TRAlNlNG
DIVISION
i
Electrostatic Spraying
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A. GENERAL DESCRIPTION:
The principle advantage of Electrostatic Spraying is
the savings in material and labor. This is accomplished by placing a high voltage electric charge on each
atomized partical of paint. The object which is to be
coated is an electrically conductive ground. Some of
the paint particles which would normally miss the
work will now be attracted to the edges and back side
of the work. This effect is commonly referred to as
the “wrap around” effect.
Bell and Disc System
One method is to use the electrostatic force created
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by a high voltage differential between a paint dispenser and the grounded work. This force tears the material apart creating atomization and deposits the material on the object to be coated. No air o r hydraulic
force is used. This method is sometimes referred to as
“true electrostatic painting”. The material is fed to a
rotating disc o r bell. A set speed will cause the material to flow by centrifugal force to the edge, but not
disperse. The disc or bell is charged to 120,000 volts
D.C. Negative (excess of electrons). As the object to
be coated passes by the rotating disc o r bell, the material is pulled off by a current exchange between the
emitter and the product and is attracted to the work.
This type of electrostatic finishing is used by most
major appliance manufacturers because of the high
production and uniformity of coatings on the parts
to be coated.
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is spread over the inner surface of the cup and is
atomized on its edge. The greater the speed of rotation, the finer and more homogeneous is the resulting
spray. The atomization of material, however, does
not result in effective deposition on t h e ware without
the electrostatic held.
Air ports concentric with the cup serve both to control the atomized particles in the electrical field and
to aid in establishing the diameter of the cone of
atomized paint particles. To prevent the migration of
the paint into the air turbine a separate low pressure
air supply is introduced in the bearing area.
Air, Airless and Air-Assisted Airless Electrostatics
The second method is to use air or hydraulics as the
atomizing force. The high voltage charge is then induced into the spray pattern and in turn adds an
electrostatic charge to the atomized material particles.
The attraction between the atomized particles and
work is strong enough to bend the overspray around
the product depositing most of the material on the
back side of the work.
The principles of equipment operation and malerial
supply are the same as for standard airless or con\entional equipment. However, the appearance of the
equipment is somewhat different as it is constriicted
of materials designed to carry the necessary high
voltage.
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B. PRINCIPLES OF ELECTROSTATICS
The basic principle of electrostatics is that like
electrical charges repel one another and unlike electrical charges attract. We use the unlike charges. The
phenomoqon which permits this svstem t o operate is
as follows:
1. When small particles are introduced into a high
voltage corona discharge, the particles will
accept the electrostatic charge.
2. When these charged particles are permitted to
move about, they will travel to the nearest
grounded surface.
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Rotational Atomizers
Recent developments have allowed rotating atomizers
to operate at speeds up to 70,000 RPM.
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The coating to be sprayed is supplied to the center of
the cup and under the influence of centrifugal force it
This phenomonon can be compared to a bolt of
lighting when it veers from its course to strike a
lighting arrestor or some other high point on the landscape. The description of this process has been made
in general terms to illustrate that electrostatic painting is simply a unique application of the motion of
charged particles in an electric field. The condition
which must exist in order for a process of this type to
be efficient is as follows:
A condition to be considered is an uneven coating
one may receive on objects that have complicated
surfaces containing deep cavities, abrupt changes or
sharp protrusions. The reason for the uneven coating
is in the basic process itself. The charged particles,
when brought into the proximity of the grounded
part will travel by the most direct route to all high
points, corners and sharp edges.
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1. The particles must be small and light, i.e.; the
smaller the mass, the higher the efficiency.
2. The particles should be spherical in shape and
remain as wet as possible.
3. 30 to 120 Kilovolts is necessary to establish a
corona discharge in air that will impart a maximum charge to the particles involved.
4. An electric field must be s e t up so that the
force of the resultant voltage gradient (change
in voltage) will b e in the proper position to
direct the charged particles to the work.
