Janusz W. Sikora , Anna Kliszowska and Bjorn Noack
The properties of a composite based on a high-density polyethylene Hostalen GD 7255 filled with a 10% addition of a glass powder called Mikrover were studied. The composite was obtained in the process of twin screw extrusion with cold pelletizing. The apparatus included a co-rotating twin-screw extruder with the extruder head equipped with a circular die, as well as a water cooling bath and a pelletizer. The mechanical properties of the composite were studied by producing appropriate specimens in the injection moulding process, at variable cooling times of the injection moulded parts and at variable volume rates of polymer composite flow to the injection mould cavity. The basic strength properties were determined by uniaxial tensile testing, and hardness was determined by the Shore method. It was found that injection moulding conditions influenced the mechanical properties under study. For example, an increase in cooling time was accompanied by an increase in stress at break. An increase in the volume rate of polymer composite flow to the injection mould cavity was accompanied by an increase in hardness, stress at break, tensile strength and strain at break.