This paper discusses the systems for microcellular injection moulding developed and patented by Trexel and IKV. It then introduces a third design with initial findings and recommendations for modifications. The results suggest that microcellular foaming is possible introducing supercritical carbon dioxide in the nozzle providing certain design criteria are met such as a sufficient pressure drop from the plastication unit to the mould to enable rapid nucleation. Results from experiments with polystyrene are presented with consideration for pressure drop, weight reduction and injection speed.
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