Powder coating is entirely a dry finishing process. It is composed of grinded particles of resins, pigments and other raw materials that are electrostatically charged and sprayed onto objects to be coated.
The objects to be coated are electrically grounded, so that the charged particles adhere to them until melted and fused together into a smooth coating in a curing oven, resulting in a uniform and durable high-quality finish.
There are two types of powder coatings, thermosetting and thermoplastic powder coatings. Thermosetting powder coatings are the most commonly used. They undergo an irreversible chemical change during the curing process and will not soften back to the liquid phase when reheated. Thermoplastic powder coatings will repeatedly melt when subjected to heat, will solidify when cooled, and are especially well suited for thick film applications capable of extreme performance requirements.