SEPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/4-79-014
September 1979
Air
Graphic Arts:
An AP-42 Update
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EPA-450/4-79-014
GRAPHIC ARTS:
AN AP-42 UPDATE
PACIFIC ENVIRONMENTAL SERVICES, INC.
1930 14th Street
Santa Monica, California 90404
Contract No. 68-02-2583
Work Assignment No. 12
EPA Project Officer: Audrey McBath
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
September 1979 Property Of
EPA Li::rc;y
RTP LO 27711
Pacific Environmental Services, INC.
CORPORATE AND ENGINEERING 1930 14th Street Santa Monica. California 90404 Telephone (213) 450-1800
MIDWEST OPERATIONS 465 Fullerton Avenue Elmhurst, Illinois 601 26 Telephone (31 2) 530-7272
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This report is issued by the U.S. Environmental Protection Agency to
report technical data of interest to a limited number of readers.
Copies are available free of charge to Federal employees, current con-
tractors and grantees, and nonprofit organizations - in limited quan-
tities - from the Library Services Office (MD-35), U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711; or,
for a fee, from the National Technical Information Service, 5285 Port
Royal Road, Springfield, Virginia 22161.
This report was furnished to the U.S. Environmental Protection Agency
by Pacific Environmental Services, Inc., 1930 14th Street, Santa
Monica, California 90404. The contents of this report are reproduced
herein as received from Pacific Environmental Services, Inc. The
opinions, findings, and conclusions expressed are those of the authors
and not necessarily those of the Environmental Protection Agency.
Mention of company or product names is not to be considered as an
endorsement by the Environmental Protection Agency.
Publication No. EPA-450/4-79-014
n
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TABLE OF CONTENTS
Page
FIGURES iv
TABLES iv
INTRODUCTION 1
GRAPHIC ARTS 2
4.9.1 Process Description 2
4.9.1.1 General 2
4.9.1.2 Web Offset Lithography 3
4.9.1.3 Ueb Letterpress 5
4.9.1.4 Rotogravure 5
4.9.1.5 Flexography 9
4.9.2 Emissions and Controls 10
4.9.2.1 General 10
4.9.2.2 Web Offset Lithography 11
4.9.2.3 Web Letterpress 13
4.9.2.4 Rotogravure 13
4.9.2.5 Flexography 15
REFERENCES FOR SECTION 4.9 17
BACKGROUND DOCUMENT 19
m
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FIGURES
Number Page
4.9-1 Web offset lithography publication printing line
emission points 4
4.9-2 Web letterpress publication printing line emission
points 6
4.9-3 Rotogravure and flexography printing line emission
poi nts 8
TABLES
Number
4.9-1
4.9-2
Page
Typical parameters for computing solvent emission
from uncontrolled web offset lithography, web
letterpress, rotogravure and flexography printing
1i nes
Estimated control technology efficiencies for web
offset lithography, web letterpress, rotogravure
and flexography printing lines
12
16
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INTRODUCTION
As the Table of Contents indicates, this report was written for
inclusion in EPA Publication No. AP-42, Compilation of Air Pollutant
Emission Factors. A preliminary draft of this section was begun when
the draft version of the Control Techniques Guideline (CTG) document
on "Graphic Arts" became available in April 1978. This work was
performed under Work Assignment No. 7 of EPA Contract No. 68-02-2583.
The publication date of the CTG document was subsequently postponed
from July to December 1978, so completion of this AP-42 section was
likewise delayed and was completed under Work Assignment No. 12 of the
contract.
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4.9 GRAPHIC ARTS
4.9.1 Process Description
4.9.1.1 General--The term "graphic arts" as used here means four
basic processes of the printing industry: web offset lithography, web
letterpress, rotogravure and flexography. Screen printing and manual
and sheet fed techniques are not included in this discussion.
