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The programme, filmed at the Rolinx Plant in Manchester, examines the process for injection moulding of thermoplastics, particularly the production of large shapes such as sailing dinghies.
Metadata describing this Open University video programme
Module code and title: T352, Materials processing
Item code: T352; 12
First transmission date: 31-07-1979
Published: 1979
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Barrie Whatley
Contributors: Peter Lewis; William Woollard
Publisher: BBC Open University
Keyword(s): Frozen in strain; Injection pressure; Locking force; Mould breathing; Polymer flow ratio; Vertical/horizontal flash moulds
Footage description: Excerpts from a Tomorrows World programme. William Woollard looks at a finished sailing dinghy, the Topper, and then at the process by which it was made. Peter Lewis, at the Rolinx plant in Manchester examines a small injection moulding machine and describes the injection moulding process. He demonstrates the machine without filling it with polymer. Peter Lewis goes on to describe the technique by which more complicated shapes such as milk bottles and car manifold housings are produced by injection moulding. He holds up a bottle and a car manifold cover as he talks. Lewis next explains how the locking force needed for any particular injection moulding machine is calculated. Shots of an automated injection moulding machine in operation. Looking at the strain patterns in a plastic battery box produced by injection moulding, Lewis explains how this frozen in strain can be minimised by better mould design such as rounding off corner etc. He examines a mould and also a machine for making fan housings to illustrate his point.Lewis goes on to explain how problems of mould abrasion and degradation of moulds through acid attacks are overcome. With the aid of animated diagrams, Lewis explains how a homogeneous polymer melt is achieved for large injection moulding machines. He points out the problems which arise when injecting very large moulds and how these are minimised. Peter Lewis interviews John Heasman, the technical manager at Rolinx. They discuss the economics of producing large shapes such as the Topper sailing dinghy by injection moulding. Shots of the Topper being produced as they talk.
Master spool number: 6HT/73058
Production number: FOUT016Y
Videofinder number: 1439
Available to public: no