Compression Molded Sheet Molding Compound (SMC) for Automotive Exterior Body Panels: A Cost and Market Assessment

Automotive exterior body panels are a critical component of today's vehicle. They provide a surface for painting, offer the first line of defense against damage from accidents and the elements, and in most cases add to the overall stiffness of the vehicle. Despite small inroads from aluminum and polymer systems, steel remains the predominant body panel material. Of the alternatives, sheet molding compound (SMC) has been the most successful challenger.

This paper examines the cost and market conditions affecting SMC today and in the near future. The impact on cost of SMC compression molding process improvements is assessed over a ten year period for a full body panel set. These results are compared to stamped steel as a function of annual production volume and other key factors. The result is a cost “crossover” point below which SMC has the lower cost.

On the market side, the idea of decreasing annual model builds is quantified to understand the overall number of panels that are candidates for SMC adoption. These are compared to current examples of SMC use in order to put a realistic upper bound on SMC substitution.