Electrostatic powder coating principle

Electrostatic powder coating is based on the principle of high-voltage electrostatic corona electric field. The metal guide ring on the spray gun head is connected to the high-voltage negative electrode, and the workpiece to be coated is grounded to the positive electrode. A strong electrostatic field is formed between the spray gun and the workpiece.

When the carrier (compressed air) transports the powder from the powder feeding device to the air guide ring of the spray gun and passes through the delivery pipe, since the air guide ring is connected to the high-voltage negative electrode to generate corona discharge, charges are generated around the dense powder, which makes the powder negatively charged. Under the joint action of compressed air, the powder flies from the spray gun to the workpiece and is evenly adsorbed on the surface of the workpiece.

After heating, the powder dissolves and remains flat, forming an even, continuous and smooth coating.