& EPA
United States Control Technology EPA-450/3-89-33
Environmental Protection Center October 1989
Agency Research Triangle Park NC 27711
Powder Coatings
Technology Update
control * technology center
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EPA-450/3-89-33
POWDER COATINGS TECHNOLOGY UPDATE
CONTROL TECHNOLOGY CENTER
SPONSORED BY:
Emission Standards Division
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Air and Energy Engineering Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park.NC 27711
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
October 1989
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EPA-45-/3-89-33
October 1989
POWDER COATINGS TECHNOLOGY UPDATE
Prepared by:
Charles I. Hester
Rebecca L Nicholson
Midwest Research Institute
401 Harrison Oaks Boulevard
Gary, North Carolina 27513
EPA Contract No. 68-02-4379
Project Officer
Karen P. Catlett
Chemicals and Petroleum Branch
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Prepared for:
Control Technology Center
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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ACKNOWLEDGEMENT
This report was prepared for EPA's Control Technology
Center (CTC) by Charles Hester and Rebecca Nicholson of
Midwest Research Institute. The project officer was Karen
Catlett of EPA's Office of Air Quality Planning and Standards
(OAQPS). Also on the project team was Robert Blaszczak of
OAQPS and Michael Kosusko of the Air and Energy Engineering
Research Laboratory.
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PREFACE
The Powder Coating Technology Update report was funded as a project
of the U. S. Environmental Protection Agency's (EPA's) Control Technology
Center (CTC). The CTC was established by EPA's Office of Research and
Development (ORD) and Office of A1r Quality Planning and Standards (OAQPS)
to provide technical assistance to State and local air pollution control
agencies.
This report describes the current status of powder coating
technology. It Includes discussions of the advantages, costs, perfor-
mance, and end uses of powder coatings. The report 1s available to State
and local agencies for their use 1n demonstrating the feasibility of
powder coatings as an alternative to coatings containing volatile organic
compounds (VOC's).
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TABLE OF CONTENTS
Page
List of Abbreviations 1v
LIST OF TABLES v
SECTION 1.0 INTRODUCTION 1
SECTION 2.0 BACKGROUND 3
SECTION 3.0 POWDER COATING MATERIALS 5
3.1 THERMOPLASTIC POWDERS 5
3.2 THERMOSETTING POWDERS 6
3.3 NEWLY DEVELOPED POWDERS 7
SECTION 4.0 POWDER COATING EQUIPMENT 11
4.1 PRETREATMENT 11
4.2 POWDER APPLICATION 12
4.2.1 Powder Delivery System 12
4.2.2 Electrostatic Spray Gun 12
4.2.3 Powder Spray Booths 14
4.2.4 Powder Recovery and Recycle System 14
SECTION 5.0 END USES OF POWDER COATING. 16
SECTION 6.0 ECONOMIC ADVANTAGES OF POWDER COATING VS. LIQUID
COATINGS 21
6.1 ENERGY SAVINGS 21
6.2 LABOR SAVINGS 21
.6.3 GREATER OPERATING EFFICIENCY 22
'6.4 ENVIRONMENTAL BENEFITS 22
6.5 COST COMPARISON: POWDER VS. LIQUIDS 22
6.5.1 Total Capital Costs 22
6.5.2 Material Costs 25
6.5.3 Total Annual Operating Costs 25
SECTION 7.0 CONCLUSIONS 33
SECTION 8.0 REFERENCES 37
APPENDIX A. SURVEY SUMMARY: POWDER COATING EQUIPMENT SUPPLIERS... A-l
APPENDIX B. SURVEY SUMMARY: POWDER COATING MANUFACTURERS B-l
APPENDIX C. SURVEY SUMMARY: POWDER COATING USERS C-l
111
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List of Abbreviations
ft » foot
ft2 » square foot
ft3 * cubic foot
g » gram
gal » gallon
1n. = Inch
kg = kilogram
1b a pound
i - liter
m a meter
m2 * square meter
m3 = cubic meter
m1n - minute
urn » micron » 1x10" meter
TGIC a trlglyddyl Isocyanurate
VOC » volatile organic compound
yr » year
1v
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LIST OF TABLES
Page
TABLE la. TYPICAL PROPERTIES OF THERMOSETTING POWDER COATINGS
(Metric Units) 8
Table 15. TYPICAL PROPERTIES OF THERMOSETTING POWDER COATINGS
(English Units) 9
TABLE 2. END USES FOR EPOXY AND HYBRID POWDER COATINGS 17
TABLE 3. END USES FOR TGIC-POLYESTERS AND ALIPHATIC POLYESTER-
URETHANE POWDER COATINGS 18
TABLE 4. END USES FOR AROMATIC URETHANE AND ACRYLIC POWDER
COATINGS 19
TABLE 5. TOTAL CAPITAL COSTS 23
TABLE 6a. MATERIAL COSTS (Metric Units) 26
TABLE 6b. MATERIAL COSTS (English Units) 28
TABLE 7a. TOTAL ANNUAL OPERATING COSTS (Metric Units) 30
TABLE 7b. TOTAL ANNUAL OPERATING COSTS (English Units) 31
TABLE 8a. VOC REDUCTION COMPARISON (Metric Units) 34
TABLE 8b. VOC REDUCTION COMPARISON (English Units) 35
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1.0 INTRODUCTION
The purpose of this report 1s to provide an overview of the current
status of powder coating technology. Powder coating use 1n North America
1s Increasing at a rate approaching 20 percent per year 1n terms of
quantities of powder sold.1 Recent Improvements 1n the technology
required to manufacture and apply powder coatings, 1n conjunction with
environmental considerations, have led to this rapid growth. Many of the
drawbacks previously associated with the use of dry powder coating as an
Industrial finish have been virtually eliminated. As a result, there are
currently about 2,000 powder coating operations 1n the United States and
the number 1s Increasing rapidly.2
From an environmental standpoint, the Increased use of powder
coatings as an alternative to liquid, solvent-based coatings represents a
significant reduction 1n emissions of VOC's. Because powder coatings are
applied as dry, finely divided particles, there are no VOC's released
durfng application and only minute quantities are released during the
curing process. Therefore, the use of powder coatings as a means of
reducing VOC emissions from Industrial finishing operations 1s being
encouraged by many air pollution control agencies. This report 1s
Intended to be helpful to those agencies by providing them Information
regarding the types of products being powder coated. It 1s anticipated
that this will assist them 1n evaluating powder as a recommended air
pollution control technology by answering questions concerning the
performance, applicability, costs, and availability of powder coatings.
The Information presented 1n this report 1s based on data obtained
from literature searches, contacts with several State and local air
pollution control agencies, and written survey questionnaires. Survey
questionnaires were submitted to nine powder coating equipment suppliers,
nine powder coating manufacturers, and nine powder coating users. Three
of the nine equipment suppliers responded, and a summary of their
responses 1s presented in Appendix A. A summary of the responses from the
seven powder coating manufacturers who took part 1n the survey is
presented in Appendix B. Four powder coating users responded and that
summary 1s contained in Appendix C.
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The remainder of this report is divided into five sections. The
first provides a brief history of powder coatings from the 1950's through
the 1980's. The next section describes the different classes of powder
coatings that are currently available, including those types of powder
resins that have recently been developed. The types of equipment required
for a powder coating line and the types of products that are typically
powder coated are discussed in Sections 4.0 and 5.0. A list of represen-
tative products currently being powder coated is also included in
Section 5.0. Section 6.0 discusses the economic advantages of using
powder coatings and presents a cost comparison between powder and liquid
coatings. Section 7.0 presents the major points discussed in this report
and conclusions.
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2.0 BACKGROUND
The technology for finishing metal products with dry powder coatings
rather than with conventional liquid paints has been available in this
country since the mid 1950's. By the late 50's, powder was being used to
coat pipe for corrosion protection and electric motor parts for
Insulation. These coatings were applied using a flu1d1zed-bed process In
which heated parts were dipped Into a vat containing powder suspended In
air. In this process, once the particles of powder contact and adhere to
the heated metal parts, they begin to soften and flow Into a smooth, even
layer. Most of the coatings applied 1n fluldlzed beds were vinyl or epoxy
powders. Typical coating thicknesses ranged from 150 to 1,000 um (6 to
40 mils) and the applied coatings were functional rather than decorative.3
During the historical development of powder coating technology, there
were several disadvantages or potential problems Identified. Today, most
of these have been resolved or minimized. The following are some of the
major Issues that were problems in the past:
1. Frequent color changes could entail extensive downtime for
production lines and the ability to apply a wide range of colors could be
restricted by equipment requirements and changeover times. Multiple
booths are required for rapid color changes and special equipment is
required to recover different colors separately (for recycle).
2. Storage and handling of powder requires special "climate"
controls; powder will not remain "fluid" 1f exposed to moisture.
3. Accurate feeding of powder to the spray gun might be difficult,
resulting in uneven flow.
4. Color matching and color uniformity appear to be more difficult
to achieve than with liquid coatings.
5. Uniformity of coating thickness is sometimes difficult to
maintain and thin films 25 to 51 um (1 to 2 mils) are sometimes difficult
to achieve.
6. Cure temperatures required for some powders are so high that
damage may occur to solder joints or temperature-sensitive parts of the
item being coated. High cure temperatures and long cure times require
high fuel usage.
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7. Powder coatings are especially susceptible to "Faraday cage"
effects on sharp Internal corners.
8. Airflow 1n the booth and the area prior to the oven must be
carefully controlled to avoid dislodging the unbaked powder.
9. Because of the extra equipment requirements (multiple booths,
powder handling and recovery systems), conversion of an existing liquid
line could be very expensive.
Technological advances in powder coating have addressed most of these
Issues. These advances are discussed in this report.
The development that opened the way for powder coatings to become a
major factor 1n the metal finishing industry was the Introduction of the
electrostatic spray process in the early 1960's. Electrostatic spraying
of powders allowed the application of relatively thin layers of coatings
and allowed powders to be used on parts not suitable for dipping in a
fluidized bed. Thus, powder coatings became a viable alternative for
decorative as well as functional coatings.
The emergence of powder coatings as an alternative to liquid
decorative coatings led to the development of a variety of resin systems
designed to meet the needs of the diverse user Industries. Epoxy resins
were used almost exclusively during the early years of powder coatings.
Polyesters, polyester/urethanes, acrylics and (most recently)
polyvinylidene fluoride, have now become equally accepted resin systems,
with each haying its own market share depending on the performance
characteristics needed for the product. Powder coatings currently are
available in virtually any color, gloss level, and texture.
Recent advances in application technology also have allowed powder
coatings to be used in an Increasing number of Industries. Automated
finishing systems that allow rapid and frequent color changes and
extremely high powder utilization efficiencies have made powder an
economical coating in many high-volume industries. (Powder utilization
efficiency is defined as the percentage of purchased powder that Is
deposited on the work piece [Including any powder that is recovered and
resprayed].)
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3.0 POWDER COATING MATERIALS
As recently as the early 1970's, the powder coating Industry had a
limited number of solid resin systems on which to base their powder
formulations. Consequently, the ability of the powder coating Industry to
meet the diverse needs of the finishing Industry was also limited.
Because of the Increased concerns over VOC emissions, worker safety, and
energy costs during the 1970's, the popularity of powder coatings grew
until powder coatings represented 8 percent of coating used In the
finishing Industry by 1987.* As the Interest 1n powders grew, the
Industry responded with technological Improvements 1n the resins and with
many new resin systems. Powder coatings are now formulated 1n a virtually
limitless range of colors, glosses, and textures. The two major types of
powder coatings, thermoplastics and thermosettlngs, are discussed below.
3.1 THERMOPLASTIC POWDERS
A thermoplastic powder coating Is one that melts and flows when heat
1s applied, but continues to have the same chemical composition once 1t
cools and solidifies. Thermoplastic powders are based on high molecular
weight polymers that exhibit excellent chemical resistance, toughness, and
flexibility. These resins tend to be difficult to grind to the consfstant
fine particles needed for spray application, and they have a high melt
viscosity. Consequently, they are used mostly 1n thicker film
applications and are applied mainly by the fluldlzed bed application
technique.
Typical thermoplastic powder coatings Include: polyethylene powders,
polypropylene powders, nylon powders, polyvlnyl chloride powders, and
thermoplastic polyester powders. Polyethylene powders were the first
thermoplastic powder coatings to be offered. They provide excellent
chemical resistance and outstanding electrical Insulation properties.
Polyethylene coatings are smooth, have a medium gloss, and good release
properties that allow sticky materials to be cleaned from their
surfaces. They are often used as coatings for laboratory equipment.
Polypropylene powder produces a surface that 1s very Inert and 1s often
used 1n applications where the powder-coated part may be exposed to
chemicals. Nylon powders offer excellent abrasion, wear and Impact
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resistance, and a low coefficient of friction. They are commonly used as
mechanical coatings for sliding and rotating bearing applications 1n
appliances, farm equipment, and textile machinery. Polyvlnyl chloride
powders provide good durability as well as flexibility. An example of
products coated with polyvinyl chloride powders 1s dishwasher racks.
Thermoplastic polyesters offer good exterior durability and weather-
ability. They do not usually require a primer for good adhesion to most
metals and are often used for outdoor metal furniture.
Thermoplastic powders are especially well suited for a thick coat
capable of extreme performance requirements. Because of the Inherent
thickness of these coatings, they do not generally compete In the same
market as liquid paints.
3.2 THERMOSETTING POWDERS
Thermosettlng powder coating's are based on lower molecular weight
solid resins. These coatings melt when exposed to heat, flow Into a
uniform thin layer, and chemically cross-link within themselves or with
other reactive components to form a higher molecular weight reaction
product. The final coating has a different chemical structure than the
basic resin. These newly formed materials are heat stable and, after
curing, do not soften back to the liquid phase when heated. Resins used
1n thermosettlng powders can be ground Into very fine particles necessary
for spray application and for applying thin, pa1nt-Hke coatings. Because
these systems can produce a surface coating that 1s comparable to, and
competes with, liquid coatings, most of the technological advancements 1n
recent years have been with thermosettlng powders.
Thermosettlng powders are derived from three generic types of resins;
epoxy, polyester, and acrylic. From these three basic resin types, five
coating systems are derived. Epoxy resin-based systems are the most
commonly used thermosettlng powders and are available 1n a wide range of
formulations. They are used for both functional and decorative
coatings. Functional properties of epoxles Include corrosion resistance
and outstanding electrical Insulation. Decorative epoxles offer
attractive finishes that are tough, corrosion resistant, flexible, and
have high Impact strength. These lack ultraviolet resistance and
therefore, are not recommended for outdoor use 1n direct sunlight because
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of their tendency to chalk and discolor. High chemical reactivity and the
use of various classes of hardeners are opening a wide range of
applications for epoxles. Recent developments allow epoxles to be cured
at temperatures as low as 121°C (250°F) for 20 to 30 minutes, or even
shorter times at higher temperatures.5
Epoxy-polyester hybrid coatings consist of epoxy and polyester
resins. These coatings are used mainly for decorative applications. They
are more resistant to chalking and yellowing than epoxles but have a lower
surface hardness and are less resistant to solvents.
Polyester-TGIC coatings contain a polyester resin cross-linked with
trlglyddyl Isocyanurate (TGIC) as a curing agent. These powders offer
very good mechanical properties, Impact strength, and weather
resistance. They are resistant to chalking and are often used for such
outdoor applications as patio furniture, lawn mowers, and aluminum
extrusions and panels for large commercial buildings.
Aery11c-urethane coatings are formulated with acrylic resins
crosslInked with blocked Isocyanates. They have excellent color, gloss,
hardness, weatherability, and chemical resistance. They have an excellent
thin film appearance but are less flexible than polyesters.
Polyester-urethane coatings are formed by cross-Unking polyester
hydroxyl resin with blocked Isocyanate hardeners. Polyurethanes have an
outstanding thin film appearance and toughness as well as good weathering
properties.
Tables la and Ib provide a summary of the key physical properties of
the thermosettlng powder coatings described above.
