Krauss Maffei (Munich, Germany) announced on Aug. 4 that a new inmold painting process to produce tractor engine covers recently went into operation at Harita TVS Technologies Ltd. (Bangalore, India). The covers, made of fiber-reinforced PUR in a long-fiber injection process, are given their high-gloss surface finish in the mold. Harita is the world’s first PUR processor to use this technique in series production. The company produces around 500 engine covers a month for the Tiger 10 tractor made by Same Deutz (Treviglio, Italy). The tractors are currently made for the Indian market, but there are plans to export them to China and Europe.
The LFI process differs from other PUR processes in that the long glass reinforcing fibers are wetted with the PUR in the mixing head. In recent years, this technique has proved a resounding success. What makes the Harita system innovative is the fact that the high-gloss surface to the LFI parts is achieved by spraying the paint directly onto the surface of the mold. A barrier coat is applied between the paint layer and the LFI substrate to prevent the glass fibers from spoiling the smoothness of the paint surface.
More than 12,000 hours in agricultural operation have shown that the engine covers are rugged and long-lasting. They can withstand temperatures up to 100°C/212°F and have good mechanical properties. The new production process has other advantages, for instance, color matching of the engine covers with the injection molded front end, as well as the possibility of integrating metal inserts in the production process.