&EPA
United States
Environmental Protection
Agency
Industrial Environmental Research EPA-600 2 80 .44
Laboratory June 1980
Cincinnati OH 45268
Research and Development
Calculations of
Painting Wasteloads
Associated with
Metal Finishing
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution-sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-80-144
June 1980
CALCULATIONS OF PAINTING WASTELOADS
ASSOCIATED WITH METAL FINISHING
by
GEORGE E. F. BREWER
Coating Consultants
Brighton, Michigan 48116
Grant No. R 803467
Project Officer
HUGH B. DURHAM
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory - Cincinnati, U. S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily re-
flect the views and policies of the U. S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory-Cin-
cinnati (lEKL-Ci) assists in developing and demonstrating new and improved
methodologies that will meet these needs both efficiently and economically.
The subject of the present study is the tabulation of the relative sizes
of the waste loads generated by commonly used industrial paints and painting
processes. A system of mathematical equations has been developed for the com-
putation of the waste loads expected for any size and for almost any kind of
industrial painting operation. All parties concerned with the selection of
less wasteful methods of industrial painting will find this report to be a
ready tool for their work. For further information regarding this study the
Industrial Pollution Control Division should be contacted.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
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Bake Curing 41
Radiation Curing 41
Formation of Coreactants 43
7 - Sanding and Stripping 45
Sanding 45
Stripping 46
8. Calculation of Waste Loads 48
General 48
Prediction of Waste Loads 48
Determination of Waste Loads 49
Predicted vs Determined Waste Loads 53
9. Commercial Paint Compositions Surveyed 55
General 55
Classification of Paint Compositions 56
Waste Load Computation Data 57
Computations Using Manufacturer's Literature 57
Glossary 68
vi
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CONTENTS
Foreword iii
Abstract iv
Figures vii
Tables ix
Abbreviations and Symbols x
Conversion Factors xi
Acknowledgments xii
1. Introduction 1
General 1
Scope 2
Purpose 2
Theoretical Approach . 3
Phases 3
2. Conclusions 5
3. Recommendations 6
4. Survey Processes and Development of Calculations 7
General 7
Objectives 8
Sources of Information 8
Paint Compositions 8
Selection of Paints 11
Buying and Using Paints 12
Units of Measurement 13
Volume Calculations 14
Organic Volatiles in Paints 17
Organic Volatile Calculations 19
5. Painting Methods and Equipment 23
General 23
Spray Painting 23
Dip Coating 27
Flow Coating 28
Curtain Coating ' 28
Roll Coating 29
Electrocoating 30
Powder Coatings 31
Paint Losses vs Transfer Efficiency 34
Waste Loads vs Transfer Efficiency 35
Transfer Efficiency Calculations 36
Summary 38
6. Paint Curing Methods 40
Ambient Temperature Curing 40
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ABSTRACT
This study presents methods for predicting the waste loads that will be
generated in planned painting operations, and for determination of the actual
waste loads in current operations.
Nine major classes of industrial paints and the most widely used indus-
trial painting processes were surveyed and have been described. The upper
and lower limits of frequently encountered waste loads have been tabulated.
Twelve mathematical equations have been developed for the prediction of
waste loads or for determination of actual waste loads.
This study indicated that the waste loads generated in most painting
operations can be significantly reduced through the use of better paint
materials and more efficient painting processes. Such technologies are
currently in various stages of development, but their wide-spread adoption
will require years of field testing so that environmental demands and con-
sumer quality expectations can be"fully assured.
This report is submitted in fulfillment of Grant No. R 803467 by
Coating Consultants, Brighton, Michigan under the sponsorship of the U. S.
Environmental Protection Agency.
iv
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FIGURES
Number Page
1 Film coating using an ideal nonvolatile filmforming solid. .... 9
2 Film coating using organic volatile solvent based liquid
paint compositions 10
3 Film coating using water based liquid paint compositions 10
4 Film coating using organic volatile solvent and water based
liquid paint compositions 11
5 Calculations Schematic 14
6 Maximum coverage equals mininum consumption 17
7 Volume relationship of paint components 18
8 Volume relationship of paint components "as used" 19
9 Vol% ratio of 0V to NV components 20
10 Air atomized spray 23
11 Pressure atomized spray 24
12 Electrostatic field assisted spray painting 25
13 Centrifugal atomized spray 25
14 Water bath spray paint booth 26
15 Dip coating rigid, profiled merchandise 27
16 Dip coating flexible, unprofiled merchandise 27
17 Flow coating 28
18 Curtain coating 28
19 Roll coating 29
20 Electrocoating 30
vii
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21 Fluidized bed dip tank 32
22 Electrostatic fluidized bed 32
23 Fluidized electrostatic powder spraying 33
24 Waste loads vs percent expected transfer efficiency 39
25 Electron beam curing 41
26 Ultra-violet ray curing 42
27 Sanding painted surfaces 45
viii
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TABLES
Number Page
1 Commonly Used Paint Measurement Units 15
2 Expected Transfer Efficiency 35
3 Waste Loads vs Percent Expected Transfer Efficiency 38
4 Classification and Composition of Paints Surveyed 60
5 Range of 0V and NV Within Paint Classes Surveyed 67
ix
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ABBREVIATIONS AND SYMBOLS
area W
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CONVERSION FACTORS
From: Metric
cm
cm
cm3
kg
kg /I
1
m
m2
ym
To: U. S.
in
in2
in3
Ib
Ib/gal
gal
ft
ft2
mil
Multiply by
0.3937
0.155
0.061
2.203
8.338
0.264
3.281
10.753
0.0394
From: U. S.
ft
ft2
gal
in
in2
in3
Ib
Ib/gal
mil
To: Metric
m
m2
1
cm
cm2
cm3
kg
kg/1
ym
Multiply by
0.3048
0.093
3.785
2.54
6.452
16.393
0.454
0.12
25.4
xi
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ACKNOWLEDGMENTS
Special thanks are due to Mr. James R. Blegen, Ashland Chemical Company,
Columbus, Ohio, for making typical paint formulations and advice available.
Thanks for advice and assistance are extended to Dr. Hugh B. Durham, Pro-
ject Officer, and to Mr. George F. Weesner and Mr. Gordon Haller of the Metals
& Inorganic Chemicals Branch, Industrial Environmental Research Laboratory,
U. S. Environmental Protection Agency, Cincinnati, Ohio.
xii
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SECTION 1
INTRODUCTION
GENERAL
Large quantities of contaminants are emitted into the environment as a
result of painting operations in the metal fabricating and finishing indus-
tries.
Prior to 1960, typical industrial paint formulations contained approxi-
mately 40 wt% of paint solids dispersed in volatile organic solvents. Thus,
60% of the total weight of all paints sold in the United States resulted in
organic volatile waste. In addition, an estimated 20% of the total paint
solids weight became waste due to overspray, drip-off, and spillage.
Painting operations result in the generation of three classes of con-
taminant wastes:
1) Vapors of organic volatile solvents which are emitted into the at-
mosphere unless they are captured and incinerated. (Incineration
may cause secondary pollutional waste loads which were not consid-
ered in this study.)
2) Solid or semisolid nonorganic materials (resins or pigments) com-
bined with some adhering organic volatile solvents which must be
buried in the ground, either directly or after partial incineration.
(In certain cases, some paint solids waste may be economically re-
claimed.)
3) Minor quantities of nonvolatile waste (water soluble solvents, salts,
surfactants, and other additives) which may find their way into
clearing lagoons, sewers, or waterways.
Since 1960, an increased awareness of environmental factors has resulted
in replacement of many particularly detrimental liquid paint components with
less objectionable materials. Numerous new ecologically desirable improve-
ments in paint technology have been reported; in particular there have been
waterborne paints, high solids paints, paint powders, and radiation cured
paints introduced on the market.
In 1970, it was estimated that the annual waste load generated by indus-
trial painting operations was more than 200 million kilograms (220 thousand
tons) of organic volatile waste plus an additional 100 million kilograms
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(110 thousand tons) of semisolid waste that contained some organic volatiles.-1
At that time, approximately 60% of all industrial painting was done by conven-
tional spraying processes. By use of this method, 40 to 60% of the paint
solids which enter the plant are not transferred onto the merchandise, but are
lost as unavoidable overspray. Paint transfer methods other than conventional
air atomized spraying were variously reported as operating with much higher
transfer efficiencies, some as high as 98%.
In 1973, inquiries which were addressed to the two largest organizations
in the field —the Federation of Societies for Paint Technology, Philadelphia,
Pa., and the National Paint and Coatings Association, Washington, D.C.— did
not produce any comprehensive surveys or statistics. At that time, no tabu-
lations existed as to the quantities of waste generated by various types of
paints or by the use of different painting processes.
A literature search produced a number of articles dealing with narrow
facets of the problem of painting wastes, but the literature did not reveal
a generally accepted method that would allow the determination of the waste
load generated by any given industrial painting operation. No method was
found in the literature for th*e mathematical prediction of the waste load
that would be generated by a given size and kind of painting operation. The
literature did not contain a method to predict the change in waste load that
would result from replacing one kind of paint or painting process with another.
SCOPE
This study presents data which allows the calculation of predicted waste
loads generated during the application of widely used paints by various com-
mon painting processes. The reported data were compiled from the reviewed
scientific and trade literature and through direct communications with experts
in the painting field.
Liquid or vaporized wastes and semisolid wastes are reported in weight
and volume units for a specific size of painting operation and allow, there-
fore, the computation of the waste load for any size of painting operation.
PURPOSE
This study is intended to be a useful tool for the prediction of waste
loads that will be generated by an industrial painting operation when a given
quantity of merchandise is to be painted using common paints and painting
techniques.
This study can also be used for the determination of the actual waste
loads generated by a specific industrial painting operation and for pinpoint-
ing unnecessary costly and pollutional losses. It should also be an aid to
those engaged in the selection of the best available paint and painting pro-
cess for a particular job.
1 Wapora, Inc.: EPA Contract No. 68-01-2656
2
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THEORETICAL APPROACH
Premises
1) Paint formulations are varied somewhat from user to user and batch
to batch to adjust to changes in the market, color, processing equip-
ment, etc.
2) Paints are invoiced either by weight or by volume.
3) The user buys most paints in liquid form, but actually uses only the
paint solids on the finished product. The total volume of the organ-
ic volatiles in the liquid constitutes a waste load.
4) Loss of some portion of the paint solids is inherent in all painting
processes. Accidental losses will also occur and contribute addi-
tional organic volatiles plus nonvolatile paint solids to the waste
loads.
5) Industrial painting operations vary in size, and production output
fluctuates with the market.
Method
In consideration of the above premises, the waste load for an industrial
painting operation can be predicted and/or determined when the following data
are known:
1) The weight and volume of paint solids and organic volatiles that
enter the plant.
2) The surface area of the merchandise painted and the film thickness
of the applied paint solids. In other words, the volume of paint
solids that are actually utilized and that leave the plant on the
merchandise.
The difference between the volume of paint solids that enter the plant
and the volume that leave the plant on the merchandise represents the solid
and most of the semisolid waste generated by the painting operation.
The total volume of organic volatile material (paint components, solvents,
thinners, additives, cleaning fluids, etc.) that enter the plant represents the
organic volatile waste load generated by the painting operation.
PHASES
The scientific and trade literature was surveyed for the weights and
volumes of the nonvolatile components (resins, pigments, etc.) of typical,
widely used paints, and also for the weights and volumes of their organic
volatile components (solvents, etc., exclusive of water).
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The surveyed paint compositions were arranged into nine paint classes
according to the application techniques (spray, dip, etc.) for which the
paints had been formulated.
The paint application techniques were surveyed and studied for their ex-
pected transfer efficiency; i.e. their inherent unavoidable paint losses.
Mathematical equations were then developed by which the expected waste
load for any planned painting operation can be predicted from the composition
of the paint and the equipment and painting process to be used.
All these data were compiled into a preliminary 25 page report that was
sent to about 30 experts in the field who were requested to provide their
criticisms, suggestions, comments, etc. Where appropriate, the replies from
these experts have been incorporated into this final report.
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SECTION 2
CONCLUSIONS
The waste loads generated in painting processes for metal products are
governed by four factors: 1) paint composition, 2) painting equipment,
3) curing method, and 4) miscellaneous unavoidable losses.
Solvents (water or organic volatiles) are an essential part of paint com-
positions . The more recently developed paint compositions —sometimes called
"low polluting"— are remarkably efficient in reducing the need for evapora-
tion of water or organic volatile solvents, and they also reduce the quantity
of semisolid waste generated.
The efficiency of the equipment for transferring the paint from the pot
onto the surface of the merchandise varies from about 50% to almost 99%. The
waste loads are, therefore, very much influenced by the type of painting equip-
ment used.
Organic volatiles or water are emitted into the air by an evaporative
process during the curing cycle. Comparatively small quantities of coreact-
ants are also liberated during the cure of some commercial paints.
Most unavoidable losses are inherent with the method of applying the paint
to the product. Additional unavoidable losses occur during normal handling of
the equipment, cleaning of the equipment, and repair of defective paint coats
(sanding, stripping, etc.).
A series of mathematical equations has been developed that allows the pre-
diction of the waste loads for almost any kind and size of industrial painting
operation or planned alternate, and for the determination of the actual waste
loads calculated from production data.
In theory, the waste loads in painting operations could be significantly
reduced by the judicious choice of paint, equipment, and curing method, and
by the skill and techniques of operating personnel.
In practice, many efforts toward waste reduction in paint operations is
currently underway, both for reasons of pollution law enforcement and for the
economic savings possible. However, in order to ensure the quality of new
coatings, it may take years of field testing before currently used paints and
processes can be completely replaced by other more efficient ones.
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SECTION 3
RECOMMENDATIONS
1) An effort should be made to familiarize government and industry per-
sonnel with the use of the mathematical prediction and actual deter-
mination of painting waste loads. Half or 1 day conferences should,
therefore, be arranged for the presentation of the plaint waste load
computations.
2) Though an effort has been made to include typical paints and painting
processes, a continuing effort should be made towards the detection
of wasteful practices and encouragement of cheaper, more protective,
and less wasteful practices.
3) Current literature does not refer to the nature of the malodorous
fumes that are sometimes observed during painting operations. Lab-
oratory devices should be developed for the study and generation of
data towards the elimination of the fume-causing substances and/or
practices.
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SECTION 4
SURVEY PROCESSES AND DEVELOPMENT OF CALCULATIONS
GENERAL
Paint is a general term that is given to compositions that can be applied
in comparatively thin, even layers onto solid surfaces where they convert into
solid, adhesive, wear-resistant film coatings. Conventional filmforming ma-
terials are organic polymeric compounds; that is, materials containing carbon,
hydrogen, oxygen, and sometimes minor quantities of other elements. Typical
nonvolatile filmformer solids are known as acrylics, epoxies, urethanes, al-
kyds, etc. These generic names refer to the atomic arrangement of the elements
which constitute the filmformer solid.
Filmformers, often called "resins", must be soluble in a liquid vehicle
or meltable at reasonable temperatures so that they can be applied in thin,
even layers onto the desired surface. Furthermore, filmformers must convert
into solid film coatings through a "curing" process (drying, baking, etc.).
Most conventional filmformer solids, when they are used as the only non-
volatile component of a paint composition, will result in transparent film
coatings. However, to meet the needs and desires of users, most paints are
designed to hide the substrate of the material coated and to impart color to
the finished merchandise. This is accomplished by the incorporation of pig-
ments into the paint compositions. Pigments are usually nonvolatile solids
intimately mixed or ground into the filmforming solids. Most pigments also
increase the durability of the film coating.