3.3 NEWLY DEVELOPED POWDERS
In addition to the coating types discussed above, new developments
are occurring 1n the area of enamel powders. Conventional porcelain
enamel, the glassy coating traditionally found on metal surfaces such as
bathtubs and washing machines, 1s a vitreous Inorganic coating bonded to
metal by fusion. The porcelain enameling process Involves the re-fusing
of powdered glass on the metal surface. The powdered glass 1s formed by
melting oxide components and then quenching to form enamel frits. The
frits can be converted to wet sprayable suspensions or to dry enamel
powders through ball-milling. The resultant enamel coating 1s heat stable
to over 450°C (842°F), color fast, and scratch resistant.7 Enamel
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00
TABLE la. TYPICAL PROPERITES OF THERMOSETTING POWDER COATINGS6
(Metric Units)
Properties
App 1 1 cat 1 on th 1 ckness
Cure cycle (metal temperatures )b
Outdoor weather ab II Ity
Penc 1 1 hardness
Direct Impact resistance, cm-kgc
Adhesion
Chemical resistance
Epoxy
25-510 Jim*
232'C-3 mln
121*C-30 mln
Poor
HB-5H
92-184
Excel lent
Excel lent
Epoxy /polyester
hybrid
25-250 ym
232'C-3 min
163*C- 25 mln
Poor
HB-2H
92-184
Excellent
Very good
T6IC polyester
25-250 |im
204 'C-7 mln
154*C-20 mln
Excellent
HB-2H
92-184
Excellent
Good
Polyester
urethane
25-89 vim
204*C-7 mln
177*C-17 mln
Very good
HB-3H
92-184
Excellent
Good
Acrylic
urethane
25-89 )im
204*C-7 mln
182*C-25 mln
Very good
H-3H
23-69
Excellent
Very good
^Thickness of up to 3,800 urn can be applied via multiple coats In a fluldlzed bed.
Time and temperature can be reduced, by utilizing accelerated curing mechanisms, while maintaining the same general properties.
cTested at a coating thickness of 51 ym.
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TABLE Ib. TYPICAL PROPERITES OF THERMOSETTING POWDER COATINGS6
(English Units)
Properties
Application thickness
Cure cycle (natal temperatures)'*
Outdoor weatherabl 1 Ity
Pencil hardness
Direct Impact resistance, ln-lbc
Adhesion
Chemical resistance
Epoxy
1-20 alls8
450*F-3 aln
250*F-30 m\n
Poor
HB-5H
80-160 |
Excellent
Excellent,
E poxy /polyester
hybrid
1-10 alls
450'F-3 aln
325 *F- 25 ain
Poor
HB-2H
60-160
Excellent
Very good
T6IC polyester
1-10 alls
400'F-7 Bin
310*F-20 aln
Excellent
HB-2H
80-160
Excel lent
Good
Polyester
urethane
1-3.5 mils
400*F-7 «ln
350*F-17 aln
Very good
HB-3H
80-160
Eiccellent
Good
Acrylic
urethane
1-3.5 alls
400* F-7 ain
360*F-25 aln
Very good
H-3H
20-60
Excel lent
Very good
"Thickness of up to 150 alls can be applied via aultlple coats In a fluldlzed bed.
"Time and temperature can be reduced, by utilizing accelerated curing mechanisms, while maintaining the same general properties.
Tested at a coating thickness of 2.0 nil.
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powders, a potential replacement for porcelain, are presently available 1n
a limited range of colors and are relatively expensive to manufacture.
Continued development 1s expected to make these coatings more competitive.
Polyv1nyl1dene fluoride coatings have recently become available 1n
powder form.8 These fluoropolymer powder coatings have been available in
Europe for about 2 years and are now sold 1n the United States. Because
of their high resistance to weathering, Industrial pollution, and
corrosion, they are used for exterior aluminum extrusions and panels for
architectural purposes.
Advancements 1n powder coating formulations are occurring at a rapid
pace. Powders are being developed to compete with almost every market
that has traditionally been held by liquid coatings. Architectural
coatings (based on fluoropolymers), heat resistant coatings, metallic and
textured coatings, low-temperature-cure powders, transparent and clear
powders, and powders that can be used to color plastic parts by
Introducing the powder Into the mold used for compression-molded plastic
are 1n production use at this time. Most of these developments have
occurred during the last 4 to 6 years and most powder coating
manufacturers believe that the potential of powder coatings 1s only
beginning to be realized.
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4.0 POWDER COATING EQUIPMENT
The process of applying powder coatings to the surface of a product
1s, In general terms, Identical to the traditional painting line used to
apply liquid coatings. For powder coating or traditional painting, parts
to be coated must first go through a pretreatment operation to ensure that
the surface to be coated is clean and free of grease, dust, rust, etc. In
many cases, the parts are also subjected to treatments such as pickling,
phosphating, or chromatlzing to Improve the adhesion of the surface
coating. After pretreatment, the parts enter the spray booth where the
coating 1s applied with spray guns which are available in a wide variety
of designs. When the coating has been applied, parts enter the curing
oven to dry (in the case of traditional painting) and cure the coating.
The following sections present information about the types of
equipment that are available for each step in the process outlined
above. There are numerous manufacturers of powder coating equipment
competing in today's market, and each has various products that are
capable of performing the same basic task. The discussions presented here
will be generic, in that manufacturers' brand names will not be used, and
will focus on the spray application of powder to a metal substrate. (The
curing ovens used with powder coating systems are similar to those used
for liquid coating lines, and therefore, are not discussed here.)
4.1 PRETREATMENT
Although the substrate pretreatment process is critical to achieving
an acceptable powder coated product, it is not a requirement that ts
unique to powders. All industrial surface coatings require a substrate
that 1s clean and dry. There 1s a wide range of pretreatment requirements
for powder coating as well as for liquid coating. The pretreatment
process steps required are a function of the characteristics of the
coating and the substrate and the end use of the product being coated.
The pretreatment process is normally carried out in a series of dip tanks
containing degreasing solvents, alkali cleaners, and rinses. Parts that
are not easily dipped because of their size or shape may be cleaned with
pressurized and/or heated sprays. An additional step that is used in many
powder coating lines is a phosphating application that adds to the
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corrosion protection provided by the coating system and improves the
adhesion of the coating to the substrate. When the parts have passed
through all of the pretreatment steps, they are normally dried in a low
temperature dry-off oven. After drying, the parts are ready to be sprayed
with the powder coatings.
4.2 POWDER APPLICATION
The powder coating application process makes use of four basic types
of equipment: the powder delivery system, the electrostatic spray gun
system, the spray booth and overspray exhaust air system, and the powder
recovery system.
4.2.1 Powder Delivery System
Powder 1s -supplied to the spray gun by the powder delivery system.
This system consists of a powder storage container or feed hopper, a
pumping device that transports a stream of powder into hoses or feed
tubes. A compressed air supply is often used as a "pump" because 1t aids
1n separating the powder into individual particles .for easier transport.
The powder delivery system is usually capable of supplying powder to one
or several guns, often many feet from the powder supply. Delivery systems
are available in many different sizes depending on the application, number
of guns to be supplied, and volume of powder to be sprayed in a given time
period. Recent improvements in powder delivery systems, coupled with
better powder chemistries that reduce clumping of the powder, have made
possible the delivery of a very consistent flow of particles to the spray
gun. Agitating or fluidizing the powder in the feed hopper also helps
prevent clogging or clumping of the powder prior to its entry into the
transport lines.
4.2.2 Electrostatic Spray Guns
Electrostatic powder spray guns function to shape and direct the flow
of powder; control the pattern size, shape and density of the powder as it
is released from the gun; Impart the electrostatic charge to the powder
being sprayed; and control the deposition rate and location of powder on
the target. All spray guns can be classified as either manual (hand-held)
or automatic (mounted on a mechanical control arm). Both manual and
automatic guns are manufactured by many different companies, with about 8
to 10 of these companies supplying the majority of these guns. Although
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the basic principles of operation of most guns are the same, there 1s an
almost limitless variety 1n the style, size, and shape of spray guns. The
type of gun chosen for a given coating line can, thus, be matched to the
performance characteristics needed for the products being coated.
Traditionally, the electrostatic charge was Imparted to the powder
particles by a charging electrode located at the front of the spray gun.
These "corona charging" guns generate a high-voltage, low-amperage
electrostatic field between the electrode and the product being coated.
The charge on the electrode 1s usually negative and can be controlled by
the operator. Powder particles', passing through the Ionized electrostatic
field at the tip of the electrode become charged and are thus directed by
the electrostatic field. The particles follow the field lines and air
currents to the target workpiece and are deposited on the grounded surface
of the workpiece. One drawback to the use of this type of gun Is the
difficulty of coating Irregularly shaped parts that have recessed areas or
cavities (that may be affected by Faraday cages) Into which the
electrostatic field cannot reach. Because the powder particles are
directed by the presence of the field, Insufficient powder may be
deposited on surfaces outside the reach of the field.
A relatively recent Innovation 1n electrostatic spray guns 1s the
"trlbo" electric gun. The powder particles 1n a tribo electric gun
receive an electrostatic charge as a result of friction which occurs when
powder particles contact a solid insulator or conductor inside the
delivery hose and gun. The resulting charge 1s accomplished through the
exchange of Ions, or electrons, between the powder and the material used
for construction of the supply hose and gun barrel. Because there is no
actual electrostatic field, the charged particles of powder migrate toward
the grounded workpiece and are free to deposit 1n an even layer over the
entire surface of the workpiece. With the elimination of an electrostatic
field, the Farraday cage effect can be prevented.
Other improvements that have been made to spray guns involve
variations in the spray patterns to improve the coating transfer
efficiency. Nozzles that resist clogging have been introduced. Spray
guns with variable spray patterns are also available to allow the use of
one gun on multiple parts of different configurations." Innovations in
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spray gun design have resulted 1n versatile and efficient guns with
Increased ease of operation. Manual coating 1s characterized by simple
operation of both the equipment and controls. After a short period of
training, personnel are capable of meeting the requirements for quality
and uniformity of coating.
4.2.3 Powder Spray Booths
The primary function of the powder spray booth 1s to contain the
spraying operation so that oversprayed powder cannot migrate Into other
work station areas. Several criteria must be met in selecting the
appropriate spray booth for a given coating line. The entrance and exit
openings must be properly sized to allow clearance of the largest product
part. The airflows through the booth must be sufficient to channel all
overspray to the collection device, but not so forceful that it disrupts
the powder deposition and retention on the part. If one booth 1s to be
used for multiple colors, the booth interior should be free of narrow
crevices, seams, and Irregular surfaces that would be difficult to
clean. This 1s especially Important 1f collected overspray 1s to be
recycled. Airflow rates for powder spray booths are considerably lower
than those for booths used for spraying solvent-based paint. The OSHA
requires a minimum of 2.8 m3/m1n (100 ft3/m1n) of air movement through the
booth in a system using solvent paint. During the cooler months, an air
makeup differential of 8° to 14°C (15° to 25°F) is required to replace
solvent-laden air that is exhausted through the booth. With powder
9
coating, there is no makeup requirement for spray booth air movement.
Also, because there is no solvent loading of the air exhausted from a
powder coating booth, the air can be recirculated within the plant.
4.2.4 Powder Recovery and Recycle System
In most manufacturers' designs, the powder recovery and recycle
systems are an integral part of the spray booth. The fact that
oversprayed powders can be collected and reused has led equipment
manufacturers to develop systems designed especially to accommodate powder
recovery. Traditional spray booths for liquid coatings have either dry or
wet filter systems to remove overspray from the exhaust air stream. The
collected paint is of no value and 1s therefore discarded. In this
situation, color changes are accomplished b'y simply changing the spray gun
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from one paint delivery system to one filled with the next color to be
applied. The resulting collected overspray 1s a combination of all the
colors applied between filter replacements or booth cleanings.
For collected oversprayed powder to be of greatest value, It should
be free of cross-contamination between colors. When a pellet of the wrong
color adheres to the part being powder coated, 1t will not blend in with
the color being used. There are numerous systems now available that are
designed to accomplish this segregation of colors and still allow several
colors to be applied 1n the same booth. Most of these systems make use of
a moveable dry filter panel or a cartridge filter that can be dedicated to
one color and can be removed easily when another color Is needed. Color
changes can then be accomplished by disconnecting the powder delivery
system and purging the lines, cleaning the booth with compressed air or a
rubber squeegee, exchanging the filter used for the previous color with
the filter for the next color, and connecting the powder delivery system
for the new color. Equipment manufacturers have made significant design
Improvements 1n spray booths that allow color changes to be made with a
minimal downtime and allow the recovery of a high percentage of the
overspray. As with spray guns, there are a large number of spray booth
and powder recovery designs from which to choose, depending on the exact
requirements of a given finishing system.
15
-------
5.0 END USES OF POWDER COATINGS
As can be seen 1n Tables 2 through 4, the 11st of products that are
being coated with powder coatings 1s extensive. There are certain market
sectors where powder coatings have shown particularly strong growth
rates. For example, powder coatings are being used extensively to produce
linings on the Inside of oil drilling pipe where severe pressures, high
temperatures, and corrosive materials allow only a few types of coatings
to be effective. The automotive Industry 1s Increasing Its use of powder
coatings for economic, quality, and ecological reasons. Powder 1s being
used for the exterior body Intermediate coat known as a "primer-surfacer",
as well as for finishing of underhood components. Parts that require
extra protection as well as a decorative finish are Increasingly being
powder coated. Wheels, bumpers, shock absorbers, mirror frames, oil
filters, engine blocks, battery trays and coll springs are some of the
many automotive products being powder coated. Clear powder coatings, as
an alternative to solvent-borne clear coats, for use over automotive
exterior basecoats, are being evaluated..
The appliance Industry 1s the largest single market sector for
thermosettlng powders accounting for about 30 percent of powder sales.12
As porcelain-replacement powders become further developed, the appliance
market will continue to grow. Current uses Include range housings,
freezer cabinets, dryer drums, and washer tops and Hds.
Outdoor furniture, farm Implements, and lawn and garden equipment are
also major markets for powder coatings. The general metal finishing
Industry accounts for over 40 percent of thermoset powder sales.12 (The
general metal finishing Industry 1s defined here as Including all metal
finishing Industries except for the automotive, appliance, and
architectural finishing Industries.)
Potential large market areas for powders are the aluminum extrusion
and architectural products markets. The recent advances 1n polyester-TGIC
and fluoropolymer powders have enabled powder coatings to compete with
liquid architectural coatings 1n durability, weatherablHty, and
resistance to fading. Some of these coatings have been 1n use In Europe
since 1976 and are now being Introduced Into this country.
IS
-------
TABLE 2. END USES FOR EPCXY AND HYBRID POWDER COATINGS
10
Hardware and consumer goods
Bunk beds
Kitchen blenders
Kitchen mixers
Crock pots
Desk lamps
Pens
Vacuum cleaners
Speaker frames
Barbecue gri11s
Microphones
Glass containers
Thumb tacks
Water heaters
Faucets
.Tape player doors
Space heaters
Can openers
Gas meters
Curtain hardware
Floor polishers
Cigarette Iighters
Mine racks
Closet hardware
Chair frames and bases
Safe deposit boxes
Archery bows
Steel toys
Wire baskets
Bed frames
Fishing reels
Book ends
Waste baskets
Christmas tree stands
Notebook spiral wires
Lawn and garden edgers/tools
Luggage frames
Desk accessories
EIectronIc/eIectr i caI
Electrical motor stators
Electric motor rotors
Switch boxes
Electric boxes
Thresholds
Transformers
Electric meters
Electric connectors
Electronic instrument housing
Electronic instrument cabinets
Computer room floor systems
Automot i ve
Steering wheels
Air conditioning components
Interior trim parts
Engine blocks
Oil filters
Shock absorbers
Motor windings
Motor housings
Motor mounts
Coil springs
Valve covers
Brake shoe frames
Intake manifolds
Truck light housings
Truck seat frames
Seat bases
Seat belt latches
Seat belt mounts
Auto jacks
Jack stands
Functional and specified
Internal and external pipe
Gas riser pipe
Reinforcing bar for concrete
Cable for prestressed concrete
Rebar saddles
Structural steel
Conduit
Military projectiles
Military tent hardware
General industrial
Medical furniture
Steel carts
Power tools
Office furniture
Two-wheel hand trucks
Computer frames/cabinet
Copier cabinets
Storage cabinets
Reta iI store racks
Retail store shelving
Refrigerator shelving
Air cleaners
Lighting fixtures
Folding furniture
Water pumps
Steel drums
Scaffolding
Fertilizer spreaders
Wire cloth/screen
Industrial mixers
Alarm system bells
Propane tanks
Thickness gauges
Grain storage systems
FiI ing cabinets
Lab cabinets/furniture
Drawer suspension units
Warehouse rack systems
Lug wrenches
Tool boxes and chests
Air compressors
Camp stoves
Polished hardware
Refrigerator liners
Hand tools
Grapevine support poles
Pressure reserve tanks
Friction disc binders
Electrostatic spray
equipment
Office partitions
Escalator steps
17
-------
TABLE 3. END USES FOR TGIC-POLYESTERS AND ALIPHATIC
POLYESTER-URETHANE POWDER COATINGS1
Hardware consumer goods Automotive
General Industrial
Barbecue grills
Mailboxes
Screen doors
Ice machines
Water cans
Snowblowers
Antennas
Microwave ovens
YardHghts
A1r conditioner cabinets
Flash bulbs
Shower curtain hardware
Recreational vehicle
hardware
Playground equipment
garden tillers
Gas cans
Battery cases
Screen
Wagons
Luggage frames
Pool hardware
Laundry appliances
Chain saws
Wheels
Automotive trim
Truck tool boxes
Instrument bulbs
Windshield wipers
Bumpers
Roll bars
Mirror brackets
Outdoor patio furniture
Lawn mowers
Tractors
Motorcycle frames
Bicycle frames
Highway signs
Fence wire and poles
Extruded aluminum doors
Extruded aluminum windows
Guardral1
Golf carts
Building facade panels
Satellite dishes
Marine motors and drives
Vending machines
Roofing tile
Irrigation pipe
Refrigerator skins
Propane tanks
Water tanks
F1re extinguishers
Light poles
Electric boxes
Transformers
Junction boxes
Gas pumps
Sonar equipment
Parking meters
18
-------
TABLE 4. END USES FOR AROMATIC URETHANE AND ACRYLIC POWDER COATINGS11
Aromatic urethanes Acrylics
Interior metal furniture Wheels
Industrial racking systems Ranges
Primers for light poles Garden equipment
Residential aluminum window and door frames Clothes dryers
Low cost outdoor furniture Automotive topcoat
Store front window and door frames
Office equipment
19
-------
The Powder Coating Institute estimates that powder coating use 1n
North America will grow from about 57xl06 kg (125xl06 1b) 1n 1989 to about
102xl06 kg (225xlOs Ib) 1n 1993. During this period, the projected annual
growth rate for selected market areas 1s; automotive—19 percent,
appliance—12 percent, architectural—40 percent, and general metal
finishing—21 percent.12
20
-------
6.0 ECONOMIC ADVANTAGES OF POWDER COATINGS VS. LIQUID COATINGS
When comparing powder coating systems with liquid coating systems,
several significant advantages are readily apparent. There are also
other, seemingly less significant advantages that, when viewed
collectively, contribute substantial cost savings. This section discusses
the economic advantages of powder vs. liquid coating systems in the
following areas: energy savings, labor savings, greater operating
efficiencies, and environmental benefits. A detailed cost comparison of
powder vs. liquid coating systems also is provided at the end of this
section.
