In the plastics processing industry, there is a trend towards the application of specific micro- and nano-structured surfaces to components. Components can only fulfill the desired function if treated in this way. Applications include surfaces with tailored cell attachment (biomedical application) or surfaces with maximum light transmission (optical application). The challenge is to refine established but relatively costly methods that have been developed in the laboratory in order to create affordable techniques suitable for mass production. This calls for improvements along the complete production chain, in particular in quality control.
Within the scope of the EU research project “IMPRESS”, the department “Machine Vision and Signal Processing” has developed a system for monitoring the quality of structured surfaces during production. It is based on the existing modular system “NEPRES”, which has been extended to include the new functions required. The system continuously analyzes machines and process data from diverse injection-compression molding processes in order to forecast the surface quality of the manufactured components.
The performance of the system was evaluated on the basis of concrete productions; in the manufacture of micro needle arrays, the system demonstrated a forecasting accuracy of up to 98%. The information is available directly after completion of the components, therefore enabling rejects to be identified promptly and process optimization measures to be taken.