Influence of Raw Material Properties on Parameters of Injection Press during the Injection of Composites Based Biomass and Plastic Waste

Abstract

The main aim of this paper is to present the research findings which come out from the experimental determination of the influence of input raw material properties and composition on the operating parameters of an injection press during the injection of biomass-plastic composites (BPC). During the injection process, important operating parameters such as injection speed, injection pressure and the temperature profile along the chamber can be recognized. In this research study, the aim was to produce BPCs of an acceptable and competitive level of quality which is determined from the final mechanical properties of BPCs. Using a variety combination of influencing variables the final quality of composites and also the operating parameters of the injection moulding press can be improved. Raw waste material variables influence, especially (a type of plastic matrix, type of biomass, particle size, moisture content) and biomass/plastic concentration ratio can be recognized during the production of composites. Their effect can be seen from the quality indicators and from the operating parameters of the injection press which has a direct impact on the production costs. The paper deals with the determination of the impact and the relationship between the input raw material variables and the operating parameters of the injection process (pressure, speed, and temperature profile). The experimental research findings were obtained using a semi-operational injection moulding press where the injection is provided by a working screw. As the input raw material, wheat straw and spruce sawdust, HDPE plastic matrix and recycled HDPE, represented by lids from PET bottles, was used. The effect of the input raw material composition was determined according to a combination and default levels of biomass/HDPE concentration ratio, using recycled HDPE instead of virgin HDPE and particle size of biomass.