EFFECTS OF PROCESSING PARAMETERS ON THE SURFACE STRUCTURE OF INJECTION MOLDED PARTS: APPLICATION OF IMAGE ANALYSIS FOR THE INVESTIGATION OF 2D CAVERN STRUCTURES WITH RESPECT TO ELECTROPLATING QUALITY REQUIREMENTS

摘要

For the production of injection molded parts with a subsequent electroplated coating, technical polymers like acrylonitrile butadiene styrene or polycarbonate/ acrylonitrile butadiene styrene blends are used. The quality of these parts is affected by both the electroplating parameters and the properties of the surface and subsurface structures of the injection molded part. Processing parameters influence these structures during injection molding and hence are responsible for the adhesion of the polymer and the metal [1],[2]. The effects on the resulting caverns in polymer surfaces (after etching) caused by changing injection molding parameters are investigated. For this purpose, relevant processing parameters affecting the surface structure are examined. Furthermore, image analysis is applied as an objective evaluation method to quantify the two-dimensional shape of caverns. This analysis is based on electron microscope (SEM) images of chemical etched polymer part surfaces (ABS, PC/ABS). Meaningful key figures, such as roundness, degree of orientation, caverns/μm~2, and area of caverns, are emerged to quantify the surface structure. An ABS and PC/ABS material is tested and compared, and coherences between the shape of the caverns, processing parameters, material properties, and geometry influences are elaborated.