Noble Materials for Thin-Walled Bumper Fascia with Enhanced Processibility and Dimensional Stability 980105

A new noble material for automotive bumper fascia has been developed by compounding of ethylene-propylene block copolymers with ethylene-α-olefin copolymers and some additives. Also mineral fillers are added, if necessary. This material is suitable for injection molding of large parts including automotive bumper fascia. By using selected rubbers which have proper melt viscosity, molecular weight, and co-monomer content, and adding modified polymer containing polar group, it has enhanced processibility and paintability maintaining general properties such as tensile strength, impact strength at low temperature, and thermal and UV stability. The remarkable characteristics of this material is good processibility compared to the conventional TPOs. This material has especially high melt flow index(20∼30g/10min at 230°C) and stable flow behavior at the processing conditions. Furthermore, according to the results of CAE analysis, it is possible to reduce the injection pressure and clamping force of the injection molding machine. Another characteristic of this material is excellent dimensional stability. So, it is possible to reduce the wall thickness of the molded parts up to 2.5mm with proper dimensional stability.