Powder coatings are essentially based on electrostatic technology. This application method uses a spray gun, which applies an electrostatic charge to the powder particles, which when sprayed attracted to the grounded part. After the spray of powder, the parts are cured in an oven where with the addition of heat the coating chemically is cured and becomes a strong layer of film. Powder coatings can also be applied to non-metallic substrates such as plastics and medium-density fibreboard (MDF). Sometimes a powder coating is applied during a fluidized bed application. Preheated parts are dipped in a hopper of fluidizing powder and the coating melts and flows out on the part.
1. Epoxy Powders
Epoxy-based coatings are good for chemical resistance, wear and tear and provide great corrosion protection. However, epoxy coatings are susceptible to ultraviolet rays instability. Therefore they are not best suited for outdoor applications.
The two most widely used types of powder coatings are polyester and Urethane polyester. They provide excellent wear resistance and outdoor durability. Polyester Urethane also provides good chemical resistance. They are mainly used in automobile industries.