5. Extraneous forces, such as air movement
opposing the field force, should be removed or
minimized as much as possible.
6. Particles must be produced and moved to the
region of the corona discharge by a process
which will not overcome the force of the electrostatic process.
7. The particles must be produced and charged in
sufficient quantity to meet production requirements.
8. Since this process is electrical, it follows the
laws of electricity and, therefore, the product
to be coated must be conductive.
NOTE
If a metallic or otherwise electrically conductive
object is in the vicinity which is NOT properly electrically grounded, an entirely different process can
occur. Initially, because it is in an electrically neutral
condition, it will attract the charged particles or
droplets of coating material. However, as more and
more coating material arrives and shares its charge
with the object, the electrical charge will build up in
the object because there is no pathway to ground,
turning the object into a static electricity "battery".
Eventually, and in many cases this can mean just a
few seconds, enough electrical charge can accumulate in t h e object t h a t a s p a r k can b e generated
between it and the nearest grounded surface. Or,
similarly, an ungrounded metallic object can simply
retain its electrical charge for an indefinite time until
a grounded surface is brought near enough for a
s p a r k t o occur. This grounded surface can be a
swinging conveyor hook or an operator reaching out
to touch the charged object. Likewise, a spark can
occur between the electrostatic device itself and a
grounded object if the electrodes or other high voltage portions of the device are brought too close to
ground.
It is these sparks being generated in a wet paint and
solvent vapors environment or within an explosive
concentration of powder dust that represent the
greatest, although by no means only, fire and explosion hazard i n electrostatic spray finishing
operations. It is for this reason that it is absolutely
necessary to establish and maintain proper electrical
grounding to all metallic objects in an electrostatic
spray area.
PROPER ELECTRICAL GROUNDING IS DEFINED
AS A N ELECTRICAL PATHWAY TO NEUTRAL
EARTH WITH A RESISTANCE OF LESS THAN 1.0
MEGA-OHM.
2
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ELECTROSTATIC SPRAY GUN
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H.V.ELECTRODE
ELECTRICAL LINES
OF FORCE
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C. TYPES OF ELECTROSTATIC SYSTEMS:
Following is a list of the various types of systems
available:
1. Standard automatic spray guns and external grids or electrodes.
2. Stationary mounted bells.
3. Reciprocating discs.
4. Electrostatic rotating atomizers.
5. Hand held, operated bell.
6. Hand operated air atomizing electrostatic
spray guns.
7. Hand operated airless electrostatic spray
guns.
8. Hand operated air-assisted airless electrostatic spray guns.
9. Automatic air atomizing electrostatic guns.
10. Automatic airless electrostatic guns.
11. Automatic air-assisted airless electrostatic
spray guns.
To illustrate the types listed, each system, which uses
the same basic principle, will be described separately.
1. Standard Automatic Spray Guns and External
Grids or Electrodes.
SPRAY PATTERN
i
A
HIGH VOLTAGE GRID\
120 KV.
SIDE VIEW
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-FRONT
ELECTROSTATIC GRID SYSTEM
VIEW
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This system employs the standard automatic spray
guns such as the Binks 21 spray gun and all related
control equipment such as air and fluid regulators.
The spray guns are mounted in a stationary position.
The quantity of spray guns depends on the vertical
dimensions of the piece to be coated. Under certain
conditions it is possible to coat a 3 6 vertical dimension
with one spray gun. The guns, although standard, do
use special air atomizing nozzles designed to operate at
low air pressures (10 to 25 p.s.i.).
Low pressure is used to avoid the possibility of overcoming the electrostatic force. When a particle traveling at the proper velocity should miss the object being
coated, it will t u r n around 180 degrees and
return to the back side of the work. Hence the term
“wrap-around”.
The isolation of the high voltage electrodes or grids
from the spray gun permits this system to handle
conductive (low resistance paints) as well as non conductive paints (high resistance paints).
