Multi-component reaction injection moulding (MC-RIM): A processing technology for the manufacturing of multi-component polyurethane mouldings

Multi-component injection moulding technologies are gaining constantly in i mportance for thermoplastics processing, in particular the gas-assisted inj ection moulding (GIM) technique. These multi-component moulding concepts co uld also offer a great potential of application to the manufacture of polyu rethane (PU) parts. However, due to the significant differences between the material behaviour of thermoplastics and reactive PU systems with their co upled chemical and physical processes the transference of the experiences g athered in thermoplastics injection moulding has to be regarded critically. Therefore, focusing on the gas-assisted reaction injection moulding of hol low parts, designated as GRIM technique, numerous experimental investigatio ns 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. [GRAPHICS]