Strain Rate Effects on Tensile Properties of HDPE-PP Composite Prepared by Extrusion and Injection Moulding Method

The present paper investigates the effect of strain rate on different tensile properties of high density polyethylene (HDPE) and polypropylene (PP) composite. Tensile specimens of virgin HDPE-PP composites are prepared via twin screw extruder and injection moulding methods as per ASTM D638-02a (Type-I); with gage length 50 mm, width 13 mm and thickness 3 mm. Composites are fabricated with PP as reinforcing agent at a loading rate of 10%, 20%, 30%, 40% and 50% by weight. Experiments are carried out at room temperature of 23°C and absolute humidity of 54% at a cross head speed of 30, 40, 50, 60 and 70 mm/min. Stress and strain values at yield and break points are reported. Atomic force microscopy (AFM) is used to study the distribution of polymer molecules in the mixture and surface roughness. As in last, experiments are designed by Taguchi optimization method to find out the dominating factors on tensile strength.