 145
$6, 145
Tax Savings on
Savings on Ink
and Solvent
$39, 165
'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




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

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