Powder coating is a dry finishing process, using finely ground particles of pigment and polyester resin. Prior to coating, the parts to be coated are first pretreated and primed similar to conventional liquid coated parts.
There are essentially two common ways of applying powder coating: by electrostatic spray and by fluidized bed powder coating.
Electrostatic spray method of application:
The powder is supplied by a hose to the spray gun, which has a charged electrode in the nozzle fed by a high voltage dc power. The electrostatically charged powder is sprayed onto the electrically grounded parts which are usually hung from an overhead chain conveyor. The charged powder particles adhere to the parts and are held there until carried into a curing oven where the coating is melted and fused into a smooth impervious coating.
Fluidized Bed Application:
The fluidized bed coating process is a simple dipping process that can be either conventional or electrostatic. The fluidized bed is a tank with a porous bottom plate. Low pressure air blows uniformly up through the powder. The rising air surrounds and suspends the finely divided polyester powder particles, so the powder-air mixture resembles a boiling liquid. The steel parts are preheated above the melt temperatures of the powder and are dipped into the fluidized bed. The powder melts and fuses onto the steel forming a smooth continuous coating.
At ParknPool, both methods of application are used based on the highest quality and most efficient manufacturing process for the applicable steel part.
Benefits of Powder Coating