Various other additives of volatile and/or nonvolatile nature may be in-
corporated in small quantities to paint compositions. These additives may
facilitate the deposition and adhesion of the filmforming solids on the sur-
face to be coated, enhance the curing process, effect a gloss or matte finish
to the coating, etc.
Water is used in many paint compositions as most or part of the liquid
component. Water is volatile and though the moisture emitted during painting
operations may cause serious operational problems, water vapor is generally
considered nonpollutional in nature. For the purpose of this study, attention
has been directed specifically to the two classes of paint components that
generate pollutional waste loads:
1) Organic Volatiles (0V) (solvents, thinners, plasticizers, and other
liquid additives).
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2) Nonvolatiles (NV) (resins, pigments, and other solid additives).
OBJECTIVES
The objectives of this study were to develop methods for:
1) The prediction of pollutional waste loads that will be generated by
any size or type of planned industrial painting operation.
2) The determination of actual pollutional waste loads generated by any
size or type of existing industrial painting operation.
3) A basis to be used for the selection of alternate paints or painting
processes to reduce the predicted and/or actual pollutional waste
loads in industrial painting operations.
SOURCES OF INFORMATION
The commercial paint manufacturing industry is highly competitive, there-
fore, the actual formulation of commercial paints is considered proprietary
and, in most cases, will be released only as confidential information that
may not be used in a study of this nature.
However, the resin manufacturers who supply basic materials to the paint
manufacturers demonstrate the quality of their products by means of prototype
formulations which are provided freely to the public. As a result, portions
of this study have been based on the use of such detailed prototype formula-
tions .
Where actual commercial paints have been used in calculation examples and
tabulations, the organic volatile and nonvolatile components of the formula-
tion have been lumped into single figures; that is, without consideration of
the proportion of solvent, thinner, additives, resins, pigments, etc.
To insure the validity of the data developed using this approach and the
relationship of prototype formulations to actual formulations of commercial
paints on the market, the basic findings of the study were circulated to about
30 experts in the paint industry who were requested to provide their correc-
tions, comments, and suggestions. The cooperation of these experts is greatly
appreciated, and their replies have been incorporated in this final report as
appropriate.
PAINT COMPOSITIONS
The ideal paint would be simply a nonvolatile filmforming substance that
could be applied directly and evenly to any solid surface. Ideally, by use
of this principle, no material would be lost in the transfer process, and no
waste load would be generated (Figure 1).
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NONVOLATILE
FILMFORMER
(SOLID)
TRANSFER
IDEAL PAINT
NONVOLATILE
FILM
COATING
MERCHANDISE
Figure 1. Film coating using an ideal nonvolatile
filmformer solid.
There are certain newer classes of paints which aim at the use of this
principle presently under development and a few are currently in use in lim-
ited applications. However, due to the time necessary to perfect and produce
the required transfer equipment and the extensive field testing necessary to
insure the quality of the new coatings, it will be a number of years before
these new classes of paints widely replace the more conventional paints cur-
rently on the market.
These newer classes of paints present some minor pollutional problems in
that a small organic volatile waste load is generated by the liberation of a
small quantity of coreactants during the transfer and curing processes.
The vast majority of conventional paints currently on the market consist
of compositions of nonvolatile filmformer solids mixed with a liquid vehicle
(organic volatile solvents, water, or in some cases both) and are handled and
applied in this liquid form. The use of paint compositions in liquid form
provides two major advantages:
1) They allow for the use of a wide variety of transfer equipment and
curing processes (spray, dip, roll, air drying, baking, etc.).
2) The viscosity of the paint composition as bought can be adjusted by
increasing the ratio of liquids to solids. This allows for both an
adaptation to the equipment and process used for the transfer opera-
tion and for control of the film coating layer applied to the mer-
chandise.
The major disadvantage in using conventional liquid paint compositions
is that the entire quantity of liquids is emitted into the air as waste loads
during the transfer and curing processes. Only the nonvolatile solids depos-
ited on the surface of the merchandise actually leave the plant as part of the
finished product.
The greatest pollutional problems are encountered in the use of liquid
paint compositions mixed with organic volatile solvents. The entire quantity
of solvents in these paint compositions becomes organic volatile waste loads
during the transfer and curing processes (Figure 2).
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ORGANIC VOLATILE
SOLVENT
(LIQUID)
NONVOLATILE
FILMFORMER
(SOLID)
ORGANIC VOLATILE WASTE LOAD
TRANSFER
SOLVENT BORNE PAINT
NONVOLATILE
FILM
COATING
MERCHANDISE
Figure 2. Film coating using organic volatile solvent
based liquid paint compositions.
The generation of the organic volatile waste load from these paint com-
positions is through an evaporative process that occurs during the entire
transfer and curing cycles of the painting operation. Emission of the waste
load begins as soon as the paint composition is exposed to the air and con-
tinues until the film coating is fully cured.
Paint compositions mixed with water as the liquid component function in
much the same manner as the organic volatile solvent based compositions. The
entire quantity of water in the composition is emitted as a water vapor waste
load during the transfer and curing processes (Figure 3).
WATER
(LIQUID)
NONVOLATILE
FILMFORMER
(SOLID)
WATER VAPOR WASTE LOAD
TRANSFER
WATER BORNE PAINT
NONVOLATILE
FILM
COATING
MERCHANDISE
Figure 3. Film coating using water based liquid paint compositions.
Water vapor waste loads are generally considered nonpollutional in nature,
therefore, little further consideration or discussion has been devoted to this
factor in the remainder of this study. However, it should be noted that due
to the corrosive nature of water vapor, this waste load may cause serious
operational problems.
Paint compositions mixed with a combination of organic volatile solvents
and water as liquid components generate both the organic volatile and water
vapor waste loads described above (Figure 4).
10
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WATER
(LIQUID)
ORGANIC VOLATILE
SOLVENT
(LIQUID)
NONVOLATILE
FILMFORMER
(SOLID)
WATER VAPOR WASTE LOAD
ORGANIC VOLATILE WASTE LOAD
TRANSFER
WATER & SOLVENT BORNE
NONVOLATILE
FILM
COATING
MERCHANDISE
Figure 4. Film coating using organic volatile solvent
and water based liquid paint compositions.
SELECTION OF PAINTS
Until quite recently, industrial paint users selected paint compositions
and painting processes on the primary basis of the quality of the film coating
and the basic cost of the paint materials. Today, environmental factors and
the energy consumed by the transfer and curing processes must also be given
weighted consideration in the selection process. As a result, the paint man-
ufacturing industry is currently engaged in extensive efforts to develop more
desirable paint compounds and more efficient painting processes.
The quality and durability of the film coating remains the primary con-
sideration of the ultimate paint consumer. It generally takes about five years
of product experimentation and extensive laboratory and field testing before an
industrial paint user can have reasonable assurance that a new paint will meet
quality, cost, environmental, and energy requirements. Therefore, an indus-
trial switch to newer classes of paints and painting processes is expected to
be a slow and cautious process.
The reason for the long periods of laboratory, field, and sometimes out-
door exposure testing is to subject the film coatings to the same conditions
they will meet when used for the actual purpose for which they are designed.2
Obviously, if a paint manufacturer is expected to guarantee a film coat-
ing for a service life of two years, laboratory and field testing will require
a minimum of two years. In most cases, a film coating is applied to hundreds
or even thousands of pieces of material to be used in the tests. If the film
Gardner, H. A., and Sward, G. G. ASTM Paint Testing Manual, 13th Edition,
American Society for Testing and Materials, Philadelphia, Pa. 1972, pg 251-
494.
11
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coating fails on an unacceptable number of pieces during the tests and the
paint composition or painting process is changed for improvement, a new series
of tests must be initiated.
In the case of paints made for use on merchandise designed for outdoor
use extensive exposure tests to a wide range of climatic conditions is fre-
quently required.
Even after a new paint has been developed in the laboratory or pilot
plant and has met all requirements of quality, cost, environment, and energy,
still further delays may be expected before it is widely adopted. It may be
several years before the raw materials are available or can be produced in
sufficiently large quantities. It may also require time for the development,
planning, capital investment, manufacture, and installation of the required
equipment for the new painting process.
BUYING AND USING PAINTS
The industrial user normally buys paint as a composition consisting of
nonvolatile filmforming solids and sacrificial liquids. During the painting
operation the nonvolatile solids are applied to the surface of the mechandise
and the liquids are emitted as waste loads. The film coating on the merchan-
dise must meet certain specifications, such as, durability, color, hardness,
gloss, corrosion resistance, etc., and in many cases film thickness.
The^re are a number of factors which must be determined before an indus-
trial paint user can figure the cost of a painting operation and make a de-
cision as to what quantity of what paint to buy.
First, the volume of nonvolatile solids required to coat the surface
area of the merchandise to the specified thickness must be determined. This
can be found by multiplying the total surface area by the thickness of the
film coating.
Next, the volume of nonvolatile solids contained in a purchased unit of
paint composition must be known. Commercial paint compositions are usually
sold by weight, and the quantity of nonvolatile solids in the composition is
also often given by weight. If this is the case, the weight of the nonvola-
tile solids must be converted to volume.
From the above factors the quantity and cost of the paint composition
for a specific operation can be calculated. Suppose several paint manufac-
turers offer paint compositions which meet all the requirements of the film
coating but vary in formulation and cost. Obviously the most economical com-
position to buy is that which contains the most nonvolatile solids at the low-
est cost. However, this is only one of the factors in the over-all cost of
the painting operation.
Since all liquids in paint compositions are emitted as waste loads during
painting operations, the costs for controlling these waste loads is a factor
in the over-all cost of the painting operation. The most serious pollutional
12
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waste loads are those generated by organic volatile solvents. From an envir-
onmental standpoint it might appear that the least pollutional paint composi-
tion to buy would be that which contains the least volume of organic volatile
solvent. However, most paint compositions are sold with nonvolatile concen-
trations too high to be used in most painting processes and must be "thinned"
by the addition of more liquids before they are used. Waste loads must be
calculated by the volume of liquids in the composition "as used" rather than
"as bought". The cost of the additional liquids must also be figured into the
over-all cost of the painting operation.
The use of paint compositions that use water as part or all of the liquid
content may reduce or eliminate pollutional waste loads. However, the cost of
overcoming the operational problems, such as corrosion, caused by the water
vapor waste load, and the cost of energy to evaporate the water may exceed the
costs of controlling environmentally pollutional waste loads.
Energy consumption required for transfer and curing processes is becoming
an ever greater factor in the over-all cost of a painting operation. If the
present energy shortage trend continues, it may become more than a matter of
cost and become a matter of availability.
Another major factor in the calculations of the quantity and cost of ma-
terials and the generation of waste loads is the transfer efficiency of the
equipment and process used in the painting operation. Unavoidable losses of
part of the total volume of nonvolatile solids occurs in all painting process-
es. For example, if the transfer efficiency of a painting process is only 50%
it means that only half of the nonvolatile solids in the paint composition "as
used" is actually deposited on the surface of the merchandise; the other half
becomes nonvolatile waste.
The final factors which must be considered are other minor unavoidable
losses such as cleaning and repair of equipment, sanding or stripping to re-
pair or remove defective coatings, and accidental spillage or wastage,
UNITS OF MEASUREMENT
Metric system units of measurement have been used as the primary standard
throughout this study. In most cases examples have also been shown using U.S.
standard units of measurement for better understanding.
As stated previously, paint compositions may be bought in either metric
or U.S. units of weight (kilograms or pounds) or volume (liters or gallons).
The quantity of nonvolatile solids and liquids in the composition may also be
provided in units of weight or volume, or may be expressed in percentages of
the total units.
In order to use the equations developed in this study the industrial
paint user must convert the known units of weight or volume to the other fac-
tor for specific calculations. The quantity of nonvolatile solids required
to form the film coating on the surface of the merchandise must be calculated
in units of volume (area coated x thickness of film = volume). The volume
13
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of volatile waste loads, particularly those generated by organic volatile sol-
vents, does not represent meaningful data due to large variances in density
possible from the range and variety of liquids used in paint compositions.
Normally, all waste loads are calculated in weight units, though the volume
of semisolid waste loads may be desired in some cases. The method for devel-
oping calculations is shown schematically in Figure 5.
VOLATILE LIQUID
THINNERS
PAINT
COMPOSITION
(as bought)
VOLATILE
WASTE LOADS
(WEIGHT)
TRANSFER
(WEIGHT & VOLUME)
SOLIDS
WASTE LOADS
NONVOLATILE
FILM
COATING
(VOLUME)
(WEIGHT OR VOLUME)
Figure 5. Calculation Schematic
VOLUME CALCULATIONS
A constant (K) factor can be developed to represent the maximum area that
can be film coated to a specified thickness by a standard metric or U.S. unit
of volume of nonvolatile (NV) paint solids. This K factor is developed on the
assumption that the entire volume of NV solids are transferred to the surface
of the merchandise, that is, 100% transfer efficiency.
Since there are some unavoidable NV losses in all painting processes, the
maximum area coverage will never be achieved in actual operation. However, by
using maximum data, computations may be developed for the following three pur-
poses:
1) Cost comparison between available paint compositions by direct compar-
ison of costs per unit volume of NV.
2) The maximum area that may be coated to a specified thickness in any
painting operation by a given volume of NV. (Shown in Equation 1.)
3) The minimum volume of NV required to coat a specified area to a spec-
ified thickness. (Shown in Equation 2.)
14
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The volume calculations which follow have been developed using the metric
and U. S. Standard measurement units commonly used by both the paint manufac-
turing industry and industrial paint users (Table 1).
TABLE 1. COMMONLY USED PAINT MEASUREMENT UNITS
MEASUREMENT
Length
Area
Thickness
Volume
METRIC
1m = 100 cm
1m2 = 10,000 cm2
or 1 x 104 cm2
1 ym = .0001 cm
or 1 x lO"4 cm
11 = 1,000 cm3
or 1 x 103 cm3
U. S. STANDARD
1 ft = 12 in
1 ft2 = 144 in2
1 mil = .001 in
or 1 x 10~3 in
1 gal = 231 in3
Using these units of measurement, the theoretical maximum area that can
be covered by 1 liter of NV 1 ym thick, and by 1 gallon of NV 1 mil thick,
can be established, (volume / thickness = area)
METRIC
11 _ 1 x 103
cm"
1 ym 1 x 10"1* cm
= 1 x 107 cm2
convert to m2
_ 1 x 107 cm2
1 x
cm
= 1,000 m
2
U. S. STANDARD
1 gal = 231 in3
1 mil 1 x 10~3 in
= 231 in2 x 103
convert to ft2
= 231 in2 x 103
144 inz
= 1,604 ft2
Equation 1
The following equation may be used to calculate the maximum surface area
that may be coated to a specified thickness by a given volume of NV:
15
-------
x v NV
where (metric)
Amax. = maximum possible area in m2
K = 1,000 m2 x 1 ym/liter
t = film thickness in ym
v = volume in 1
or, where (U. S. Standard)
Amax. = maximum possible area in ft2
K = 1,604 ft2 x 1 mil/gallon
t = film thickness in mil
v = volume in gal
Example 1
To calculate the maximum area that can be coated with a film 38.1 ym
(1.5 mil) thick with a quantity of paint containing 64 liters (16.9 gal) of
nonvolatile (NV) solids:
1,000 ,. (1,604)
Amax. = 387Tx64 (1.5) x (16'9)
1,680 m2 (18,072 ft2)
Equation 2
The following equation may be used to calculate the minimum volume of
NV required to coat a given surface area to a specified thickness:
vNVmin. = (Ap/K) x t
where
vNVm^n = minimum volume of nonvolatiles in 1 (gal)
Ap = area to be painted in m2 (ft2)
K = 1,000 m2 x 1 ym/1 (1,604 ft2 x 1 mil/gal)
t = film thickness in ym (mil)
16
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Example 2
To calculate the minimum volume of nonvolatiles (NV) necessary to cover
a surface area of 9,295 m2 (100,000 ft2) with a film 19 ym (.75 mil) thick:
vNV,
min.
x 19
(100.000)
(1,604) :
(46.8 gal)
(.75)
Summary
It should be noted that "Maximum Area" and "Minimum Volume" have been
emphasized in computing the consumption of nonvolatile solids (Figure 6)-
PAINT
VOLUME
NV
MAXIMUM
COVERAGE
MINIMUM
CONSUMPTION
FILM
VOLUME
NV
1 LITER = 1,000 m2 X 1 ym
1 GALLON = 1,604 ft2 X 1 mil
Figure 6. Maximum coverage equals minimum consumption.
