Electrostatic coating
Encyclopedia
Electrostatic coating is a manufacturing process that employs charged particle
s to more efficiently paint a workpiece. Paint, in the form of either powdered particles or atomized liquid, is initially projected towards a conductive workpiece using normal spraying methods, and is then accelerated toward the workpiece by a powerful electrostatic charge
.
towards to a paint booth, where it is sprayed with electrostatically charged paint particles. Integrated into the paint booth is a powder recovery unit, which recovers between 95% and 100% of the paint over-spray coatings.After the workpiece is coated, it continues on the conveyor belt to an oven
, where the paint is cured. The benefits to the process of electrostatic coating is the ability to recover the little over-spray and having the process automatic which will cut costs. The reason for the little over spray is the paint particles that do not hit the piece will turn in the air and go back to the piece. There are also some drawbacks to the process everything in the area of the coating must be grounded
to prevent static buildup. All hangers, conveyors, etc. must be cleaned often to ensure a good ground and prevent anyone in the area from getting a severe shock. Any recesses on the piece that is being coated can be missed because the electrostatic paint is more attracted to corners and sharp edges; this means that another process for coating crecesses.
of the workpiece is limited only by the size of the paint booth. Using Electrostatic coating it is possible to apply paint in various thicknesses being limited only by the paints tendency to run and therefore ruin the coating if applied in too thick a manner. It is usually preferred to apply many thin coats as opposed to one thick coat.
. After passing through the booth and getting coated the workpiece then either goes into a baking oven
or out into the open air to allow the paint to cure on the part. Many different spray nozzles may be used depending on the desired paint consistency and the shape of the workpiece.
s available for use in electrostatic coating. The type of nozzle used will largely depend on the shape of workpiece to be painted and the consistency of the paint.
Charged particle
In physics, a charged particle is a particle with an electric charge. It may be either a subatomic particle or an ion. A collection of charged particles, or even a gas containing a proportion of charged particles, is called a plasma, which is called the fourth state of matter because its...
s to more efficiently paint a workpiece. Paint, in the form of either powdered particles or atomized liquid, is initially projected towards a conductive workpiece using normal spraying methods, and is then accelerated toward the workpiece by a powerful electrostatic charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
.
Process Characteristics
- Uses a high voltageHigh voltageThe term high voltage characterizes electrical circuits in which the voltage used is the cause of particular safety concerns and insulation requirements...
electrostatic charge which is applied to both the workpiece and the sprayer mechanism - Is incredibly efficient, using 95% of sprayed paint due to reduced over-spray and better wrap-around
- Paint materials can be either powdered or liquid
- Process can be either automatic or manual
- Workpieces must be conductive
- Workpieces are usually baked after coated.
Process
The workpiece travels down a conveyor beltConveyor belt
A conveyor belt consists of two or more pulleys, with a continuous loop of material - the conveyor belt - that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley...
towards to a paint booth, where it is sprayed with electrostatically charged paint particles. Integrated into the paint booth is a powder recovery unit, which recovers between 95% and 100% of the paint over-spray coatings.After the workpiece is coated, it continues on the conveyor belt to an oven
Oven
An oven is a thermally insulated chamber used for the heating, baking or drying of a substance. It is most commonly used for cooking. Kilns, and furnaces are special-purpose ovens...
, where the paint is cured. The benefits to the process of electrostatic coating is the ability to recover the little over-spray and having the process automatic which will cut costs. The reason for the little over spray is the paint particles that do not hit the piece will turn in the air and go back to the piece. There are also some drawbacks to the process everything in the area of the coating must be grounded
Grounded
Grounded, may refer to:*Grounding , restrictions placed on movement or privileges*Grounded, a song by My Vitriol*Unaccompanied Minors, a film*Grounded , a comic book by Mark Sable for Image Comics...
to prevent static buildup. All hangers, conveyors, etc. must be cleaned often to ensure a good ground and prevent anyone in the area from getting a severe shock. Any recesses on the piece that is being coated can be missed because the electrostatic paint is more attracted to corners and sharp edges; this means that another process for coating crecesses.
Workpiece Geometry
The geometryGeometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
of the workpiece is limited only by the size of the paint booth. Using Electrostatic coating it is possible to apply paint in various thicknesses being limited only by the paints tendency to run and therefore ruin the coating if applied in too thick a manner. It is usually preferred to apply many thin coats as opposed to one thick coat.
Setup and Equipment
The workpiece may be delivered to the coating booth in any fashion, most commonly using either hands or pliersPliers
Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other...
. After passing through the booth and getting coated the workpiece then either goes into a baking oven
Oven
An oven is a thermally insulated chamber used for the heating, baking or drying of a substance. It is most commonly used for cooking. Kilns, and furnaces are special-purpose ovens...
or out into the open air to allow the paint to cure on the part. Many different spray nozzles may be used depending on the desired paint consistency and the shape of the workpiece.
Typical Tools and Geometry Produced
There are a wide variety of spray nozzleSpray nozzle
A spray nozzle is a precision device that facilitates dispersion of liquid into a spray. Nozzles are used for three purposes: to distribute a liquid over an area, to increase liquid surface area, and create impact force on a solid surface...
s available for use in electrostatic coating. The type of nozzle used will largely depend on the shape of workpiece to be painted and the consistency of the paint.