Powder coating is a method of applying coatings to surfaces without using solvents. The coating is applied as a free flowing powder and heated to cause it to flow and adhere to the surface. The powder may be a thermoplastic or a thermoset polymer. It is normally used to create a hard finish on metals. Powder coating is mainly used for coating of metals, such as "white goods", aluminium extrusions and automobiles, although some other materials (like MDF-medium-density fibreboard) also can be coated in this way.
The most common polymers used are polyester, polyester-epoxy(known as hybrid), fusion-bonded epoxy and acrylics.
Production: 1) Mixing the polymer granules with pigments and other powder ingredients in a mixer 2) Heat the mixture in an extruder. 3) The extruded mixture is rolled flat, cooled and broken into small chips 4) The chips are milled to make a fine powder
The most common way of applying the powder coating is to spray the powder using an electrostatic gun. The gun imparts an electric charge on the powder, which is then sprayed to the object. The object is then heated, and the powder melts to form a hard coating.