Since there are some unavoidable losses of NV in all painting processes,
maximum coverage with a minimum volume will never be achieved. The discussion
of these losses is one of the objectives of this study and is provided in the
following sections of this report.
ORGANIC VOLATILES IN PAINTS
All paint compositions contain some amount of organic volatile (0V) ma-
terial. Even, the so-called "water borne" paint compositions contain a moder-
ate amount of 0V. ' These 0V materials are necessary to provide compatibility
of components during the manufacture of the compositions and to facilitate the
application of the nonvolatile (NV) solids to the desired surface. Compara-
tively, the largest amount of 0V material is usually found in paint composi-
tions designed for use in spray painting operations, while the least amount
is found in dry paint powder compositions.
As Bought
Most paint manufacturers list the various components in their paint com-
positions as volume percentages (vol%). For example, a certain water borne
paint (Code lAw 1) surveyed during this study is listed by the manufacturer
as containing:
17
-------
26.6 vol% NV
15.1 vol% 0V
58.3 vol% water
Since the volume of the NV components is the basis used for buying and
using paint compositions, the vol% of NV can be established as a measurement
unit (liter or gallon) of volume. The vol% relationship of all components
can then be shown as units of volume: (Figure 7)
1.000 vol (liter or gallon) NV
0.568 vol (liter or gallon) 0V
2.192 vol (liter or gallon) water
3.760 vol (liter or gallon) paint composition
2
0
1
.192 VOL
WATER
.568 VOL
0V
.000 VOL
NV
EQUALS
3.750 VOL
PAINT
COMPOSITION
(as bought)
(Code: lAw 1)
Figure 7 - Volume relationship of paint components.
As shown above, in order to provide one unit volume (liter or gallon) of
NV for a painting operation it is necessary to buy and use 3.76 unit volumes
(liters or gallons) of this particular paint composition (Code lAw 1). The
entire volumes of 0V and water are emitted during the painting operation as
0V and water waste loads as previously shown in Figure 4.
As Used
Most commercial paint compositions are manufactured and sold for use in
a variety of painting processes. Many of these compositions contain a solids
concentration too high to be used by most painting equipment and processes.
Therefore, the user must add an additional volume of liquid (0V solvent and/or
water) to reduce the viscosity as necessary for his specific painting opera-
tion.
When "thinners" are added to a paint composition "as bought" the volume of
NV remains the same, but the volume of 0V and/or water and the total volume
is increased proportionally. In order to calculate waste loads it is neces-
sary to correct the vol% and volume relationship to reflect the actual "as
18
-------
used" composition. For example, a certain solvent borne paint (lAs 6) survey-
ed is listed as containing:
As Bought
36.4 vol% NV
63.6 vol% 0V
As Used
28.6 vol% NV
71.4 vol% 0V
The vol% of all components, both as bought and as used, can then be shown
as units of measure: (Figure 8)
Buy
1.000 vol
1.747 vol
2.747 vol
Use
1.000 vol (1 or gal) NV
2.496 vol (1 or gal) 0V
3.496 vol (1 or gal) paint composition
0.749 VOL
0V THINNER
(added)
1.747 VOL
0V
(as bought)
1.000 VOL
NV
EQUALS
3.496 VOL
PAINT
COMPOSITION
(as used)
(Code: lAs 6)
Figure 8. Volume relationship of paint components "as used".
The total paint composition under the "buy" column can be used to calculate
the quantity of paint that must be bought. The difference in the volume of 0V
between the buy and use columns can be used to calculate the quantity of thin-
ner that must also be bought. The total volume of 0V under the "use" column be-
comes an 0V waste load during painting and curing processes.
ORGANIC VOLATILE CALCULATIONS
Since the volume of NV is the controlling factor in the quantity of paint
composition required in a painting operation, the ratio of 0V to NV in the com-
position is required to determine the 0V waste load. This ratio must be estab-
lished for the 0V and NV components in the mixture "as used". For solvent
borne paint compositions, such as lAs 6 used in the example above, the total
"as used" volume contains only 0V and NV components. This example shows a
ratio of 2.496 vol (liter or gallon) of 0V for each vol (liter or gallon) of
-------
NV in the "as used" composition. For water borne paint compositions, such as
lAw 1 used in the "as bought" example and shown in Figure 7, it may be desired
to establish a vol% ratio between just the 0V and NV components and disregard
the water in the composition (Figure 9).
WATER
0
1
.568
0V
.000
NV
VOL
VOL
0.568 VOL 0V x 100
1.568 VOL 0V + NV
36.3 VOL% 0V
Figure 9. Vol% ratio of 0V to NV components.
For 0V waste load calculations, the vol% ratio of 0V to NV must first be
reduced to the volume (liter or gallon) of 0V associated with 1 volume (liter
or gallon) of NV (Equation 3) and then the volume (liter or gallon) converted
to weight (kilogram or pound) (Equation 4).
EquatioQ 3
The following equation may be used to calculate the volume (liter or gal-
lon) of 0V associated with 1 volume (liter or gallon) of NV:
vOV
vol% 0V
(100 - vol% 0V)
or
vol% 0V
vol% NV
where
vOV = volume of 0V in liters or gallons
Example 3
The volume of 0V associated with 1 volume of NV in paint composition
lAw 1 can be found by using the vol% ratio established in Figure 9:
vOV
36.3
36.3
63.7
0.57 (liter or gallon)
(100 - 36.3)
or, by using the original vol% ratio of 0V to NV given on page 18:
15.1 vol% 0V
vOV
26.6 vol% NV
0.57 (liter or gallon)
20
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Equation 4
The following equation may be used to calculate the weight (kilograms or
pounds) of a given volume (liter or gallon) of 0V:
wOV = vOV x dOV
where
wOV = weight in kilograms or pounds
vOV = volume in liters or gallons
dOV = density weight for 1 volume unit in kg/1 or Ib/gal
Example 4
The weight of 0V associated with 1 volume of NV in paint composition
lAw 1 can be found if the density weight of the 0V is known:
wOV = 0.57 x 0.91 (0.57 x 7.5)
0.52 kg (4.3 Ib)
where
dOV = 0.91 kg/1 (7.5 Ib/gal)
Variations of Equation 4
Paint manufacturers may show the ratio of 0V to NV in their compositions
in several different ways. Frequently the ratio is expressed as "weight (kg
or Ib) of 0V per volume (liter or gal) of paint composition less water"; i.e.
wOV/(vOV + vNV). In other cases the ratio is expressed as "weight (kg or Ib)
of 0V per volume (liter or gal) of NV"; i.e. wOV/vNV. These ratios can each be
converted to the other by use of Equations 4a and 4b respectively.
Equation 4a—
The following equation can be used to find the weight of 0V associated
with 1 volume unit of NV when the wOV/(vOV + vNV) and dOV are known:
w'OV/v'NV = . W°Iov
I dOV
where
w'OV/v'NV = weight (kg or Ib) of 0V per 1 volume (1 or gal) of NV
21
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Example 4a—
w'OV/v'NV = °'348 . (2.90)
f 1 - 0.348] L _ (2.90)
I 0.930' \ (7.75)1
= 0.348 (2.900)
0.626 (0.626)
0.556 kg OV/1 NV (4.63 Ib OV/gal NV)
where
wOV = 0.348 kg/1 (0V + NV) (2.9 Ib/gal (0V + NV))
dOV = 0.93 kg/1 (7.75 Ib/gal)
Equation 4b—
The following equation can be used to find the weight of 0V associated
with 1 volume unit of (0V + NV) when the wOV/vNV and dOV are known:
w'OV/(v'OV + v'NV) « W°V
[1+wOV]
1 dOV J
where
\
w'OV/(v'OV + v'NV) = weight (kg or Ib) of 0V per 1 volume of
(0V + NV)
Example 4b—
w'OV/(v'OV + v'NV) = °-556 £4-^
0.930] I (7.75)
= 0.556 (4.63)
1.598 (1.598)
= 0.348 kg/1 (0V + NV) (2.9 Ib/gal
(0V + NV))
where
wOV = 0.556 kg/1 NV (4.63 Ib/gal NV)
dOV = 0.93 kg/1 (7.75 Ib/gal)
"22
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SECTION 5
PAINTING METHODS AND EQUIPMENT
GENERAL
It was shown in the previous Section that the first factor in paint cal-
culations is the ratio of organic volatiles to nonvolatile solids in the paint
composition. The next factor to be considered is the "transfer efficiency" of
the painting method and equipment used to apply the paint composition to the
surface of the merchandise.
The most commonly used methods and equipment used for painting operations
by the metal fabricating and finishing industry were surveyed and are discuss-
ed in this Section.
SPRAY PAINTING
The principle of spray painting is to break up the liquid paint composi-
tion into tiny droplets and propel them through the air onto the surface of
the merchandise to be coated. There are several methods for atomizing the
paint composition and there is a variety of spray painting equipment current-
ly in use.
Air Atomization
In this method a j et of compressed air impinges on a stream of liquid
paint which emerges from an orifice in the tip of the spray gun. The air jet
atomizes the paint and propels (transfers) the droplets onto the surface of
the merchandise (Figure 10).
COMPRESSED
AIR
OVERSPRAY
Figure 10.
Air atomized spray.
23
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Conventional spray painting using the air atomized method has the lowest
expected transfer efficiency" (about 50%) of all the methods surveyed. This
low transfer efficiency is due in part to the unavoidable overspray necessary
to achieve full coverage of the film coating on the merchandise and in part to
a factor called "air back bounce" which prevents many of the paint droplets
from reaching the surface of the merchandise.
Pressure Atomization
In this method the liquid paint is forced through a small diverging ori-
fice at a relatively high pressure of about 600 psi. The paint emerges from
the orifice as a fine spray with sufficiently high kinetic energy to propel
(transfer) it through the intervening air onto the surface of the merchandise
(Figure 11).
<£n
VENT
OVERSPRAY
PRESSURE
PUMP
Figure 11. Pressure atomized spray.
The pressure atomized method has a higher "expected transfer efficiency"
(about 65%) than the air atomized method. Though relatively the same amount
of unavoidable overspray is necessary to achieve full coverage, the "air back
bounce" factor is considerably reduced due to the smaller mass volume of air
movement.
Electrostatic Field Assisted Spray Painting
In this method the atomized paint is given a polarized high voltage elec-
trical charge (usually about 100,000 volts) at or near the point where it
emerges from the paint gun and the merchandise is electrically grounded to
the opposite polarity of the power source. Thus, the charged paint particles
are electrically attracted to the surface of the merchandise (Figure 12).
By using electrostatic field assistance in either the air atomized or
pressure atomized method, the "expected transfer efficiency" can be increased
to approximately 85%. Both the necessary unavoidable overspray and "air back
bounce" factors are appreciably overcome by the electrical attraction of the
paint particles to the surface of the merchandise.
24
-------
•x
HIGH
VOLTAGE
DC
Figure 12. Electrostatic field assisted spray painting.
Centrifugal Atomization
In the most commonly used centrifugal atomization method, liquid paint is
oozed onto the center inside surface of a rapidly rotating bell. The centri-
fugal force of the rotating bell moves the paint to the open end where it pass-
es through an electrostatic field and emerges as a charged, atomized spray.
As the spray emerges, the electrostatic field directs (transfers) it to the
surface of the merchandise (Figure 13).
HIGH
VOLTAGE
DC
ROTATING
BELL
COMPRESSED
AIR
Figure 13. Centrifugal atomized spray.
The centrifugal atomization has the highest "expected transfer efficiency"
of all spray painting methods surveyed (about 93%).
A common variation of the centrifugal atomization method uses a horizon-
tally rotating disk instead of the bell described above. This variation has
about the same transfer efficiency and provides a wider coverage area. In
this method the merchandise is usually carried by a conveyor in a horse shoe
shaped loop around the disk.
25
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Associated Equipment
Due to the airborne solid and semisolid wastes generated by spray paint-
ing operations they must be performed in a confined area. A paint spray booth
may simply be an area enclosed on three sides with an exhaust fan and filter
in an overhead hood, or it may be a much more elaborate arrangement.
Strippable Coatings—
There are several products on the market that can be applied to the inner
surfaces of spray booths. When a layer of waste has accumulated on these coat-
ings, they can be peeled off along with the waste and a new coating applied.
Water Bath Spray Booth—
In this type of booth, the sides consist of a series of baffles over which
a curtain of water cascades (Figure 14).
WATER
EXHAUST AIR
_ WASTE
WATER
Figure 14. Water bath spray paint booth.
The airborne solids are absorbed by the water curtain so that the exhaust
air contains only volatile wastes. The solids form a sludge in an associated
tank or reservoir and in some limited circumstances may be reclaimed. Waste
water from such methods may contain both organic liquids and solid contamin-
ants and require additional treatment.
Hot Melt Spray Paints
There are a number of spray paint compositions manufactured that are de-
signed to be preheated before use. These paints have such high concentrations
of solids that the viscosity at ambient temperatures is too high to be handled
by spray devices, but when preheated thin sufficiently for normal application.
These paint compositions are satisfactory for use in any of the spray
methods described above and have approximately the same "expected transfer
efficiency" as other paints used by the same method.
26
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DIP COATING
In the dip coating method the merchandise is actually submerged in a con-
tainer of liquid paint and then lifted back out. The excess paint drips off
the merchandise either directly back into the paint container or into a drip
recovery tray. Dip coating of rigid, profiled merchandise requires that each
piece be submerged individually (Figure 15).
PAN
Figure 15. Dip coating rigid, profiled merchandise.
The drip off process is sometimes aided by the use of a high voltage elec-
trostatic field which is effective in eliminating drops of paint that might
otherwise form on the bottom of the merchandise.
Flexible, essentially unprofiled merchandise such as coil stock or wire
is dip coated by a continuous process (Figure 16).
BLADE
OR DIE
Figure 16. Dip coating flexible, unprofiled merchandise.
The drip off process from continuous material is usually aided by passing
the merchandise through a blade or die that serves to wipe off excess paint.
The "expected transfer efficiency" for both the dip coating methods cited
above is in the range of 75 to 90%.
27
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FLOW COATING
In the flow coating method liquid paint is poured over the top of the
merchandise and allowed to drip off the bottom. The merchandise is position-
ed over a container of paint, part of the paint is pumped to a dispensing
head over the merchandise, the paint flows over the merchandise forming a
coating, and the excess drips back into the container (Figure 17).
CONVEYOR
o o
Figure 17. Flow coating.
Drip off is sometimes aided by use of a high voltage electrostatic field.
The "expected transfer efficiency" for the flow coating method is about the
same asxfor the dip coating method (75 to 90%).
CURTAIN COATING
The curtain coating method is similar in principle to the flow coating
method. Curtain coating is usually used to paint flat, relatively thin pieces
of merchandise. The merchandise is passed beneath a paint trough that has a
slit in the bottom that is perpendicular to the direction of movement of the
merchandise (Figure 18).
