Screw design plays a fundamental role in efficient injection moulding (IM), keeping manufacturing costs down and delivery times short. James Hines, Process & Training Engineer at Sumitomo (SHI) Demag, talks about the significance of the screw patented in 1956, and how the actual screw design affects the processing of polymer and impacts the quality of moulded components.
Technology wise, little has changed since Demag Plastics Group (Ankerwerk Nürnberg) developed the first reciprocating screw for IM machines in the 1950s. During this decade, post World War II, manufacturers in all sectors switched from producing metal components using plungers to the mass production of plastic products. In response, Anker built the world’s first single-screw IM machine in 1956. It was a milestone moment, giving moulders more precise control over the speed of injection and enabling materials to be mixed before injection.
Just as it did 60 years ago, the screw continues to perform four key roles – consistently feeding and melting the resin, pumping fluid steadily and mixing resin homogeneously.