This system is of early vintage and may still be found
operating in the coating industry. However, new systems are now being installed because of advancements
in electrostatic equipment.
2. The Disc or Bell Variety.
These are available in automated or hand held systems.
This type is sometimes called the “true electrostatic
system”. This term implies, and rightly so, that the atomization is created by the high voltage itself. The rotation of the unit evenly disperses the paint to the edge of
the disc or bell. When the unit is charged with high
negative D.C. voltage a current flow develops between
it and a grounded (positive polarity) object to be coated. This current flow pulls the particles of paint from
the edge of the dispenser and carries them along to the
product.
PAINT
SUPPLY
HIGH VOLTAGE
r
. WORK
DISC MOVEMENT
The paint particles will travel directly to the area of the
work that is closest to the emitter. This fact is important to remember because the more directly the particles travel in the system the less chance there is of
painting the more complicated areas and shapes. A
true electrostatic system is very efficient in paint usage,
but requires more hand touch-up on complicated
shapes. This is true because the only force transporting
the paint particles from the emitter is the current exchange. If one watches, the particles appear to drift
lazily to the work. Because of this low velocity drift,
there is very little force t o drive the particles into
recesses, right angle bends etc., which are electrically
shielded. The current flows to the highest points such
as edges and protrusions. One might say, “where the
current goes, so goes the paint”. Paint applications using the hand held spinning bell method are too limited
for high production application of maintenance paints
and protective coatings. The bell with the largest
capacity, 6” has an approximate delivery of 6 ounces
per minute. This rate however, is suitable for painting
chain link fences and some ornamental grill work from
both sides.
There are times when this highly efficient system is not
the proper system to use as the cost of touch-up may
out weigh material savings. If this is the case, other
methods of electrostatic applications such as air atomized or airless should be considered. While neither of
these are as efficient in paint savings, they can, through
spray gun positioning or pressure changes, cause the
sprayed fluid to reach into facing areas that are electrically dead. By reaching these shielded areas, much
touch-up work may be saved and in doing so, a less
efficient system may be desired. The spray guns,
however, exhibit all the inherent advantages and disadvantages of conventional air or airless methods.
These systems minimize touch-up by imparting more
forward velocity on the paint particles by employing
more air or hydraulic pressure in the atomization of
the material. However, the lower the velocity of the
particles, the more efficient the coverage.
3. The Electrode Built Into The Spray Gun:
The third type is where the electrode is placed inside
the spray gun itself. This system is designed to use air,
airless, or air-assisted airless atomization principles.
The spray gun can be hand held or automatically operated depending on the requirements.
HIGH VOLTAGE
75KV NEGATIVE DC
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- - _ _-_ _ _ _ _ _ _- ELECTROSTATIC SPRAY GUN
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The hand held system using 75,000 volts of electricity is
safe provided that the recommended operating procedures are followed. Even holding the spray gun in one’s
hand while touching the electrode with the free hand
will not produce a shock. The main safety requirement
is that the equipment system be properly grounded.
The equipment is designed in such a way as to automatically reduce the voltage to “zero” as the spray gun
electrode approaches any grounded object. This effect
may be illustrated in simple terms as outlined below.
The illustration shows a simple circuit and the path the
electrons take in completing the circuit.
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INTERNAL RESISTANCE-16 MEG. OHM
OUTPUT RESISTANCE-100 MEG. OHM
RESISTANCE IN GUN-160 MEG. OHM
PAINT RESISTANCE 1
AIR GAP RESISTANCE BETWEEN
NEEDLETIP 8 GROUNDED TARGET
C=CAPACITANCE OF CABLE a POWER SUPPLY
The high voltage at the needle tip will vary depending
on the amount of current being drawn through the circuit. The illustration below shows in simplified terms
what takes place as more current flows through the circuit. The more current that flows through the circuit,
the greater the voltage drop at the needle tip. This is a
safety feature which prevents the possibility of a discharge of electricity as the spray gun approaches a
grounded object. In order for a “wrap-around effect to
be present, it takes an elevated voltage of 30KV or more
for this to happen.
