Optimizing flame treatment of polymer surfaces in the automotive industry

Mobile contact angle measurements on glass fiber reinforced composite materials for automobile interiors

In order to achieve stable adhesion and coating of polymer-based composite materials, they are usually pretreated. Based on body trim parts for the automobile interior as an example, we show how flame treatment can be accurately followed using mobile contact angle measurements. In the present case, the reject rate after applying a decorative foil on flame-activated polypropylene was very high.

After unsuccessful efforts with test inks, on-site measurements of the surface free energy (SFE) showed where the problem came from. Within a few hours, various parameters of the flame treatment process on site were varied and the SFE 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.

Download the full application report here: AR280