| The injection and moulding subsystem of a two-stage microcellular plastic manufacturing process, using an existing decoupled extrusion technology and a low tonnage injection moulding machine, was developed. Mechanisms to enable the solution accumulation, microcell nucleation and growth, and part shaping functions were designed, constructed, and experimentally verified. Specifically, a simple solution conveying channel, accumulation mechanism, flow control system, and modular mould were developed. In addition, the machine's injection nozzle was substantially modified to suit the unique processing requirements of foam, and a recovery device was designed to reduce material consumption.;True microcellular plastic parts (i.e., with a cell density >1 × 109 cells/cm3) could not be produced. Fine-celled foam parts, with a cell density up to 3 × 107 cells/cm3, an average cell size of 30 to 50 microns, and a relatively wide cell size distribution, were achieved. Average cell size was similar to that obtained by Trexel Inc. and Shimbo et al. |