Tip Voltage, KV
BO
70
60
50
40
30
20
10
20
60 SUlTABLE
100
OPERATlNG
RANGE‘
140
180
220
‘SEE MICROAMMETER OF POWER SUPPLY 1DR
METER ON FLUID CONDUCTIVITY TESTER
Material used in this type system should be formulated
so that the paint resistance be within the suitable operating range as shown. If the amount of current drawn is
greater than 105 milliamps, then the paint is too conductive and will show little or no wrap effect.
When the equipment is operating properly and the
paint conductivity is low, a “wrap-around” effect is
present. If a weak or no “wrap-around‘’ is present, the
paint conductivity may be too high or the equipment
may have a malfunction. When using automatic spray
guns with this system, all material can be sprayed.
Materials that are conductive will electrify the material
supply and therefore it will be necessary to isolate the
fluid supply from the electrical ground. When these
“hot” systems are used, precautions must be taken to
avoid physical contact with the material supply.
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D. POWER SUPPLY:
High voltage charges of this type are difficult to collect
and store for use. We can however, transform a normal
alternating current of 110 volts into a very high voltage,
rectify it to direct current and closely control the
amperage. It should be remembered that only a small
amount of current is required to make an electrostatic
system feasible. While the current is relatively small,
the voltage is extremely high.
The voltage will vary in each type of system. In an automatic electrostatic system 60,000 to 150,000 volts D.C.
is required. Tests indicate, however, that there is little
advantage in voltages over 120,000 volts. Current ratings vary from 210 microamps to 5 milliamps depending on the type of system.
Hand held electrostatic spray guns usually operate at
lower voltages and current ratings, i.e.; 35,000 to 75,000
volts and approximately 100 microamperes. The
low amperage ratings are in the interest of safety. Theoretically, it takes a current flow of at least fifteen
milliamperes at any elevated voltage to cause death by
electrocution. For this reason, all reputable manufacturers of electrostatic power supplies design the units
to produce a safe current flow.
Anyone who has come in contact with 60,000 to 150,000
volts from an electrostatic emitter will attest to a
severe shock, but still walk away to tell their story. As
for the hand held units, the current limitations are so
low that when purposely touching the emitter, no
shock is felt.
To avoid danger, proper power supplies themselves
play an important role by having current limiting
switches, safety interlocks and warning systems. Since
we require only a small amount of current to operate
an electrostatic system, the input is generally not more
than that used by a 60 watt light bulb. Almost any 110
volt A.C. lighting circuit is sufficient to operate any
power supply. The newer power supplies use selenium
rectifiers for converting the 110 volts A.C. into the high
voltage D.C. In addition to the rectifiers, a step-up
transformer, condensers, resistors, and integrated circuits are the main components in the power supply.
The high voltage section is then sealed to stop a discharge of the high voltage corona which could damage
the other components of the power supply. The cavity
of the high voltage section contains a small amount of
dielectric oil (non-conducting) to prevent the release of
the high voltage corona during use. The result is a very
light, very compact unit. The newer power supplies
also have safety features built into them to prevent a
discharge of high voltage should a hazardous situation
occur. These safety features basically monitor the current output of the power supply and either automatically turns the voltage down to a safe level or de-energizes
the entire power supply, depending on the situation.
Due to the sophisticated electronics inside the power
supply, repairs should be performed only by qualified
technicians in order to maintain the integrity and
reliability of the safety features.
