Injection mouldings with improved surface characteristics - by inserting a laminated foil into the mould prior to moulding

摘要

In the parent patent, a heated flat thermoplastics foil is placed between 2 half-moulds defining a cavity and deformed by injecting an expansible thermoplastics, contng. a foaming agent, into the non-gas tight mould. The present patent provides a foil which is a laminate, in which the layer nearest the gate side of the tool comprises a thermoplastics which is compatible with the expansible material. Mouldings with superior surface characteristics are obtd. more economically than by prior-art spraying, painting or glueing.