TROUGH WITH SLIT IN BOTTOM
-------
Liquid paint in the paint trough flows through the slit by gravity onto
the merchandise as it passes below. Excess paint flow and drip off is caught
in a container positioned below the merchandise. The system usually contains
a circulating pump which recycles the paint from the container below the mer-
chandise back up into the trough and maintains the paint level in the trough.
The "expected transfer efficiency" for the curtain coating method is a-
bout the same as for the dip and flow coating methods (75 to 90%).
ROLL COATING
In this method liquid paint is applied by a transfer roll directly to the
surface of the merchandise. This method can be used to paint any flat mater-
rial, rigid or flexible, individual pieces or continuous sheets, to one side
or to both sides simultaneously. The principle of roll coating is to cover
the surface of the transfer roll with liquid paint, control the amount of paint
on the surface of the transfer roll by means of a metering roll, and then to
transfer the paint from the transfer roll directly to the surface of the mer-
chandise by direct contact (Figure 19).
CROTCH FED PAINT
MERCHANDISE
PAN FED PAINT
Figure 19. Roll coating.
The above illustration shows basically a typical arrangement for roll
coating both sides of a continuous sheet of material simultaneously. In a
typical arrangement for coating only one side, the transfer and metering
rolls on the opposite side would be replaced by a single "nip" roll for the
purpose of maintaining pressure between the transfer roll and the material.
29
-------
There are a number of variations to the typical method of roll coating
shown in Figure 19. For example, a better application of the paint to the
surface of the merchandise is sometimes achieved by "reverse roll coating".
In other words, at the point of contact between the transfer roll and the ma-
terial the transfer roll is rotating in the opposite direction from the direc-
tion of travel of the material. This causes a "wiping" action at the point of
transfer.
The "expected transfer efficiency" for the roll coating method is in the
range of 90 to 98%. Another advantage of this method is that roll coating
paints are used at relatively high viscosity and, therefore, contain a compar-
atively low ratio of organic volatile solvents to nonvolatile solids.
ELECTROCOATING
In this method the merchandise is submerged into a dilute (low viscosity)
dispersion of specially formulated nonvolatile paint solids mixed with water.
A low voltage (50 to 500 volt), direct current electrostatic field is applied,
which attracts the nonvolatile paint particles to the surface of the merchan-
dise, -where they form a highly viscous deposit. The merchandise is then lift-
ed out of the electrocoating bath and subjected to several ultrafiltrate rinse
stages. Any droplets of paint lifted out of the bath on the newly painted sur-
face are rinsed back into the dip tank (Figure 20).
frnl
CONVEYOR
ELECTROCOATING
BATH
ULTRAFILTER
3 RINSE STAGES
Figure 20. Electrocoating.
Theoretically, the electrocoating method should create no waste loads.
In practice, however, some waste is unavoidable. It has been reported that
the freshly deposited film contains from 0.07 to 2.0 wt% organic volatiles.d
Phillips, G. Electrocoat 71, paper No. 5, National Paint and Coating Asso-
ciation, Washington, D.C.
30
-------
Using these weight percentages, and assuming a nonvolatile density of 1.44 kg/1
(12 Ib/gal), for each liter (gallon) of film coating 0.01 to 0.03 kg (0.08 to
.12 Ib) of organic volatile waste will be generated during the bake curing
process. There is also a very minor amount of organic volatile waste caused
by evaporation from the electrocoating tank, and a very small quantity of both
organic volatiles and nonvolatile solids in ultrafiltrate waste water that may
sometimes be discarded.
The electrocoat (Code 4Bw) paint compositions surveyed during this study
and reported in Section 9 of this report list the weight 0V associated with
1 unit volume of NV ranging from 0.31 to 0.47 kg/1 (2.6 to 3.9 Ib/gal). This
is given as the ratio for the original fill of the electrocoating tank, and
there are indications that replenishment paint, which must be continuously
added to the tank, contains less 0V, but detailed information is lacking.
The "expected transfer efficiency" of the electrocoating method is better
than 90% and is thought by some to be as high as 99%. Compared with the other
methods discussed previously, the electrocoating method generates markedly
less organic volatile and nonvolatile semisolid waste loads. There may also
be a cost advantage in using the electrocoating method. In one case the cost
has been described as "...equal to or even less than conventional dip coating
methods...".5
POWDER COATINGS
The principle of the powder coating method is to apply a layer of fusible
powdered plastics (powder paint) to the surface of the merchandise where it is
melted and heat cured into a nonvolatile solid film coating. There are sever-
al techniques for applying the powder paint composition to the merchandise,
each requiring a different arrangement of equipment.
Characteristics
Powder paint compositions have characteristic differences from liquid
paint compositions. A bulk volume of liquid paint composition contains a
specific volume percentage of nonvolatile solids, with the balance being vol-
atile liquids. A bulk volume of powder paint composition contains only about
50 volume percent of nonvolatile solids, with the balance being air. Powder
paint compositions "as bought" have a bulk volume density weight in the range
of 0.6 to 0.84 kg/1 (5 to 7 Ib/gal), however, when the powder is melted into
a nonvolatile solid, the solid density is in the range of 1.2 to 1.8 kg/1
(10 to 15 Ib/gal).
Fluidized Bed Technique
A "fluidized bed" is achieved by installing a false bottom made from a
4 Burnside, G. L., Brewer, G. E. F., Strosberg, G. G. Journal of Painting
Technology, Vol. 41, No. 534, pp 431-437, July 1969.
5 Levinson, S. B. Journal of Painting Technology, pp 41-49, June 1972.
31
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porous material inside the paint tank. A thin layer of powder paint is placed
on top of the porous material. A controlled flow of air or an inert gas such
as nitrogen is pumped into the tank chamber below the porous material. The
turbulence caused as the air or gas passes through the porous material and out
the top of the tank causes the particles of paint powder to rise and remain
suspended much as dust particles in the air. The flow rate is controlled at
a point where none of the particles are raised as high as the top of the tank
(Figure 21).
=Tl
VERY FINE SCREEN
"FLUIDIZED"
POWDER .
PAINT :
COMPRESSED AIR
OR INERT GAS
Figure 21. Fluidized bed dip tank.
The merchandise is preheated to a temperature above the melting point of
the paint powder and then is dipped into the fluidized bed. The paint powder
particles that contact the surface of the merchandise melt and form a film
coating.
Fluidized Bed Plus Electrostatic Field Technique
A shallow ''fluidized bed" is formed as described above, then the paint
powder particles are charged by a high voltage electrostatic field (Figure 22)
AIR
VM*^*
.»••«•«
i ' : ; ' , I
' ' ' "' ''/' ,4p f""' ' ' '• , n'n " /'
, ' ', ' >t,/tys* ' * / ' ' ' ' ^>
,./'%/$/"$}'"'" ' ' " *'
"""^"^k^'- •"---'' •'< ' ''^*fsfci;$
1
IGH
VOLTAGE
DC
Figure 22. Electrostatic fluidized bed,
32
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In this technique, the merchandise is not preheated but is electrically
grounded to the power source that supplies the electrostatic field. The mer-
chandise does not actually enter the fluidized bed, but when it passes above'
the surface the charged paint powder particles are attracted to it and form a
coating of powder. The particles are retained on the surface of the merchan-
dise by the residual electrostatic charge. The merchandise is then processed
into a heating chamber where the paint powder particles melt and form a film
coating.
Fluidized Spray Technique
The powder paint is fluidized by mixture with air or an inert gas such as
nitrogen and sprayed from a paint gun under a very small pressure. The paint
particles are charged by an electrostatic field at or near the point at which
they leave the spray gun and the merchandise is grounded electrically to the
power source that provides the field. The paint powder particles are attract-
ed to the surface of the merchandise where they form a powder coating (Fig-
ure 23).
FLUIDIZED
POWDER PAINT
HIGH
VOLTAGE
DC
ELECTROSTATIC
ATTRACTION
ELECTROSTATIC
REPELLENCY
Figure 23. Fluidized electrostatic powder spraying.
The thickness of the powder coating on the merchandise can be predeter-
mined and controlled by the strength of the electrostatic field. Due to the
weight of the paint particles and the low pressure of the operation, without
the electrostatic charge they would settle as they emerged from the paint gun.
Even if they contacted the surface of the merchandise they would not be re-
tained. When the powder coating has reached the desired thickness, the at-
traction is counteracted by the residual charge in the particles already at-
tached and no more particles will be retained. This residual charge in the
particles attached to the merchandise will also cause them to be retained on
the surface while the merchandise is processed to a heat chamber where they
melt and form a film coating.
Unlike liquid paint spraying, all the
erations is collected in a filter chamber and reused.
"overspray"
in powder spraying op-
33
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Summary
The "expected transfer efficiency" for powder paints using any of the
techniques described above is very good, possibly as high as 98%.
The powder paints surveyed in this study and reported in Section 9 show
a very favorably low generation of organic volatile waste loads. The weight
of organic volatiles per unit volume of final nonvolatile film is in the range
of 0.001 to 0.12 kg OV/1 NV (0.05 to 1.0 Ib OV/gal NV) . This is the result of
coreactants in the paint powders.
There may also be a material cost savings in using powder paints. The
coat has been described as "...equal to conventional films at equal film thick-
ti C ^
ness. "
PAINT LOSSES VS TRANSFER EFFICIENCY
It has been shown in the discussion of the various painting methods that
some paint loss must be expected in the process of transferring a paint com-
position from the container to the surface of the merchandise. Losses will
occur whether the most primitive or most sophisticated methods and equipment
are used. These are called "unavoidable losses" in that they are inherent to
the method and equipment used for the painting operation.
There are many factors which must be considered when determining the meth-
od and equipment to be used for a specific painting operation. Some factors,
such as the quality of the finished film coating, may automatically eliminate
the use of some classes of paint compositions and, therefore, some painting
methods. The nature of the merchandise may also be a determining factor. For
example, the roll coating method is obviously unsuited to merchandise with a
highly irregular surface configuration.
When two or more painting methods are equally acceptable for a specific
painting operation, the "unavoidable losses" associated with each method may
become the deciding factor in the method selected.
The total amount of "unavoidable losses" represents the difference of the
volume of nonvolatile solids in the paint used in the operation and the volume
of nonvolatile solids in the film coating on the finished merchandise. For
planning and calculation purposes this is usually expressed as "percent ex-
pected transfer efficiency" (% exp.t.e.).
However, a single distinct % exp.t.e. cannot be established for each
painting method. "Unavoidable losses" for each method will vary with the pe-
culiarities of the specific operation. For example, there are more overspray
losses when painting small irregular pieces of merchandise than when painting
large flat surfaces; there are more clean-up losses if the operation requires
frequent changeover or shutdown; etc. Table 2 shows the range of % exp.t.e.
found through the review of literature and/or received by direct communica-
b Levinson, S. B., Journal of Painting Technology, pp 39-56, July 1972.
34
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tion during the period of this study.
TABLE 2. EXPECTED TRANSFER EFFICIENCY
PAINTING METHOD
PERCENT EXPECTED TRANSFER EFFICIENCY
Air Atomized, Conventional
Air Atomized, Electrostatic
Pressure Atomized, Conventional
Pressure Atomized, Electrostatic
Centrifugally Atomized, Electrostat.
Dip, Flow, and Curtain Coating
Roll Coating
Electrocoating
Powder Coatings
43%*; 50%2; 30-60%3
87%*; 68-87%^
65-70%5
85-90%6
93%J; 85-95%"*
75-90%6
90-98%6; 96-98%7
90-96%6; 99%2
50-80%8; 98%2; 90-99%9
1 E. P. Miller, Ransburg Co.; SME Paper, FC73-553.
2 J. A. Antonelli, duPont Co.; SME Paper, FC74-654.
3 J. A. Antonelli, duPont Co.; "depending upon equipment and shape of
merchandise" (direct communication)
4 E. P. Miller, Ransburg Co.; "depending upon object being coated"
(direct communication)
5 W. H. Cobbs, Jr., Nordson Corp.; (direct communication)
6 F. Scofield, Wapora, Inc.; EPA Contract 68-01-2656
7 M. Wismer, PPG Industries; (direct communication)
8 S. B. Levinson, D. Litter Lab.; Journal of Painting Technology
pp 35-56, July 1972
9 T. W. Seitz, Sherwin-Williams Co.; "newer reuse methods" (direct com-
munication)
WASTE LOADS VS TRANSFER EFFICIENCY
The following factors were established in Section 4:
1) All volatile components in paint compositions are sacrificed during
the transfer and curing operations.
2) The quantity of paint composition required for a painting operation
is determined by the volume of nonvolatile solids required in the
film coating on the finished merchandise.
35
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3) The greatest pollutional waste loads generated by painting operations
are the organic volatile vapors emitted during transfer and curing.
4) The volume of waste loads does not provide meaningful data and must
be converted to weight.
Assuming that a 100% transfer efficiency could be achieved, only volatile
waste loads would be generated, and these would be in direct proportion to the
ratio of the components in the "as used" paint composition. However, since
100% transfer efficiency is never realized, not only are volatile waste loads
increased in proportion to the actual percentage of transfer efficiency, but
nonvolatile waste loads are also generated.
A certain water borne spray paint (Code lAw 1) was shown in Section 4 to
have a volume relationship of:
1.000 vol (liter or gallon) NV
0.568 vol (liter or gallon) 0V
2.192 vol (liter or gallon) water
3.760 vol (liter or gallon) paint composition
If this paint composition is used in an operation with only a 50% trans-
fer efficiency, only half the volume of NV would actually become film coating
on the merchandise; the other half would become an NV waste load. The entire
volume of 0V would become an 0V waste load.
TRANSFER EFFICIENCY CALCULATIONS
The weight of NV, 0V, and total waste loads can be calculated by use of
the following three equations.
Equation 5
The following equation may be used to calculate the weight of NV waste
at any given "percent expected transfer efficiency":
wNV Wet = [(100/et) - 1] x (Ap/K) x t x dNV
where
W = waste
et = percent expected transfer efficiency
A = area to be painted in m2 (ft2)
JC = 1,000 m2 x 1 ym/1 (1,604 ft2 x 1 mil/gal)
t = thickness of coating in ym (mil)
36
-------
d = density in kg/1 (Ib/gal)
Example 5
To calculate the weight of the NV waste load generated by painting a sur-
face area of 149 m2 (1,604 ft2) with a film coating 25.4 ym (1 mil) thick at
an expected transfer efficiency of 85% using a paint with an NV density of
1.75 kg/1 (14.6 Ib/gal):
wNV Wet = [(100/85) - 1] x 149/1,000 x 25.4 x 1.75
(1.176 - 1) x 0.149 x 44.45
0.176 x 6.62
= 1.17 kg NV waste expected
or, using U.S. standards
wNV Wet = [(100/85) - 1] x 1,604/1,604 x 1 x 14.6
0.176 x 14.6
2.57 Ib NV waste expected
Equation 6
The following equation may be used to calculate the weight of 0V waste
at any given "percent expected transfer efficiency":
wOV Wet = (100/et) x (A^/K) x t x wOV/vNV
where
wOV/vNV = weigh (kg or Ib) of 0V per volume (1 or gal) of NV
Example 6
To calculate the weight of the 0V waste load generated by the same paint-
ing operation used in example 5: (wOV/vNV =0.50 kg/1 (4.3 Ib/gal))
wOV Wet = (100/85) x (149/1,000) x 25.4 x 0.52
1.176 x 0.149 x 13.21
2.31 kg 0V waste expected or (5.06 Ib)
Equation 7
The following equation may be used to calculate the weight of Total
waste at any given "percent expected transfer efficiency":
37
-------
wT Wet
where
Example 7
wNV Wet + wOV Wet
total
To calculate the weight of total waste loads generated by the operation
described in Examples 5 and 6:
wT W
et
1.17 kg NV + 2.31 kg 0V
3.48 kg total waste (7.6.7 Ib)
SUMMARY
Transfer efficiency has a direct relationship to all the waste loads gen-
erated by any painting operation. 0V waste loads are generated by;all painting
operations and are directly proportional to the amount of 0V in the total quan-
tity of paint composition used in the painting operation. NV waste loads are
the direct result of transfer efficiency; ideally, if a 100% transfer effi-
ciency could be achieved, no NV waste loads would be generated, however, since
this is nearly impossible, some NV waste loads are generated by all painting
operations. NV waste loads rise at an accelerated rate with decreasing trans-
fer efficiency.
