INFLUENCES OF PROCESSING PARAMETERS, MATERIAL, AND MOLD GEOMETRY ON THE SHAPE OF CAVERNS AS A QUALITY PARAMETER FOR ELECTROPLATING ON PLASTICS

摘要

For automotive application processing technical polymers like acrylonitrile butadiene styrene (ABS) or polycarbonate blends (PC/ABS) with injection molding and refining them by electroplating is state of the art. The surface quality and processing parameters during the injection molding mandatorily influence the resulting part quality. Besides the electroplating parameters, the surface of the injection molded part is responsible for the conjunction of the polymer and the metal layer system. The surface and adhesion of the hybrid material combination is defined by etching butadiene in the part surface to a cavern structure. An objective evaluation method for quantifying the two-dimensional shape of caverns is developed by using image analysis. The analysis is based on scanning electron microscope (SEM) images of chemical etched polymer part surfaces (ABS, PC/ABS). For quantifying the surface, meaningful key figures (e.g. roundness, degree of orientation, caverns/μm~2, and area of caverns) are emerged. Finally, different materials, etching times, and processing parameters are compared to results of climate change tests and the analytical valuation of the surface structure.