Composite thermally conductive plastic moulds for foamed mouldings - to obtain smooth moulded surfaces without tool heating

摘要

The mould tools are of composite construction and comprise a plastic body made thermally conductive by incorporating a metallic filler and lined with a thermally semi-conductive layer of epoxy resin filled with 30% wt. powdered Al and reinforced with glass fibre matting, a layer of thermally insualting epoxy resin reinforced with glass cloth, and a thermally insualting surface coating of epoxy resin. The body incorporates passages (copper pipes) for circulating coolant. Suitable for mfr. of large structural foam mouldings such as 600 litre rubbish containers from thermoplastic, thermosetting or rubber materials. The surface finish is sufficiently good not to require buffing or painting. Avoids use of steam to keep a metal tool surface warm during injection of the melt. Strong enough to contain foam generation pressures, with significant wt. saving compared with metal moulds for large tools.