A Concise History of Injection Moulding

Plastics may seem a very modern concept, but in fact they have been around for over 150 years and have revolutionised manufacturing. Injection moulding is the process of manufacturing a wide range of rubber, plastic and silicone products for a large range of industries. The word plastic means ‘pliable and easily shaped’ and has only in recent years come to be the classification for a group of polymers. Polymers are very common in Nature, with the most common naturally occurring polymer being cellulose.

Image Credit

19th-Century Beginnings

– In 1847 Jons Jacob Berzelius produced the first condensation polymer – a polyester made from glycerine and tartaric acid.
– In 1861 the first commercial plastic was invented by Alexander Parkes in Britain.
– Just one year later Parkes demonstrated his plastic at the International Exhibition in London. He named this material parkesine. Although brittle, expensive and flammable, it could be heated and moulded to retain its shape.
– In 1868 production moves to America, with John Wesley Hyatt developing celluloid as an ivory substitute.
– In 1872 Hyatt developed an injection moulding machine with his brother Isaiah.

Image Credit

20th-Century Developments

– Bakelite was developed in 1909 in Belgium by Leo Hendrik Baekeland. Although this had been available in 1872, Baekeland made its production more viable on a larger scale.
– The 1930s saw the development of thermoplastics still in use today – polystyrene, PVC and Perspex. At the outbreak of World War Two plastic came into its own, as mass-produced cheap materials were needed.
– In the 1940s and 50s polyethylene, polystyrene and polycarbonate are produced more cheaply – the latter by General Electric.
– In the 1960s aromatic polyesters, polyamides and polysulphones are produced.
– In the 1970s James Watson Hendry developed the first gas assisted injection moulding process. This improved flexibility and production time, meaning less waste. In 1979 plastic production overtook steel production.

For more information on the history and future of plastics see https://www.sciencehistory.org/the-history-and-future-of-plastics.

Silicone moulding was a significant development, and it was in 1979 that the manufacturer http://www.meadex.co.uk/silicone-mouldings was established. With over 35 years’ experience, this company manufactures rubber, plastic and silicone moulding for a huge range of industries.

The UK plastics industry has shrunk from being worth £18 billion in 2002 to £3.5 billion today. This follows a general trend of manufacturing decreasing in the UK.