A unique research collaboration has resulted in the development of interrelated technologies that allow sheet molding compound (SMC) to be powder primed.

A unique research collaboration has resulted in the development of interrelated technologies that allow sheet molding compound (SMC) to be powder primed. A new SMC primer from Red Spot Paint & Varnish Co., Evansville, Ind., and a new low-moisture-content polyester resin system from AOC, Colliersville, Tenn., are key components of a new approach that is near commercialization. General Motors R&D spearheaded the multi-pronged industry effort, which also included Tier 1 SMC molder Meridian Automotive Systems, Allen Park, Mich. In response to environmental mandates, car makers have pushed for powder primers for both steel and SMC body parts as a replacement for liquid solvent-based systems in order to reduce volatile organic compounds (VOCs) and overspray waste. However, research showed that powder-primed conventional SMC develops a leather-like surface during the primer's high-temperature cure cycle. The reason, according to GM, was a combination of air and moisture that are released when a common low-profile additive is used. In response, AOC developed a resin formulation that incorporates new low-profile additives that reduce moisture by up to 60%. Meanwhile, Red Spot Paint & Varnish developed a liquid spray-on conductive sealer/primer that controls the release of moisture from the SMC into the subsequent powder primer. The sealer/primer (which replaces the older liquid in-mold coating) is applied by Meridian before SMC parts are shipped to the GM facility for powder priming. The combination of the new sealer/primer and low-moisture SMC is said to raise the surface quality of powder-primed SMC to acceptable OEM levels. AOC: (901) 854-2800/PTDirect: 643BB . Red Spot: (800) 457-3544/PTDirect: 911BD . Meridian: (313) 336-4182 . www.meridianautosystems.com

Meridian Automotive Systems
550 Town Centre Dr Ste 475 Dearborn, MI 48126
Phone (313) 336-4182 Fax (313) 253-4026