Electrostatic Powder Spray Coating System

The electrostatic powder coating system is the application of electrically charged powder coating materials to grounded object or parts. The object is then heated causing the powder to flow and cure. However, if the uncured powder coat is damaged or blemished in any way, then the powder can simply be blown off with air or vacuumed and a new powder coat applied.

There are four basic pieces that make up the electrostatic powder spray coating system, which are the powder feeder, power unit, electrostatic spray gun, and powder booth recovery system.

The spray gun is supplied with powder from a feeder unit, which diffuses the powder with compressed air into a fluid-like state. High velocity air flows through a venturi and siphons out the fluidized powder, which is then propelled through the powder feed tubing to the spray gun.

The powder feeder also allows for a controlled flow of powder to the guns. The system has independent controls for powder and air volume, which allows for adjustable dilution ratios so that the desired thickness coverage can be attained for each object. The powder feeder has the capability of providing ample discharge pressure and velocity to feed an electrostatic gun to approximately 25 feet away.

When the powder leaves the spray gun, it does so in the form of a diffused cloud, which is propelled toward the workpiece. A charging electrode at the front of the spray gun is powered by a high voltage, low amperage power unit, which emits a field charge that imparts a negative charge onto the particles of powder. This negative charge causes the powder to seek out and attach to the grounded work piece.

In closing the functions of the electrostatic powder spray gun are to shape and direct the flow of powder, control the size, shape, and density of the powder pattern, impart an electrostatic charge to the powder being sprayed and control the accumulation of powder onto the objects that are being coated.