Powder coating is a type of coating that is applied as a free-flowing, dry powder. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a “skin”. It is usually used to create a hard finish that is tougher than conventional paint.
Chemical pre-treatments involve the use of phosphates or chromates in submersion or spray application. These often occur in multiple stages and consist of degreasing, etching, de-smutting, various rinses and the final phosphating or chromating of the substrate. The pre-treatment process both cleans and improves bonding of the powder coating to the metal. Recent additional processes have been developed that avoid the use of chromates, as these can be toxic to the environment.
Spray paint is an aerosol product designed to be dispensed as a fine mist. Compared to conventional brush methods of painting, spray painting is faster and provides a more uniform application. While industrial spray painting relies on special air compressors that break the paint particles into a fine mist, commercial spray paints are self-contained aerosol cans that use liquefied gasses to atomize the paint.