Powder coating is a dry finishing process that involves applying a free-flowing, dry powder to a surface. Unlike conventional liquid paint, which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. Powder coating is mainly used for coating metals, such as household appliances, aluminum extrusions, drum hardware, automobiles, and bicycle frames. Advancements in powder coating technology like UV-curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF (medium-density fiberboard) to be powder coated due to the minimum heat and oven dwell time required to process these components.
The powder coating process was invented around 1945 by Daniel Gustin and received US Patent 2538562 in 1945. This process puts a coating on an item electrostatically, which is then cured by heat. The finish is harder and tougher than conventional paint. Because powder coating does not have a liquid carrier, it can produce thicker coatings than conventional liquid coatings without running or sagging. Powder coating produces minimal appearance differences between horizontally coated surfaces and vertically coated surfaces.
Advantages of powder coating include:
- Thicker coatings than conventional liquid coatings without running or sagging
- Minimal appearance differences between horizontally coated surfaces and vertically coated surfaces
- Durable architectural finish
- Suitable for both internal and external applications
- Ideal method for achieving a specific color match
Disadvantages of powder coating include:
- Requires specialized equipment and training
- Initial investment cost can be high
- Difficult to touch up or repair once applied
Overall, powder coating is a popular and effective method for coating metals and other materials, offering a durable and attractive finish.
