Decorative electroplated chrome coatings on plastics have been produced for decades. For environmental reasons, there has been a shift away from hexavalent chrome (Cr6) to trivalent chrome (Cr3). Interest in alternatives to electroplated chrome is expanding dramatically. The process steps of applying chrome and other metal coatings to plastic are very different when comparing electroplating and physical vapor deposition (PVD). In electroplating, numerous chemical baths and rinses are required to deposit 15 to 30 microns of metal for producing a durable chrome appearance. Electroplating processing steps are well known and can include conditioning, neutralizing, acid etching, catalyzing, accelerating, nickel flash, copper plating, nickel plating, chrome plating, and effluent care and disposal. For this reason, there are increasing investments towards elemental chrome PVD coatings to maintain the true chrome appearance. Collectively, the automotive, home appliance and cosmetic markets are actively searching for alternatives with the appearance and durability of electroplating, but without the environmental side effects, appearance and functional design limitations, and costs associated with it. Finishers have been looking to focus on a safer, greener, more cost-effective, quicker alternative without sacrificing appearance and performance.
Traditional chrome plating is limited to coating-grade substrates like acrylonitrile butadiene styrene (ABS) and polycarbonate/ABS. Certain thermoplastics, like polyamide/polyphenyl ether, cannot be chrome plated due to either chemical attack or the duration in high-temperature baths (up to 140 °F for 11 min) causing substrate deformation.