Introduction
This study, performed under the U.S.
Environmental Protection Agency's (EPA's)
Waste Reduction and Innovative Technol-
ogy Evaluation (WRITE) Program, was a
cooperative effort among EPA's Risk Re-
duction Engineering Laboratory, Connecti-
cut Hazardous Waste Management Ser-
vice, and The Hartford Courant. The goal
of the WRITE Program is to evaluate, in a
typical workplace environment, examples
of prototype or innovative commercial tech-
nologies that have potential for reducing
wastes and to provide this information to
potential users. The objectives of the waste
ink recycling study were to evaluate (a)
the quality of the recycled ink, (b) the
waste reduction potential of the technol-
ogy, and (c) the economic feasibility of
the technology. The recycling process is
shown in Figure 1. The major components
of the recycling unit were purchased on a
skid from Separations Technologies Inc.'
Other equipment was added as required.
Trays containing waste ink (consisting of
75% black and 25% colored ink) from the
press room are emptied on a 1/4-in. wire
mesh to remove nuts, bolts, and other
gross contaminants. The waste ink then
goes to a large waste ink storage tank.
When enough ink is available in this tank,
the batch is processed. Processing prima-
rily involves vacuum distillation, filtration,
and blending.
Waste ink from the storage tank is trans-
ferred to the distillation still and distilled at
140°C under vacuum. Solvent and water
from the waste ink are vaporized, con-
densed (by a chiller), and collected in a
separator tank where water and solvent
separate out into two phases under grav-
ity. The water is drained off and discharged
to the municipal sewer (under permit), and
* Mention of trade names or commercial products does
not constitute endorsement or recommendation for
use.
Printed on Recycled Paper

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Black and
Colored Waste
Ink
Larger Particles

Traj
'res
1 t '
1 1/4 in. \Wire Mesh ,

s Room 1
" 1

Waste Ink \ \
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k Recycled ianK \ |
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er | '
k Virgin 1 , |
ink ,:: 1

lank < \
l-ffitrtfrtn T-rnlr < —_ /%--^— 1

(Recycled Ink) [_ _^

1
Vacuum
1 1
Mixer
r
Distillation
Still
CO

Coarse
Filters
1 »
| '
Fine
Filters

Condenser
To Reuse
To
Municipal
Drain
Separator
Tank
Paper Dust
• Residue
Process Skid
FIgtm 1. Waste Ink recycling process.
the solvent Is reused In the presses. The
Ink in the distillation still is sent through
100- and 325-mesh filters to remove pa-
par dust and then transferred to a blend-
ing tank. At this point, a grind test and a
drawdown test are performed, and the
amount of virgin black ink required (typi-
cally three to four times the amount of the
processed ink) for blending is determined.
The virgin Ink is added to improve the
color, consistency, and other functional
properties of the processed Ink to an ac-
ceptable range. The processed ink, after
blending with virgin black ink, is called the
final "recycled* Ink.
The study was done at The Hartford
Courant, which employs about 1,500
people and has a daily circulation of
225,000 and a Sunday circulation of
320,000. Approximately 175 gal of waste
ink are collected per week. Previously,
the Ink was sent to a vendor location
where it was blended with other solvents
to create a supplemental fuel. Since Octo-
ber of 1990, waste ink has been recycled
on-sfte and reused for printing.
Product Quality Evaluation
During the printing process, the excess
(waste) ink is collected underneath the
presses, along with excess fountain solu-
tion (water) and the blanket wash solution
(typically an aliphatic-aromatic blend sol-
vent). Paper dust and fibers generated by
the newsprint also enter the waste ink.
The recycling process should remove
these impurities and restore the proper-
ties of the ink.
Two batches of waste ink were pro-
cessed through the recycling unit and
samples of the waste and recycled
(blended) ink were collected for analysis.
Samples of the virgin (new) ink used at
The Courant were also collected and ana-
lyzed. A comparison of the analytical re-
sults of the waste and recycled inks indi-
cates the improvement achieved by recy-
cling, and a comparison of the recycled
and virgin inks indicates how closely the
recycled product approximates the virgin
product.
The results of the product quality analy-
ses are shown in Table 1. The recycled
ink fared well in most of the analyses. The
viscosity, as measured by ASTM ID 4040-
89, of the recycled ink was within ± 1
Poise and in the normal range for news-
paper inks. The grind (ASTM D 1316-87)
and residue (U.S. Printing Ink Method #12)
analyses indicated that some very fine
particulates were retained in the recycled
ink, although this did not cause any prob-
lems in the printing process at The Cou-
rant. Tack (ASTM D 4361-89) was mea-
sured at speeds specific to The Courant
(1200 rpm at 1 min for web-fed inks). One
sample was slightly above industry rec-
ommendation and the other was: within
this standard. Press operators at the The
Courant did not think that the sample that
was slightly out of range was of any sig-
nificant concern.
Relative tinting strength was measured
by a method similar to ASTM D 387, D
2745, and D 4838, and again, one sample
was slightly out of range. Since the re-
cycled ink is blended with virgin ink, the
ratio of virgin-to-processed ink could be
increased to improve the tinting quality of
the ink. Water content (ASTM D 1744-83)

