Gas-assisted injection moulding specialist Cinpres Gas Injection (Middlewich / UK; www.cinpres.com) has been granted a patent in Europe for its Plastic Expulsion Process, following an intensive period of R&D and applications engineering over the past four years. CGI says the process has significant advantages in the manufacture of thick section parts, as well as components having a combination of thick and thin sections.

In the Cinpres PEP process, the mould cavity is filled with material while temporarily holding back packing pressure exerted by the machine. This is followed by gas injection, which applies further packing pressure. One or more shut-off valves are then opened sequentially for expulsion of melt from the core of the moulding to one or more secondary cavities. Hesitation marks are said to be eliminated completely and surface finishes can be greatly enhanced. Managing director Jon Butler expressed confidence that PEP will be an important technology, particularly in the production of automotive, white goods and home and garden products.