Printing may be performed on coated or uncoated paper and on other
surfaces, as in metal decorating and some fabric coating (see 4.2
Industrial Surface Coating). The material to receive the printing is
called the substrate. The distinction between printing and paper
coating, which may employ rotogravure or lithographic methods, is that
printing invariably involves the application of ink by a printing
press. However, printing and paper coating have the following
elements in common:
• Application of a relatively high solvent content material
to the surface of a moving web or film
• Rapid solvent evaporation by movement of heated air across
the wet surface
• Solvent laden air exhausted from the system
Printing inks vary widely in composition, but all consist of three
major components:
• Pigments, which produce the desired colors and are composed
of finely divided organic and inorganic materials
» Binders, the solid components that lock the pigments to the
substrate and are composed of organic resins and polymers, or
in some inks, oils and rosins
-2-
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• Solvents, which dissolve or disperse the pigments and binders and
are usually composed of organic compounds
The binder and solvent make up the "vehicle" part of the ink. The
solvent evaporates from the ink into the atmosphere during the drying
process.
4.9.1.2 Web Offset Lithography—Lithography, the process by which
about 75 percent of books and pamphlets and an increasing number of
newspapers are now printed, is characterized by a planographic image
carrier (i.e., the image and nonimage areas are on the same plane).
The image area is ink wettable and water repellant, and the nonimage
area is chemically repellant to ink. The solution used to dampen the
plate may contain 15 to 30 percent isopropanol, if the Dalgren
dampening system is used.8 when the image is applied to a rubber
covered "blanket" cylinder, which then transfers the wet inked image
onto the substrate, the process is known as "offset" lithography.
When a web (i.e., a continuous roll) of paper is employed with the
offset process, this is known as web offset printing. Figure 4.9-1
illustrates a web offset lithography publication printing line. A web
newspaper printing line contains no dryer because the ink contains
very little solvent, and somewhat porous paper is generally used.
Web offset employs "heatset" (i.e., heat-drying offset) inks that
dry quickly. For publication work, the inks contain about 40 percent
solvent, and for newspaper work, 5 percent solvent is used. In both
cases, the solvents are usually petroleum derived hydrocarbons.11
For publication work, the web is printed on both sides simultaneously
and passed through a tunnel or floater dryer at about 200-290°C (400-
£%ii
•9ae°F). The dryer may be hot air or direct flame. Approximately 40
percent of the incoming solvent remains in the ink film and more may be
-3-
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<»••
Thermal or
Catalytic (
Incinerator •
'
Ink Solvent and
r •* •
1
1
1
i- —
Thermal Degradation
Products
;
Heat i
Excr
*
l
Danger '
L__J
— 1
Shell
and
flat
Tube
Heat
Exchanger
Co
prc
orn
°2
air
Exhaust (an
I
Fan
[ Filter
Combustion
products
•Unburned
or n a nic s
02 depleted
Fresh air
Filter
Fan
Gas
Air Heater
for dryer
Ink Solvent and
Thermal Degradation
Products
Heatset Ink
Wash-up
solvents
Water and
Isopropaf
vapor
Neb
Printed Web (6 ,
Water and
isopropanol vapor
Water1
Isopropanol
(With Dalgren
Dampening System)
Figure 4.9-1. Web offset lithography publication printing
line emission points (dashes show optional control equipment).
11
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thermally degraded in a direct flame dryer. The web passes over
chill rolls prior to folding and cutting. For newspaper work, no
dryer is used, and most of the solvent is believed to remain in the
ink film on the paper.^
4.9.1.3 Web Letterpress—Letterpress is the oldest form of printing
(limited to movable types) and still predominates in periodical and
newspaper publishing, although numerous major newspapers are convert-
ing to web offset. In letterpress printing, the image area is raised
relative to the nonimage area, and the ink is transferred to the paper
directly from the image surface. The image carrier may be made of
metal or plastic. Only web presses using solvent-borne inks are
discussed here because letterpress newspaper and sheet fed printing
use oxidative-drying inks which are not a source of volatile organic
emissions. Figure 4.9-2 shows one unit of a web publication
letterpress line.
