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 coating and is then cured under heat to allow it to flow and form a “skin”.
Powder Coating Ingredients:
- Resin is the foundation for powder. It comes in two distinct types to yield a specific finish—either polyester or epoxy.
- Additives for things like color, matte finish, or hardening properties are also present in the powder. Benzoin is a common additive, added to epoxy resin, and it results in a reduction of surface tension along with melt viscosity. Other examples of additives include BYK 356, CERAFLOUR 920, DISPERBYK-2200, GARAMITE-7305.
- Post additives prevent the powder from clumping as it’s applied or while it’s in storage. They’re what give the powder its evenness.
- Tint pigments are what define the finished color of the powder after it’s baked and cured. Pigments can have properties like organic and inorganic.
- Curing agents are what cause the powder to harden and bond with the metal during the baking process. They’re what gives the process strength. The dicyandiamide curing agent when the epoxies are present in the coating, and primid curing agents if the coating contains polyesters.
- Extenders give the final baked coating a glossy, durable finish that stands out appealingly.
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, drum hardware and automobile and bicycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods. The powder coating process was invented around 1945 by Daniel Gustin US Patent 2538562.
Because powder coating does not have a liquid carrier, it can produce thicker coatings than conventional liquid coatings without running or sagging, and powder coating produces minimal appearance differences between horizontally coated surfaces and vertically coated surfaces. Because no carrier fluid evaporates away, the coating process emits few volatile organic compounds (VOC). Finally, several powder colors can be applied before curing them all together, allowing color blending and bleed special effects in a single layer.
Powder coated products are more resistant to diminished coating quality as a result of impact, moisture, chemicals, ultraviolet light, and other extreme weather conditions. In turn, this reduces the risk of scratches, chipping, abrasions, corrosion, fading, and other wear issues.