Polymer-based composite materials are increasingly being used in automobile construction to reduce weight. As a rule, it is necessary to treat the surface of these materials to achieve stable adhesion and coating. Using body trim parts for the automobile interior as an example, we show how flame treatment can be accurately followed using mobile contact angle measurements.
One of our customers observed an unacceptably high reject rate after applying a decorative film – the film became increasingly detached at certain points. Test inks showed no local differences. Within a few hours, various parameters of the flame treatment process on site were varied and the surface free energy was determined at different points. The SFE was calculated based on contact angle measurements at the treated surface with the help of the Mobile Surface Analyzer – MSA. This showed that one side of the workpieces was systematically underactivated, which was presumably due to an increased distance between flame and composite surface.