Publication letterpress printing uses a paper web that is printed
on one side at a time and dried after each color is applied. The inks
employed are heatset and usually contain about 40 volume percent sol-
vent. The solvent in high-speed operations is generally a selected
petroleum fraction akin to kerosene and fuel oil, with a boiling point
of 200-370°C (4'00-700°F).13
4.9.1.4 Rotogravure--!n gravure printing, the image area is
engraved or "intaglio" relative to the surface of the image carrier,
which is a copper plated steel cylinder that is usually also chrome
plated to enhance wear resistance. The gravure cylinder rotates in an
ink trough or fountain. The ink is picked up in the engraved area,
-5-
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Thermal
Incinerator
Heat
I Exchanger
I
i
I
Notary
~" Head
lExchor
Comb istm-
products
Unb.irned
organics
C> Depleted
Web
Exn
lust
18
nf
i
*^
Fan
/-
V
P
Heatset Ink
1
GD
•
»•
J
\ filter |
,
c
1 ] Tresh air
filter
Fan
•N
1
Air
i
Heater
For
Dryer
I Gas
1 L
I
t
I
i
i
i
i
' only when
Gas , catalytic
' i unit is
_ _ _ * _ _ 1 , used here
Catalytic j J
—Incinerator . ]
,1
1 ,
l-r --J1
ST\
Solvent and thermal
degradation product*
Wash-up
solvents
Tunnel
or
Floater f*)\
Dryer ^—
) Supply fan
Air and smoke
Chill
©
Printed Web
(4)
I
Air
Air
Cool water
Figure 4.9-2. Web letterpress publication printing
line emission points (dashes show optional equipment).
11
-6-
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and excess ink is scraped off the nonimage area with a steel "doctor
blade". The image is transferred directly to the web when it is
pressed against the cylinder by a rubber covered impression roll.
The product is then dried. Rotary gravure systems are known as
"rotogravure" presses.
Rotogravure can reproduce illustrations with excellent color con-
trol, and it may be used on coated or uncoated paper, film, foil and
almost every other type of substrate. Its use is concentrated in (1)
publications and advertising such as newspaper supplements, magazines
and mail order catalogues; (2) folding cartons and other flexible
packaging materials; and (3) specialty products such as wall and
floor coverings, decorated household paper products, vinyl upholstery
and health products. Figure 4.9-3 illustrates one unit of a publica-
tion rotogravure press. Multiple units are required for multiple
color printing.
The inks used in rotogravure publication printing contain from 55
to 95 volume percent low boiling solvent, and they must have low vis-
cosities. Typical gravure solvents include alcohols, aliphatic naph-
thas, aromatic hydrocarbons, esters, glycol-ethers, ketones and nit-
roparaffins. Water based inks are in regular production use in some
packaging and specialty applications, such as sugar bags.
Rotogravure is similar to letterpress printing in that the web is
printed on one side at a time and must be dried after the application
of each color. Thus, for four color, two-sided publication printing,
eight presses are employed, with each press including a pass over a
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Tottmosp
here
Traces of
water and
solvent
i
i Solv
T Hot water
1 Solvent Still l
J — " i I" ~\ Mixture
^ ' Condenser | ^ ' Decanter | Warm
i | I Jwater | _,
Ji Cool water
Steam Plus
Solvent Vapor f ~\
fc* 1 ^B_^^.i«-.^«
Adsorber j products
,_ J r__ 1 .
1
1 Activated Carbon [^ "^ J
1 Adsorber j ' T~P
1 1 GasT 1 ,
Air 'Water
Solvent-laden air
Web
Ink
1 •
Ink Fountain
^^^^^^
i i
Press
(One
Unit)
(D
^ 1
Steam Drum or
(3)
^
r*hi 1 1 Rnllc
©
^Air f IT T |T Cool weier
1 1 f Heat Alr
Alr from
steam,
hot water,
or hot air
Printed
Web
Figure 4.9-3. Rotogravure and flexography printing line
emission points (dashes show optional control equipment).11
-8-
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steam drum or through a hot air dryer at 38-93°C (100-200°F), where
nearly all of the initial solvent is removed.3
4-9.1.5 F1exography--In flexographic printing, as in letterpress, the
image area is raised above the surface of the plate. The distinction
is that flexography uses a rubber image carrier and alcohol based
inks. The process is usually web fed and is employed for medium or
long multicolor runs on a variety of substrates, including heavy
paper, fiberboard, metal and plastic foil. The major categories of
the flexographic market are flexible packaging and laminates, multi-
wall bags, milk cartons, gift wrap, folding cartons, corrugated paper-
board (which is sheet fed), paper cups and plates, labels, tapes, and
envelopes. Almost all milk cartons and multiwall bags and half of
flexible packaging are printed by this process.
