New thermoplastic powder coating systems have been developed by Germany’s Lehmann & Voss also known as LuV (U.S. office in Pawcatuck, Conn.) and Impreglon GmbH (U.S. office in Fairburn, Ga.) for use with thermoplastic compounds and composites based on materials such as nylon and PEEK that are injection molded into sliding and rolling components of various machines and devices.
Manufacturer of customized high-performance compounds sold under the trade name Luvocom, LuV recently expanded its portfolio to include powdered thermoplastics materials to serve as both antifriction coatings as well as laser sintering applications. The first commercial product of the Luvocom P family is an acetal (POM) coating and others, including one based on PBT, are now becoming available. Marcus Rechberger, who heads the new group, explains that while POM top coating Luvocomp P 80-7858 B was developed by LuV, the coating system--pretreatment, primer and topcoat—was jointly developed with Impreglon. The coating system is called TempCoat 7510 by Impreglon which operates five powder coating facilities in the U.S. alone.
Rechberger explains that the powder coating works best with LuV’s Luvocom high-performance compounds. “The substrate of the injection-molded part is optimally adapted to the coating system. The latter consists of a primer and a thermoplastic layer with a thickness of 100 micrometers. The result is high-strength components with optimally lubricated surfaces, he says. The lubricant-modified POM surface exhibits a coefficient of friction of 0.06 against steel (measured on an interfacial corrosion testing apparatus). No running-in effects were observed during the process, according to Rechberger. Unlike injection-molded parts, the POM layer is not “frozen” by a cold tool surface. Instead, a highly crystalline morphology forms on the surface. These tightly-packed crystals ensure high wear resistance and a matte surface. Layer thicknesses of 100 to 200 µm can be applied with uniform layer thickness distribution.