An OEM-led research collaboration is developing new interrelated technologies that allow sheet molding composite (SMC) parts to be powder-primed without sacrificing the quality of the SMC Class A surface. Key technology participants include General Motors Research and Development, Tier-One supplier Meridian Automotive Systems, resin supplier AOC and coatings supplier Red Spot Paint & Varnish.

Powder primers help improve the workplace and environment by reducing volatile organic compound (VOC) emissions and overspray waste. OEM facilities want to apply powder primers to steel and SMC body parts that are sent side-by-side through E-coat and paint coating cycles. However, when powder primed, conventional SMC develops a leather-like surface appearance during the powder primer high-temperature cure cycle.

To achieve a greater surface quality in powder primed parts, Hamid Kia, principal researcher at General Motors R&D and a world-renowned automotive SMC authority, encouraged automotive plastics coating leader Red Spot to develop a new SMC primer. The Red Spot primer is applied by Meridian before SMC parts are shipped to the GM facility. The Red Spot primer is conductive so that the electrostatically charged solid particles of the OEM powder coating process will be attracted to the SMC part surface. In essence, the new low-permeability coating technology forms a layer that significantly controls the release of moisture from the SMC into the powder primer.