Steam set inks, employed in the "water flexo" or "steam set flexo"
process, are low viscosity inks of a paste consistency that are gelled
by water or steam. Steam set inks are used for paper bag printing,
and they produce no significant emissions. Water based inks, usually
pigmented suspensions in water, are also available for some flexo-
graphic operations, such as the printing of multiwall bags.
Solvent-based inks are used primarily in publication printing, as
shown in Figure 4.9-3. Like rotogravure, flexography publication
printing uses very fluid inks, containing about 75 volume percent or-
ganic solvent. The solvent, which must be compatible with rubber, may
be alcohol or alcohol mixed with an aliphatic hydrocarbon or ester.
Typical solvents also include glycols, ketones and ethers. The inks
dry by solvent absorption into the web and by evaporation, usually in
high velocity steam drum or hot air dryers, at temperatures below
3 13
120°C (250°F). ' Like letterpress publishing, the web is printed
-9-
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on only one side at a time. The web passes over chill rolls after
drying.
4.9.2 Emissions and Controls
4.9.2.1 General—Significant emissions from printing operations con-
sist primarily of volatile organic solvents. Such emissions vary with
the printing process, ink formulation and coverage, press size and
speed, and operating time. The type of paper, coated or uncoated, has
little effect on the quantity of emissions, although low levels of
organic emissions are derived from the paper stock during drying.^
High volume web fed presses such as those discussed in Section 4.9.1
are the principal sources of solvent vapors.
Total annual emissions from the industry in 1976 were estimated to
be 340,000 MT (380,000 tons). Of this total, lithography emits 28
percent, letterpress 18 percent, gravure 41 percent and flexography 13
percent.^
Most of the solvent contained in the ink and used for dampening and
cleanup eventually finds its way into the atmosphere, but some solvent
remains with the printed product as it leaves the plant and is re-
leased to the atmosphere later. Overall solvent emissions can be
computed from Equation 1 using a material balance concept, except in
cases where a direct flame dryer is used and some of the solvent is
thermally degraded.
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Etotal=T
where
Etotal = to1:al solvent emissions including those from the
printed product, kg (pounds)
T = total solvent usage including solvent contained in ink,
kg (pounds)
The solvent emissions from the dryer and other components that are
connected to the main exhaust system can be computed from Equation 2.
The remaining solvent leaves the plant with the printed product and/or
is degraded in the dryer.
Edryer = SI (100 - P) (2)
aryer 100 100
where
E . = solvent emissions from dryer, kg (pounds)
I = ink usage in kg (pounds)
S and P = factors from Table 4.9-1
4.9.2.2 Web Offset Lithography—Emission points on web offset litho-
graphy publication printing lines include: (1) the ink fountains, (2)
the dampening system, (3) the plate and blanket cylinders, (4) the dryer,
(5) the chill rolls and (6) the product. Emission point numbers refer to
Figure 4.9-1 .
Alcohol is emitted from points 2 and 3. Washup solvents are a small
source of emissions from points 1 and 3. Drying is the major source be-
cause 40 to 60 percent of the ink solvent is removed from the web during
this process (emission point 4).
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The quantity of web offset emissions may be estimated from Equation 1
or from Equation 2 and the appropriate parameters from Table 4.9-1.
Table 4.9-1. TYPICAL PARAMETERS FOR COMPUTING SOLVENT EMISSIONS FROM
UNCONTROLLED WEB OFFSET LITHOGRAPHY, WEB LETTERPRESS, ROTOGRAVURE AND
FLEXOGRAPHY PRINTING LINES3
Process
WEB OFFSET
Publ ication
Newspaper
WEB LETTERPRESS
Publication
Newspaper
ROTOGRAVURE
FLEXOGRAPHY
Typical Solvent
Content of Ink
(percent)
S
40
5
40
0
75
75
Typical Solvent Remaining in
Product and Destroyed in Dryer
(percent)
P
40 - hot ai r dryer
60 - direct flame dryer
100
40
(not applicable)
2 - 7
2 - 7
Emission
Factor
Rating
A
B
B
C
C
a References 1 and 14. For certain packaging products, the amount of
solvent retained is regulated by the FDA.