6.1 ENERGY SAVINGS
There are two significant advantages of powder coating which
contribute to lower energy costs as compared to liquid coating. The first
advantage is that the air used to exhaust the powder spray booth can be
redrculated directly to the plant since the powder does not contain
volatile compounds at room temperature. This eliminates the cost of
heating or cooling the makeup air that occurs when air is exhausted from
the plant, a particular advantage where extreme weather conditions are
prevalent. The second advantage 1s the lower cost of heating the curing
oven. Ovens that cure solvent-based coatings must heat and exhaust huge
volumes of air to Insure that the solvent fumes do not approach the lower
explosive limit. Because powder coatings have no solvent content, the
airflow 1n the curing ovens is considerably lower.
6.2 LABOR SAVINGS
The required operator skills and training for operation of a powder
coating system are less than those needed for a liquid system and
considerably less than those required for an electrocoat system. In
addition, powder 1s "ready to use" when purchased and does not require
labor for mixing with solvents or catalysts as is necessary with liquid
coatings. Also, there are no critical operating parameters to monitor
such as viscosity and pH (which are monitored in many liquid coating
systems) or percent solIds, specific resistance, and binder to pigment
ratio, (which all must be monitored in electrocoatlng systems).
21
-------
6.3 GREATER OPERATING EFFICIENCY
Because no drying or flash-off time 1s required, and the powder
application system allows parts to be racked closer together on a
conveyor, more parts can pass through the production line resulting In
greater operating efficiency and lower unit costs. Despite the greater
line speeds, powder coating systems generally have significantly lower
reject rates than do liquid coating systems. One reason for this lower
reject rate 1s that 1t 1s virtually impossible to have drips, runs, or
sags when applying powder coatings. In addition, 1f a powder-coated part
is found to be Improperly sprayed (prior to curing) the powder coating can
•be blown off with an air gun and the bare part recoated. Another factor
which contributes to a greater operating efficiency 1s the fact that
oversprayed powder can be reclaimed and thus, reused.
6.4 ENVIRONMENTAL BENEFITS
As regulatory agencies further limit the amount of solvent that can
be emitted, many plants that use liquid coating systems are finding it
necessary to purchase VOC control equipment, such as afterburners, to
incinerate the emitted solvents. Another environmental problem faced by
liquid coating users is the Increased difficulty and cost of disposing of
hazardous waste generated by liquid coating operations. With a dry powder
coating system, there 1s no liquid paint sludge to send to a disposal
site.
6.5 COST COMPARISON: POWDER VS. LIQUIDS
A detailed cost comparison between powder and liquid coating systems
is provided below. The three types of liquid coating systems included in
the comparison are: conventional solvent, water-borne, and high sol Ids.
Total capital and annual operating costs are provided for each of the four
coating systems. Material costs represent two-thirds or more of the total
annual.operating costs, and therefore, detailed material costs are also
provided.
6.5.1 Total Capital Costs
Capital costs for four different coating systems (I.e., conventional
solvent, water-borne, higher solids, and powder) are presented in
Table 5. The two sources of these costs are a reprint from Products
Finishing entitled "Powder Coating Today" (1987), and an earlier
22
-------
TABLE 5. TOTAL CAPITAL COSTS
Type of coating
Equipment
(Ref.)
installed
cost, $
Conventional solvent
Water-borne
Higher-solids
Powder
Two water-wash booths (13) 150,000
One dry filter booth (14)
Four automatic guns
Two manual guns
Two reciprocators
Paint heating equipment
Solvent recovery or incineration equipment
Two waterwash booths (13) 110,000
One dry filter booth (14) 108,000
Four automatic electrostatic guns
Two reciprocators
Safety interlocks and stand-offs
Two waterwash booths ' (13) 110,000
One dry filter sooth (14) 110,000
Four automatic electrostatic guns
Two manual electrostatic guns
Paint heating equipment
Two powder spray booths (13) 120,000
Four automatic electrostatic guns (14) 190,000
One manual electrostatic gun
Two reciprocators or gun movers
Two powder recovery systems with automatic
recycle
23
-------
publication entitled "VOC Emission Reductions and Other Benefits Achieved
by Major Powder Coating Operations" (1984).13»l" Both of these sources
contain Information generated by the Powder Coating Institute. The
"Powder Coating Today" article 1s actually an updated version of the 1984
publication. Cost estimates cited 1n these two sources were used because
they are consistent with cost estimates provided by powder coating
equipment suppliers 1n response to questionnaires submitted by the
Agency. The capital costs from each literature source are similar with
one notable exception—the cost of the same powder coating equipment
purchased 1n 1983 ($150,000) has decreased to $120,000 by 1986. (Note:
costs listed 1n the two references are based on the year prior to the
publication year.) In addition, the "Powder Coating'Today" article
Included the cost of solvent recovery or Incineration equipment 1n the
total capital cost for the conventional solvent coating system. These
costs were considered reasonable based on EPA experience with paint
application and control equipment. No costs were provided 1n the earlier
reference for a conventional solvent coating system.
The capital costs presented 1n Table 5 are based on the following
assumptions:
1. The parts to be coated are formed sheet steel parts that are of
average complexity;
2. Both sides of each part are automatically coated and touched up
manually;
3. Two colors are used;
4. l.lxlO6 m2 (12xl06 ft2) of parts are surface coated per year;
5. Conveyor speed 1s 4.6 m/m1n (15 ft/m1n);
6. The Installation 1s new and has automatic equipment to more
efficiently apply either a conventional solvent, water-borne, high solids,
or powder coating;
7. A solvent recovery system or Incinerator (cost: $40,000) 1s
Included 1n the system applying conventional solvent coatings to satisfy
emission regulations; and
8. The same pretreatment systems and ovens can be used with each
system with little or no modification.
24
-------
6.5.2 Material Costs
Materials costs for the four coating systems are presented In
Tables 6a and 6b; these costs are based on six different sources of
Information. Each source calculated the material costs 1n a similar
manner with the higher solIds system generally having a lower material
cost. Cost Information that was obtained from the powder coating surveys
supported the cost Information that was found 1n the literature and
presented 1n Tables 6a, 6b, 7a, and 7b. The most complete and up-to-date
source of cost Information 1s the "Powder Coating Today" article
(Reference Nos. 16 and 21 1n Tables 6a, 5b, 7a, and 7b). Costs obtained
from other sources were Included in Tables 6a, 6b, 7a, and 7b for
comparison purposes. (Note that in Table 6a and 6b, the columns for
powder costs are 1n terms of kg (Ib) rather than i (gal).
The material costs presented in Reference Nos. 16 and 21 are based on
1986 data and the following assumptions:
1. The conventional solvent coating 1s a 38 percent (by volume)
solIds acrylic or alkyd baking enamel applied at an average thickness of
30 um (1.2 mils);
2. The water-borne coating is a 35 percent (by volume) solids
acrylic latex applied at an average thickness of 30 um (1.2 mils);
3. The higher solids coating is a high-performance acrylic or
polyester-type coating applied at an average thickness of 30 um
(1.2 mils); and
.4. The powder coating is a high-quality polyester-urethane type
applied an average thickness of 30 um (1.2 mils).
6.5.3 Total Annual Operating Costs
The total annual operating costs for the, four coating systems are
presented in Tables 7a and 7b. These costs are based on five different
sources of Information (note that reference No. 18 in Table 7 did not
provide operating costs). Operating costs were not provided by those
companies that responded to the powder coating surveys, and therefore, it
was not possible to make a comparison between actual plant-specific
operating costs and those operating costs supplied in the literature.
All literature references and survey respondent information used to
create Tables 7a and 7b identified powder coating as having the lowest
25
-------
TABLE 6a. MATERIAL COSTS, DOLLARS
(Metric Units)
Item
Coating cost, $/4
Volume solids, percent
Reducing agent cost,
S/l
Mix ratio (coating:
reducing agent)
Mixed coating costs,
S/l
Volume solids at spray
v i scos i ty , percent
Specific gravity
•
Theoretical coverage
m /Z/wm
(Ref.)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
Conventional
solvent
__
2.70
3.15
2.30
—
3.15
__
38
47
43
~
47
•»_
0.40
~
0.40
—
0.40
_
4:1
3:1
5:2
—
3:1
__
2.26
2.48
1.77
2.38
2.48
__
30.5
35
31
35
35
__
—
—
~
—
--
305
350
310
—
Water-borne
—
2.90
2.90
«
—
2.90
• —
35
35
~
—
35
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
_
2.90
2.90
—
~
2.90
__
35
35
—
—
35
__
~
—
—
—
~
350
350
—
—
Higher
sol ids
5.55
3.90
4.50
—
—
4.50
__
63
63
~
—
63
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
5.55
3.90
4.50
—
3.70
4.50
54
63
63
—
55
63
__
—
—
~
—
—
540
630
630
—
— -
Powder3
5.30
4.65
5.10
4.75
4.75
5.10
-_
98
98
98
100
100
N/A
N/A
N/A
N/A
N/A
N/A.
N/A
N/A
N/A
N/A
N/A
N/A
5.30
4.65
5.10
-—
—
5.10
98
98
98
98
100
100
__
.6
.6
.6
.5
.6
614
624
614
614
—
Substitute kg for i in all calculations
(continued)
26
-------
TABLE 6a. (continued)
Item
Dry filoi thickness, ]im°
Transfer efficiency,
percent0 a
Actual coverage, ar/J.
Appl led cost, S/m2
Annual cost to coat
l.lxlO6 m2. S
(Ref.)
(15)
(16) .
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
Conventional
solvent
—
30
30
30
30
30
50
60
40
50
60
•*
5.00
6.86
4.07
5.71
6.86
^^
0.4510
0.3606
0.4338
0.4155
0.3606
502,800
402,000
483,600
463.200
402,000
Water-borne
—
30
30
—
—
30
55
60
~
—
60
__
6.30
6.86
—
_
6.86
„ _
0.4607
0.4220
—
~
0.4220
513.600
470,400
320,400
—
470,400
Higher
solids
30
30
30
—
30
30
80
60
70
—
80
70
14.1
12.4
14.5
~
14.4
14.4
0.3918
0.3154
0.3100
—
0.2562
0.3111
436,800
351.600
345,600
310,800
285,600
346,800
Powdera
30
30
30
30
30
30
95
96
97
97
98
97
19.0
19.7
19.5
19.5
21.3
19.5
0.2777
0.2357
0.2605
0.2433
0.2228
0.2605
309,600
262,800
290,400
271,200
248,400
290,400
^Substitute kg for I in all calculations.
"Coating thicknesses Mere normalized to put costs on a common basis.
cTransfer efficiency is the ratio of coating that adheres to the part and the coating that is
sprayed through the gun. In the case of powder coating, where powder is recovered and
recycled, the term "utilization efficiency" is used.
The transfer efficiencies used by the sources for this table are somewhat high. This may
cause the costs of the nonpowder alternatives presented here to appear lower than they
'.'actual ly would be.
27
-------
TABLE 6a. (continued)
Item
Dry film thickness, UOID
Transfer efficiency,
percent
Actual coverage, ar/i
Applied cost, S/ffl2
Annual cost .to coat
l.lxlO6 a2, $
(Ref.)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
Conventional
solvent
—
30
30
30
30
30
50
60
40
50
60
_ _
5.00
6.86
4.07
5.71
6.86
__
0.4510
0.3606
0.4338
0.4155
0.3606
502,600
402,000
483,600
463,200
402,000
Water-borne
—
30
30
—
—
30
55
60
—
—
60
w—
6.30
6.86
--
—
6.86
— *»
0.4607
0.4220
—
—
0.4220
513,600
470,400
320,400
•— '
470,400
Higher
solids
30
30
30
—
30
30
80
60
70
—
80
70
14.1
12.4
14.5
—
14.4
14.4
0.3918
0.3154
0.3100
—
0.2562
0.3111
436,800
351,600
345,600
310,800
285,600
346,800
Powder8
30
30
30
30
30
30
95
96
97
97
98
97
19.0
19.7
19.5
19.5
21.3
19.5
0.2777
0.2357
0.2605
0.2433
0.2228
0.2605
309,600
262.800
290,400
271,200
248,400
290,400
"Substitute kg for jt in all calculations.
Coating thicknesses were normalized to put costs on a common basis.
cTransfer efficiency is the ratio of coating that adheres to the part and the coating that is
sprayed through the gun. In the case of powder .coating, where powder is recovered and
recycled, the term "utilization efficiency" is used.
The transfer efficiencies used by the sources for this table are somewhat high. This may
cause the costs of the nonpowder alternatives presented here to appear lower than they
actually would be. Traditionally, high transfer efficiency has been of importance to a
coating facility for several reasons. The value added to most products by the coating is
small and the cost of the coating is usually almost negligible in comparison to labor and
equipment costs. One major automobile manufacturer represented its transfer efficiency at
almost twice the 30 percent that was subsequently determined by tests. Modern reciprocating
systems and highly robotic!zed systems can operate poorly, as tests of state of the art
equipment demonstrated in the nid-1980's. A new auto assembly line with reciprocators was
found to be operating at 15 percent transfer efficiency and a second plant with a state of
the art coating line was found to achieve less than 20 percent. In fact, the EPA authority
on transfer efficiency has been quoted "never underestimate people's inability to recognize
how low their transfer efficiency really is."
27
-------
TABLE 6b. MATERIAL COSTS, DOLLARS
(English Units)
(ten
Coating cost, S/gal
Volume solids, percent
Reducing agent cost,
S/gal
Mix ratio (coating:
reducing agent)
Mixed coating costs,
S/gal
Volume solids at spray
viscosity, percent
Specific gravity
Theoretical coverage
ftVgal/mil
(Ref.)
C5)
(16)
(14)
(17)
(18)
(19)
(15)
C6)
(14)
(17)
(18)
(19)
('5)
(16)
(14)
(17)
(18)
(19)
(13)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
Conventional
solvent
—
10.30
12.00
8.75
—
12.00
__
38
47
43
—
47
„
1.50
~
1.55
—
1.50
__
4:1
3:1
5:2
—
3:1
«
8.54
9.38
6.69
9.00
9.38
__
30.5
35
31
35
35 ...
__
—
—
—
—
~
489
561
497
~
Water-borne
—
11.00
11.00
—
—
11.00
__
35
35
__
—
35
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
__
11.00
11.00
—
--
11.00
__
35
35
—
«
35
«.
—
—
—
—
—
561
561
—
.
Higher
sol ids
21.00
14.80
17.00
—
•
17.00
^—
63
63
—
—
63
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
21.00
14.80
17.00
~
14.00
17.00
54
63
63
-.
