Thermosetting powder coating and thermoplastic powder coating
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”.They are applied as a dry material and they contain very little, if any, Volatile Organic Compounds (VOC). The raw material is literally a powder, mixed dry, extruded, and ground into the final material.An environmentally safe coating that can provide a variety of high quality finishes makes powder a popular alternative in the ecologically sensitive climate that we live in today.
The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, and automobile and bicycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods.
Thermoplastic powder coating does not chemically react in a cure phase. They are typically used for functional applications and applied in thick films, typically 6–12 mils. They are used for a wide range of applications that require a tough finish with impact resistance and/or chemical resistance.
Thermosetting powder coating is applied and then cured in an oven at a certain temperature for a certain time. The cure process will cause a chemical crosslinking to take place, changing the powder into a continuous film that will not remelt.They are used for a variety of functional and decorative applications and usually applied in thinner films, typically in a film thickness of 1.5 to 4 mils.