A History of Plastic Injection Moulding

Injection moulding has been a popular form of manufacture from its birth in 1872 when the first moulding machine was invented, but how did it all begin?

1868 saw John W Hyatt patent a process that produced celluloid, which he used as a replacement for ivory in billiard balls. 

In 1872 he became the first to inject hot celluloid into a mould.  Together with his brother Isaiah they patented a moulding machine that used a plunger to inject the plastic through a heated cylinder into a mould, some of the early products manufactured by the process were buttons and combs.

The moulding machine remained much the same until the demands for inexpensive mass-produced products rose in World War II. The plastics industry was revolutionised by James Hendry who built the first screw injection moulding machine in 1946.   This time also saw major change in colour being added to virgin materials and pre-mixing before injection.

Even in modern times a large percentage of injection moulding machines use screws to heat, mix and inject polymers into the mould.

The first plastic made from synthetic polymer was created by Leo Hendrik Baekeland in 1912 following several years of experimentation. Bakelite was the first synthetic plastic to be developed without a single molecule found in nature, this polymer is still used today for production of products that require insulating and heat resistant properties. 

2021 sees plastic injection moulded products of some sort used in every aspect of our lives, from our light switches at home to shop shelving and from public transport seating to hospital equipment.

There is no getting away from it, Injection moulding has been a popular and essential form of manufacture for over 150 years.