Surface structuring of sheet moulding compounds (SMC) for process reliable coatings

This study investigates how roughness and coatability of sheet moulding compound (SMC) components can be improved by modifying the surface morphology of the compression tool. A modular tool was developed that allowed to mould SMC work pieces simultaneously with different tool surfaces. In this study, mainly the tool roughness was modified using various surface treatments. Three different SMC formulations were applied to mould 2D components using the modular system. It was found that the demoulding was affected by both the tool morphology and the SMC formulations. Contamination of the tool by SMC material could be reduced by chromeplating. The morphology of the tool was transferred to the SMC work piece if the structures were larger than 5 ìm. The adhesion strength of a coating system differed for the three SMC formulations. While two of them showed generally good coatability, the coating adhesion on the third formulation decreased with increasing roughness of the tool used for moulding.