The phrase Powder Paint is often used as a generic term to describe Powder Coating.
Powder Paint is a misnomer or inaccurate description of the powder coating process.
Paint is applied as a wet film coating, i.e. wet paint is sprayed out of a gun and a film of wet paint is applied to the component or workpiece. The wet paint is then put in an oven and force dried so that the paint hardens. The thickness of one coat of paint is in the region of 20 microns.
Powder Coating is more complicated;
Firstly the Powder itself, this is made by Powder Manufacturers who take all of the ingredients that would normally make up paint such as resins, pigments, curing and flowing agents and other chemicals. This is heated up and mixed into a homogenous paste that is then extruded into a layer rather like toffee. It is then ground into a fine powder with each grain being in the region of 15-20 microns in size.
The powder can then be sprayed using a spray gun that charges the powder with an electrostatic charge. The charged powder flows to the workpiece that is earthed and adheres through a residual charge.
The Powder Coated part is then placed into an oven and cured for 10 minutes at a metal temperature of 180-210 degrees centigrade. During this process the powder grains melt and fuse together into a continuous film of about 60- 80 microns. The resins in the powder through the application of the heat ‘cure’ and harden.
If you need to protect your components from corrosion and give them a long life then Powder Coating is the best choice.