Powder coating is much different from painting because there are no liquids or solvents. Therefore, it is the best coating for environmental friendliness. The powder over-spray has very high application efficiency because it is dry. The powder is converted from a powder to a continuous film by using heat on it. The powder coating materials are basically plastics that are ground into a fine powder. The coating powder is formulated with pigments, plastic resins, flow agents and other special ingredients to provide the preferred characteristics of the coating film.
Typical steps in the powder coating process for metal parts:
- Cleaning – the purpose is to remove grease, oils, polishing compound, wax, particulates, and light oxides from the surfaces of the part .
- Rinsing – This step is critical in the metal finishing process
- Phosphating (optional step to improve adhesion and corrosion protection) – Provides improved powder coating adhesion and acts as a corrosion barrier.
- Drying – High pressure blowers, air drying: high velocity air, heated air, combination of hot and high velocity air, and infrared drying
- Powder Coating
- Curing -The thermostat powder begins to melt, flows out, and then chemically reacts to form a higher molecular weight polymer in a network-like structure when it is exposed to elevated temperatures.