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4-9.2.3 Web Letterpress—Emission points on web letterpress publica-
tion printing lines are: (1) the press (which includes the image
carrier and inking mechanism), (2) the dryer, (3) the chill rolls and
(4) the product. Emission point numbers refer to Figure 4.9-2.
Web letterpress publication printing produces significant emis-
sions, primarily from the ink solvent, about 60 percent of which is
lost from the drying process (point 2). Wash-up solvents are a small
source of emissions (point 1). The quantity of emissions can be com-
puted as discussed above for web offset.
Letterpress publication printing uses a variety of papers and inks
that lead to problems in emission control, but losses can be reduced
by use of a thermal or catalytic incinerator, either of which may be
coupled with a heat exchanger.
4.9.2.4 Rotogravure—Emissions from rotogravure printing occur at
(1) the ink fountain, (2) the press, (3) the dryer and (4) the chill
rolls. Emission point numbers refer to Figure 4.9-3. The dryer is
the major emission point, because most of the VOC in the low boiling
ink is removed during drying. The quantity of emissions can be com-
puted from Equation 1 or from Equation 2 and the appropriate para-
meters from Table 4.9-1.
Ventilation systems are necessary to minimize solvent loss around
the ink fountain and at the chill rolls (points 1 and 4). Fume in-
cinerators and carbon adsorbers are the only devices that have a high
efficiency in controlling vapors from rotogravure operations (points
1 to 4).
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Solvent recovery by carbon adsorption systems has been quite suc-
cessful at a number of large publication rotogravure plants. These
presses use a single, water immiscible solvent (toluene) or a simple
mixture that can be recovered in approximately the proportions used in
the ink. All new publication gravure plants are being designed to
include solvent recovery.
Some smaller rotogravure operations, such as those that print and
coat packaging materials, use complex solvent mixtures in which many
of the solvents are water soluble. Thermal incineration with heat
recovery is usually the most feasible control option for such oper-
ations. With adequate primary and secondary heat recovery, the amount
of fuel required to operate both the incinerator and the dryer system
can be reduced to less than that normally required to operate the
dryer alone.
In addition to thermal and catalytic incinerators, pebble bed in-
cinerators are also available. Pebble bed incinerators combine the
functions of a heat exchanger and a combustion device, and can achieve
a heat recovery efficiency of 85 percent.
VOC emissions can also be reduced by using low solvent inks.
Water-borne inks, in which the volatile portion contains up to 20
volume percent water soluble organic compounds, are used extensively
in rotogravure printing of multiwall bags, corrugated paperboard and
other packaging products, although water absorption into the paper
limits the amount of water-borne ink that can be printed on thin stock
before the web is seriously weakened.
14-
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4.9.2.5 Flexography—Emission points on flexographic printing lines
are (1) the ink fountain, (2) the press, (3) the dryer and (4) the
chill rolls. Emission point numbers refer to Figure 4.9-3. The dryer
is the major emission point, and emissions can be estimated from Equa-
tion 1 or from Equation 2 and the appropriate parameters from Table
4.9-1.
Ventilation systems are necessary to minimize solvent loss around
the ink fountain and at the chill rolls (points 1 and 4). Fume incin-
erators are the only devices that have proven highly efficient in con-
trolling vapors from flexographic operations (points 1 to 4). VOC
emissions can also be reduced by using water-borne inks, which are
used extensively in flexographic printing of packaging products (refer
to Section 4.9.2.4).
Table 4.9-2 shows estimated control efficiencies for the printing
operations discussed herein.