Table 3 has been prepared to show the waste loads generated at various
"percent expected transfer efficiency" for the specific painting operation
TABLE 3. WASTE LOADS VS PERCENT EXPECTED TRANSFER EFFICIENCY
%
exp . e . t .
100
95
90
85
80
75
70
65
60
55
50
*33
wOV Wet
kg
1.97
2.07
2.19
2.31
2.46
2.63
2.81
3.03
3.28
3.58
3.94
5.91
(Ib)
(4.34)
(4.56)
(4.83)
(5.09)
(5.42)
(5.79)
(6.19)
(6.68)
(7.23)
(7.89)
(8.68)
(13.02)
wNV Wet
kg
0.00
0.35
0.74
1.17
1.66
2.21
2.84
3.56
4.41
5.47
6.62
13.28
(Ib)
(0.00)
(0.77)
(1.63)
(2.57)
(3.66)
(4.87)
(6.26)
(7.84)
(9.72)
(12.05)
(14.58)
(29.16)
wT Wet
kg.
1.97
2.42
2.93
3.48
4.12
4.84
5.65
6.59
7.69
9.05
10.56
19.19
(Ib)
(4.34)
(5.33)
(6.46)
(7.67)
(9.08)
(10.66)
(12.45)
(14.52)
(16.95)
(19.95)
(23.26)
(42.18)
vOV + vNV
liter
5.90
6.24
6.54
6.96
7.37
7.86
8.43
9.07
9.83
10.77
11.80
17.70
(gal)
(1.56)
(1.65)
(1.73)
(1.84)
(1.95)
(2.08)
(2.23)
(2.40)
(2.60)
(2.85)
(3.12)
(4.68)
* Used for the purpose of illustration only.
38
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used in Examples 5, 6, and 7; i.e. to paint a surface area of 149 m (1,604
ft ) with a film coating 25.4 m (1 mil) thick using paint composition Code
lAw 1.
The information contained in Table 3 is shown graphically in Figure 24.
kg
11.0—1
10.0-
90 80 70 60
•*• "% expected transfer efficiency" -»•
Figure 24. Waste loads vs percent expected transfer efficiency
The two most important factors to remember are:
1) 0V waste loads are the result of both the ratio of 0V to NV in the
paint composition (wOV/vNV) and the expected transfer efficiency.
Minimum waste loads are generated at maximum transfer efficiency and
increase in direct proportion to the total volume of paint used.
2) NV waste loads are generated only as the result of transfer efficien-
cy. Minimum waste loads are generated at maximum transfer efficiency
and increase at an-accelerating rate as percent of transfer efficien-
cy decreases.
39
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SECTION 6
PAINT CURING METHODS
The process by which the paint composition "as used" is transformed into
a solid, wear-resistant nonvolatile film coating on the merchandise is known
as "curing". Most paint compositions are formulated to function best when a
specific curing method is used. However, some compositions may be used under
several curing methods, or even with a combination of methods. Curing methods
fall in the three general principles described below.
AMBIENT TEMPERATURE CURING
The simplest method of curing is provided by those paint compositions that
"dry" in an atmosphere at or near the ambient temperature of the work area.
There are three general classes of paint compositions that are normally cured
at ambient temperature: 1) solvent and/or water borne paints that cure through
evaporation of the liquid components; 2) paints which cure through the absorp-
tion of moisture from the atmosphere; and 3) two component paint compositions
which, when mixed, solidify within a few minutes.
Evaporation
Air drying through evaporation was, historically, the earliest used method
of paint curing. Paint compositions may undergo a strictly physical change as
the solvents are evaporated, or they may undergo a combination of physical and
chemical changes. Some paints, such as lacquers used for nail polish, cure by
physical evaporation only. This is a reversible, process, and the nonvolatile
solid film can be redissolved into a liquid state by use of the same solvents.
Paint compositions with oils, such as linseed, as part of the liquid com-
ponents cure by a combination of physical evaporation and chemical reaction.
During the evaporation of the solvents, other components undergo a chemical
combination with oxygen from the air. This is an irreversible process and the
film cannot be redissolved.
Moisture Curing
Some paint compositions contain liquid components which when exppsed to
the air react with the moisture in the air to form solids. This is actually
a combination of physical evaporation and chemical reaction during the curing
process, and as such is irreversible. These paint compositions require special
handling and must be kept sealed until they are used.
40
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Two Component Paints
A comparatively new family of paints form polymerized films at ambient
temperatures when two liquid components are mixed together. When the two com-
ponents are mixed, they react chemically with each other to form a solid poly-
mer. Since only a limited time is available to apply the paint after the two
components are mixed, they are usually used in spray operations where they are
mixed in the spray gun chamber.
BAKE CURING
The application of heat to accelerate the evaporation process is the most
widely used curing method by industry. There are a number of ways to achieve
"bake" curing, but they all function on the principle of subjecting the paint-
ed merchandise to temperature in the range of 120 to 175°C ( 250 to 350°F) for
a period usually about 8 to 30 minutes. Continuous air circulation through the
baking chamber is essential to remove the organic volatile waste and to dilute
the vapors to below the explosive level.
RADIATION CURING
There are several classes of liquid paint compositions that will solidify
quite rapidly when exposed to radiant energy. The two classes surveyed in this
study were the electron beam activated and the ultra-violet ray activated.
Electronic Beam Curing
Electronic beam radiation curable paint compositions are identified as
Code 6eb in Section 9. These paints may be applied to the merchandise by a
variety of methods such as spray, roll, flow, dip, etc. After the paint is
applied the merchandise is placed in a chamber containing a relatively oxygen
free atmosphere (usually less than 500 ppm) and exposed to high energy elec-
tron beams (g-rays). When the beta-rays impinge on the liquid paint compon-
ents, a chemical reaction is initiated which causes them to solidify into a
solid film coating (Figure 25).
ELECTRONIC
BEAM
GENERATOR
BEAM
TAINTED
SURFACED
Figure 25. Electron beam curing.
41
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Paints in this class are used where a comparatively thick film coating is
required on either flat or profiled merchandise. The composition may be either
pigmented or clear. The weight of organic volatiles associated with a unit vol-
ume of final solid nonvolatile film is approximately 0.048 kg OV/1 NV (0.40 Ib
OV/gal NV).
In comparison with other classes of paints, electron beam curing paints
have been reported as competitive: "...cost of liquid coating mil x ft2 may
be less than that of solvent thinned coatings...".7
Ultra-Violet Ray Curing
Ultra-violet ray curable paint compositions are identified as Code 6uv in
Section 9. These paint compositions are used where a comparatively thin film
coating is required on virtually flat surfaces, therefore, they are generally
applied to the merchandise by the roll coating method. The freshly coated mer-
chandise is then passed within a few inches of one or more ultra-violet lamps
(usually mercury vapor tubes) which emit 315 to 400 millimicron waves (Figure
26).
REFLECTOR
ULTRA-VIOLET
LAMP
r^f ?" /'"'' ''i" i V' " "v-v ' v "v ^ '-\
£?&-, / / > * \ v \ \ \
~. ; * ^ \ s \ \ v
^^-/ i \ . . < \
"^ ^.-' -'fc-'^ -'^ ,,VA ,.,*.;
Figure 26. Ultra-violet ray curing
The weight of organic volatiles associated with a unit volume of final
solid nonvolatile film ranges from 0.024 to 0.060 kg OV/1 NV (0.20 to 0.50 Ib
OV/gal NV).
Ultra-violet ray curing paint compositions have been described as having:
"...limited applicability: thin films and special pigments...low capital
cost...less floor space...".7
7 Levinson, S. B. Journal of Painting Technology, pp 29-40, August 1972.
42
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FORMATION OF COREACTANTS
In addition to the organic volatile wastes previously discussed, there
are certain organic volatiles generated by chemical reaction during the curing
process of some paint compounds. These organic volatiles are called "coreact-
ants (COR). The coreactants most frequently encountered are water, methanol,
etc. The weight of coreactants has been reported as usually less than 5 wt%
of the nonvolatile solids portion of the paint compositions.8
The weight of vaporized, organic volatile coreactants has not been in-
cluded in the previous calculations of weight 0V/volume NV. (An exception has
been made for the powder paints surveyed in Section 9. The weight of coreact-
tants has been included in the tables in Section 9 for powder paints (Code 5B)
as these are the only organic volatile wastes for these compositions.)
Prior to the chemical reaction that causes them to vaporize, coreactants
are actually a part of the nonvolatile solids in the paint composition.
Equation 8
The following equation may be used to calculate the weight of coreactants
generated during the curing process. The weight of organic volatile coreact-
ant waste must then be added to the organic volatile waste calculated by other
considerations.
wCOR = (Ap/K) x t x dNV x (wt% COR/100)
where
A^ = area painted
K = 1,000 m2 x 1 ym (1,604 ft2 x 1 mil)
t = thickness of nonvolatile film coating
dNV = density of nonvolatiles
wt% COR = weight percentage of coreactants in nonvolatiles
Example 8
To calculate the wCOR generated during the curing of a painted surface
area of 149 m2 (1,604 ft2) with a film thickness of 25.4 ym (1 mil) assuming
a dNV of 1.98 kg/1 NV (16.5 Ib/gal NV) and a wt% COR of 4.5:
wCOR = (149/1,000) x 25.4 x 1.98 x (4.5/100)
= 0.34 kg (0.74 Ib)
8 Greer, S. T.; and Anderson, C.; Industrial Finishing, April 1973. (and
direct communications with the authors and others)
43
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Odors
Heavy malodorous fumes have been detected at times during the curing pro-
cess of some paint compositions. These fumes are currently the subject of
odor analysis and further study.9
Schuetzle, D.; Prater, T. J.; and Ruddell, S. R.; "Sampling and Analysis
of Emissions from Stationary Sources: I. Odor and Total Hydrocarbons",
Journal of the Air Pollution Control Association, Volume 25, Page 925, (1975)
44
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SECTION 7
SANDING AND STRIPPING
There are certain unavoidable losses of paint solids that are caused by
the nature of the painting operation and in some cases by mistakes made in
the operation. Primary among these are the losses caused by sanding opera-
tions between coats and stripping necessary to remove defective coats.
SANDING
Sanding may be necessary to achieve the desired smoothness to the surface
of the film coating on the merchandise. Cured film coatings may show some im-
perfections due to defects in the original surface of the merchandise, by the
settling of dust or lint on the paint before it dries, and some roughness or
"orange peel" effect inherent in the paint or painting technique. These im-
perfections are removed by either a wet or dry sanding process, which removes
part of the film coating and generates a small amount of nonvolatile waste
(Figure 27).
ORANGE PEEL
LINT OR DUST
PRIMER PAINT
SANDED SURFACE
PRIMER PAINT
Figure 27. Sanding painted surfaces.
Merchandise with a highly uneven or porous surface is often painted first
with a primer coat and sanded smooth before the application of the finished
coatings. Calculation of the waste loads generated by sanding operations is
extremely difficult. Actually, the waste should include the weight of the dis-
carded disks or belts of sandpaper, and in the case of a wet sanding process,
45
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the total weight of the detergents, oils, or organic solvents used.
STRIPPING
Occasionally the film coating applied to some pieces of merchandise may
be defective or may be damaged to a point where it must be removed. In many
painting processes, paint may also accumulate on equipment used in the process
that must be stripped.
A paint "stripping" operation usually consists of a stripping bath into
which the parts to be stripped are submerged. The stripping bath is composed
of water and paint-lifting chemicals, usually caustic soda, surfacants, melted
salts, etc. The bath is usually heated to near the boiling point. The pro-
cess may include scraping or wire brushing and two or more emersions may be
necessary.
The weight of paint stripped is usually relatively small in comparison to
the total paint consumption in the overall operation, except in refinishing
shops where it may be a normal part of the operation.
Equation 9
The following equation may be used to calculate the weight of stripped
paint :
wWs = (dNV/K) xtCAjn x 1^) + (Ah x th)]
where
wWs = weight of stripped off waste
Am = area of merchandise stripped
1^ = thickness of film on merchandise
Ah = area of hangers stripped
t^ = thickness of film on hangers
Example 9
To calculate the wWs generated by a stripping operation consisting of a
merchandise area of 12.9 m2 (138.9 ft2) with a film thickness of 50.8 ym (2
mil) and a hanger area of 1.35 m2 (14.5 ft2) with a film thickness of 557.2
(18 mil) assuming a dNV of 2.02 kg/1 (16.83 Ib/gal):
wW = (2.02/1.0) x [(166.4 x 0.0000508) + (1.82 x 0.0005572)]
s
= 2.02 x (0.0085 + 0.001)
= 0.019 kg (.158 Ibs)
46
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Summary
It should be noted that the thickness of the film coating on the merchan-
dise is usually only about 25.4 to 76.2 pm (1 to 3 mils), while the thickness
of the film on the hangers may be 500 ym (20 mils) or more. It should also be
noted that the nonvolatile paint solids:
-------
SECTION 8
CALCULATION OF WASTE LOADS
GENERAL
It has been shown in the preceding Sections of this report that both or-
ganic volatile (0V) and nonvolatile (NV) waste loads are generated by all paint-
ing operations. Procedures and equations have been given for the prediction
of waste loads based on known factors.
The actual waste loads generated can be determined based on these same
known factors plus production and inventory data developed during the period
of operation.
PREDICTION OF WASTE LOADS
Equations 1 through 9 were developed and have been presented as tools to
be used for the calculation of predicted waste loads from a specific, planned
painting operation. Actually, equations 1 through 4 are used for basic paint-
ing calculations and equations 5 through 9 are used for waste load calculations.
Each calculation requires the use of known or estimated factors. For ex-
ample:
1) The surface area of the merchandise to be painted.
2) The thickness of the film coating to be applied.
3) Percent of expected transfer efficiency of the painting method and
equipment to be used.
4) The nature of the components of the paint composition to be used.
(Specifically the density weight of the nonvolatile components per
volume unit and the weight of organic volatile components per volume
unit of nonvolatiles.)
5) If applicable, the weight percent of coreactants in the nonvolatiles.
Using the above factors and equations 5, 6, and 8, the predicted NV, 0V,
and COR waste loads can be calculated.
Additional waste loads are occasionally generated by paint losses result-
48
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ing from accidental spills and leaks, cleaning and repairing of equipment, the
use of organic volatile cleaning materials, and paint sanding and stripping op-
erations. Though these waste generations usually evade prediction, it is esti-
mated that in most painting operations they actually add less than 5 percent to
the predictable waste loads. '
DETERMINATION OF WASTE LOADS
The actual waste loads generated during a painting operation include all
organic volatile and nonvolatile solids which are consumed during the opera-
tion except the weight of the nonvolatile solids that actually leave the plant
in the form of the finished film coating on the merchandise.
In addition to the five basic factors required to calculate the predicted
waste loads, the following factors are required to calculate the determined
waste loads:
1) The total consumption of paint compositions, thinners, cleaning fluids,
etc. during a specific production or inventory period.
