PLANT TRIALS FOR POWDER PRIMING OF SMC

摘要

Based on the information generated at GM R&D Center, six SMC formulations were developed and produced by SMC suppliers and subsequently molded into automotive body panels for powder primer application readiness tests. The panels were evaluated in the lab for shrinkage, moisture absorption, adhesion to the conductive coating, and powder application. Based on the results, ail six formulations were approved for plant trials. The trials took place in Shreveport and Lordstown assembly plants. It was noted that the use of infrared heating to bake the powder is detrimental to SMC as it causes rapid heating of SMC substrate, resulting in a high flux of moisture in a short period of time. It was also learned that the experimental conductive coating improves the powder prime capability of SMC and allows powder priming after an extended exposure to the plant environment.