Powder Coatings can be applied using one of three standard methods, Fluidized Bed, Electrostatic spray-Corona charge and Tribo charge.
Electrostatic Corona Gun
The corona gun requires a high voltage of 30-100 KV at the electrode around the tip of the gun. This creates a field of electrical attraction between the gun and the grounded parts.
As the powder are transported through the tip of the gun, the powder particles are negatively charged in the electrostatic field, repel each other and form a cloud before being attracted to the item to be coated.
The particles deposit on to the part and form a layer after layer of powder. The thickness of the deposition can be controlled by position of the gun, spray duration time, level of charging and velocity of the powder flow from gun to part and part aperture.
It is vital that parts to be coated are well grounded or earthed. Jigs or hangers must be kept clean to yield good grounding at all time.
Over spray or powder not adhering to the part is collected for recycled.
Electrostatic Tribo Gun
Powder Coatings, upon transported through barrel of the Tribostatic gun to the part to be coated, are positively charged with no electrostatic field created. This method of application eliminates faraday cage effect and back ionization. Hence, it is good for use in coating intricate parts such as detailed automotive rims and heatsinks.