Powder coatings are used to produce highly wear-resistant, thick, color coatings with high gloss or matt finish on automobiles and other components. The process of powder coating involves applying electrostatically charged powder in a dry state to the component. It is done by spraying the finely ground powder coating of pigments and resins onto a component with an electrostatic gun.
After the coating is applied, the component is heated in an oven so that the powder melts evenly to flow over and fuse itself to the item to form a thin protective film on the material. This coating is tough, hard, fade resistant and durable and will help to protect the item from things such as corrosion, heat, electrical interference, scratching and other abrasions, and thermal shock, etc. Coatings can also be used to add and enhance the functionality in terms of electrical/thermal conductivity, etc.
There are many kinds of substances that can be coated such as stainless steel, leather, glass, ceramic, wood, fiber, plastic, and metals, etc. The coating can generally vary in thickness from a few microns to a few millimeters.
Powder coating is a more precise way to cover objects and surfaces than dip coating. A lot of items need a tough protective coating that is uniform in thickness and consistency and powder coatings is the best way to get this because of the ways it is applied. Powder coating uses electrostatic principles because they are uniform.
It is very critical that before the coating is applied that the surface is treated with a series of preparatory processes such as cleaning, rinsing, etching, rinsing again and using a chromate or phosphate treatment, rinsing again and then ensuring final rinse. This will remove all oil, grease and other impurities that may have adhered to the surface of the item. It is important that after the cleaning operation, the components are not touched without proper gloves.
Coatings can be of thermoplastic or thermosetting type. The component to be coated is at ground electrical potential. Types of electrostatic guns are corona charged guns, tribo charging guns and bell charging guns. Various colors can be added to the powder as required.