Injection of Polypropylene Reinforced with Short Glass Fibers: Rheological Behavior

An experimental study of the thermorheological behavior of polypropylene (PP) reinforced with short glass fibers during the injection processing is described in this paper. This study was carried out using a proprietary rheometer which was designed and developed within our laboratory and is mounted on the injection machine. We have studied the variations of PP viscosity and elasticity, during isothermal flow, as a function of temperature, shear rate and glass fiber content. Furthermore we have studied the influence of the injection thermomechanical parameters during non-isothermal flowing and a pressure drop inside the feed channels and within a molding cavity of cylindrical cross section.