Powder is a thermosetting coating, whereas liquid is thermoplastic. As a thermosetting coating, once applied and in the oven, powder undergoes a chemical reaction that causes it to crosslink and harden into a hard, infusible, and insoluble film. Once cured, thermosetting coatings cannot be re-melted.
Thermoplastic coatings, on the other hand, are coatings that soften and become fluid when heated and harden again when cooled. Unlike thermosetting coatings, they do not undergo any chemical change when heated, and can be re-melted and re-dissolved.
Architectural grade powder coatings deliver great film integrity, as well as excellent scratch resistance. Powder coatings are inherently tough, with the thermosetting properties delivering an improved scratch resistance of around 4H in a pencil hardness test compared to only around an “H” result for liquid paint.
There are so many finishes available in powder. Solid colors and metallic or mica finishes in thousands of shades are available, but so are anodic style finishes and even textures, plus a great range of gloss levels depending on the product type. For example, in FEVE fluoropolymer powder, there are options from low gloss of around 20 to 25, through to a high gloss of 70. In a polyester-based powder, it may go as low as a five gloss and up, and as high as a 90 gloss, and anywhere in between.
Powder also delivers great abrasion resistance, as demonstrated in both Taber and sand abrasion testing, and improved performance against damage. It may seem obvious, but in the construction world this is important, as the need for replacements and touch-ups is much decreased. Powder can also offer superior protection against mechanical damage in high use or high traffic areas. The thermosetting properties of powder also mean the coated surface is less susceptible to the settling of dirt and mildew growth.
Is there a color or gloss warranty with performance powders?
The simple answer is yes. This will depend on the powder manufacturer, and most powder companies require warrantied finished to be applied by a registered applicator—a professional powder coater who has been through rigorous testing and regular retesting to ensure they can apply powders to meet the above performance requirements. Most of the liquid coating warranties that are used in the architectural world are built around the FGIA coating specifications. As such, there are equivalent warranties available with equivalent powders.
