Design Innovations Facilitating Economic Production of Giant Mouldings

The philosophy behind the technical developments described in the paper is the belief in the need to raise the standard of the injection moulding machine to meet the moulders' economic needs for efficient machine loading, low reject rates, and flash-free moulding. It describes progress made in the development of hydraulic circuitry, valve gear, and electronic controls, to provide the greater accuracy needed for fine setting of the injection and the clamping units.

It shows how the design of the circuitry permits the use of more than one clamping unit or injection unit in parallel to produce mouldings of very large projected area economically. It also describes an up-to-date method of devolatising thermoplastic materials during plasticising, without pre-drying, as a contribution to both economics and quality.