2) The total area and thickness of the nonvolatile film coating on the
merchandise that actually leaves the facility.
Using all this data, the weight of nonvolatile waste (wNV W), the weight
of organic volatile waste (wOV W), and the weight of total waste (wT W) can be
determined by calculations using Equations 10, 11, and 12.
Equation 10
The following equation may be used to calculate the determined nonvolatile
waste load generated by a specific painting operation:
wNV Wd£t = wNVcons - [(Ap/K) x t x dNV]
where
Wj t = determined waste load
wNV = weight of the nonvolatile components of all paint com-
position consumed during the painting operation
As you can see, this equation is quite similar to equation 5 except that
actual consumption data is used in place of an "expected transfer efficiency"
factor. The determined NV waste load will include all losses of nonvolatile
solids caused by transfer efficiencies, sanding and stripping processes, clean-
up, spillage, etc. However, NV wastes from sources other than the paint com-
position, such as discarded sand paper or abrasives used in sanding operations
are not included. It is estimated that NV waste from such sources will add
only a very small percentage to the plant waste load, and in many cases may be
entirely insignificant. If such wastes are considered significant, they must
be added separately.
49
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Example 10
To calculate the weight of the determined NV waste load generated by an
operation in which 9,290 m2 of essentially flat merchandise has been painted
with a nonvolatile film coating 30.5 ym thick. Assume that inventory records
show that 863 liters (228.4 gallons) of paint composition Code IBs 2 contain-
ing 412 kilograms (908 pounds) of NV with a density of 1.15 kg/1 (9.6 Ib/gal)
were consumed during the operation:
wNV Wdet = 412 - [(9,290/1,000) x 30.5 x 1.15]
= 412 - (9.29 x 35.08)
= 412 - 325.89
= 86.11 kg (189.7 Ibs)
The above example shows only the determined waste load generated by the
NV solids in the paint composition used. If significant additional waste is
generated by other sources such as discarded sand paper or abrasives used in
sanding or stripping operations, that weight must be added to the above total
Equation 11
The following equation may be used to calculate the determined organic
volatile waste load generated by a specific painting operation:
wOV wdet = vNVcons x
where
W(jet = determined waste load
vNVcons = volume of the nonvolatile components of all paint com-
position consumed during the painting operation
wOV/vNV = weight of 0V per unit volume of NV
This equation produces a result similar to equation 6 by using actual con-
sumption data rather than "expected transfer efficiency" and finished film coat-
ing data. The determined 0V waste load will include all wastes generated by
the organic volatiles in the paint composition as used. However, 0V wastes
from sources other than the paint composition, such as organic volatile clean-
ing fluids, chemicals used for paint stripping, etc., are not included. This
additional 0V waste in most painting operations represents only a small per-
centage of the plant waste load, but in some cases may be quite significant.
If such wastes are considered significant, they must be added separately.
Example 11
To calculate the weight of the determined 0V waste load generated by the
same painting operation used in Example 11: (The weight ration of 0V to unit
50
-------
volume of NV for paint composition Code IBs 2 as used is 1.28 kg/liter (10.7
Ib/gal.)
wOV Wdet = 863 x 1.28
= 1104.6 kg (2444 Ibs)
The above example shows only the determined waste load generated by the
organic volatile solvents in the paint composition used. If significant ad-
ditional waste is generated by other sources such as cleaning fluids or strip-
ping compounds, that weight must be added to the above total.
Equation 12
The following equation may be used to calculate the determined total waste
loads generated by a specific painting operation:
wT Wdet = wNV Wdet = wOV wdet x wCOR
where
= weight of the total determined waste loads
wNV Wdet = result of equation 10 with any other significant NV
waste added
wOV Wj t = result of equation 11 with any other significant 0V
waste added
wCOR = result of equation 8
The weight of coreactant waste as calculated by use of equation 8 is
based on the volume of NV applied as a film coating on the merchandise. This
factor is used for two primary reasons: 1) Coreactants are most often found
in paint compositions designed for bake or radiation curing; and 2) the re-
lease of coreactant waste is stimulated by the curing process.
Actually, since coreactant waste is the result of chemical reaction which
transform a percentage of the nonvolatile paint solids into volatile coreact-
ants, for a finite calculation of waste loads the weight of coreactant waste
should be subtracted from the weight of NV waste as determined. In fact, co-
reactant waste may be generated by the entire weight of NV consumed, though
coreactants released from NV waste may be much slower than that released from
the NV film on the merchandise during the curing operation.
Example 12
To calculate the weight of the determined total waste loads generated by
a painting operation in which 9,290 m2 of essentially flat merchandise has been
prime coated with a film coating 20.3 iam thick and top coated with a film coat-
ing 35.6 um thick. Assume that inventory records show that 277 liters (73.4
gallons) of paint composition Code 4Bw 4 containing 295 kilograms (650 pounds)
51
-------
of NV with a density of 1.43 kg/1 (11.9 Ig/gal) were consumed during the prime
coating operation and that 969 liters (256.4 gallons) of paint composition Code
IBs 3 containing 704 kilograms (1,551 pounds) of NV with a density of 1.58 kg/1
(13.2 Ib/gal) were consumed during the top coating operation: (Primer paint
composition Code 4Bw 4 contains no coreactants; top coat paint composition
Code IBs 3 contains approximately 4 wt%.)
Prime Coat—
wNV Wdet = 295 - [(9,290/1,000) x 20.3 x 1.43]
= 295 - (9.29 x 29.03)
= 295 - 270
= 25 kg NV waste determined (56 Ib)
wOV Wdet = 0.31 x 206
= 64 kg 0V waste determined (142 Ib)
wT wdet = 25+64+0
= 89 kg Total waste determined (198 Ib)
Top Coat—
wNV Wdet = 704 - [(9,290/1,000) x 35.6 x 1.58]
= 704 - (9.29 x 56.25)
= 704 - 523
= 181 kg NV waste determined (399 Ib)
wOV Wdet = 1*06 x 446
= 473 kg NV waste determined (1,042 Ib)
wCOR = (9,290/1,000) x 35.6 x 1.58 x (4/100)
= 9.29 x 56.25 x 0.04
= 21 kg COR waste determined (46 Ib)
wT Wdet = 181 + 473 + 21
= 675 kg Total waste determined (1,487 Ib)
Total Plant Waste—
The total plant waste for this specific painting operation can be found
by adding the sum of the prime coat total waste to the sum of the top coat
52
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waste:
Total Plant Waste = 89 + 675
= 764 kg Total Plant waste determined (1,683 Ib)
PREDICTED VS DETERMINED WASTE LOADS
For a comparison of the predicted and determined waste loads for the oper-
ation described in example 12, first calculate the predicted loads using the
highest "expected transfer efficiency" for the painting method used in accord-
ance with equations 5 and 6:
Prime Coat (Electrocoating method at 96% expected transfer efficiency)
wNV Wefc = [(100/96) - 1] x (9,290/1,000) x 20.3 x 1.43
= 0.042 x 9.29 x 29.03
= 11.33 kg NV waste predicted (25 Ib)
wOV Wet = (100/96) x (9,290/1,000) x 20.3 x 0.31
= 1.042 x 9.29 x 6.3
= 61 kg 0V waste predicted (134.4 Ib)
Top Coat (Air atomized spray method at 87% expected transfer efficiency)
wNV Wet = [(100/87) - 1] x (9,290/1,000) x 35.6 x 1.58
= 0.149 x 9.29 x 56.25
= 77.8 kg NV waste predicted (171.4 Ib)
wOV Wet = (100/87) x (9,290/1,000) x 35.6 x 1.06
= 1.149 x 9.29 x 37.74
= 402.85 kg 0V waste predicted (887.5 Ib)
As you can see, the predicted loads at these transfer efficiencies are
less than the determined loads calculated in example 12. Next, calculate the
predicted loads using the lowest "expected transfer efficiency":
Prime Coat (At 90% expected transfer efficiency)
wNV Wet = [(100/90) - 1] x (9,290/1,000) x 20.3 x 1.43
= 0.111 x 9.29 x 29.03
53
-------
= 29.94 kg NV waste predicted (66 Ib)
wOV Wet = (10.0/90) x (9,290/1,000) x 20.3 x 0.31
= 1.111 x 9.29 x 6.3
= 65 kg 0V waste predicted (143.2 Ib)
Top Coat (At 68% expected transfer efficiency)
wNV Wet = [(100/68) - 1] x (9,290/1,000) x 35.6 x 1.58
= .47 x 9.29 x 56.25
= 245.6 kg NV waste predicted (541 Ib)
wOV Wet = (100/68) x (9,290/1,000) x 35.6 x 1.06
= 1.47 x 9.29 x 37.74
= 515.4 kg 0V waste predicted (1,135.4 Ib)
Using the lower transfer efficiencies, the predicted waste loads are
greater than the determined loads calculated in example 12. Therefore, the
determined waste loads are within the acceptable percentage of transfer ef-
ficiency range.
54
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SECTION 9
COMMERCIAL PAINT COMPOSITIONS SURVEYED
GENERAL
During the course of this study, a number of commercial paint compositions
currently available on the market were surveyed. Such paint compositions are
usually classified generically according to the filmformer content. The film-
formers contained in the surveyed paints included: acrylic, alkyd, epoxy, phen-
olic, cellulose acetate butyrate, polyester, polythioester, urethane, and vinyl.
The filmformers constitute the majority of the nonvolatile solids in most
paint compositions, with pigments and other additives constituting the rest.
The greatest and most troublesome waste loads are generated by the organic
volatile solvents used in the paint compositions. Most paint compositions are
carefully formulated for compatibility with specific painting methods and equip-
ment and curing processes. For example, compositions containing acrylic film-
formers may be designed for application by spray, dip, roll, etc. methods. Dip
coating requires less organic volatile solvents than spray coating, and roll
coating requires still less. Also, solvent borne paint compositions are more
suitable for air drying, and water borne more suitable for bake drying.
It is obvious from the above that the organic volatile solvent content of
paint compositions is influenced by the paint method and equipment and curing
process for which it was designed. Furthermore, it has been established in the
earlier Sections of this report that the normal unavoidable losses of nonvola-
tile paint solids during painting operations are also directly related to these
two factors.
This study has identified the following causes for waste generation and
paint losses during industrial painting operations:
1) All volatile components of paint compositions are sacrificed during
the transfer and curing processes and result in waste load generation.
2) Some loss of nonvolatile solids are inherent in all painting methods
and equipment which result in nonvolatile waste load generation.
3) Sanding and stripping operations cause paint losses and contribute to
nonvolatile waste load generation.
4) Cleaning and repair of equipment cause paint losses and contribute to
both organic volatile and nonvolatile waste load generation.
55
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5) Coreactants generated by chemical reaction during the curing process
of some paint compositions cause the loss of nonvolatile paint solids
and contributes to waste load generation.
6) Some losses will occur from accidental spillage and leakage.
CLASSIFICATION OF PAINT COMPOSITIONS
Early in the survey of available commercial paint compositions it was
deemed advisable to classify the surveyed paints in accordance with the paint-
ing method and curing process for which they were designed, and to assign codes
to each class to facilitate cross reference. The first step was to assign each
paint surveyed to one of the following general numeric classes:
1 Spray coatings
2 Dip, Flow and Curtain coatings
3 Coil and Roll coatings
4 Electro coatings
5 Powder coatings
6 Radiation Cured coatings
7 High Solids Spray coatings
8 Low Solvent Emulsion coatings
9 Powder Slurry coatings
During the survey, attention was particularly drawn to the last three
classes of paints identified above due to their relatively low organic volatile
content and resulting low generation of 0V waste loads. These paints are com-
paratively new and are not presently in generally wide usage. These new paint
compositions have been developed by resin and paint manufacturers largely to
meet environmental requirements for low 0V waste generation.
It was found that in many of the paint classes some of the compositions
were designed for air drying and others for bake curing. The capital letters
A and B were assigned to these compositions respectively to identify the curing
process. For class 6, Radiation Cured coatings, it was found that some compo-
sitions were designed for electron beam curing and others for ultraviolet light
curing. The lower case letters eb and uv were assigned to these compositions
respectively to identify the type of radiation that is required.
Finally, it was found that in many of the paint classes, some of the com-
positions contain only organic volatile solvents as liquid components while
others contain primarily water. These compositions are commonly referred to
as solvent borne and water borne. The lowercase letters s and w were assigned
to these compositions to identify the primary liquid component.
Also, since more than one commercial paint composition was surveyed within
some of the paint classes and having the same characteristics, a serial number
was assigned to each composition surveyed. Thus, the first surveyed Spray
paint, designed for Mr drying, solvent borne, was assigned a Code lAsl.
56
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WASTE LOAD COMPUTATION DATA
The computation of either predicted or determined waste loads requires the
use of basic data related to the paint composition used in the painting oper-
ation. The two basic factors required to use the equations given in the pre-
vious sections of this report are: 1) the density of the nonvolatile compon-
ents (dNV); and 2) the weight of organic volatiles associated with a volume
unit of nonvolatiles (wOV/vNV).
These data are usually obtained in one of the following ways:
1) Directly from the manufacturer of the paint composition. This is by
far the easiest course, and will be provided by most manufacturers in
immediately usable form in response to communications if they under-
stand the purpose for which it is requested.
2) By using formulation data provided in the manufacturer's literature.
This process requires the mathematical computations necessary to de-
velop the desired information.
3) By laboratory determination of a quantity of the paint composition.
Such analysis should be conducted in accordance with the ASTM Paint
Testing Manual, Philadelphia, Pa.
COMPUTATIONS USING MANUFACTURER'S LITERATURE
The following illustrates the computations necessary to develop the den-
sity of NV components (dNV) and weight of 0V associated with a volume of NV
(wOV/vNV) from typical information provided in the manufacturer's literature.
Typical Manufacturer's Data
The following is the data supplied in manufacturer's literature for paint
composition Code lAw 1. This composition is an air drying, water borne, short
oil alkyd white enamel, designed for use in spray painting operations "as
bought" without the addition of thinners, based on Arolon 363 resin binder
(Formula 8042-50-29b), ADM Formulary No. P-216.
ADM Formulary No. P-216
Component
Rutile
Arolon 363 Resin
Naptha
Water
57
Weight
Ib kg*
170.0 77.2
102.0 46.3
3.4 1.5
68.0 30.9
Volume
gal. lit.*
4.86 18.4
11.65 44.0
0.52 2.0
8.35 31.5
-------
Weight Volume
Component lb kg* gal. lit.*
Pebble Mill Grind-24h
Arolon 363 Resin 323.0 146.6 36.87 139.4
24% Lead Naphthenate Drier 0.4 0.2 0.04 0.15
6% Cobalt Naphthenate Drier 1.8 0.8 0.22 0.83
Water 307.0 139.4 37.49 141.71
TOTALS 975.6 442.9 100.00 377.99
* Weight and volume were given by the manufacturer in U.S. measures;
metric measures added by the author.
Formula 8042-50-29b
Density
Ib/gal kg/1
Arolon 363
50 wt% NV
25 wt% 0V
25 wt% H20
8.76
9.89
7.50
8.20
1.052
1.188
0.901
0.985
Computations
Using the above manufacturer's data, the following computations must be
made before dNV and wOV/vNV can be calculated;
Arolon 363—
Vol% NV = [(density Arolon 363 x 0.5)/dNV] x 100
= [(8.76 x 0.5)/9.89] x 100
- (4.38/9.89) x 100
= 44.2
ADM Formulary No. P-216—
Weight 0V Volume NV
Component lb kg_ gal. lit.
Rutile Ti02
4.86 18.4
58
-------
Weight 0V Volume NV
Component Ib _kg_ gal, lit.
