Mould tools with flexible linings to disengage undercut profiles - for simplicity of construction and change of shape

摘要

Mould tools having the plug and/or cavity mould lined with a flexible material or thick skin which can be deformed to disengage undercut portions of the moulding. Linings may be perforated to accommodate injection nozzles or may be attached to multi-piece supports which can extend the lining to produce lateral contraction for releasing the moulding. Alternatively, the male lining may be supported by hydraulic pressure. Mould tools may be of composite construction, e.g. reinforced polyester mouldings for support and polynorbornene ('Norsorex' RTM) or silicone rubber ('Silastic' - RTM) for the deformable linings. Suitable for producing injection moulded or cast mouldings. Mould construction is simpler than with use of multi piece solid tools requiring relative movement of sliding parts to release undercut parts.