55
63
__
—
—
—
—
— -
866
1,010
1,011
—
—
Powder3
2.40
2.10
2.30
2.15
2.15
2.30
__
98
98
98
100
100
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
2.40
2.10
2.30
—
--
2.30
98
98
98
98
100
100
__
1.6
1.6
1.6
1.5
1.6
118
120
118
118
—
'Substitute pounds for gallons in all calculations
(continued)
28
-------
TABLE 6b. (continued)
Item
Dry filn thickness, mils0
Conventional
(Ref.) solvent
(15) —
(16) .2
(14) .2
(17) .2
(18) .2
(19) .2
Water-borne
1.2
1.2
1.2
Higher
solids Powder8
1.2 .2
1.2 .2
1.2 .2
„„ 2
1 .2 '.2
1.2 .2
Transfer efficiency,
percent0
•
Actual coverage, ft^/gal
Applied cost, J/ft2
Annual cost-to coat
12x10° ft2, S
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
(15)
(16)
(14)
(17)
(18)
(19)
50
60
40
50
60
__
204
280
166
233
280
__
0.0419
0.0335
0.0403
0.0386
0.0335
__
502,800
402,000
483,600
463,200
402,000
55
60
—
—
60
__
257
280
—
—
280
_»
0.0428
0.0392
—
~
0.0392
__
513,600
470,400
320,400
—
470,400
80
60
70
~
80
70
577
505
590
~
588
588
0.0364
0.0293
0.0288
~
0.0238
0.0289
436,800
351,600
345,600
310,800
285,600
346,800
95
96
97
97
98
97
93
96
95
95
104
95
0.0258
0.0219
0.0242
0.0226
0.0207
0.0242
309,600
262,800
. 290,400
271,200
248,400
290,400
^Substitute pounds for gallons in all calculations.
°Coating thicknesses were normalized to put costs on a common basis.
cTransfer efficiency is the ratio of coating that adheres to the part and the coating that is
sprayed through the gun. in the case of powder coating, where powder is recovered and
.recycled, the term "utilization efficiency" is used.
°The transfer efficiencies used by the sources for this table are somewhat high. This may
cause the costs of the nonpowder alternatives presented here to appear lower than they
actually would be. Traditionally, high transfer efficiency has been of Importance to a
. coating facility for several reasons. The value added to most products by the coating is
small and the cost of the coating is usually almost negligible in comparison to labor and
equipment costs. One major automobile manufacturer represented its transfer efficiency at
almost twice the 30 percent -hat was subsequently determined by tests. Modern reciprocating
systems and highly robotic I zed systems can operate poorly, as tests of state of the art
equipment demonstrated in the mid-1980's. A new auto assembly line with reciprocators was
found to be operating at 15 percent transfer efficiency and a second plant with a state of
the art coating line was found to achieve less than 20 percent. In fact, the EPA authority
on transfer efficiency has been quoted "never underestimate people's inability to recognize
how low their transfer efficiency really is."
29
-------
TABLE 7a. TOTAL ANNUAL OPERATING COSTS, DOLLARS*
(Metric Units)
Item
Material, S/yr
Labor and cleanup, S/yr
Maintenance, S/yr
Energy, S/yr
S 1 udge d i sposa 1 , S/h
F i 1 ter rep 1 acement , $/h
Amortization. 10-vr
straight 1 me, S
Total annual cost, $b
Applied cost, $/m2
(Ref.)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21 )
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
Conventional
solvent
__
502,800
402)000
483,600
402,000
— _
141,900
132,100
118)000
_ _
121 ,300
^^
24,000
18,000
14,500
—
••
30,500
29 100
23)200
„_
14,640
__
48,758
10,800
13)480
11,280
«_
.—
— —
2,500
3,000
15,000
_—
—
~ .
_^
762,960
592,000
655)280
552,220
_ —
0.6846
0.5307
0.5877
0.4952
Water-borne
,,
513,600
470 400
320,400
470,400
——
141,900
132,100
126)200
• ^
121,300
^^
24,000
18,000
18,800
~
.«
32,514
3l)lOO
22,600
_ _
11 ..140
— ^
40,750
10,800
_
1 1 ,280
^_
—
»
— —
_.
3,000
11,000
10,800
9,800
— —
—
— —
763,760
673,200
497)800
__
617,120
^^
0.6846
0.6039
0.4467
0.5533
High solids
436,800
351,600
345 600
310,800
«
346,800
111,440
141,900
- 128,400
126,200
__
121,300
1 1 ,840 "•
24)000
18,000
18,800
~
39,460
28,300
27,100
19,700
__
11,200
8,460
31,500
7,100
— •
~
11,280
1,920
— —
—
— —
— —
3.000
11,000
11,000
10,000
—
"
609,920
588 300
537,200
485)500
—
493,580
0.5468
0.5274
0.4822
0.4349
0.4424
Powder
309,600
262,800
290 400
271,200
«
290,400
85,200
82,900
75,600
72)000
_«
74,540
5,060
16)000
10,000
9,000
— —
35,800
16,400
15 700
11,400
.»
7,420
N/A
700
1,100
l)000
—
1,080
N/A
—
—
500
—
840
12,000
15,000
1 5 ,000
—
— —
435,660
391 400
407,800
380)100
—
374,280
0.3907
0.3509
0.3660
0.3412
0.3358
^Assumed 2,000 operating hours per year
Numbers have been rounded.
30
-------
TABLE 7b. TOTAL ANNUAL OPERATING COSTS, DOLLARSa
(English Units)
Iten
Material, S/yr
Labor and cleanup, S/yr
Maintenance, S/yr
Energy, $/yr
Sludge disposal , S/h
F i 1 ter rep 1 acemen t , S/h
Amortization. 10-yr
straight line, S
Total annual cost, Jb
Applied cost, S/ft2
(Ref.)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
(20)
(21)
(14)
(17)
(18)
(19)
Conventional
solvent
__
502,800
402 000
483,600
_..
402,000
__
141,900
132,100
118)000
121,300
24,000
18,000
14,500
~
_.
30,500
29)100
23)200
^^
14,640
__
48,758
10,800
13)480
11,28*0
__
_
__
2,500
3,000
^^
15,000
__
„_
—
762,960
592,000
655)280
552,220
^m
0.0636
0.0493
0.0546
0.0460
Water-borne
. »
513,600
470)400
320,400
**
470,400
»»
J.41,900
132,100
126)200
121,300
24,000
18,000
18,800
~
__
32,514
31)100
22,600
» »
11,140
_
40,750
10)800
—
—
11,280
_
—
__
__
•HW
3,000
•w
11,000
10)800
9)800
__
—
763,760
673,200
497)800
617,120
^^
0.0636
0.0561
0.0415
»
0.0514
High solids
436,800
351,600
345)600
310,800
••
346,800
111,440
141,900
128,400
126)200
__
121,300
11,840
24)000
18,000
18,800
— -
39,460
28,300
27)100
19,700
_.
1 1 ,200
8,460
31,500
7,100
— —
— —
11,280
1,920
—
-—
-—
••
3,000
— —
11,000
11,000
10,000
—
—
609,920
588)300
537,200
485)500
—
493,580
0.0508
8.0490
.0448
0.0404
— •
0.0411
Powder
309,600
262,800
290)400
271 ,200
«
290,400
85 ,200
82,900
75,600
72)000
—
74,540
5,060
16)000
10,000
9,000
— —
35,800
16,400
15 700
11,400
»
7,420
N/A
700
1,100
1,000
—
1,080
N/A
—
— —
500
« .
840
— —
12.000
15,000
15,000
—
--
435,660
391 )400
407,800
380)100
—
374,280
0.0363
0.0326
0.0340
0.0317
«
0.0312
^Assumed 2,000 operating nours per year.
lumbers have been rounded.
31
-------
annual operating costs. The highest operating costs were associated with
the conventional solvent or water-borne coating systems. Labor, cleanup,
maintenance, energy, and waste disposal costs were lowest for the powder
coating system, which contributed to overall lower annual operating
costs. The "Powder Coating Today" article (Reference No. 21) again
provided the most complete and up-to-date Information on annual operating
costs. The operating costs presented 1n that brochure are based on 1986
data and the following assumptions:
1. Labor costs $12.00 per hour and supervision costs $15.20 per hour
2. Cost of electricity = $0.076 per kWh
3. Cost of natural gas = $162 per thousand m3 ($4.60 per thousand
ft3), and
4. Removal of nonhazardous paint sludge was estimated to cost $255
per 208 i (55-gal) drum.
As shown 1n Tables 7a and 7b, material costs represent about 2/3 or
more of the total operating costs of a coating line. The material costs
for any of the four coating systems could be less than those shown 1f
either the volume sol Ids and/or transfer efficiency 1s Increased and/or
the film thickness lowered. For example, 1f the transfer efficiency for
the higher sol Ids case (Reference 16, Tables 6a and 6b) 1s Increased from
60 to 70 percent, the annual cost to coat (material cost) will drop from
$351,600 to $301,400. The annual cost to coat - [(coating thickness)
(mixed coating cost)(surface area coated per year)]+[(theoretical
coverage)(utilization efficiency)]. Likewise, 1f the powder coating
thickness in Reference 16 (Tables 6a and 6b) were decreased from 30 to
25 ym (1.2 to 1.0 mils), the material cost would drop from $262,800 to
$219,000.
It should be noted that, currently* the minimum consistent powder
coating film thickness 1s in the range of 25 um (1 mil). If the product
to be coated requires less film thickness, the cost of applying more
powder than necessary should be considered when comparing powder coating
costs to costs of alternative coatings.
32
-------
7.0 CONCLUSIONS
The use of powder coatings as functional and decorative Industrial
finishes 1s Increasing at a dramatic rate. At an annual rate of nearly
20 percent, powder coating 1s the fastest-growing finishing technology on
the market.1 (However, the Initial sales volumes of powder coatings were
much lower than those of liquid coatings 1n the same time period. There-
fore, a direct comparison of growth rates 1s misleading.) Significant
Improvements 1n the powder coatings, the application systems, and the
powder recovery systems have made powder one of the most cost-effective
finishing systems available. In addition, because powder coatings contain
no solvents and usually are applied 1n dry filter booths, air and water
pollution problems are eliminated 1n well-operated facilities. Energy
costs attributable to heating and ventilation are significantly reduced.
The use of powder coatings as an alternative to liquid, solvent-based
coatings results in a significant decrease in VOC emissions. Powder
coatings can be characterized as the lowest VOC-content coating among the
compliance options available to Industrial finishers. Tables 8a and 8b
present a VOC reduction comparison of the four coating systems. The
values in this table were based on the average of the values presented in
Tables 6a and 6b. As shown in Tables 8a and 8b, VOC emissions for powder
coating systems are substantially lower than those for the liquid coating
alternatives. Emissions are 98.4 percent lower than those shown for
conventional solvent coating systems, 98.1 percent lower than those shown
for higher sol Ids coating systems, and 97.7 percent lower than for water-
borne systems.
Most of the drawbacks to the use of powders that existed a few years
ago (see Section 2.0) have been eliminated. New resin systems allow
powders to meet the coating specifications for almost any product. Thin
films (from less than 25 urn [1 mil] to about 76 urn [3 mils!) in a very
wide range of colors, glosses, and textures can be applied at powder
utilization rates of 95 percent or higher.22 Many of these coatings can
be cured at temperatures of 121°C to 177°C (250°F to 350°F) 1n 15 to
30 minutes. Powder manufacturers are continuing to work toward
perfecting resin and curing agent designs that will allow lower cost
33
-------
OJ
TABLE 8a. VOC REDUCTION COMPARISON3
(Metric Units)
Volume solids at spray viscosity, percent13
Volume VOC content, percent0 d
Actual coverage, in2/* (m2/kg for powder)b e
VOC emissions, metric tons/yrf
Conven-
tional
solvent
33
67
5.71
34.5
Mater-
borne
35
16
6.66
23.6
Higher
solids
60
40
14.0
28.1
Powder
99
1
19.7
0.54
A 6 2 '
"Assumed 1.1x10 m of parts coated per year.
^Average of values presented In Table 6a.
^Assumed density of solvent equals 882 g/i.
^Mater-borne coating VOC content assumed to be 25 percent of the nonsollds portion.
fBased on transfer efficiencies presented 1n Table 6a.
TControl device assumed for conventional solvent coatings with overall efficiency of about 70 percent
(based on capture efficiency of about 75 percent and destruction efficiency of about 95 percent). All
other systems assumed to have no control device.
-------
CO
01
TABLE 8b. VOC REDUCTION COMPARISON3
(English Units)
Volume solids at spray viscosity, percent*1
Volume VOC content, percent0 d
Actual coverage, ft2/g*1 (ft2/lb for powder)b e
VOC emissions, tons/yrf
Conven-
tional
solvent
33
67
233
38
Water-
borne
35
16
272
26
Higher
solids
60
40
570
31
Powder
99
1
96
0.6
^Assumed 12x10 ft of parts coated per year.
^Average of values presented In Table 6b.
^Assumed density of solvent equals 7.36 Ib/gal.
^Water-borne coating VOC content assumed to be 25 percent of the nonsollds portion.
*Based on transfer efficiencies presented 1n Table 6b.
'Control device assumed for conventional solvent coatings with overall efficiency of about 70 percent
(based on capture efficiency of about 75 percent and destruction efficiency of about 95 percent). All
other systems assumed to have no control device.
-------
coatings and low-temperature cure coatings. Significant advancements are
also being made In the weatherabllity of powders for use in automotive and
architectural applications. Clear powder coatings are used for a wide
range of applications 1n a number of markets, Including the automotive
industry. Clear polyester and acrylic powders are being used to finish
wheels, and resin systems are available in powder coating technology that
provide the exterior durability properties required of an automotive
exterior body topcoat.
Recent and ongoing developments in the equipment used for powder
application have significantly reduced the time and effort required for
color changes. Properly designed powder systems can change colors in
minutes. Currently, high-production powder systems apply more than
20 different colors, with several color changes per day.23- Coil coating
technology for powder is being developed. (Coil coating is the coating of
flat metal sheet or strip that comes 1n rolls or colls. The metal is
coated on one or both sides on a continuous production line basis.)
Vertical coating booths are enabling powder to compete more effectively in
the aluminum extrusion finishing market. Advances in microprocessors,
robotics, and Infrared curing technology are allowing Increased production
1n powder coating facilities. All of these advances, plus the Inherent
advantages of working with powder ensure that powder coatings will have a
permanent and ever-increasing share of the finishing market.
36
-------
8.0 REFERENCES
1. Bocchl, 6. J. Powder Coatings: A World Market Overview. In:
Conference Proceedings, Powder Coatings '88. Sponsored by the Powder
Coating Institute. November 1-3, 1988. p. 1-3.
2. User's Guide to Powder Coating, II Ed. Dearborn, Michigan, Society
of Manufacturing Engineers. 1987. p. 151.
3. Miller, E. P. and Taft, 0. 0. Fundamentals of Powder Coating.
Dearborn, Michigan. Society of Manufacturing Engineers. 1974.
p. 13.
4. Reference 1, p. 1-16.
5. Reference 2, p. 12.
6. The Powder Coating Institute Technical Brief No. 1. January 1986.
7. Electrostatic Powder Coating. Dow Chemical Europe. Undated
brochure, p. 7.
8. Sigma Coatings, The Specialist 1n Exterior Paint Systems, Introduces
Sigma PVOF, a New Generation of Powder Coatings. Sigma Coatings,
Industrial Coatings Division, NL-3700 AC Zelst. Undated brochure.
9. Montenaro, 0. Economics of Powder Coating. In: Conference
Proceedings, Powder Coating '88. Sponsored by The Powder Coating
Institute. November 1-3, 1988. p. 9-7.
*
10. G111, 0. E. Powder Coatings and Their Uses. Metal Finishing.
August 1988. p. 41.
11. Reference 10, p. 42.
12. Reference 1, p. 1-17.
13. Bocchl, G. J. Powder Coating Today. Reprint from Products
Finishing. 1987. p. 4.
14. Cole, G., Jr. VOC Emission Reductions and Other Benefits Achieved by
Major Powder Coating Operations. The Powder Coating Institute,
Greenwich, Connecticut. (Presented at the A1r Pollution Control
Association Meeting. San Francisco. June 24-29, 1984). p. 13.
15. Reference 2, p. 25.
16. Reference 13, p. 5.
17. Armstrong Powder Coatings. Cost Comparison Worksheet. Armstrong
Products Company. Undated brochure.
37
-------
18. Why Powder Coat? A Practical Guide to Powder Coating. Volstatic,
Inc., Florence, Kentucky. Undated brochure, p. 6.
19. Cost Analysis: Powder Coatings Versus Other Finishing Systems.
GUdden Chemical Coatings. Undated literature, pp. 67-74.
20. Reference 2, pp. 27 and 28.
21. Reference 13, p. 7.
22. Reference 2, p. 3.
23. Reference 18, p. 1.
38
-------
APPENDIX A.
SURVEY SUMMARY: POWDER COATING EQUIPMENT SUPPLIERS
-------
APPENDIX A. SURVEY SUMMARY: POWDER COATING EQUIPMENT SUPPLIERS
Three of the nine powder coating equipment suppliers surveyed
responded to the survey. A brief summary of their responses is provided
below. A list of the equipment suppliers who responded and a compilation
of their individual responses are also attached.