Arolon 363 Resin 25.5 11.6 5.15 19.5
Naptha 3.4 1.5
Arolon 363 Resin 80.8 36.7 16.30 61.6
24% Lead Naphthenate Drier 0.399 0.199 0.001 0.001
6% Cobalt Naphthenate Drier 1.799 0.799 0.001 0.001
TOTALS 111.9 50.8 26.3 99.5
As you can see, all the water component has been dropped from the above
computation. The driers add an insignificant volume of coreactant solids to
the total volume of NV which is actually even less than the 0.001 shown. The
estimated wCOR generated by use of this paint composition is less than 0.05%
of total NV weight so is seldom worth the effort to calculate.
Total Weight of NV—
wNV = w Rutile + (w Arolon 363 x wt% NV)
= 170 + (425 x 0.5)
= 382.5 Ib (173.6 kg)
Density of NV—
dNV = wNV/vNV
= 382.5/26.3 (173.6/99.5)
= 14.5 Ib/gal (1.75 kg/1)
Weight of 0V Associated With 1 Unit Volume of NV—
wOV/vNV = 111.9 Ib OV/26.3 gal NV (50.8 kg OV/99.5 1 NV)
= 4.26 Ib OV/gal NV (0.51 kg OV/1 NV)
Similar computations were performed for each paint composition surveyed
during the study and the resulting dNV and wOV/vNV data has been entered in
the appropriate columns in Table 4. (In a few cases, manufacturer's data was
not available, hence computations were not possible and Unk has been entered
on the Table.) Table 5 is a summary showing the range of dNV and wOV/vNV
within each class of paint compositions surveyed.
59
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TABLE 4. CLASSIFICATION AND COMPOSITION OF PAINTS SURVEYED
PAINT CLASS
lAs - SPRAY, Air drying,
solvent borne
lAw - SPRAY, Air drying,
water borne
IBs - SPRAY, Bake cured,
solvent borne
PAINT DESCRIPTION
(FORMULATION)
1. Medium Oil Alkyd White
Enamel (Ashland P-31)
2. Modified Alkyd Red Primer
(Ashland Q-405a)
3. Modidied Alkyd Brown Primer
(Ashland Q-315a)
4. Modified Alkyd Green Primer
(Ashland P-lll)
5. Ur ethane Lacquer Blue
(Ashland R-501)
6. Short Oil Alkyd White
Enamel (Ashland P-49)
7. Medium Oil Alkyd White Gloss
Enamel (Ashland 1-46)
8. Zinc Rich Primer (Mirasol
601)
1. Short Oil Alkyd White Enamel
(Ashland P-216)
1. Thermoset Acrylic White
Enamel (Ashland P-36)
2. Thermoset Acrylic Black
Enamel (Ashland P-188)
3. Thermoset Acrylic White
Enamel (Ashland P-232)
4. Short Oil Alkyd White Primer
(Ashland P-63)
5. Non-oxidizing Alkyd White
Enamel (Ashland P-122a)
COMPOSITION OF BINDER .
52% Soybean Oil, 34% Phth. Anh.
in Alphatics (Aroplaz 1082M60)
32% Linseed/Tung Oil, 39* Phth.
Anh. in Xylene - Modifier:
Phenolic rosin (Aroplaz X663X50)
32% Linseed/Tung Oil, 39% Phth.
Anh. in Xylene - Modifier:
Phenolic rosin (Aroplaz X663X50)
29% Linseed Oil, 30% Phth. Anh.
in VM & P - Modifier: Rosin
(Aroplaz 1385V50)
25% Urethane in Xylene/MIBK/but .
20/50/30 (Arothane M529)
30% Tall Oil, 40% Phth. Anh. in
Xylene (Aroplaz 6065X50)
51% Soybean Oil, 30% Phth. Anh.
in mineral spirits
Epoxyester Xylene, naphtha/
acetate
Soybean Oil resin in Butoxy
ethanol /water solution
(Arolon 363)
Selfcrosslink acrylic in ethoxy
ethanol/xylene (Aroset 701XA3-50
Acrylic resin in Xylene cross-
link/melamine (Aroset 4110X60)
Acrylic resin in Xylene cross-
link/melaraine (Aroset 4110X60)
32% Tall Oil, 40% Phth. Anh. in
Xylene (Aroplaz 1453X50)
35% Coconut Oil, 41% Phth. Anh.
in Xylene (Aroplaz 2580X60)
SUGGESTED USE
TTR266d - Type IV,
low vis., color fast
TTE515 & TTP664c
fast dry, lift resist.
Rust inhibiting, lacq.
resisting
Fast drying, It. color,
Drums, machinery, etc.
For flexing parts like
bumpers, etc.
Fast drying, economical,
industrial finish
High viscosity, general
purpose, flexible, hard
Industrial weld-through
primer
Industrial coatings
Quality coat, good ad-
hesion
High gloss automotive,
industrial coatings
High gloss automotive,
industrial coatings
Light color industrial
finishes
Ultradurable exterior &
automotive
NV
kg/lit
(Ib/gal)
1.50
(12.5)
1.90
(15.8)
2.21
(18.4)
1.70
(14.2)
1.69
(14.0)
1.73
(H.4)
1.61
(13.4)
3.82
(31.8)
1.75
(14.6)
1.64
(13.7)
1.15
(9.60)
1.58
(13.2)
1.67
(13.9)
1.66
(13.8)
kg OV/lit NV
(Ib OV/gal NV)
buy
2.09
(17.4)
1.09
(9.10)
1.39
(11.6)
1.69
(14.1)
3.37
(28.1)
1.50
(12.5)
1.24
(10.3)
1.10
(9.20)
0.51
(4.26)
1.63
(13.6)
1.03
(8.60)
1.06
(8.80)
1.22
(10.2)
0.90
(7.50)
use
2.09
(17.4)
1.39
(11.6)
1.39
(11.6)
1.69
(14.1)
4.45
(37.1)
2.12
(17.7)
1.78
(14.8)
Unk
Unk
0.51
(4.26)
1.94
(16.2)
1.28
(10.7)
1.06
(8.80)
1.51
(12.6)
1.03
(8.60)
ON
O
(continued)
-------
TABLE 4. (continued)
PAINT CLASS
IBs - (continued)
IBw - SPRAY, Bake cured,
water borne
2As - DIP, FLOW, CURTAIN,
Air drying, solvent
borne
2Aw - DIP, FLOW, CURTAIN,
Air drying, water
borne
2Bs - DIP, FLOW, CURTAIN,
Bake cured, solvent
borne
PAINT DESCRIPTION
(FORMULATION)
6. Non-oxidizing Alkyd Yellow,
Gray, Green (Ashland R-322)
1. Modified Meleinize Gray
Surfacer (Ashland Q-509)
2. Medium Short Alkyd Orange
Enamel (Ashland P-225)
3. Medium Short Alkyd Red
Primer (Ashland Q-514)
4. Medium Short Alkyd Green
Enamel (Ashland P-223c)
1. Medium & Short Alkyd /Modi-
fied Rosin Gray Enamel
(Ashland P-134)
2. Medium & Short Modified
Rosin Black Enamel
(Ashland P-134)
1. Short, Modified Alkyd Orange
Enamel (Ashland P-235a)
2. Short, Modified Alkyd White
Enamel (Ashland P-238)
1. Short Alkyd Yellow Enamel
(Ashland P-140)
COMPOSITION OF BINDER
47% Castor Oil, 37% Phth. Anh.
in Xylene (Aroplaz 2477X65)
Linseed/Castor Oil in Butixy
Ethanol water solution (Arolon
324)
Saf flower Oil Alkyd in water/ t.
but./butoxyl ethanol water
solution (Arolon 376)
Safflower Oil Alkyd in water/t.
but./butoxyl ethanol water
solution (Arolon 376)
Safflower Oil Alkyd in water/t.
but./butoxyl ethanol water
51% Soybean, 30% Phth. Anh.
(Aroplaz 7307M50)
35% Soybean, 37% Phth. Anh.
(Aroplaz 7424X50)
Phenol-Rosin (Arochem 335)
51% Soybean, 30% Phth. Anh.
(Aroplaz 7307M50)
35% Soybean, 37% Phth. Anh.
(Aroplaz 7424X50)
Phenol-Rosin (Arochem 335)
Safflower Oil Rosin - water dis-
persion type (Arolon 585)
Safflower Oil Rosin - water dis-
persion type (Arolon 585)
35% Tall Oil, 38% Phth. in Xy-
lene/Aliphatics (Aroplaz
7435XM50)
SUGGESTED USE
Semi-dry Alkyd lacquer &
baked enamel
Sandable primer
Exterior, durable, bake
or air dry
Exterior, durable, bake
or air dry
Exterior, durable, bake
or air dry
Fast drying, general use,
flexible, hard, tough
Fast drying, general use.
flexible, hard, tough
Fast drying, good adhe-
sion & toughness
Fast drying, good adhe-
sion & toughness
Toys, etc. Excellent for
electrostatic spray
NV
kg/lit
(Ib/gal)
2.35
(19.6)
2.08
(17.3)
1.92
(16.0)
2.35
(19.6)
1.54
(12.8)
1.51
(12.6)
1.10
(9.20)
1.49
(12.4)
1.69
(14.1)
1.27
(10.6)
kg OV/lit NV
(Ib OV/gal NV)
buy
2.65
(22.1)
0.67
(5.60)
0.84
(7.00)
0.76
(6.30)
0.84
(7.00)
1.36
(11.3)
1.45
(12.1)
0.11
(0.90)
0.12
(1.00)
1.73
(14.4)
use
7.27
(60.6)
0.67
(5.60)
0.84
(7.00)
0.76
(6.30)
0.84
(7.00)
1.96
(16.3)
2.09
(17.4)
0.11
(0.90)
0.12
(1.00)
2.09
(17.4)
CT>
(continued)
-------
TABLE 4. (continued)
FAINT CLASS
2Bs - (continued)
2Bw - DIP, FLOW, CURTAIN,
Bake cured, water
borne
3As - COIL & ROLL, Air or
mild heat drying,
solvent borne
3Bs - COIL & ROLL, Bake
cured, solvent borne
PAINT DESCRIPTION
(FORMULATION)
2. Oil Free Alkyd
1. Short Oil Alkyd Red Enamel
(Ashland P-243)
2. Short Oil Alkyd White Enamel
(Ashland P-233)
3. Short Oil Alkyd Black Enamel
(Ashland P227)
4. Modified Oil Maleinized
Black Primer (Ashland Q-510)
5. Medium Short Alkyd Orange
Primer (Ashland P-234)
6. Modified Alkyd Gray Primer
(Ashland 8635P1154)
7. Maleinized Oil Resin Black
Primer (Ashland Q-519)
8. Maleinized Oil Resin Black
Primer (Ashland Q-515)
1. Medium Oil Alkyd Red Shop
Coat (Ashland Q-14)
2. Medium Oil Alkyd Flat White
Enamel (Ashland H-305a)
3. Short Oil Alkyd White Enamel
(Ashland B-15)
1. Oil Free Polyester White
(Ashland P-87)
COMPOSITION OF BINDER
Polyester in aromatic solvents
(Aroplaz 6025R70)
Saf flower Oil Resin in water
dispersion (Arolon 585)
Safflower Oil Resin in water
dispersion (Arolon 585)
Safflower Oil Resin in water
dispersion (Arolon 585)
Linseed/Castor Oil Resin in eth-
oxy ethanol glycol butyl
(Arolon 324)
Safflower Oil Resin in Butoxy
ethanol/t. butanol water solu-
tion (Arolon 377)
Meleinized Oil Resin in Butoxy
ethanol/mineral spirits water
solution (Arolon 507)
Linseed Oil Resin in water solu-
tion (Arolon 525)
Linseed Oil Resin in water solu-
tion (Arolon 525)
52% High Soya, 34% Phth. Anh. in
Min. Spirits (Aroplaz 1082M50)
52% High Soya, 34% Phth. Anh. in
Min. Spirits (Aroplaz 1082M50)
38% Soyabean Oil, 43% Phth. Anh.
in Xylene/Min. Spirits (Aroplaz
7310X50)
Non-oxidizing Alkyd in Arom./
methyl-heptyl ketone (Aroplaz
6022R65)
SUGGESTED USE
Industrial high flexi-
bility
High gloss, high solids,
industrial use
High gloss, high solids,
Industrial use
High gloss, high solids,
industrial use
Rust inhibitive
High gloss, hard flexible
mar-resistand
Tough resin, outstanding
pigment suspension for
automotive use
Corrosion resistant,
economical
Automotive use
Low viscosity TTR266d-IV,
high color retention
Low viscosity TTR266d-IV,
high color retention
Very flexible, high
weather durability
Exterior coil coat
NV
kg/lit
(Ib/gal)
1.20
(10.0)
1.32
(11.0)
2.04
(17.0)
1.46
(12.2)
2.17
(18.1)
1.52
(12.7)
1.92
(16.0)
1.34
(11.2)
1.46
(12.2)
1.60
(13.3)
2.06
(17.2)
2.24
(18.7)
1.79
(14.9)
kg OV/lit NV
(Ib OV/gal NV)
buy
1.16
(9.70)
0.48
(4.00)
0.28
(2.30)
0.29
(2.40)
0.64
(5.30)
1.01
(8.40)
0.60
(5.00)
0.95
(7.90)
0.76
(6.30)
1.10
(9.20)
1.16
(9.70)
1.27
(10.6)
0.79
(6.60)
use
1.16
(9.70)
0.48
(4.00)
0.28
(2.30)
0.29
(2.40)
0.64
(5.30)
1.01
(8.40)
0.60
(5.00)
0.95
(7.90)
0.76
(6.30)
1.10
(9.20)
1.69
(14.1)
1.57
(13.1)
0.79
(6.60)
ON
(continued)
-------
TABLE 4. (continued)
FAINT CLASS
3Bs - (continued)
3Bw - COIL & ROLL, Bake
cured, water borne
4Bw - ELECTROCOATS, Bake
cured, water borne
PAINT DESCRIPTION
(FORMULATION)
2. Silicone modifier Polyester
White Enamel (Ashland P-77)
3. Oil Free Polyester White
Gloss Enamel (Ashland P-84)
4. Oil Free Polyester White
Gloss Enamel (Ashland P-88)
5. Oil Free Polyester White
Gloss Enamel (Ashland P-89)
6. Oil Free Polyester White
Gloss Enamel (Ashland P-81)
1. Oil Free Polyester White
Gloss Enamel (Ashland P-240)
2. Medium Short Alkyd Red
Primer (Ashland Q-514)
3. Medium Short Alkyd Green
Enamel (Ashland P-223c)
1. Short Oil Alkyd Red Primer
(Ashland Q-602)
2. Short Oil Alkyd Flat Black
(Ashland P-702)
3'. Short Oil Alkyd Gloss Black
(Ashland P-704)
4. Short Oil Alkyd Gray Primer
(Ashland Q-601)
5. Short Oil Alkyd White
Enamel (Ashland P-701)
COMPOSITION OF BINDER
70* Oil Free Alkyd, 30% Silicone
in Aromatic/polyester/butanol
(Aroplaz 1711A960)
85% Oil Free Alkyd, 15% Silicone
in Arom./but. ac. (Aroplaz
6025R70)
Oil Free Alkyd in Aromatics
(Aroplaz 6023R70)
Oil Free Alkyd in Aromatics
(Aroplaz 6029S60)
Oil Free Alkyd in Aromatics
(Aroplaz 6025R70)
Thermoset Alkyd in Butoxy ethan.