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Table 1. Results of Analytical Tests for Product Quality
Analytical Tests
Batch
No.
1,2
1
2
Sample Type
Waste Ink
Recycled Ink"
Recycled Ink"
Virgin Ink
Industry Standard
Viscosity
(Poise)
NA°
19
21
20
Grind (mil)
4/10 •
NA
0.4/0.3
0.6/0.3
0.3/0.0
93
Water
Content (%)
23.6
0.102
0.049
0.057
Water
Pickup (%)
NA
86
80
50
• 4/10 refers to 4 or 10 scratches at reported endpoints.
6 Strength of recycled ink was compared to the virgin ink and given as a percentage of the virgin ink strength.
0 AM = A/of analyzed. Tests could not be performed because of the large amount of water in the sample.
" Processed ink blended with virgin ink in the ratio 1:3.
analyses showed that most of the water is
removed in the recycling process. No in-
dustry standards are indicated for this be-
cause it depends on the individual printing
process. Operators at The Courant ob-
served no problems resulting from water.
Water pickup (ASTM D 4942-89) analy-
ses determines the emulsifying capability
of the ink. This parameter also varies with
the printing process, and the recycled ink
results posed no problems.
The visual effect and behavior of the
recycled (blended) ink, once it is printed
on a newspaper, was evaluated by (a)
densitometer readings of black image ar-
eas of newspapers printed with virgin and
recycled inks and (b) analysis by 11 expe-
rienced viewers of newspaper pages
printed with recycled or virgin inks. Table
2 shows the results of the densitometer
measurements. In general the recycled
ink was much denser than the virgin ink
on the wrapper, or exterior pages, of the
newspaper. The virgin ink was only slightly
denser than the recycled ink on the core,
or interior pages. The results of the visual
judging (Table 3) showed that the news-
papers printed with recycled ink were of
comparable quality to those printed with
virgin ink.

Waste Reduction Potential
Waste reduction potential was measured
in terms of (a) volume reduction and (b)
pollutant reduction. Volume reduction ad-
dresses the gross waste stream and af-
fects environmental resources (e.g., land-
fill space) expended during disposal (e.g.,
waste ink), whereas pollutant reduction
addresses the specific hazards of indi-
vidual pollutants (e.g., heavy metals) in
the gross waste stream.
The waste-volume reduction potential
of the technology involves the amount of
waste ink and solvent that does not enter
the environment (by fandfilling, waste in-
cineration, or as supplemental fuel). The
Courant generates approximately 175 gal/
wk, or 9,100 gal/yr of waste ink. This
waste ink consists of 5,460 gal of ink, 546
gal of solvent and 3,049 gal of water.
Recycling at 7/70 Courant means 6,006
gal of ink and solvent will not be disposed
of. 7?7e Courant is also considering install-
ing an activated carbon filter for polishing
off organics in the wastewater from the
separator so that the water can also be
reused.
Waste ink contains a number of compo-
nents that potentially could render it haz-
ardous. The waste ink at The Courant has
been tested and is not considered a haz-
ardous waste per Resource Conservation
and Recovery Act (RCRA) regulations and
can be disposed of according to state
regulations for oily wastes. Solvent washes
for other inks that contain lead or chro-
mium in their formulation are, however,
listed as hazardous wastes (EPA Waste
Number K086) under RCRA. In addition,
Table 2. Results of Densitometer Readings on the Newspapers
Densitometer Readings (units)
Paper Type '
Wrapper -
Newspaper 1
Wrapper -
Newspaper 2
Wrapper -
Newspaper 3
Core-
Newspaper 1
Core-
Newspaper2
Core-
Newspaper 3
Location
on
Page"
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Paper Printed
with
Virgin Ink
0.95
0.99
0.98
0.91
0.95
1.00
0.94
0.97
0.91
1.05
1.00
1.02
1.08
1.02
1.01
1.05
1.01
0.97
Paper Printed
with
Recycled Ink"
1.10
1.00
1.09
1.08
1.03
1.11
1.07
1.02
1.04
0.99
1.01
0.92
1.06
1.01
1.02
1.01
0.97
0.98
% Difference d
(Recycled to Virgin)
14.6
1.0
10.6
17.1
8.1
10.4
12.9
5.0
13.3
-5.9
1.0
-10.3
-1.9
-1.0
-1.0
-3.9
-4.0
1.0
Wrapper refers to the exterior pages of a newspaper section while core refers to the interior pages.
Three complete editions were printed with virgin ink and three with recycled ink.
The same three locations were tested on each wrapper page and each core page.
Processed ink blended with virgin ink in the ratio 1:3.
A positive % difference indicates that the tested areas were denser for recycled ink according to the
densitometer, and vice versa.