Types of equipment sold
One of the responding companies only sells a portable powder coating
unit equipped with either a manual or an automatic electrostatic spray
gun. The other two respondents sell a wide range of powder coating
application and recovery equipment for both electrostatic spraying and
fluldlzed bed dipping. None of the three respondents sells curing ovens.
Color chanqeovers
The portable powder coating unit sold by one of the respondents can
be color changed effectively by one operator in approximately 5 minutes.
The other respondents noted that the color change time depends upon the
size of the booth, the number of guns, and the type of powder collection
equipment used. The color change times ranged from as little as 5 minutes
for laboratory-size equipment to as long as 4 hours for a large, 10 gun
unit using a filter cyclone for powder recovery.
Transfer efficiencies
The transfer efficiency provided by the portable powder application
unit 1s estimated at 20 to 45 percent, depending on the technique and
material applied. Manual spray systems may achieve transfer efficiencies
of 60 to 75 percent depending upon the equipment and powder used. The
respondents also cited the following factors that affect transfer
efficiencies: (1) powder composition (i.e., resistivity, particle size,
particle shape, moisture content, resin chemistry, flow properties),
(2) efficiency of charging the powder with either internal or external
electrodes, (3) shape and velocity of the atomized powder cloud exiting
the discharge nozzle, (4).distance to the grounded workpiece, (5) shape,
complexity, and "openness" of the parts to be coated, and (6) film
thickness. In general "open" parts like large frames will have transfer
efficiencies of 50 to 60 percent at a coating thickness of about 2 mils.
Dense parts such as flat panels may have transfer efficiencies of 65 to
85 percent at the same coating thickness. Fluldlzed bed dipping achieves
100 percent transfer efficiency, but at higher film thicknesses and on a
limited range of parts.
Coating thickness
Minimum coating thicknesses of about 0.6 to 0.8 mils and "typical"
thicknesses of 1.2 to 2.5 mils were reported. Maximum thicknesses of 20
to 30 mils were also reported. One respondent noted that automatic
application systems provide the most consistent thin films; he also noted
that preheating parts greatly Increases the maximum achievable film
thickness.
A-l
-------
New powder coating technology
One respondent felt that recent equipment developments have not had a
significant Impact on developing or expanding new markets, and that all of
the new developments have been In the powder material technology. Another
respondent noted that new fluorocarbon-based powders are expected to
permit the expansion of powder coating Into the high-performance architect
aluminum extrusion market, currently limited to two-coat liquid
coatings. The development of equipment that allows faster color changes
was also mentioned.
Equipment costs
The respondents provided costs for a wide range of equipment types
and sizes. A portable powder system costs approximately $3,700, and
laboratory models cost $14,500 and up. "Budget" prices for complete booth
equipment, powder guns, and fire detection packages ranged from $55,000 to
$141,000 depending on the size of the equipment. The powder applicators,
delivery, and recovery equipment for an eight gun, 30 1n.x66 in. (wxh)
automatic coating system may range from $90,000 to $125,000.
Experience with powder coatings and Industries served
The three respondents have been manufacturing and selling powder
application equipment from 5 to 29 years, and have an average experience
of 16 years. They service a wide variety of Industries, including metal
furniture, lawn and garden tractors, automotive parts, light poles,
lighting fixtures, and gas tanks, among many others.
Powder versus liquid coating costs
One respondent 1s not Involved 1n liquid coatings, and therefore,
could not provide a cost comparison between the two coating methods.
Another respondent does sell equipment to liquid coating users but did not
have any comparative information available. The third respondent sells a
limited amount of equipment to liquid coating users and felt that, in
general, powder coating systems are comparable in capital investment to
new liquid coating systems.
2 Attachments
A-2
-------
Attachment 1
LIST OF RESPONDENTS: POWDER COATING EQUIPMENT VENDORS
Mr. Frank A. Robinson, Jr.
Director of Marketing
The OeVllblss Company
Post Office Box 913
Toledo, Ohio 43692-0913
(419) 470-2129
Mr. Donald -S. Tyler
President
Volstatic, Inc.
7960 Kentucky Drive
Florence, Kentucky 41042
(606) 371-2557
Mr. William Diaz
National Sales Manager
Finishing Systems Services, Inc.
140 Joey Drive
Elk Grove Village, Illinois 60007
(312) 640-0111
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Attachment 2
SURVEY RESPONSES: POWDER COATING EQUIPMENT SUPPLIERS
1. Company name and address; contact name, title, and telephone
number. (See attachment).
2. List the types of equipment that you sell for each step in the powder
coating process (powder storage and handling, substrate pretreatment,
powder delivery, application, recovery, and powder curing).
DeVUblss; DeVilblss sells a portable powder coating application
unit that may be equipped with either an automatic or a manual
electrostatic spray gun.
Finishing Systems; The equipment that Finishing Systems Services,
Inc. (FSSI) fabricates is marketed under the RECLAIM" trademark. The
following equipment 1s manufactured by FSSI for the powder coating
Industry:
Powder handling and conditioning equipment
• virgin powder drum unloader
• powder sieving and conditioning equipment
• powder transfer retrofit for existing cyclone equipment
RECLAIM" powder application equipment
complete manual spray gun outfits with supply hopper
laboratory and QC station manual spray gun outfits
manual spray gun outfits for mounting on the powder booth
complete automatic/manual powder spray systems for retrofitting
existing liquid spray lines or adding provisions for powder
complete automatic/manual powder spray systems for new lines
ultra-violet fire detection system for automatic powder lines
custom design powder application equipment for special products
electric and pneumatic automatic gun movers and reciprocators
RECLAIM" brand powder recovery and recycling systems
Cartridge filter design powder recovery booth models:
laboratory and QC station cartridge powder collection booth for
spraying small samples or testing various powders
chain on edge conveyor type cartridge booths for coating small
parts on rotating fixtures which travel through a slot at the
bottom of the booth floor. Models with single color and roll-
away color change collectors
manual station single color format booths with airflow capacities
of 3,000 to 6,000 ftVmin
color change design manual and automatic powder booths with
multiple spray stations. Standard and custom models with
airflow capacities of 3,000 to 20,000 ft /min
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• special design cartridge style booths with cyclones for multiple
color capability within the same recovery system
• custom design booths for special oversize products
• custom powder management systems for fluid-bed dipping systems
• custom design dust collection booths for nondecoratlve coatings,
fire extinguisher chemicals, and rubber Industry
Volstatic: Volstatic manufactures electrostatic powder coating
application and recovery apparatus, Including:
a. Manual spray application apparatus for production use
b. Manual spray application apparatus for laboratory or field test
use
c. Automatic spray apparatus, single gun through multi-gun
configurations, typically 2 to 12 guns per booth
d. Electrostatic generators, single and multi-gun configurations
e. Spray booths for manual application
f. Spray booths for automatic application (or combination manual/
automatic configuration)
g. Powder recovery and reclaim systems: cartridge type, cyclone
separators, combinations
h. Fluid beds
1. Ancillary equipment: powder transfer pumps, vibrating drum
tables, de1on1z1ng generators/fans; powder clean-down apparatus
Vol static occasionally sells powder curing equipment when supplied
with other powder application equipment
3. Please provide Information on powder application and recovery
equipment relative to color changeovers (typical time required for
color changeover and maximum number of colors that can be applied per
booth or system).
DeVilbiss; Their powder system can be color changed effectively by
one operator 1n approximately 5 minutes.
Finishing Systems; Powder collection equipment 1s available in three
• distinct formats: cartridge filter booth which FSSI specializes in,
moving filter belt booth, and the conventional cyclone booth. The
simplest and most efficient of these is the cartridge booth since all
the recycled powder stays within the unit. This compact booth design
has no moving parts other than the fan. The collector, the housing
which has the dedicated color filters, is very easy to change. The
filters within the collector are also easily changed when a low
volume color which does not have a dedicated collector is to be
recycled. The moving filter belt booth requires the changing of the
belt for powder change and has extensive auxllHary equipment for
screening and recycling the powder.
The idea behind the cartridge design powder recovery booth is that
each recycled color has a dedicated collector with filters for that
specific color. If a powder user has a multitude of colors with no
A-5
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appreciable volume In any of these various colors, a cartridge booth
- 1s not the proper choice of equipment. MutHple color recovery
requires a booth which uses an Inline cyclone to separate each
color. Naturally, the efficiency of the cyclone will vary greatly,
and anywhere from 5 to 25 percent of the recycled powder will bypass
the cyclone into the final filter and thus, will not be recovered.
Further scrap powder 1s generated when the cyclone, ductwork and
collection hoppers on the cyclone system are not properly cleaned
during the color change.
The following are some general color change times for various types
of equipment and airflow size in cubic feet per minute.
Approximate time in minutes for color change by two operators
Cartridge Filter
Equipment model format filter belt Cyclone
1,500 ftj/min for lab or QC 5 to 10 NA 15 to 20
3,000 ft,/m1n (2) manual 10 to 20 30 to 60 30 to 60
4,500 ft,/min (2) man, (4) auto 20 to 30 45 to 90 60 to 120
9,000 ftVmin (2) manual 25 to 35 60 to 120 90 to 150
12,000 ftVmin (2) man, (8) auto 40 to 60 120 to 240 120 to 240
Vqlstatic; Powder color change time Is dependent primarily on the
size of the booth and the number of guns. Typically, a steel-
construction booth and a complement of eight guns may be cleaned in
about 30 minutes. Volstatlc's new, patented ColorSPEEDER permits
that operation to be completed in less than 5 minutes, including its
reclaim system. Even faster changes may be achieved by duplicating
the spray booths in a "roll on/roll off" configuration but this
requires additional capital investment.
Employing cyclone separators between the spray booth and final filter
sections of the reclaim system permits unlimited numbers of colors to
be applied without duplication of reclaim system sections, (e.g.,
filter modules) and they achieve quite high recovery efficiencies of
usable powder overspray (e.g., 95 to 97 percent).
4. Describe, and provide data 1f possible, the ranges of transfer
efficiencies that are expected for each type of application equipment
sold.
DeVUbiss; They do not have experimental data showing transfer
efficiencies for this equipment, but expect it to be in the range of
20 to 45 percent depending on the technique and material being
applied.
Finishing Systems: Transfer efficiency in powder application
equipment 1s dependent on many factors. The most Influential factor
1s the composition of the powder; its resistivity, particle size,
particle shape, moisture content, resin chemistry and flow
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properties. Other factors are gun dependent such as the efficiency
of charging the powder with either Internal or external electrodes,
shape of the atomized powder cloud, velocity of the powder cloud
exiting the discharge nozzle, and distance to the grounded workplace.
Transfer efficiency also varies with the various types of charging
methods: negative corona, positive corona and trlbo charge.
The RECLAIM" Ultra-100 brand of equipment has higher high voltage and
current levels at the tip of the gun electrode than other competitive
brands. The higher current allows more powder to be charged at a
specific high voltage level. FSSI has an Installation where four
Ultra-100 guns are performing the same job as six of another
manufacture on the same product. FSSI at this time does not have an
Interest 1n producing any type of friction tr1bo-charging application
equipment.
Volstatic; Transfer efficiency 1s dependent on not only the
application equipment, but the shape, complexity and "openness" of
the parts to be coated. In addition, Hne speed, film thickness and
powder chemistry play a major role. Volstatic equipment 1s generally
regarded to achieve the highest direct transfer 1n the industry and
the following are typical examples with epoxy or polyester powder at
average film thicknesses of 1.5 mils + 0.5 mils:
a. "Open" parts like large frames, etc: 50 to 60 percent TE
b. "Average" line density, e.g., dense wire goods, tubular
furniture, lighting fixtures, boxes and cabinetry, etc.: 55 to
80 percent TE
c. "Dense" parts or Hne loading, e.g., flat panels: 65 to
85 percent TE
In some special-purpose equipment, transfer efficiencies in excess of
90 percent can be achieved, but 100 percent in a spray apparatus is
not achieved. (Fluid bed dipping achieves 100 percent transfer
efficiency, but at higher film weights on a limited range of
parts.) Proper flxturing for dense Hne loading is critical to
achieve good transfer efficiency in any spray system.
Manual spray systems typically achieve 60 to 75 percent in Volstatic
systems.
5. Please provide Information on minimum and maximum coating thickness
that can be achieved with each type of application equipment sold.
Devnbiss; They believe that coating thickness is largely a function
of the powder material itself, and they do not have experimental data
in this area.
Finishing Systems: The coating thickness 1s very powder dependent.
The coating can be applied very thin, 0.6 to 0.8 mils but the hiding
capability and the appearance of the coating may not be acceptable,
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or may not offer the protection required. The thicker coatings are
easier to achieve, but again it depends on the thickness at which the
coating will start rejecting additional material and also the overall
particle size.
Nominal coating thicknesses are generally 1n the range of 1.2 to
2.5 mils on selected surfaces. In areas where manual touch-up is
done to an automatically painted part or on surfaces very close to
the nozzle of a gun the coating can be 4.0 to 5.0 mils thick.
Volstatic: Volstatic has provided large-scale, automatic combination
1 manual /automatic production systems achieving 0.8 to 1.2 mils average
film thickness. Some systems are capable of achieving greater than
10 mils single-pass coatings on nonpreheated parts. Preheating parts
greatly Increases the maximum film thickness from this range.
Thicknesses of 20 to 30 mils are certainly possible. Usually,
automatic application systems provide the most consistent thin-film
averages, with an additional 0.25 to 0.5 mil typical with manual
coating. Without production monitoring, however, manual operators
have been known to add a mil or more of unnecessary film weight.
6. Please provide as much information as possible on the types of spray
booths (from Item 2) used for powder coating lines (dimensions,
airflows, filter types, etc.).
DeVllbiss; They are not presently manufacturing spray booths for use
1n powder coating systems.
Finishing Systems; FSSI exclusively fabricates cartridge filter type
powder booths. The airflow in all the RECLAIM1" powder booths 1s full
height of the spray cavity whenever possible and horizontal towards
the collector which 1s located at the end of the booth (single
extended) or 1n the center between the manual and automatic spray
stations (double extended). In cases where the booth is not extended
1t would have a single spray station directly 1n front of the
collector as is the design of the laboratory booth.
The capacity 1s figured by the sum of all the spray and product
openings at an airflow velocity of 100 to 120 feet per minute.
Volstatic; Volstatic provided examples of spray booth configurations
along with reclaim systems. Product maximum dimensions are not truly
limited by the booth; ovens and pretreatment systems provide the
practical limits for economic feasibility. The majority of Volstatic
euqipment (approximately 95 percent) falls 1n the range of
24"w x 30"h to 72 in. wide maximum width and 312 1n. maximum height,
(product opening).
The filters are typically nonstatlc cartridge-type 1n combination
with two elements of monitoring safety filters afterward. Cyclone
separators are often used prior to the filter to maximize filter
life, improve efficiency and to allow an unlimited number of colors
to be used without filter set duplication.
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In some special equipment, (e.g., the Volstatic Freedomcoater) air
flows are unusual and aid 1n the coating performance considerably.
7. List typical sizes and operating parameters for powder curing ovens
(from Item 2) sold by your company.
DeVUblss; They do not presently manufacture or sell powder curing
ovens.
Finishing Systems; FSSI does not fabricate powder cure ovens.
Volstatic: Volstatlc normally works with oven manufacturers for the
supply of these products. The product openings match or exceed the
booth product openings (see question 6) and the lengths may vary from
6 feet to several hundred feet 1n conveyor1zed systems. Powders
typically cure between 325"F and 400°F with cure times between
5 minutes and 20 minutes. Infra-red radiation curing accelerates
these times to as little as a few seconds 1n some cases and may
permit curing powder on the outside of temperature-sensitive devices
whose Internal gaskets, seals or components could not tolerate
temperatures above, say, 250°F. Some degree of Infra-red curing is
common on massive objects, like Iron or steel castings.
8. Describe recent Improvements 1n powder coating technology that may
result 1n expanded or new market areas.
DeVUblss; Answer unknown.
Finishing Systems; Recent equipment developments have not had
significant Impact on developing or expanding new markets. All the
development has been in the powder material technology.
Volstatlc; The development of the ColorSPEEDER permits a true
5-minute color change without duplicate coating booths, filter
modules or spray guns. This saves capital investment, floor space
and permits economical "short runs" in production without wasting
overspray powder. The Freedomcoater permits high production runs of
parts arranged on an Intergral conveyor without the need for
flxturing. Automatic masking of one side of the part is a feature of
this finishing technique.
/
New fluorocarbon-based powders will permit the expansion of powder
coating into the high-performance architect aluminum extrusion market
previously limited to 2-coat liquid coatings.