water solution (Arolon 465)
Safflower Oil in butanol/butoxy
ethanol water solution
(Arolon 376)
Safflower Oil in butanol/butoxy
ethanol water solution
(Arolon 376)
Soy Oil Resin in n-butanol water
solution (Arolon 369)
Soy Oil Resin in n-butanol water
solution (Arolon 369)
Soy Oil Resin In n-butanol water
solution (Arolon 369)
Soy Oil Resin in n-butanol water
solution (Arolon 369)
Soy Oil Resin in n-butanol water
solution (Arolon 369)
SUGGESTED USE
Good durability, econ-
omical
Good exterior durability,
economical
Low temperature curing,
interior & exterior
Low temperature curing,
interior & exterior
High flexibility, color
retention, adhesion
Excellent color retention
High gloss, adhesion,
corrosion resistant,
flexible
High gloss, adhesion,
corrosion resistant,
flexible
Automotive & other high
quality uses
Automotive & other high
quality uses
Automotive & other high
quality uses
Automotive & other high
quality uses
Automotive & other high
quality uses
NV
kg/Ut
(Ib/gal)
1.82
(15.2)
1.84
(15.3)
2.04
(17.0)
1.81
(15.1)
2.82
(23.5)
1.74
(14.5)
2.35
(19.6)
1.55
(12.9)
1.44
(12.0)
1.50
(12.5)
1.14
(9.50)
1.43
(11.9)
1.33
(11.1)
kg OV/lit NV
(Ib OV/gal NV)
buy
0.70
(5.80)
0.66
(5.50)
0.73
(6.10)
0.85
(7.10)
0.66
(5.50)
0.32
(2.70)
0.76
(6.30)
0.84
(7.00)
0.31
(2.60)
0.30
(2.80)
0.47
(3.90)
0.31
(2.60)
0.34
(2.80)
use
0.70
(5.80)
0.66
(5.50)
0.73
(6.10)
0.85
(7.10)
0.66
(5.50)
0.32
(2.70)
0.76
(6.30)
0.84
(7.00)
0.31
(2.60)
0.30
(2.80)
0.47
(3.90)
0.31
(2.60)
0.34
(2.80)
U)
(continued)
-------
TABLE 4. (continued)
PAINT CLASS
5B - POWDERS, Bake cured
PAINT DESCRIPTION
(FORMULATION)
1. Epowy, Conventional
2. Epoxy, low Temperature
3. Thermoset Polyester, Mela-
mine cured
4. Thermoset Polyester, Ure-
thane cured
5. Thermoplastic Polyester
6. Thermoset Acrylic
COMPOSITION OF BINDER
SUGGESTED USE
Indoor or primer1
Outdoor metal1
Outdoor metal1
Furniture, fencing6
Outdoor metal &
equipment1
NV
kg /lit
(Ib/gal)
1.20-
1.30
(10.0-
15.0)
1.16-
1.79
(9.60-
14.9)
1.16-
1.79
(9.60-
14.9)
1.16-
1.793
(9.60-
14.9)
1.15-
1.31
(9.60-
10.9)
1.20-
1.52
(10.0-
12.7)
kg OV/lit NV
(Ib OV/gal NV)
buy
*
0.012-
0.0182
(0.120-
0.150)2
0.007-
0.0103
(0.060-
0.080)3
0.042-
0.0782
(0.350-
0.640)2
0.030-
0.04811
(0.250-
0.400)1*
0.048-
0.060
(0.400-
0.500)3
0.054-
0.0705
(0.450-
0.580)5
0.001-
0.0046
(0.010-
0.030)6
0.030-
0.0422
(0.250-
0.350)2
0.098-
0.1242
(0.820-
1.030)2
use
*
0.012-
0.0182
(0.120-
0.150)2
0.007
0.0103
(0.060-
0.080)3
0.042-
0.0782
(0.350-
0.640)2
0.030-
0.0481*
(0.250-
0.400)"
0.048-
0.0603
(0.400-
0.500)3
0.054-
0.070s
(0.450-
0.580)5
0.001-
0.0046
(0.010-
0.030)6
0.030-
0.0422
(0.250-
0.350)2
0.098-
0.1242
(0.820-
1.030)2
(continued)
-------
TABLE 4. (continued)
PAINT CLASS
SB - (continued)
6eb - RADIATION, Electron
beam cured
6uv - RADIATION, Ultra-
violet ray cured
7As - HIGH SOLIDS, Air
drying, solvent borne
PAINT DESCRIPTION
(FORMULATION)
7. Vinyl
g. Cellulose Acetate Butyrate
1. Polyester, US Pat. 3,437,514
(Ford Motor Co.)
2. Clear Acrylic, US Pat.
3,437,514 (Ford Motor Co.)
3. White Acrylic, US Pat.
3,437,513 (Ford Motor Co.)
4. White Silicone Polyester,
US Pat. 3,437,513 (Ford
Motor Co.)
1. Polyester
2. Acrylic
3. Poly-thioether (W.R. Grace
& Co.)
1. Acrylic White Enamel (Rohm
& Haas QR 568)
COMPOSITION OF BINDER
56% Styrene, 3% Maleic Anh.
97% Acrylates
90% Acrylates, 8% Styrene
30% Polyester, 30% Styrene, 10%
Acryclic Siloxane, 30% Methyl
Metacrylate
59% Acrylic oligomer, 41% Des-
modur N in ethoxy ethanol
acetate moist ener
SUGGESTED USE
Outdoor furniture,
bicycles1
Fencing, wires, under-
ground uses7
Furniture1
Wood & metal
Wood & metal
Wood & metal
Wood & metal
Printed decorations
Clear overcoats
Elevated temperature
coats, magnetic wire
Large equipment, heat
sensitive items, shop
refinishing
NV
kg/lit
(Ib/gal)
1.20-
1.68
(10.0-
14.0)
1.14-
1.32
(9. SO-
IL 0)
0.91t
(7.60)t
0.91t
(7.60)t
0.91t
(7.60)t
0.91t
(7.60)t
Unk
(Unk)
Unk
(Unk)
Unk
(Unk)
1.58
(13.2)
kg OV/lit NV
(Ib OV/gal NV)
buy
0.005-
0.0267
(0.050-
0.220)7
0.060-
0.096"
(0.500-
0.800)11
0.030-
0.0426
(0.250-
0.350)6
0.048t
(0.400)t
0.048t
(0.400)t
0.048t
(0.400)t
0.048t
(0.400)t
0.0248
(0.200)6
0.0248
(0.200)8
Unk 9
(Unk) 9
0.68
(5.70)
use
0.005-
0.0267
(0.050-
0.220)7
0.060-
0.096M
(0.500-
O.SOO)11
0.030-
0.0426
(0.250-
0.350)6
0.048t
(0.400)t
0.048t
(0.400)t
0.048t
(0.400)t
0.048t
(0.400)t
0.0608
(0.500)8
0.0608
(0.500)8
Unk 9
(Unk) 9
0.68
(5.70)
(continued)
-------
TABLE 4. (continued)
PAINT CLASS
7Bs - HIGH SOLIDS, Bake
cured, solvent borne
8Bw - LOW SOLVENT, Bake
cured, water borne
9Bw - POWDER SLURRY, Bake
cured, water borne
PAINT DESCRIPTION
(FORMULATION)
1. Acryloid OL 42 White Enamel
(Rohm & Haas)
2. Acrylic White Enamel (Rohm
& Haas)
1. Acrylic White Enamel
(Ashland EF-11)
1. Acrylic White Enamel
COMPOSITION OF BINDER
Hydroxyl acrylic oligoraer in
ethoxy ethanol crosslink with
melomine
40% Carboxyl acrylic oligomer,
60% Epoxy in crosslink with
Methyl-amyl-ketone/ toluene
75/25 wt%
Acrylic emulsion in water
(Arolon X-801)
Acrylic powder in water
SUGGESTED USE
Indoor & outdoor furni-
ture, air conditioners,
etc.
Low energy porcelain
replacements
General industrial or
outdoor over primer
General industrial
NV
kg/tit
(Ib/gal)
1.72
(H-3)
1.69
(14.1)
1.19
(9.90)
1.36
(11.3)
kg OV/lit NV
(Ib OV/gal NV)
buy
0.50
(4.20)
0.59
(4.90)
0.18
(1.50)
0.0180
(0.150)0
use
0.50
(4.20)
0.59
(4.90)
0.18
(1.50)
0.0181?
(0.150)0
ON
1 G. E.
2 R. D.
3 0. J.
it
5 P.
6 R.
7 J. W.
8 S. H.
Cole, Jr.; SME paper, FC 74-560, and direct communication.
Hardy & T. W. Seitz; SME paper, FC 74-589.
T. W.
R.
A.
Stvan, Sherwin-Williams Co.
Seitz, Sherwin-Williams Co.
Gribble, SEM-Glidden-Durkee
Newer Formulations, and direct communication.
direct communication.
direct communication.
Johnston, Eastman Chemical Products, Inc.; Newer Formulations, and direct communication.
Hagen, Union Carbide Corporation; direct communication.
Schroeter, General Electric Company; "The Ultraviolet Cure of Solventless Resins", Non-polluting Coatings & Coating Processes;
& Prane, Editors; Plenum Press, New York, N. Y. 1973.
A. D. Ketley, W. R. Grace & Company; SME paper, FC 75-331.
Gardon
* Data given for Paint Class SB only include liberated organic coreactants.
t Data given are estimates.
t Data given include liberated organic coreactants.
-------
TABLE 5. RANGE OF 0V AND NV WITHIN PAINT CLASSES SURVEYED
PAINT CLASS
SPRAY
DIP, FLOW, CURTAIN
COIL & ROLL
ELECTROCOATS
POWDERS
RADIATION
HIGH SOLIDS
LOW SOLVENT
POWDER SLURRY
CODE
lAs
lAw
IBs
IBw
2As
2Aw
2Bs
2Bw
3 As
3Bs
3Bw
4Bw
5B
6eb
6uv
7As
7Bs
8Bw
9Bw
CURE
Air dry
Air dry
Bake
Bake
Air dry
Air dry
Bake
Bake
Air dry
Bake
Bake
Bake
Bake
Elec. Beam
U' violet Ray
Air dry
Bake
Bake
Bake
CARRIER
Solvent
Water
Solvent
Water
Solvent
Water
Solvent
Water
Solvent
Solvent
Water
Water
None
None
None
Solvent
Water
Water
Water
kg OV/lit NV
1.09 - 4.45
0.52
0.90 - 7.27
0.67 - 0.84
1.36 - 2.09
0.11 - 0.12
1.16 - 2.09
0.28 - 1.01
1.10 - 1.69
0.66 - 0.85
0.32 - 0.84
0.30 - 0.47
0.005- 0.124
0.05
0.024- 0.06
0.68
0.50 - 0.59
0.18
0.018
Ib OV/gal NV
9.1 - 37.1
4.3
7.5 - 60.6
5.6 - 7.0
11.3 - 17.4
0.9 - 1.0
9.7 - 17.4
2.3 - 8.4
9.2 - 14.1
5.5 - 7.1
2.7 - 7.0
2.6 - 3.9
0.005- 1.03
0.4
0.2 - 0.5
5.7
4.2 - 4.9
1.5
0.15
kg OV/lit (OV+NV)
0.54 - 0.69
0.34
0.47 - 0.78
0.40 - 0.45
0.60 - 0.62
0.10 - 0.11
0.50 - 0.62
0.20 - 0.42
0.44 - 0.51
0.38 - 0.44
0.24 - 0.44
0.23 - 0.30
0.01 - 0.11
0.05
0.02 - 0.06
0.39
0.33 - 0.36
0.15
0.016
Ib OV/gal (OV+NV)
4.43 - 5.70
2.76
3.91 - 6.41
3.26 - 3.68
4.98 - 5.07
0.80 - 0.88
4.12 - 5.07
1.65 - 3.47
3.61 - 4.17
3.17 - 3.64
1.99 - 3.62
1.87 - 2.50
0.05 - 0.87
0.38
0.19 - 0.47
3.24
2.69 - 2.97
1.25
0.14
-------
GLOSSARY
as bought: A composition as produced by the manufacturer and delivered to the
user.
as used: A composition as used by the consumer. Some compositions may be used
"as bought" while others may have additional components added to achieve
the desired characteristics for use.
calculation: The mathematical operation used to arrive at a numerical answer.
constant (K factor): A constant factor developed for use in mathematical cal-
culations designed to provide specific results.
coreactant: An organic volatile substance liberated from a nonvolatile solid
as a result of chemical reaction.
curing method: The method by which the organic volatiles are evaporated from
the paint liquid to leave a solid nonvolatile film.
density: the specific weight/volume of a substance.
determined waste: The actual waste generated as determined after the fact.
electrostatic field: A field of static electricity that imparts a charge to
particles which pass through it.
filmformer: A nonvolatile substance consisting of particles that can be formed
into a film on a solid surface.
hot melt: A nonvolatile solid substance that will melt into a liquid state at
a relatively low temperature.
merchandise: A manufactured product made from a solid material.
nonvolatile: A nonevaporative solid substance.
organic volatile: A substance essentially composed of carbon, hydrogen, and
oxygen which will evaporate into the atmosphere.
paint composition: A formulation of materials designed for used in applying
a nonvolatile film coating to the surface of a solid material.
painting operation: An operation in which a nonvolatile solid film coating
is applied to the surface of a solid material.
68
-------
painting process: The method used to transfer a paint composition from a con-
tainer to the surface of a solid material.
predicted waste: The waste estimated to be produced by a planned painting
operation using a specific painting process and curing method.
primer coat: An initial paint coating applied to the surface of the merchan-
dise to prepare the surface for a final "top" coating.
transfer efficiency: A factor, usually expressed as a percentage, to repre-
sent the amount of nonvolatile solids in the paint composition used that
will actually become the final film coating on the merchandise.
top coat: The final film coating on the finished merchandise.
viscosity: The specific gravity of a paint composition.
volume percent: The relationship of components in a paint composition ex-
pressed in units of volume.
waste load: The pollutional waste generated during a painting operation, us-
ually expressed in units of weight.
weight percent: The relationship of components in a paint composition ex-
pressed in units of weight.
69
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-80-144
3. RECIPIENT'S ACCESSIOWNO.
4. TITLE AND SUBTITLE
Calculations of Painting Wasteloads Associated with
Metal Finishing
5. REPORT DATE
JUNE 1980 ISSUING DATE.
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
George E. F. Brewer
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
Coating Consultants
11065 E. Grand River Road
Brighton, MI 48116
1BB610
11. CONTRACT/GRANT NO.
R803467
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final-Dec 74 to Dec 76
14. SPONSORING AGENCY CODE
EPA/600712
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Twelve mathematical equations have been developed which provide a method for
predicting the wasteload that will be generated in planned painting operations and
for determining the actual waste load in current operations.
The waste load generated during the painting of metal products is governed
by four factors: paint composition; painting equipment; curing method; and
miscellaneous unavoidable losses.
The scientific and trade literature was surveyed for the weights and volumes
of the nonvolatile components (resins, pigments, etc.) of about 70 typical, widely
used paints, and also for the weights and volumes of their organic volatile
components. These have been tabulated.
Nine paint application and paint curing processes (spray, dip, coil, flow,
roll, curtain, electro, power and powder slurry coating) were surveyed and the
upper and lower reported limits of the expected transfer efficiencies were
tabulated.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Industrial Wastes 1302
Paints 1103
Calculations
Pollution
Nonmetallic coatings
Painting
Water pollution
Wasteloads
13B
18. DISTRIBUTION STATEMENT
Release unlimited
•^^
EPA Form 2220-1 (9-73)
19. SECURITY CLASS (ThisReport)
Unclassified
82
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
70
U.S. 80VERNMENT PRINTING OFFICE: 1980--657-165/0015
------- |