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E. MATERIAL FORMULATIONS:
Flammable Solvent Based Coatings
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In a basic sense virtually any atomized fluid is capable
of accepting an electrostatic charge. Careful consideration must be given, however, to the type of electrostatic
system being employed. Each system demands paint
formulation consideration acceptable to the process
being used. In the case of a true electrostatic system
(disc or bell), the polarity must be considered. Polar
solvents (conductive) are required to improve the degree of atomization.Previously it was stated that with
this system, atomization is accomplished by tiny particles of paint being torn from the edge of the emitter.
The current exchange is created by the high negative
voltage on the emitter and the product is the ground at
zero potential and positive in polarity.
If the material is nonpolar (nonconductive)in nature,
the particle being ripped or torn from the emitter will
be elongated or stringy in shape. This may result in an
undesirable finish texture such as orange peel. To allow
for this condition, a polar solvent is added that will
cause the particle to become more spherical in shape
and uniform in size. This will greatly enhance the surface texture.
In the standard type hand held electrostatic systems
utilizing air or hydraulic means of atomization,it is desirable to have nonpolar solvents used in the material
formulations. Polar solvents will only increase the conductivity of the material to a point where the material
forms an electrical path thereby causing a current feed
back to ground shorting the system out. This will cause
a lower voltage at the needle tip.
Standard type electrostatic systems will accept most
paints with only minor changes. Normally, it is only
necessary to reduce the material with solvent that has
a lower rate of evaporation. The reason being is that a
dry particle will not pick up or retain a charge as well
as a wet one. This is true, regardless of the type system
being used.
Optimum results can be obtained with formulations
having very low conductivity, in other words a very
high electrical resistance. For instance, dielectric oil
sprays very well with this type of equipment. One could
therefore say, “The deader the material the better”. The
use of a material conductivity tester for a very precise
measurement is recommended for large scale users or
when many types of material are generally being used.
The use of polar solvents should be discouraged in this
type of equipment.
Water Reducible Coatings
Recent equipment developments now make it a relatively simple matter to apply water reducible coatings
with electrostatic equipment. Both hand and automatic
air spray electrostatic guns are available.
Since the material is highly conductive, it is necessary
to isolate the material supply. The fluid supply will be
highly charged and it is therefore necessary to erect
barricades to prevent physical contact with this portion of the system.
Some metallic paints can be handled with standard
type electrostatic equipment. However, concern must
be given to the type of metallic flake that is being used
in the paint formulation. If the flake is round and has no
sharp corners or edges, then, when high voltage is applied the particles will not align themselves and cause a
conductive path. (see illustrations below).
THREE TYPES OF METALLIC PAINTS
METALLIC PARTICLE
-
NON-POLAR SOLVENT
If the metallic flakes have only a few sharp edges and
the particles are kept in circulation, there is little probability that the particles will form a conductive path.
However, if the particles are not circulated and high
voltage is present, then given sufficient time, the particles can align themselves and possibly short the system
out. (see illustration below).
mwl
IN CIRCULATION
SOME
PARTICLE
SHARP EDGES
WITH
METALLIC
NOT BEING CIRCULATED
METALLIC PARTICLES
CONDUCTIVE PATH
When the metallic flakes have extremely sharp edges
they will have a tendency under high voltage to align
themselves up quickly and short circuit the system, because electrons will always be attracted to and discharged from a sharp edge. (see illustration below).
Therefore, it is always important to check out the conductivity of a material under high voltage conditions to
be certain that a “wrap-around” effect will be present.
IMMEDIATE CONDUCTIVE PATH IS FORMED
WHEN METALLIC PARTICLES HAVE SHARP EDGES
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SOME COMMON POLAR AND NONPOLAR SOLVENT
listed in order of increasing polarity
RECOMMENDED SOLVENTS
NOT RECOMMENDED SOLVENTS
NON OR LOW POLARITY
Mineral Spirits
Textile Spirits
VM Kr P Naptha
SC-100. Enco 100, Solvesso 100
SC-150. Enco 150, Solvesso 150
Hea\y Aromatic Naptha-Han
Xylol
Toluol
Shell 303
0
N-Butyl Acetate
MEDIUM POLARITY
Ethyl Acetate
Cyclohexanol (Hesalin)
Butyl Carbitol (Dowanol 19)
Isophorone
F. ADVANTAGES:
1. Saves material because it utilizes overspray and
rebound.