9. For each type of equipment listed under Item 2, provide costs, or
cost factors, that can be used to generate "typical" costs for a
complete powder coating line.
DeVilblss; A BFA portable powder system sells to an end-user for
approximately $3,700.00.
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Finishing Systems; Typical costs are not easy to supply since the
powder booth equipment is usually custom fabricated. The following
are budget prices for complete booth equipment, powder gun and UV
fire detection packages in the various airflow and product opening
sizes.
Configuration
Product
openings
Single extended
Double extended
ft /min Man Auto Cost, $ Man Auto Cost, $
Opening:
2'wx4'h
2'wxS'h
3'wx6'h
4'wx6'h
3'wx6'h
Lab model
3«x3'
4'xS1
4,500
6,000
9,000
12,000
15,000
1,600
3,000
2
1
2
1
2
1
2
1
2
1
1
1
0
4
0
6
0
6
0
8
0
12
0
0
29,200
45,500
40,100
64,100
42,540
70,600
49,500
85,300
56,500
112,300
13,000
14,500
2
2
2
2
2
2
2
2
2
2
—
—
4
6
4
8
8
10
8
12
14
16
—
—
54,900
64,600
66,000
84,600
89,500
100,500
94,800
114,800
131,900
140,900
—
—
Volstatic: The following costs refer to equipment listed in
question 2.:
a. From under $4,000
b. From under $3,500
c. Typically, around $15,000 per gun for the whole system, including
booth, guns generator, reclaim system. This number varies a lot
depending on the particular system and degree of automation.
d. From under $5,000 per gun
e. Very dependent on size: from under $10,000 for a self-contained
48 1n.x48 in. face booth with integral reclaim system
f. Very dependent on size—see item "c" above
g. See item "c" above
h. From $500 to more than $5,000 depending on size, degree of
contents and degree of integral equipment, e.g., venturi pumps
1. From under $100 and up depending on the individual pieces
As a very general guide, not for purpose of ordering, the powder
applicators, delivery, and recovery equipment, including
architectural interlock safety equipment for an 8-gun, 30"wx66"h
automatic coating system may range from $90,000 to $125,000. It is
essential to consult with equipment manufacturers, ideally more than
one, to obtain usable cost estimates for finishing lines.
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10. In what Industries 1s your equipment most often used (provide a 11st
of major customers, If possible).
DeVUblss; Most of their more recent powder systems have been used
1n powder coating job shops and the appliance Industry.
Finishing Systems; FSSI is Involved mainly 1n the Industrial
decorative coating market. The various products being coated with
the RECLAIM" powder equipment are as follows:
lawn and garden tractors
snow blowers
patio furniture
office furniture
pallet racking
display shelving
wire displays
restaurant chairs and tables
lighting fixtures
propane and oxygen tanks
garden posts
battery chargers
boat trailers
rubber membrane roofing
radiators and coolers
stove burner liners
navy missile housings
truck air conditioners
RV after-market equipment
farm fans and coolers
radiator fans
switching gear enclosures
oil coolers
truck bumpers
hardware
TV satellite dishes
air conditioner housings
light poles
school furniture
basketball poles and hoops
security lighting
aluminum car wheels
aluminum extrusions
shop welders
boat winches and hardware
pole transformer housings
floor sweepers and vacuums
parking meters
automotive hardware
restaurant shelving
range hoods
fence fabric
communications equipment
multitude of Job shops
Volstatlc; In general, any product which 1s painted with an organic
paint and which can be transported into a cure oven and which will
withstand powder cure temperatures (see question 7) can and probably
should be powder coated. This Includes most products made of metal •
and many of other materials.
11. How long has your company sold powder coating equipment?
DeVUbissi OeVllblss Company has been manufacturing and selling
powder application equipment in excess, of 15 years.
Finishing Systems; FSSI has been manufacturing and selling powder
recycling and application equipment since March of 1984.
Volstatic; Volstatlc has manufactured and sold powder coating
application equipment since I960, over 29 years.
12. Do you also sell coating equipment to liquid coating users? If so,
please provide information on the cost differences between the types
of equipment sold for liquid and powder coatings.
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DeVllbiss; OeV11b1ss Company sells a substantial amount of equipment
to liquid coatings users. However, since they engage in very little
powder application equipment business they do not gather or maintain
comparative Information.
Finishing Systems; FSSI is not Involved in the liquid coatings
market at this time.
Volstatic; Volstatlc sells a limited range of generators for private
label liquid applications, including the NOT (nondestructive testing)
Industry. In general, productive powder coating systems are
comparable in capital investment to new liquid coating systems for a
given application.
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APPENDIX B.
SURVEY SUMMARY: POWDER COATING MANUFACTURERS
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APPENDIX B. SURVEY SUMMARY: POWDER COATING MANUFACTURERS
Seven of the nine powder coating manufactures surveyed responded to
the survey. A brief summary of their responses 1s provided below. A list
of the powder coating manufacturers who responded and a compilation of
.their individual responses are also attached.
Types of powder coatings manufactured
All of the respondents manufacture a variety of thermosettlng powders
(e.g., polyester, urethane, epoxy, acrylic, hybrid, etc.). One
manufacturer also produced the following thermoplastic powders: vinyl,
nylon, and thermoplastic polyester.
Color availability
All of the respondents stated that virtually any color can be matched
with powder coatings. The only limitation they cited was that certain
metallic effects are hard to duplicate. One manufacturer explained that,
although metallic-effect powder coatings are attractive and often accepted
as replacements for liquid paint, it 1s very difficult to match the
metallic effects displayed by liquid paint at various viewing angles of
the coated part.
Pretreatment steps
The respondents stated that the substrate pretreatments w111 vary
depending upon the substrate and the performance requirements. The
pretreatment step most often suggested by the respondents was a three to
seven stage Iron phosphate pretreatment. Five to nine stage zinc
phosphate and chrome phosphate pretreatments were also listed.
Powder storage and handling
The majority of the powder coating manufacturers recommended that
powders be s.tored at temperatures below 80°F and for a maximum of
6 months.
Minimum coating thickness
The respondents reported minimum film thicknesses ranging from about
0.5 to 1 mil. Typical film thicknesses ranged from about 1.5 to 3 mil for
thermosettlng powders and from 4 to 12 mil for thermoplastic powders.
Curing times and temperatures
Curing temperatures ranged from a low of 250°F to a high of 475°F for
thermosettlng powders, and ranged from 400 to 600°F for thermoplastic
powders. Curing times ranged from 10 to 30 minutes, depending upon the
curing temperature (I.e., at higher temperatures, the curing times were
shorter).
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Powder coating costs
Prices varied depending upon the specific formulation, the quantity
ordered, the color, and the gloss level. One powder coating manufacturer
stated that bright, sharp, clean colors are 20 to 100 percent more
expensive than earthtones, pale shades, whites, and blacks. The price of
thernrosettlng powders ranged from $1.75 to $12.00 per pound, depending
upon the quantity ordered. The cost of thermoplastic powders was somewhat
higher at $4.00 to $14.00 per pound, with the exception of vinyl powders
which ranged 1n price from $1.50 to $6.00 per pound. One respondent
stated that the "Industry average" cost of powder coatings 1s about
$2.49 per pound.
Minimum orders
Standard or "stock" powders can be purchased from the majority of the
powder coating manufacturers 1n quantities as small as 50 Ib. Nonstock
powders that are custom-manufactured for specific customers usually have
minimum orders from 1,500 to 5,000 Ib. One manufacturer stated that, for
all of their powders, the minimum order Is 200 pounds.
End users
The powder coating manufacturers supply a variety of markets
Including major home appliances, metal furniture, automotive, lighting,
lawn and garden equipment, piping, etc.
Recent trends 1n the use of powder coatings
Respondents reported a 20 to 25 percent growth 1n powder sales each
year for the past 5 years. One respondent stated that a significant
number of conversions from liquid to powder have occurred because of
regulations pertaining to the disposal of hazardous wastes. Other
reported trends are Increased user sophistication (I.e., 95 percent or
greater material utilization efficiencies), consistent thin films, and
long-term testing prior to the use of powder.
Recent developments .
The following developments 1n powder coating technology were reported
by the respondents:
• high transfer efficiency powder application equipment
• capability to apply thinner, more uniform films
• more economical powder reclaim systems, facilitating more rapid
color change
• new powders replacing porcelain in the appliance and bathroom
Industries continue to be developed
• development of new thermosettlng fluorocarbon powders for use 1n
architectural Industry
• powder coatings now available for cure as low as 250°F
8-2
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powder and application equipment 1s available for coating coil or
blank stock
powder coatings now exist for coating a variety of plastics, both
1n mold and out of mold
metallic look powders which approach chrome appearance are
recently available
less batch-to-batch variation with powders
powders now have better weathering systems for exterior exposure
2 Attachments
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Attachment 1
LIST OF RESPONDENTS: POWDER COATING MANUFACTURERS
Mr. G. E. Bond
Director
EVTECH
9103 Forsyth Park Drive
Charlotte, North Carolina 28241
(704) 588-2112
Mr. Ron F. Parrel!
General Manager
The GUdden Company
Powder Coatings Operations
3926 Glenwood Drive
Charlotte, North Carolina 28208
(704) 399-4221
Mr. Steven Klefer
Market Manager
Morton Thlokol, Inc.
Power Coatings Group
Post Office Box 15240/No. 5 Commerce Drive
Reading, Pennsylvania 19612
(215) 775-6600
Mr. Douglas Bach
Manager of Marketing and Operations
The O'Brien Corporation
Power Coatings Division
5300 Sunrise Street
Houston, Texas 77021
(713) 641-0661
Mr. Trevor Mason
General Manager
Spraylat Corporation
3465 South La denega Boulevard
Los Angeles, California 90016
(213) 559-2335
Mr. John K1sh
Customer Service Coordinator
FERRO Corporation
Power Coatings Division
Post Office Box 6550
Cleveland, Ohio 44101
(216) 641-8580
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Mr. BUI O'Dell
Operations Manager
Lilly Powder Coatings, Inc.
1136 Fayette
North Kansas CHy, Missouri 64116
(816) 421-7400
B-5
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Attachment 2
SURVEY RESPONSES: POWDER COATING MANUFACTURERS
1. Company name and address; contact name, title, and telephone number.
(See Attachment 1)
2. Types of powder coatings manufactured (vinyl, acrylic, polyester,
hybrids, etc.)
EVTECH; Polyester, urethane, epoxy/polyester, epoxy, acrylic.
Glldden; Epoxy, epoxy/polyester hybrid, polyester urethane,
polyester, acrylic, (all thermosettlng materials).
Morton Thlokol: We currently manufacture thermoplastic and thermoset
organic powder coatings as follows:
Thermoplastic: vinyl, nylon, thermoplastic polyester.
Thermoset: epoxy-all types, hybrid, urethane polyester, TGIC
polyester, acrylic.
O'Brien Corp.; Epoxy, epoxy-polyester hybrid, urethane-polyester,
and TGIC-polyester. No thermoplastic types are produced.
Spray!at; "Secura" epoxy, "Secura" hybrid, "Secura" polyester TGIC,
"Secura" polyurethane. All available 1n various gloss levels,
textures, structures and nonmetallic, metal lies.
FERRO Corp.; Epoxy, polyester, hybrid, and acrylic.
Lilly; Thermoset powder coatings 1n the epoxy, hybrid, TGIC
polyester, and polyurethane chemistries.
3. Describe limitations on color availability.
EVTECH: Colors formulated to meet customer requirements.
GUdden; There are virtually no limitations on color availability.
It should be noted that wh'lle attractive metallic effects can be
achieved, metallic particles win generally not orient (flop) the
same as they will 1n low viscosity liquids. It 1s difficult to match
the exact metallic "flop" 1n different systems. This 1s not only a
powder problem but a problem between various viscosities or solids
levels in liquids. This is often mentioned as a powder limitation.
Morton Thlokol; Virtually any color can be matched 1n any coating
type. We have 95 stock colors.
O'Brien Corp.; Virtually any color can be produced 1n solid
colors. Clear coatings and pigmented transparent colors are also
available. The one area in which we are limited by current
technology 1s that of metallic-effect coatings. Metallic-effect
powder coatings can be produced which are very attractive, and, in
B-6
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many cases, enjoy very favorable reception as replacements for liquid
paint. However, It 1s extremely difficult to match the metallic
effect displayed by liquid paint at various viewing angles of the
coated part. Usually, this difference 1s not objectionable 1f the
powder coated part 1s not placed 1n close proximity to a part coated
with liquid paint, or does not require touch-up with liquid paint.
However, for applications such as automotive topcoat, powder
metalHcs are not yet direct replacements for liquids.
Spray3at; Most colors are available with only a few exceptions.
Special finishes have some limitations when considering resin.
FERRO Corp.; The only restrictions on color is the use of
pigmentation that has been chosen as a high risk safety hazard (ex.
free-floating metals).
Lilly; Generally, any color available in liquid Industrial finishes
1s also available in powder coatings. There are some limitations in
matching liquid coatings in metallic formulations.
4. Describe the substrate pretreatment steps that are recommended or
required.
EVTECH; Three stage iron phosphate or five stage zinc phosphate
depending on product requirements.
Slldden; Substrate pretreatments vary significantly based on
substrate and performance requirements. These will be the same
requirements as for liquids, however.
Morton Thiokol; All powder coatings require a clean, dry
substrate. Further pretreatment 1s dictated by coating performance
requirements; I.e., to achieve long-term corrosion resistance five
stage or longer iron or zinc phosphating is typically used.
A. Thermoset Powders
1. Ferrous substrates
a. 3-7 stage iron phosphate with a chrome or nonchrome final
rinse.
b. Cleaning followed by shot blasting.
c. 5-9 stage zinc phosphate.
2. Nonferrous substrates
a. 3-7 stage iron phosphate with special additives
b. Chromates
c. Chrome phosphates
d. 5-9 stage zinc phosphate (for galvanized primarily).
B-7
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B. Thermoplastic powders
1. As above.
2. Nylon and vinyl may require a primer depending on
requirements.
O'Brien Corp.: Minimum recommended pretreatment is usually 3-stage
iron phosphate. For applications which require a high degree of
corrosion protection, 5 or 7-stage iron or zinc phosphate is
recommended. In applications which are strictly decorative and used
in a mild environment such as the interior of a home, vapor
degreasing, alkaline cleaning, or solvent washing may be adequate.
Spray!at; Thorough cleaning and degreasing. When higher
specifications have to be met, a chromate or phosphate coating should
be applied to the substrate.
FERRO Corp.; Generally, a good quality powder finishing system
should have a minimum of 5 stages; however, there are some coaters
using 3 stage systems for their quality requirements. A 7-stage
operation will be used if physical requirements, such as resistance
to salt spray, are extremely demanding. Example of a typical 5 stage
(zinc or iron phosphate): cleaner/rlnse/phosphate/rlnse/sealer.
Lilly; A clean metal substrate 1s required before electrostatic
application. For products exposed to Interior environments, a three-
stage pretreatment 1s generally required (washer/phosphate, clear
water rinse, and another rinse or sealer). For products exposed to
an exterior environment, a five-stage process 1s recommended. This
consists of a power wash, a rinse, an Iron or zinc phosphate, a clear
water rinse, and a seal.
5. Describe any powder storage and handling procedures that are
recommended.
EVTECH; Storage conditions should not exceed 80°F for prolonged
periods of time.
Glidden; Our standard recommendation for powder storage is that the
product be stored at 80°F maximum. The time depends upon the
specific formulation but in no case is less than 6 months with our
commercial products.
While the 80°F is a good general recommendation, it is not
mandatory. We have some Inventory areas as do some of our customers
where there is no warehouse temperature control. Just as many liquid
paints should not be stored In extremes In temperature, discretion
should be used in storing powder.
There are two fundamental mechanisms where powder can be unstable:
(1) chemical reaction, and (2) physical melting (sintering/blocking).
8-8
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The first 1s dependent upon the chemistry of the particular
formulation. More reactive systems can advance with heat. Many
formulations will be extremely stable, however. While 1t 1s very
difficult to generalize In this area, 1t would be our estimate that
75 percent of product sold have good stability in this area.
The second 1s applicable to all solid plastic materials. Depending
upon the melting point of the formulation, the particles will begin
to stick together under some conditions of elevated heat. Again, it
1s extremely difficult to give quantitative absolutes. Because of
the excellent Insulating properties of a container of powder, a
package stored at an elevated temperature could take weeks and even
months for that temperature to reach all areas of the powder. Powder
1s routinely shipped across the country and through the desert in
standard trucks without deleterious effects.
Morton TMokol: Typical powder coatings require ambient storage
(80"F at 50 percent relative humidity is Ideal). Some special fast
cure materials require cold storage.
O'Brien Corp.; We recommend storage in a cool enviroment (75° or
less) for a period of 6 months, although many applicators routinely
store powder for longer periods without experiencing any
difficulties.