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Table 4.9-2. ESTIMATED CONTROL TECHNOLOGY EFFICIENCIES FOR WEB
OFFSET LITHOGRAPHY, WEB LETTERPRESS, ROTOGRAVURE AND
FLEXOGRAPHY PRINTING LINES
Emission Technology
Application
Reduction in
Organic Emissions
(percent)
Carbon adsorption
Incineration3
Water-borne inks"
Publication rotogravure
operations
Web offset lithography
Web letterpress
Packaging rotogravure
printing operations
Flexographic printing
operations
Some packaging rotogravure
printing operations0
Some flexographic packaging
printing operations
95e
95*
60d
65-75d
60d
a Direct flame (thermal) catalytic and pebble bed. Three or more
pebble beds in a system have a heat recovery efficiency of 85
percent.
b Inks in which the solvent portion consists of 75 volume percent
water and 25 volume percent organic solvent.
c with less demanding quality requirements.
d Reference 3. Overall emission reduction efficiency.
e Reference 12. Efficiency of volatile organic removal—does not
take into account capture efficiency.
f Reference 13. Efficiency of volatile organic removal--does not
take into account capture efficiency.
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References for Section 4.9
1. "Air Pollution Control Technology Applicable to 26 Sources of
Volatile Organic Compounds", Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, Research
Triangle Park, NC, May 27, 1977.
2. Peter N. Formica, Controlled and Uncontrolled Emission Rates and
Applicable Limitations for Eighty Processes, EPA-340/1-78-004,
U.S. Environmental Protection Agency, Research Triangle Park,
NC, April 1978.
3. Edwin J. Vincent and William M. Vatavuk, Control of Volatile
Organic Emissions from Existing Stationary Sources, Volume VIII:
Graphic Arts - Rotogravure and"F1exography, EPA-450/2-78-033,
U.S. Environmental Protection Agency, Research Triangle Park,
NC, December 1978.
4. Communication with C. M. Higby, Cal/Ink, Berkeley, CA, March 28,
1978.
5. T. W. Hughes, et a!.. Prioritization of Air Pollution from
Industrial Surface Coating Operations, EPA-650/2-75-019a. U.S.
Environmental Protection Agency, Research Triangle Park, NC,
February 1975.
6. Harvey F. George, "Gravure Industry's Environmental Program",
Environmental Aspects of Chemical Use in Printing Operations,
EPA-560/1-75-005, U.S. Environmental Protection Agency, Research
Triangle Park, NC, January 1976.
7. K. A. Bownes, "Material of Flexography", ibid.
8. Ben H. Carpenter and Garland R. Hilliard, "Overview of Printing
Processes and Chemicals Used", ibid.
9. R. L. Harvin, "Recovery and Reuse of Organic Ink Solvents", ibid.
10. Joseph L. Zborovsky, "Current Status of Web Heatset Emission
Control Technology", ibid.
11. R. R. Gadomski, et al., Evaluations of Emission and Control
Technologies in the Graphic Arts Industries, Phase I: Final
Report, APTD-0597, National Air Pollution Control Administration,
Cincinnati, OH, August 1970.
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12. R. R. Gadomski, et a!., Evaluations of Emissions and Control
Technologies In THe GrapFTc Arts Industries, Phase II: Web~
Offset and Metal Decorating Processess, APTD-1463, U.S.
Environmental Protection Agency, Research Triangle Park, NC,
May 1973.
13. Control Techniques for Volatile Organic Emissions from
Stationary Sources, EPA-450/2-78-022, U.S. Environmental
Protection Agency, Research Triangle Park, NC, May 1978.
14. Communication with Edwin J. Vincent, U.S. Environmental
Protection Agency, Research Triangle Park, NC, July 1979.
-18-
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BACKGROUND DOCUMENT
SECTION 4.9 GRAPHIC ARTS
1.0 INTRODUCTION
The section on Graphic Arts is organized as two separate
sections with five subsections each, as follows:
4.9.1 Process Description
4.9.1.1 General
4.9.1.2 Web Offset Lithography
4.9.1.3 Web Letterpress
4.9.1.4 Rotogravure
4.9.1.5 Flexograpy
4.9.2 Emissions and Controls
4.9.1.1 General
4.9.1.2 Web Offset Lithography
4.9.1.3 Web Letterpress
4.9.1.4 Rotogravure
4.9.1.5 Flexography
Screen printing and manual techniques are not included due to
the lack of available information. Direct lithography, in which the
image carrier prints the image directly onto the substrate, is also
not included because most lithographic operations are web offset
(although most plants classified under commercial lithography
operate with sheet fed equipment). Sheet fed gravure is excluded
because it is slow and little used. Of the three categories of
letterpress printing, only web presses using solvent-borne inks are
discussed because
Letterpress newspaper printing (which is web fed) utilizes
oxidant drying inks composed of petroleum oils and carbon
black, but little or no volatile solvent
Letterpress sheet fed printing employs nonsolvent inks that
in racks by air oxidation at room temperature
-19-
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Moreover, flexographic newspaper printing, like letterpress
newspaper printing, uses oxidative drying inks and emits only ink
mist and paper dust, so this form of printing is also omitted from
Section 4.9.
