improved powder coatings exhibit enhanced resistance to bacterial and fungal attack , while possessing excellent toughness , appearance , corrosion resistance , durability , processability , and ease of application . the coating is comprised of anti - microbial agents melt - processed into the matrices of coating powders or bonded to coating powders . an article may be coated with a thermoset or thermoplastic powder that may be applied by electrostatic spray or fluidized bed or by thermal or flame spray .