Spray!at; Dry storage, 6 months recommended maximum, stored at not
more than 77°F. Particular attention should be paid to storage where
adverse climatic conditions are possible.
FERRO Corp.: Power storage and handling procedures;
a. Climate controlled room for storage of powder coatings;
b. Proper rotation of stock;
c. Protection clothing and proper respirator; and
d. Carefully read all M.S.D.S. information supplied with the
. product. :;•:•
Lilly; Lilly recommends that powder be stored at less than 80°F.
Powder coatings have a shelf Hfe of 6 months from date of shipment,
1f properly stored.
6. Are your powder coatings compatible with all typical application
devices? Discuss any known exceptions.
EVTECH; Compatible with all powder coating application equipment.
Glidden; Our powder coatings are compatible with all powder coating
application concepts. Of course, these materials cannot be sprayed
through liquid guns. Applicable powder equipment must be employed.
Morton Thiokol; Morton powder coatings are used 1n all known types
of powder application equipment.
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O'Brien Corp.: Our coatings are designed to apply through
electrostatic spray guns, trlboelectric guns, electrostatic fluldlzed
beds, or conventional fluldlzed beds. On occasion, formulations or
process conditions may require alterations to yield acceptable
performance on specific types of equipment, and such alterations are
generally successful.
Spray!at; Electrostatic, hand or automatic spray. Most products can
be formulated for use in fluldlzed bed.
FERRO Corp.; VEDOC powder coatings are typically compatible with all
application equipment. However, particle size distribution and/or a
post-additive may be required to Insure peak performance.
Lilly; Generally, powder coatings are applied by the electrostatic
application method. Another way of applying powder coatings 1s
electrostatic fluid bed.
7. What 1s the minimum coating thickness that can be obtained with your
powder coatings? What 1s the "typical" coating thickness?
EVTECH; Minimum thickness 0.7 mil to 1.0 mil depending on specific
color. Typical coating thickness 1.5 mils.
Glidden; Film thicknesses requirements vary significantly. We have
ongoing commercial operations applying powder in thickness ranging
from 0.7 mils to 1.3 mils. Other applications in the electrical
Industry average 15 mils. The ability to maintain consistent and low
film thicknesses depends significantly on application line design and
control. While liquids experience rejects through "runs and sags"
when thickness 1s too high, powder is more forgiving. Operators tend
to apply powders heavier to take advantage of this flexibility.
Morton Thiokol; We have thermoset powder coatings that can be
applied as thin is 0.5 mils. Typical thermoset film thickness range
1s 1.5 to 3.0 mil. Often thickness can be controlled to ±0.2 mil.
Thermoplastics are usually applied 4 to 12 mils thick.
O'Brien Corp.; In "real world" conditions, it is unusual to find
coatings applied consistently under 1 mil. In a laboratory
situation, coating thickness of under 1 mil may be obtained with
acceptable appearance, but it 1s very difficult to maintain this film
thickness on a large-scale application line. My opinion on "typical
film thickness" is that it is in the 2 to 3 mil range for most
applicators.
Spray!at; Coating thickness of 1 mil is possible but a thickness of
2 ±0.5 mils is typical.
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FERRO Corp.; Based on applications, coating thickness specifications
are maintained at ranges of 0.8 to 1.0 mils; custom coaters
environment ranges from 2 to 3 mils.
Lilly; The minimum coating thickness currently being applied by
customers of Lilly is 0.8 to 1 mil. The typical coating thickness is
approximately 1.8 to 2.2 mils.
8. Please provide Information on the range ("low," "typical," "high") of
curing times and temperatures that are required for the types of
powder coatings Identified in Item 2.
EVTECH;
Low: 30 min. at 275'F (epoxy)
Typical: 20 nrin. at 375°F (all others)
High: 5 m1n. at 400°F (epoxy)
10 m1n. at 400°F (all others)
Glidden: Minimum cure requirements can range from 250°F and
30 minutes to 375"F and 30 minutes.
Morton Thiokol;
Low Typical High
Epoxy 250°F 350° to 400°F 475°F
Hybrid 275" to 300°F 350° to 400°F 450°F
Urethane polyester 350°F 390° to 400°F 425°F
TGIC polyester 300°F 350° to 400°F 475°F
Acrylic 275°F 350° to 400°F 450°F
Nylon 475° to 600°F
Vinyl 400° to 600°F
Thermoplastic polyester 400° to 600°F
O'Brien Corp.; Cure schedule.
Epoxy, hybrid, polyester Urethane
Low 275°-350°F/8-20 min 350e-400°F/8-20 min
High 350°-425°F/8-20 m1n 375°-425°F/8-15 min
Spray!at; Low cure products are available v/1th curing schedule of
3308F, 10 minutes peak metal temperature. Standard cure is 365'F,
10 minutes peak metal temperature. Polyurethane and other low gloss
products have a cure of 400°F, 10 minutes peak metal temperature. By
Increasing the curing times a lower cure temperature can be achieved.
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FERRO Corp.; Cure schedule:
Epoxy Polyester Hybrid Acrylic
Typical 3758F/15 min 375°F/15 min 375°F/15 min 3759F/20 min
Low 300°F/15 min 360°F/30 min 325°F/30 min 360°F/30 min
High 425°F/10 min 425°F/15 min 4258F/10 min 4259F/15 min
Lilly; The typical thermoset powder coating cures at 400°F for
10 minutes (or an equivalent bake based on time and temperature).
However, coatings can be formulated to cure at temperatures of 275°
to 300°F for approximately 20 to 30 minutes, contingent upon
substrate thickness.
9. Please provide Information on the price range for each type of powder
coating identified 1n Item 2.
EVTECH; Prices vary depending on specific formulation from $2.50 to
SS.OO/lb.
GUdden; Again, price can vary significantly within any generic type
based on formulation specifics. The following generalities can be
made:
Type Cost, $/1b
Epoxy 2.40
Polyester/epoxy hybrid 2.20
Polyester urethane 2.35
Polyester 2.65
Acrylic 3.00
Price is only one piece of the economic equation, however. Please
refer to attached discussion on economics for further information.
Price for pound of our products can range from $1.75/1b to over
$10.00/1b with the average being in the $2.50/lb area.
Morton Thiokol; Price Is very dependent on color with bright, sharp,
clean colors being 20 to 100 percent more expensive than earthtones,
pale shades, whites and blacks. Quantity also plays a role in cost.
Epoxy Less than $2.00/1b to $12.00 Ib
Hybrid Less than $2.00/lb to $12.00 Ib
Polyesters Less than $2.00/lb to $12.00 Ib
Acrylics Less than $3.00/lb to $12.00 Ib
Vinyls $1.50/lb to $6.00 Ib
Nylon $4.00/lb to $14.00/lb
Thermoplastic polyester $4.00/lb to $14.00/lb
O'Brien Corp.; It is very difficult to Identify prices only by
chemistry due to the differences in pigments and additives required
for each formulation. For the purpose of this survey, they assumed
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white, high gloss coatings with a specific gravity of 1.6 to
1.54 produced 1n quantities of 21,000 pounds at a time. (Prices
listed were considered confidential.)
Spray1 at: Supply prices depend on quantity ordered, type of resin
system, gloss level and finish required.
FERRO Corp.; Information on pricing by chemical class is
proprietary, but the Industry average is $2.49/15.
Lilly; The average selling price for powder coatings varies
according to specific gravity and color. A pastel color in a hybrid
chemistry would sell for approxlmatly $2.30 [per pound] based on a
4,000 pound production.
10. What Is the minimum order (quantity) of each type of powder coating
that can be purchased by your customers (excluding samples or trial
orders)?
EVTECH; 5,000 pound minimum order for shipment over a 6 month period
for nonstock products; 55 pounds for stock or standard products.
Glidden; Their general position 1s that they do not pursue single
orders of powder less than 1,000 Ib in size. Most of their products
are custom manufactured for a specific customer. While their company
does not engage in a stock color program, many other U.S. powder
coating suppliers do with quantities as low as 50 Ib being
commercially available.
Morton TMokol; Stock materials are available in 55 Ib quantities.
Nonstock thermoset powders are available in 1,500 Ib quantities.
They have "small lots" capability. This means that any coating type
can be manufactured in 100 to 1,500 Ib quantities.
O'Brien Corp.; For products produced to a specific customer
requirement, 1,500 pound minimum. For existing products in stock,
50 pounds.
Spray!at; Minimum orders are for 200 pounds of individual products.
FERRO Corp.; Minimum order quantity 1s dependent on overall customer
volume but, a typical minimum is 2,000 Ib per color and/or chemistry.
Lilly; Minimum orders are 50 pounds for stock products and
2,000 pounds for a custom color match and manufacturing.
11. Please provide as much information as you can on the end users of
your powder coatings (I.e., 11st of major customers; major market
areas - automotive, large appliance, metal furniture, etc.; new
market areas).
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EVTECH; Automotive, appliances, metal furniture, lawn and garden
equipment.
GUdden: We market our material Into several markets which we have
segmented as:
Major home appliance: Washing machine tops and Hds, spinner
baskets, cabinets. Dryer drums and
cabinets. Refrigerator shelves, liners, and
cabinets. Air conditioner cabinets. Hot
water heaters, etc.
Automotive: Primer surfacer, anti-chip, trim parts (door
handles, etc.), under-the-hood parts
(cannlsters, oil filters, air cleaners, etc.),
wheels—aluminum and steel.
Architectural: Aluminum extrusions, building panels.
General Industrial: Electrical, lighting fixtures, office
furniture, lawn and garden, and fixtures.
Morton Thlokol; They, supply all powder coating markets Including:
Furniture—all coating types
Automotive—all coating types
Appliance—epoxy, hybrid, polyester, acrylic
Lawn and garden—all coating types
Lighting—all coating types
Electronic—all coating types
Pipe and rebar—epoxles
New market areas Include in mold coating of SMC, coil coating, and
blank coating.
On request, they can supply Individual customer contacts 1n any
market area.
O'Brien Corp.: O'Brien 1s strongest 1n the general Industrial
finishing market, Including both custom coaters (job shops) and
original equipment manufacturers. We do not actively pursue the
major appliance market. We do have a presence in the automotive
market (OEM and after-market), as well as the metal furniture and
office equipment market.
Spray!at: Decorative and functional coatings for a wide range of
manufacturers and custom coaters.
FERRO Corp.: Major market areas: automotive, appliance, and
lighting. New potentials: functional, architectural, and plastics.
Lilly; Primary market thrust 1s 1n the general metals finishing
market. Major customers include manufacturers of small appliances,
fabricated wire goods, electrical meters, and audio-visual aids.
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12. Discuss current or recent trends 1n the use of powder coatings.
Compare sales of powder coatings 1n 1988 vs. 3 years ago and 5 years
ago (for your company and nationwide, 1f known), also compare by
major market areas.
EVTECH: Powder coatings have grown 1n excess of 20 percent per year
1n volume for the last 4 years 1n the United States.
GUdden; Since 1983 powder has been growing at a 20 to 25 percent
annual compounded growth rate. Our growth has paralleled the
Industry 1n this time period.
Morton Thlokol: Total powder coating sales in the USA should exceed
120 million pounds for 1989. This 1s nearly double the figure for
5 years ago. The Powder Coating Institute can provide somewhat
accurate yearly totals.
The automotive and appliance markets currently use a total of
approximately 30 million pounds of powder annually. The annual, metal
furniture market usage approaches 20 million pounds. Growth 1n these
. markets, as well as those listed 1n No. 11, comes from converting
liquid coaters to powder. This growth Is expected to be 15 to
20 percent a year through 1995.
As the powder market grows, a significant overall trend 1s Increased
user sophistication; I.e., 95 percent or greater material utilization
efficiencies, SPC, Incoming QC, consistent thin films, long-term
testing prior to use of powder.
O'Brien Corp.: Business has Increased over the last few years.
Spray!at: Operation not started until July 1987. Therefore, no
previous history.
FERRO Corp.; Growth has averaged 15 percent per year for the last
5 years. Major market areas have seen a growth rate of 15 to .
18 percent per year over the last 5 years.
Lilly; Lilly has been manufacturing powder coatings for the last
2% years. During the past 5 years, a growth rate of approximately
20 percent has been realized in the powder coating industry. A
significant number of conversions from liquid to powder have occurred
1n the last year because of Federal and State environmental
regulations pertaining to the disposal of hazardous wastes. Most
manufacturers converting to powder have a payback period or return on
investment of approximately 2 years.
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13. Discuss recent developments in powder coating technology that may
result 1n expanded or new market areas.
EVTECH;
1. High transfer efficiency powder application equipment
2. Capability to apply thinner, more uniform films
3. More economical powder reclaim systems facilitating more rapid
color change
Glidden: Several new developments are taking place. One is the use
of powder as a "blanks" coating.
New materials replacing porcelain in the appliance and bathroom
Industries continue to be developed.
We are in the early stages of Introduction of a thermosetting
fluorocarbon powder. This product 1s aimed at the architectural .
Industry which currently uses liquid fluorocarbons because of their
excellent durability and UV resistance. We anticipate these products
to be equal to or superior to these liquids and see significant
market acceptance.
Morton Thiokol:
• Powder coatings are now available for cure as low as 250°F.
• Powder and application equipment 1s available for coating coil or
blank stock.
• Powder coatings now exist for coating a variety of plastics, both
in mold and out of mold.
• Metallic look powder coatings which approach chrome appearance are
recently available. Also metallic powder coatings can now match
most liquid appearances.
Generally any organic liquid coating performance can now be equalled
by organic powder coatings.
O'Brien Corp.; Developments in powder coating technology have tended
to be more evolutionary than revolutionary in recent years. Advances
have been made in the areas of more consistent products with less
batch-to-batch variation, tighter controls on raw material streams,
better weathering systems for exterior exposure, materials with
better application properties, and materials which may be applied at
lower film thicknesses. Progress has also been made in offering a
wider range of metallic-effect coatings, and lower bake temperatures
for heat-sensitive substrates such as plastics. The ultimate effect
of all this is to move the use of powder coatings from an art to a
science, thus establishing powder coating as a viable finishing
technology which is applicable to a broad segment of the industrial
finishing industry. This has been a significant factor contributing
to the rapid growth of the powder coatings market in recent years,
and should continue in the near term.
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Spray1at; No major changes 1n recent years.
FERRO Corp.; The development of power coatings for plastics may be
the next new market area.
Lilly: New markets are opening dally because of Improvements in the
application equipment and powder coatings. Lilly 1s now able to
develop powder coatings that can be applied at an average dry film
thickness of 1.2 mils and achieve complete opacity. The Industry is
working on the Improvement of metallic formulations, low cure powders
and different generic types that should open new markets 1n the next
few years.
14. Do you also sell liquid coatings? If so, can you provide the names
of customers that are using liquid coatings to coat Identical
products to those being powder coated by other customers?
EVTECH; No.
GUdden: Yes, we are a major supplier of liquid coatings. Many of
our customers use powder and liquid for similar applications. One
example would be in the major home appliance segment when some
manufactures use powder for the coating of cabinet enclosures and
others use liquid.
Morton Thlokol; Morton's Powder Coatings Group also markets liquid
primers and touch-up paints for powder coatings. A sister company,
Bee Chemical, markets liquid coatings. We service similar markets,
often together.
O'Brien Corp.; O'Brien sells coatings for trade sales (house paints,
etc.) and automotive reflnish coatings, but no liquid coatings which
could compete directly with powder coatings.
Spray!at: Yes, in applications where powder cannot be used I.e.,
plastics and rubbers.
FERRO Corp.: No, Ferro Corp. does not sell liquid paint.
Lilly; The parent company, Lilly Industrial Coatings, manufacturers
liquid coatings.
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APPENDIX C.
SURVEY SUMMARY: POWDER COATING USERS
-------
APPENDIX C. SURVEY SUMMARY: POWDER COATING USERS
Four of the nine powder coating users surveyed responded to the
survey. A brief summary of their responses is provided below. A 11st of
the powder coating users who responded and a compilation of their
Individual responses are also attached.
Powder coating experience
The number of years each respondent had used powder coatings ranged
from 9 to 17 years, with an average experience of about 12 years.
Types of items powder coated
Two of the four companies only coat products that they manufacture
themselves. A third company only coats Items manufactured by other
companies, and the fourth company does both. The types of items coated by
the four respondents included laboratory casework, medical examination
tables, pumps, valves, plumbing fixtures, chemical processing equipment,
computer equipment, food processing equipment, window frames, playground
equipment, electrical equipment, and aerospace parts.
