Modern profiles made of thermoplastic elastomers consist of a blend of EPDM and polypropylene (PP) and are extruded thermoplastically. The resulting products have only a very low surface tension and need to be pretreated before applying anti-friction coatings.
One major challenge to the automotive industry is achieving emission-free vehicle interiors by using VOC-free manufacturing processes. As an alternative to solvent-based coatings, it is possible to use water-based anti-friction coatings and dry lubricants. However, these will not adhere to the substrate unless it has an especially high surface tension.
At the same time, profiles made of TPE have thermally sensitive surfaces and can easily be damaged if the pretreatment is too intense. With all these conflicting requirements, it is difficult to achieve reliable activation over the whole range of products. Nevertheless, this can be done by using patented Plasmatreat rotary jets RD 1004. These can treat a wider area, distributing the plasma power uniformly over the treatment zone.