Gas-Assisted Compression Moulding of Glass Reinforced Polypropylene, Part 1: Scoping Study

Abstract

A new process of combining gas injection with compression moulding is presented. The process is called Gas Assisted Compression Moulding (or GasComp). The principle is based on the injection of nitrogen gas during a conventional compression moulding cycle. The flow of the material due to the compressive force of the press is assisted by the injection of gas into the centre of the molten material. The gas assists in the flow by coring out the material. An introduction to the process and moulding parameters are presented along with initial scoping studies using GMT, LFT and recycled GMT. Glass architecture was found to be a major factor in the shape and location of the gas cavity produced. This process is shown to be advantageous when compared to gas assisted injection moulding in that long fibre parts can be cored out.