2.0 EMISSION FACTORS (Table 4.9-1)
The values for S, solvent content of ink, for web offset and
letterpress were taken from Table 35 (pages 123-128) of Reference
11. The information was obtained through mail surveys (421 res-
ponses) and field visits (86) to printing establishments. The
values for rotogravure and flexography were supplied by Ed Vincent
of ESED in a private communication.
Values for P, the solvent remaining with the product or
destroyed in the dryer, were taken from Table 35 of Reference 11 for
web offset and web letterpress, except for the value for web offset
using a direct flame dryer, which was taken from Table 18 (page 113)
of Reference 12. The data from Reference 11 were derived from
surveys and the data from Reference 12 were derived from source
tests. Values for P for rotogravure and flexography were supplied
by Ed Vincent of ESED
-------
The term "capture efficiency" refers to the efficiency of conveying
all solvent emissions to the inlet of the control device. The term
"removal efficiency" refers to the efficiency of the control device
in removing all emissions that pass through it.
4.0 EMISSION FACTOR RATINGS
The factors are essentially based on the data base for estima-
ting the parameters S and P in Table 4.9-1. The factor for web off-
set publication printing is rated A because it is based on results
of a test program specifically designed to evaluate emissions. The
factors for web offset newspaper and web letterpress publication
printing are rated B because they are based on a combination of
engineering analysis and limited test data. The factors for roto-
gravure and flexography are rated C because they are based on engi-
neerng analysis and plant visits and may have been derived by aver-
aging data from several plants that varied substantially from each
other. The numerical rankings are as follows:
Process
Web Offset
Publication
Newspaper
Web Letterpress
Publication
Rotogravure
Flexography
Measured
Emissions
17
9
9
0
0
Process
Data
9
9
9
8
8
Engineering
Analysis
10
10
10
9
9
Total
36
28
28
17
17
-21-
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. REPORT NCX
EPA No. 450/4-79-014
Tl T I C A & i K ._.. . ' '• ~ ~ " "~
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
3. RECIPIENT'S ACCESSION NO.
: • ~y*/ -r i .
TITLE AND SUBTITLE
Graphic Arts: An AP-42 Update
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
September 1979
AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
K. Wilson and V. Scott
PERFORMING ORGANIZATION NAME AND ADDRESS
Pacific Environmnetal Services, Inc.
1930 14th Street
Santa Monica, California 90404
10. PROGRAM ELEMENT NO.
2AA635
11. CONTRACT/GRANT NO.
68-02-2583
Work Assignment No. 12
2. SPONSORING AGENCY NAME AND ADDRESS
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; April to August 1979
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
EPA Project Officer: Audrey McBath
16. ABSTRACT
This document contains the text of AP-42 Section 4.9, Graphic Arts, written in
May 1979. The section includes a description of four graphic arts processes (web
offset lithography, web letterpress, rotogravure, and flexography), process flow
diagrams, and emissions and controls discussions. A method for estimating emissions
using theoretically derived equations is also included. A background document which
discusses, in some detail, the derivation of emission quantification methodologies
follows the Section itself.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI field/Group
emission factors
air pollution control
evaporation loss sources
graphic arts industry
solvent use
"18 DISTRIBUTION STATEMENT
Unlimited
19 SECURITY CLASS /This Report)
Unclassified
21 NO OF PAGE!
26
20 SECURITY CLASS (This page)
Unclassified
22 PRICE
EPA Form 2220-1 (R«».4-77) PBEVI
OUS EDITION IS OBSOLETE
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