Für nur 12,90 EUR

Two-component PU coatings: Challenges and processing solutions for automotive applications

von Dipl. Wirt.-Ing. Janine Krebs, Dipl.-Ing. Jörg Hain, Dr. Isabelle Roth, Prof. Dr. Lothar Kroll

Two-component polyurethane coatings based on polyester polyols display a high potential for application in automotive design both in the interior and the exterior due to their scratch resistance. The manufacturing process for components with a polyurethane surface is based on two-shot injection moulding with integrated reaction injection moulding (RIM). This process offers the benefit of short cycles thanks to the components being coated directly within the tool as well as the components being produced with a contour very nearly matching that of the finished product.

However, a major drawback presents itself in the form of the high ejection forces required that result from the high adhesion of polyurethane to the metal tool surface. Presently, this is countered through the employment of liquid mould release agents and high tool temperatures. A possible environmentally friendly and economic alternative may be presented by tool coatings with non-adhesion properties. First experiments have shown a substantial reduction of tensile adhesion strength compared with uncoated tool surfaces.