DEVICE FOR CONTROLLING PRESSURE FOR CHANGING VOLUME IN MANUFACTURE OF POLYMER

摘要

Apparatus for use in moulding articles from foamed plastics material comprises a mould (1) in which the constituents are placed, the mould (1) having an upper wall or lid provided with perforations (3) and a cover member (4) is in sealing contact with the upper wall or lid and defines therewith a chamber (5), which is connected via a conduit (9) and valve (10) to a piston and cylinder device (13) which is used to control the pressure in the chamber (5) and mould (1) to a predetermined valve during foaming so that the resultant product has desired characteristics.