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Table 3. Results of Visual Judging * for Product Quality

Wrapper Page (outer)
Core Page (inner)
Parameter
Glossiness
Smoothness
Op&diy
Rub Resistance
Blackness
Absorption/
Bleed-Through
Sharpness
# Viewers
Preferring
Virgin Ink
0
0
0
3
0
2
1
# Viewers With
No Preference
or Preferring
Recycled lnkb
11
11
11
8
11
9
10
Upper 95%
Confidence
Bound on the
Proportion
Preferring
Virgin Ink
0.238
0.238
0.238
0.564
0.238
0.470
0.364
# Viewers
Preferring
Virgin Ink
2
4
4
1
4
1
3
# Viewers With
No Preference
or Preferring
Recycled Ink'
9
7
7
10
7
10
8
Upper 95%
Confidence
Bound on the
Proportion
Preferring
Virgin Ink
0.470
0.650
0.650
0.364
0.650
0.364
0.564
* Bovon experienced viewers of newspapers.
* Processed ink blended with virgin ink in tfts ratio 1:3.
other waste Inks could contain constitu-
ents that render them flammable or toxic.
Many toxtctty problems are caused by the
pigments used. Lead, chromium, barium,
and organic compounds are common
toxics In pigments. Solvents in the waste
Ink are usually aliphatic-aromatic blends.
These solvents may contain hazardous
organic constituents. By recycling, virtu-
ally all of these potential pollutants in ink
are reused and thus prevented from en-
tering the environment.
The recycling process generates paper-
dust residue, which is basically a paste-
like substance containing paper fibers cov-
ered with a thick mass of ink. The haz-
ards associated with this residue are the
same as those discussed above for the
ink, but the advantage is that, for every
200 gal of waste ink, less than 1 gal of
this residue is generated.

Economic Evaluation
The economic evaluation took into ac-
count the capital and operating costs of
the recycling equipment, as well as the
savings resulting from reduced amounts
of raw materials (virgin ink and solvent)
and disposal costs. A return on invest-
ment of about 9% is obtained in the tenth
year of recycling. With a payback period
of about 10 yr for the $318,000 capital
requirement, the recycling equipment
tested here is a large Investment, even for
a medium- to large-size newspaper such
as The Courant Smaller modules with
similar capabilities are, however, commer-
cially available and could be considered
by smaller newspapers. As the cost of
disposal continues to grow (as indicated
by current trends) and issues of long-term
liability assume greater importance, the
economic attractiveness of this system can
be expected to increase.

Discussion
The waste ink recycling evaluation dem-
onstrated that the potential for waste re-
duction with ink recycling is promising.
77?d Hartford Courant reduced waste vol-
ume from over 9,000 gal of waste ink to
approximately 46 gal of paper dust and
3,049 gal of wastewater per yr. The re-
cycled product fared well in both product
quality testing of the recycled ink and qual-
ity of the actual printed material. The slight
deviation of some recycled ink test results
from the industry standard did not cause
any noticeable reduction in print quality.
The blanket wash solvent in the waste
was also recovered and reused. The
wastewater (generated from the fountain
solution component of the waste) con-
tained some levels of contaminants that
make it toxic; however, the small volume
of this wastewater (254 gal/mo) should
not be a problem for a POTW. Neverthe-
less, it would be desirable from a resource
recovery standpoint, to recover this water
on-s'rte by passing it through an activated
carbon filter and reusing it.
Economic incentive for recycling is the
value of the ink and solvent recovered, as
well as reduced disposal costs and poten-
tially reduced liabilities through direct con-
trol over potentially hazardous waste. If
waste disposal and liability costs follow
current trends, the economic incentive for
recycling will improve.
A much smaller recycling system than
the one installed at The Courant would be
sufficient for smaller newspapers. The
technology (distillation and filtration) used
at The Courant is fairly straightforward,
and smaller scale units can be assembled.
Several smaller vacuum distillation batch
stills are commercially available at much
lower cost. Some smaller newspapers
have designed their own filtration systems
for reclamation of ink. Another option for
smaller newspapers is to use the services
of a mobile, truck-mounted recycling sys-
tem that goes from site to site and re-
cycles waste ink for a charge. One such
mobile unit is being operated by a vendor
in California. Printers other than newspa-
pers, may be able to use similar technolo-
gies.
The full report was submitted in fulfill-
ment of Contract No. 68-CO-0003 by
Battelle Memorial Institute under the spon-
sorship of the U.S. Environmental Protec-
tion Agency.

Acknowledgments
The authors wish to acknowledge the
efforts of Sumner Kaufman of ESSAR En-
vironmental Services (consultant to the
Connecticut Hazardous Waste Manage-
ment Service) and Paul Reynolds of The
Hartford Courant. Their initiative and sup-
port made this study possible.
•U.S. Government Printing Office: 1993— 750-071/60198

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A R Gavascar, R.F. Olfenbuttel, andJ.A. Jones are with Battelle Memorial
  Institute, Columbus, OH, 43201-2693.
List Brown Is the EPA Project Officer (see below).
The compbte report, entitled "On-site Waste Ink Recycling," (Order No. PB93-
    141026; Cost: $19.50, subject to change) will be available only from
        National Technical Information Service
        £285 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, Ohio 45268
   United States
   Environmental Protection Agency
   Center for Environmental Research Information
   Cincinnati, OH 45268

   Official Business
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