Macromolecular materials and engineering vol:284 issue:11-12 pages:1-7
Multi-component injection moulding technologies are gaining constantly in importance for thermoplastics processing, in particular the gas-assisted injection moulding (GIM) technique. These multi-component moulding concepts could also offer a great potential of application to the manufacture of polyurethane (PU) parts. However, due to the significant differences between the material behaviour of thermoplastics and reactive PU systems with their coupled chemical and physical processes the transference of the experiences gathered in thermoplastics injection moulding has to be regarded critically. Therefore, focusing on the gas-assisted reaction injection moulding of hollow parts, designated as GRIM technique, numerous experimental investigations concerning the most significant process parameters gas delay time, mould temperature and gas pressure has been performed. The main results of these process investigations are reported.