Similar or identical liquid-coated products
Two of the respondents also use liquid coatings to coat products that
are identical or similar to products that they powder coat. They both
preferred powder coatings for the following reasons: (1) thickness
control 1s better, (2) finish control 1s better, (3) coverage is better
and there are fewer parts rejected for areas not covered, (4) cleanup 1s
very simple and easy with powder; there are no chemicals required to
cleanup with powder, (5) powder-coated parts are more durable and can
withstand strong cleaning agents and, (6) powders are easier to handle and
apply. One of the respondents commented that, although it was more costly
for him to use powder coatings, the powder coating was necessary to
fulfill product requirements. The other respondent stated that his
company would prefer to powder coat all of their items, but it was not
cost effective for them to change all of their engineering prints and
documentation at this time. '
Color avail ability, changeover time, and powder "ecTarnation
The number of different colors of powder coatings applied at each
facility ranged from 3 to 40. The company that only used three colors
required about 20 minutes to change colors and usually changed colors
about once a day. The same company was also able to recover 95 percent of
their powder overspray (the overspray 1s collected in a filter and run
through a sifter prior to reuse to insure its cleanliness and uniformity).
The remaining three respondents apply 20 to 40 different colors. One
of these companies is able to change colors in about 25 seconds and these
changeovers are made several times an hour; however, they do not reclaim
any of their powder overspray. A second company changes colors 7 to
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10 times a day in about 15 minutes. This company also does not reclaim
any powder over spray. The third company changes colors one to four times
a day depending upon the volume of each color, and takes 15 to 20 minutes
to change. They also have the capacity to reclaim about 35 percent of the
overspray, depending upon the volume of parts being run, the particular
color, the cost of the materials, and the configuration of the part being
coated.
Powder types and application equipment
The power coating users apply a variety of different powders
Including epoxy, PVC, nylon, polyester, Teflon, Ryton and Kynar. All of
the respondents use electrostatic spray guns to apply their powders. One
company also uses a fluldized bed; however, only nylon powders are used 1n
the fluldized bed. The number of "lines" at each plant ranges from one to
three lines with 1 to 4 booths per line. Both manual and automatic spray
guns are used.
Coating Thickness
The thickness of the powder coatings applied at the responding
facilities ranges from about 1.5 mils to 125 mils. However, three of the
four respondents reported thicknesses of 4 mils of less.
Curing requirements
Required cure temperatures and times of about 350°F to 375°F and 15
to 20 minutes, respectively, were typical. One company had a maximum cure
temperature and time of 750°F and 8 hours.
Converting from liquid to power coatings
Only one of the four respondents converted from conventional liquid
coatings to powder coatings. This company switched from liquid to powder
due to requirements that the coatings be resistant to strong chemicals.
One result of their switch is that they are able to offer their customers
fewer colors and the film thicknesses have Increased; however, because the
greater film thickness covers Irregularities 1n the substrate, they tend
to have fewer rejects.
"New" powder coating facilities
Three of the four respondents were "new" powder coating facilities
(I.e., they did not convert from liquid to powder coatings). These
companies selected powder coatings rather than liquid coatings for the
following reasons: (1) greater durability of powder coatings when
subjected to strong cleaning agents, (2) powder coatings offered a
nonpolluting process, (3) powder coatings performance versus paint was
Impressive, (4) powder is less labor-intensive, and (5) powder coating can
be done using less expensive employees. All of the respondents reported
that their powder coating system either met or exceeded their
expectations.
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Capital and operating costs
The capital cost of each plant's powder coating system ranged from
$150,000 to $200,000. One company estimated the cost of powder coating to
be -0.058 per square foot of coated product.
Limitations associated with powder coatings
Two of the respondents cited the following limitations that prevent
them from applying powder on other products: (1) special colors would
require development by the suppliers, and therefore,-those items requiring
special colors are not done as powder coating, (2) special effects such as
spatter texture may pose problems; however, texture powders are available
if satisfactory to customers, (3) orange peel appearance on some powder-
coated Items, and (4) excessive buildup in corners of enclosures. Another
respondent stated that his company would prefer to powder coat all of
their Items, but that it 1s not cost effective for them to switch over at
this time.
2 Attachments
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Attachment 1
LIST OF RESPONDENTS: POWDER COATING USERS
Mr. Keith M. Long
Manager, Process Operations
American Sterilizer International
2720 Gunter Park East
Montgomery, Alabama 361104
(205) 277-6660
Mr. David T1ce
Superintendent, Maintenance
Hamilton Industries, Inc.
1316 18th Street
Two Rivers, Wisconsin 54241
(414) 793-1121
Mr. Jeffrey S. Yahn
General Manager
Erie Advanced Manufacturing
3150 West 22nd Street
Erie, Pennsylvania 16506
(814) 833-1711
Mr. Dale A. Gumm
Owner
Tuscon Spraying Technology
628 E. 20th Street, Building 0
Tucson, Arizona 85719
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Attachment 2
SURVEY RESPONSES: POWDER COATING USERS
1. Company name and address; contact name, title, and telephone number.
(See attachment)
2. How long has your company used powder coatings?
AMSCO: 12 years
Hamilton Industries; -12 years, Increased use 2 years ago
Erie Advanced Manufacturing; 17 years
Tucson Spraying Technology; 9 years
3. List the Items that your company manufactures that are coated with
powder coatings.
AMSCO; Surgical light parts, surgical table parts and sterilizer
control panels.
Hamilton Industries; Laboratory casework, medical examination
tables, Institutional
Erie; They only coat Items manufactured by other companies; they are
a "custom powder coater."
Tucson Spraying Technology; Electrical components.
4. Oo you apply powder coatings to products manufactured by other
companies? If so, please 11st the Item you coat.
AMSCO; No
Hamilton Industries: No
Erie; Yes. Pumps, valves,-plumbing fixtures, chemical processing
equipment, computer equipment, hospital equipment, food processing
r equipment, window frames, playground equipment, and electrical
components.
Tucson Spraying Technology: Electrical components, aerospace.
5. Are there identical (or similar) products coated by your company with
liquid coatings? If so, please provide a comparison of advantages
and disadvantages of the two coating types (Include factors such as
cost, performance, ease of application, etc.).
AMSCO; Yes, some similar parts are liquid coated. Powder 1s
preferred for the following reasons: (1) thickness control is better
with powder, (2) finish control is better, (3) coverage 1s better and
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there are fewer parts rejected for areas not covered, (4) cleanup is
very simple and easy with powder; there are no chemicals required for
cleanup with powder, (5) powder-coated parts are more durable and can
withstand strong cleaning agents, and (6) powders are easier to
handle and apply.
Hamilton Industries: Yes, identical products in their laboratory
casework line are finished with liquid coatings; advantages of powder
coating are: (1) cost of powder coating is greater than cost of
liquid coating, but the p.c. performance 1s better and fulfills
product requirements, (2) powder coatings are easier to apply.
Erie; No
Tucson Spraying Technology: Powder coating is more cost effective
than liquid coating; less EPA problems, less rejects with powder
coatings.
6. How many different colors of powder coatings are applied?
AMSCO; Three different colors applied
Hamilton Industries: 22 different colors applied
Erie; 20 different colors applied
Tucson Spraying Technology; Approximately 40
7. If several colors are applied, how much time is required for a color
changeover? How often are changeovers made?
AMSCO; 20 minutes to change colors, -I color change per day
Hamilton Industries; Colors are changed in -25 seconds; change overs
are made several times an hour
Erie; 15 to 20 minutes between changes; changes are made one to four
times a day depending upon the volume of each color
Tucson Spraying Technology; We can color change 1n 15 minutes. We
may change colors 7 to 10 times dally.
8. How many "lines" are used to apply powder coatings? How many booths
and spray guns per line?
AMSCO; One line with three spray booths (one spray gun per booth)
Hamilton Industries: Three lines; one Hne has four booths and five
operators, another line has one long continuous booth and five
operators, the third line has two booths and two operators
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Erie: Three conveyor lines; one has four auto guns and one manual
gun (two booths); another has one manual gun or a fluid bed (one
booth), and the third has one manual gun (one booth). They also have
four batch coating areas that each uses one manual gun.
Tucson Spraying Technology; Two job shop booths.
9. What type of application equipment do you use to apply powder
coatings? What types of powders do you apply?
AMSCO: Powder 1s applied using Nordson Paint equipment; they use
three powder coating suppliers: (1) O'Brien Corp., (2) International
Paint, and (3) Morton Thlokol, Inc.
Hamilton Industries; Electrostatic spray for all but a small
percentage which 1s applied via fluldlzed bed; coating types are
epoxy (electrostatic) and nylon (fluldlzed bed).
Erie; Nordson and Volstatlc electrostatic guns; all types of powders
Including; PVC, nylon, epoxy, polyester, Teflons, Ryton, Kynars,
etc.
Tucson Spraying Technology; Nordson Equipment, many powder
suppliers—primarily Morton.
10. What coating film thickness Is routinely achieved on your powder
coated products?
AMSCO; -4 mils
Hamilton Industries; Average -1.5 mil or greater
Erie; 1 to 125 mils routinely applied
Tucson Spraying Technology; 1.5 mils
11. What are the curing requirements for your powder coated products
(temperature and time)?
AMSCO; All coatings baked at 375°F for 15 minutes
Hamilton Industries; Cure requirements, are 350°F for 18 minutes
Erie; Minimum temperature of 350°F for 40 minutes and maximum
temperature of 750°F for 8 hours
Tucson Spraying Technology; Average 20 to 30 minutes per load
12. If your powder coating line replaced a conventional liquid coating
line, please provide the following information:
AMSCO: Old not replace conventional liquid coating line
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Erie: Did not replace conventional liquid coating line
A. *Why did you convert to powder coatings?
Hamilton Industries; Switched due to requirements for resistance
to strong chemicals in their laboratory casework line
Tucson Spraying Technology: We started with powder and added
liquid
B. Which components of the existing liquid line could be adapted to
powders?
Hamilton; Conveyors and booths easily adapted
Tucson Spraying Technology: None
C. What additional equipment had to be added to apply powders?
Hamilton; Electrostatic application equipment and hoppers
Tucson Spraying Technology: All
0. Old product specifications have to be changed (colors, film
thickness, etc.)?
Hamilton; Color offerings reduced; film thicknesses increased
Tucson Spraying Technology: Some manufacturers had to initiate a
powder specification as none existed with their company
E. If you operate a coating job shop, did you lose (or gain)
customers as a result of changing to powders?
Hamilton; N/A
Tucson Spraying Technology; Gain
F. Has productivity been affected? How and why?
Hamilton; Fewer rejects because greater film thickness covers
irregularities in the substrate
Tucson Spraying Technology; Yes. Powder is less labor-intensive
G. Was extensive operator training required? How did training time
compare with training an employee to use liquid coatings?
Hamilton; Training time was about the same for application of
powder vs. liquid
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Tucson Spraying Technology; Powder coating can be done by less
expensive employees than liquid
H. What unexpected problems have you encountered? How were they
resolved?
Hamilton: Tendency 1s to apply excessive film; this was overcome
by zone spraying in conjunction with the use of smaller nozzles
by certain operators
Tucson Spraying Technology; Pretreatment equipment is an
absolute
I. What reactions have you received from customers?
Hamilton; Customers prefer powder coat; specially formulated
coatings are highly chemical resistant on their products
Tucson Spraying Technology; They like the durability. They can
get more product to market with less assembly damage
J. Are you pleased with your decision to convert to powder coatings?
Hamilton; Yes
Tucson Spraying Technology; We did not convert to powder, we
started with powder coatings—answer yes.
13. If your powder coating line is a new facility (not a converted line),
please provide the following Information:
Hamilton; N/A
Tucson Spraying Technology: Although their powder coating line was a
new facility, they responded to question 12 rather than 13
A. Why did you select powder coatings rather than liquid coatings?
AMSCO; Greater durability of powder over liquid coatings; their
products are subjected to some strong cleaning agents in the
sterile environment and powder-coated surfaces are much more
durable
Erie; Selected powder coating because it offered a nonpolluting
process that was competitive with paint; also, powder coatings
performance vs. paint was impressive
B. Did you obtain cost quotes for powder and liquid systems? (If
so, please provide copies or summarize differences.)
AMSCO: No response
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Erie: No
C. Has the powder system met your expectations? If not, please
describe problems.
AMSCO; Yes
Erie; Exceeded their expectations
0. Are you pleased with the decision to use powder coatings?
AMSCO; Yes, powder met expectations and is much easier to handle
and apply
Erie; Yes
14. Have you encountered problems with the storage, handling,
distribution, or application of powders? If so, what were they and
how did you resolve these problems?
AMSCO; No problems. They, only order -2 weeks quantity of powder at
a time
Hamilton Industries; Powders of limited use, which may be stored
during hot weather, and may be stored for periods longer than
6 months, may produce rough surfaces. Powders should be stored in a
cool area; old powder may have to be discarded
Erie; No problems
Tucson Spraying Technology; No
15. Please provide information on the capital and operating costs of your
powder coating system, broken out by components if possible.
AMSCO; Total capital cost -$200,000; this includes booths,
application equipment and two ovens. Estimated cost of the powder
coating -$0.058 per square foot
Hamilton Industries; Information not readily available
Erie; Paid $150,000 for "used" coating Hne
Tucson Spraying Technology; We have a capital equipment investment
of approximately $150,000.
16. Please describe limitations associated with powder coatings that
prevent you from using them on other products. (Include items such
as cost, performance, and application limitations.)
AMSCO; Would prefer to powder coat all items, but 1t is not cost-
effective to change all of their engineering prints and documentation
at this time
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Hamilton Industries; (1) special colors would require development by
the suppliers, and therefore, those items requiring special colors
are not done as powder coating, (2) performance has improved,
(3) special effects such as spatter texture may pose problems;
however, texture powders are available, if satisfactory to customers
Erie: No limitations. They powder coat parts from 1 Inch in
diameter to 4 feet long and 12 inches in diameter
Tucson Spraying Technology: (1) orange peel, (2) excessive build up
1n corners of enclosures, (3) color selection and availability
17. What percentage of your "overspray" 1s collected for recycle or
reuse? How 1s this done?
AMSCO: 95 percent of all powder overspray is collected in a filter
for reuse; the powder is run through a sifter prior to reuse to
insure its cleanliness and uniformity
Hamilton Industries; None
Erie; Depends upon: volume of parts being run-, the particular
color, cost of the materials, and the configuration of the part being
coated; they have the capacity to reclaim -35 percent of the
overspray
Tucson Spraying Technology; None
18. Are there solid waste disposal problems associated with your powder
coating system?
AMSCO; None. Because 95 percent of powder 1s reclaimed, there is
very little waste to deal with
Hamilton Industries: No
Erie; None; when they have powders to dispose, they put the powder
In boxes and "cure" the powder into a hardened block to prevent
problems with "dust"
Tucson Spraying Technology; None
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TECHNICAL REPORT DATA
Please read instruct tons on me reverse oetore camoiennei
1. REPORT NO.
12.
3. RECIPIENT'S ACCSSSION NO.
4. TITLE AND SUBTITLE
Powder Coating Technology Update
5. REPORT DATE
: September 1989
,S. PERFORMING ORGANIZATION CODE
I
7. AUTHOR(S)
Hester, C. I., Nicholson, R. L., Cassidy, M. A.
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
Midwest Research Institute
401 Harrison Oaks Boulevard, Suite 350
Gary, North Carolina 27513
10. PROGRAM ELEMENT NO.
ill. CONTRACT/GRANT NO.
68-02-4379
12. SPONSORING AGENCY NAME ANO ADDRESS
U. S. Environmental Protection Agency
Control Technology Center
Research Triangle Park, N.C. 27711
13. TYPE OF REPORT ANO PERIOD COVERED
Fi'nV?
14. SPONSORING AGENCY CODE
IS. SUPPLEMENTARY NOTES
Work Assignment Manager: Karen Catlett, Office of Air Quality Planning and Standards
16. ABSTRACT
The objective of this report Is to provide an overview of the current status of
powder coating technology. Because powder coatings are applied as dry, finely
divided particles, there are no volatile organic compounds (VOC's) released during
application, and only minute quantities are released during the curing process.
Therefore, the Increased use of powder coatings, as an alternative to liquid
solvent-based coatings, represents a significant reduction in emissions of VOC's.
This report describes current powder coating materials and equipment, end uses, and
economic advantages of the use of powder coatings. Included 1n the report are
discussions of the disadvantages and potential problems Identified early in the
powder coating development process. The report addresses the resolutions of many of
'these problems.
This report is Intended to be of use to State and local agencies 1n their
evaluation of powder coatings as an alternative to coatings containing VOC's.
7.
KEY WORDS ANO DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS c. C3SATI I leld.'CrOUp
Powder coating technology
Powder coating end uses
VOC emissions reduction
Surface coating
Coating systems
Industrial finishes
VOC's
• 18. DISTRIBUTION STATEMENT
i Release unlimited
i
19. SECURITY CLASS /TliiSKeporti
:1. NO. OF PAGES
20. SECURITY CLASS /This page I
12. PRICE
SPA form JI20-1 (R»». 4-77) =H«viouS COITION is OBSOUCTC
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