Improved properties of CFRTP composites by pre-dispersing and post-drawing process

Continuous Glass Fiber Reinforced HDPE Composites(CFRTP) manufactured by conventional melt impregnating process, has poor properties like impregnation degree and mechanical behaviors, because of the high viscosity of molten resin to the difficulty of impregnating between resin and fiber bundles, and the resin flow rate during processing to the waviness and twisting of fiber in CFRTP. In this paper, a new method is presented to obtain improved CFRTP materials by pre-dispersing and post-drawing. From both model and experiment investigation, we find, if fiber bundles pass through the dispersing device and its cover angle of dispersing is more than 300 degree, the bundles could be well-dispersed to lead good impregnation of CFRTP. However, the mechanical properties of such CFRTP are still low compared to the theoretical value. Experiments show that the weight suspending process can reduce the waviness in CFRTP to modify its properties about 15% and the twining process in Calendar can eliminate CFRTP both the bundles waviness and twisting, which especially improves its longitudinal tensile properties.