2. Reduces clean-up and maintenance time.
3. Increases production rates in some instances.
4. Reduces equipment wear because lower air and
fluid pressures are used.
5. Eliminates secondary operations in some cases
because of wrap-around.
6. Better atomization because like charges repel
each other causing the spray pattern to open up
better using less air pressure
G. JUST1 FlCATlON OF COST:
Increased transfer efficiency, material, and labor savings will justify equipment costs in a short period
of time.
H. CONSIDERATIONS I N SELECTING
AN ELECTROSTATIC UNIT
1. Production requirements: that is, the amount
of material being sprayed in a given time. The
greater the volume of fluid required, the less
efficient the electrostatic effect beyond a certain point.
2. Shape and size of the product; electrostatic
force will not permit in some instances uniform
distribution of material. (Material will tend to
build up on edges and high spots).
3. The type of material for hand spraying operations should not be conductive, such as water
base paints or those having a high concentration
of metallic pigments. Automatic systems are
available to handle these materials.
4. Method of material atomization - airless or
conventional.
5. Type of spray operation - hand held, or automatic equipment.
6. Number of spray guns required.
I. OPERATION:
1. Material is supplied to the electrostatic spray
guns by standard pressure tanks, or pumps for
conventional applications and airless high pres
sure pumps for airless spraying.
2. The material is atomized in the same manner as
standard equipment, either by airless or conventional means.
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HIGH POLARITY
MEK
MIK
Acetone
Isopropyl Alcohol
Methyl Cellosolve
2-Nitropropane
1-Nitropropane
Diacetone Alcohol
Ethyl Alcohol
Methyl Alcohol
hlethyl Acetate
3. High voltage electrostatic charge is placed on
the paint particles.
4. The charged paint particles travel to the closest
grounded object which should be your product.
5. Those particles which miss the target are turned
around and begin to coat the backside of the
product.
6. Particles which strike the product and rebound
are attracted again to the surface.
J. LIMITATIONS:
1. Uniformity of coverage will vary depending on
the size and contour of the object.
2. Material formulations may require alterations
to work efficiently in the system selected.
3. The product to be sprayed must be a conductor.
Parts which are not conductors can be sprayed
by having parts immersed in a special solution
to make them conductors or backed by a conductive mantle.
4. Conveyors, as well as the product, must be
grounded at all times.
5. Electrostatic spray guns are limited to the amount of fluid they can efficiently charge in a
given period of time.
6. The front end of electrostatic spray guns are
made of plastic materials, therefore they can
not take as much abuse as metal spray guns.
The air and fluid nozzles are especially vulnerable to damage when using improper tools to
service the spray equipment.
K. PRECAUTIONARY NOTES:
1. Normal operating procedures are used for the
standard equipment which is to be used in conjunction with the electrostatic system, such as
pressure tanks and airless pumps.
2. Articles being painted must have an electrically
conductive surface and be grounded at all times.
3. Paint must never be allowed to accumulate at
points where articles touch the work holders.
4. All electrically conductive objects within ten to
fifteen feet of the spray area must be grounded - spray booth, power supply and especially
solvent and paint containers. These objects can
develop high voltage charges as they come in
contact with the electrified air molecules and
paint particles. A spark in this instance may
easily ignite solvent vapors.
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9. High velocity exhaust systems should be avoided since they decrease the efficiency of the
electrostatic force. Check with local codes for
proper exhaust requirements.
5. The higher the voltage being emitted from the
spray gun, the greater the electrostatic field
radiates into the surrounding area. The further
out the electrical field radiates the greater the
need that proper safety precautions be followed. This is because of the possibility of charging other objects which have the ability to collect and store charges producing a higher electrical potential than is being emitted from the
spray gun.
