Daniel Maetens is group leader of R&D Powder Coatings for Cytec Surface Specialties. For more information about advanced UV powder coatings, call 800.652.6013 or 973.357.3193, e-mail custinfo@cytec.com or visit www.surface-specialties.com.
Powder coating cured by ultraviolet light (UV powder) is a technology that combines the advantages of thermosetting powder coatings with those of liquid ultraviolet-cure coating technology. The difference from standard powder coatings is that melting and curing are separated into two distinct processes: upon exposure to heat, UV-curable powder coating particles melt and flow into a homogeneous film that is crosslinked only when it is exposed to UV light.
Ultraviolet (UV) powder coatings combine the advantages of thermosetting powder coatings with those of liquid ultraviolet cure coating technologies. The difference between standard and UV powder coatings is that in UV systems, melting and curing are separated into two distinct processes. Upon exposure to heat, UV curable powder coating particles melt and flow into a homogeneous film that is cured only when it is exposed to UV light. The most popular curing mechanism used for this technology is the free-radical process, in which UV light activates photoinitiators in the molten film to form free radicals that initiate a polymerization reaction involving resin double bonds. The final coating appearance and performance depends on the selection of resin systems, photoinitiators, pigments, fillers and additives, as well as on the powder coating process conditions and curing parameters.