6. The hand spray gun operator should hold the
electrostatic spray gun in his bare hands at all
times or use gloves with the palm sections removed, so he does not accumulate a charge. Metallic objects such as coins, keys. pencils. nail
clippers, etc. must be removed from the pockets as these items can acquire a chargc largo (’nough to cause ignition of solvent vapors as the
painter moves near a grounded paint but-ket.
7. Floors should be conductive. I f t h r y art’ 1101.
grounded metal grating must he installcsd.
8. Persons other than tho opcrator should not
wear insulated shoes such iis thosc~with composition rubber or cork .soIcs. Ixather soles will
dissipate the chargt..
10. Use only the recommended electrically conductive air and fluid hoses such as those originally furnished with the equipment.
11. The power supply must be plugged into a properly grounded 110 volt A.C. receptacle.
12. When cleaning an electrostatic spray gun, make
certain that the power supply and air and fluid
supplies are turned off. The spray gun should
be discharged. This can be accomplished by
grounding the electrode briefly.
L. EQUIPMENT MAINTENANCE:
When maintaning electrostatic equipment, follow the
same basic procedures and precautions as for conventional or airless equipment. Care should be taken,
however, as many of the components in an electrostatic system are made of plastic. Again, be sure that
the unit is discharged as outlined above.
GLOSSARY OF TERMS USED IN ELECTROSTATIC APPLICATIONS
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High voltage power supply-An electric power transformer which converts 115 volts A.C.house voltage into
high voltage and fully rectifies it (changes type of current)
to D.C. Example: 115 volt input, converted to 75 KV (kilovolts) D.C. output.
Voltage-An electro-motive force (or pressure) which is
used to move current.
Electric charge-A difference in a level of energy where
the charge at a higher rate or level, seeks a ground to enable it to become neutral.
Electrostatic attraction-The force between two unlike
electrical charges, such as a charged particle and a neutral
ground.
Air Flow Switch-An
the flow of air.
electric switch that is activated by
Charged particle-A particle of paint with a surface
charge of high voltage electricity.
Electrode-The high voltage point where the electrons or
ions are “boiled off’ and attach themselves to the paint
particle.
Boil Off-The separation point where the electrons move
from the electrode to the paint particle.
High voltage cable-A specially designed cable which
carries the high voltage charge of the spray gun.
Ground line (electricall-A conductor of electricity
which is attached to the earth, and is used to transport
electrons to a point at where they become neutral, e.g.,
A water pipe.
Conductive materials-Materials which permit the easy
flow of electrons, e.g., copper wire.
Wrap-around-The effect attained from electrostatic
spraying where some of the paint particles will be
attracted to the back side of the object being sprayed.
Polar or high polarity solvents-Solvents
electrically conductive.
which are
Non-Polar or low polarity solvents-Solvents
offer high electrical resistance.
Corona-A
electricity.
which
glowing blueish or reddish discharge of
Ampere-A unit of measure of electrical current flow.
The current produced by one volt applied across a resistance of one ohm.
Ohm-A
unit of electrical resistance.
Milliampere-.001 of an ampere.
Microampere-.000001 of an ampere.
Fuse-An electrical safety device usually consisting of
a wire or flat metal strip that melts when the heat resistance caused by a direct short or current overload,
reaches a pre-determinedtemperature and thereby breaks
the circuit.
Voltage gradient-The change in the value of voltage in
a specified direction either upward or downward.
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Binks ELECTROSTATIC SYSTEMS
Air Atomized
Airless
Air-Assisted Airless
(Siphon)
Disc
Movement
U
Material Supply
Power Supply
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II
Binks Manufacturing Company
.Printedin USA 12/89
0 9201 W. Belmont Ave., Franklin Park, IL 60131 0 Telephone (708) 671-3000