Today, injection moulding is one of the most widely used manufacturing methods in the world. It is responsible for the creation of products across every sector of industry and as varied as Lego bricks and other toys to the most advanced computer systems, from micro mouldings for medical devices to massive bumpers for cars. The introduction and continual improvement of injection moulding led to an invention that none of us could manage without today.
But where did the story of injection moulding begin? How long ago was it invented and who came up with the idea originally? How has it grown from where it started to be the most used manufacturing process in the world?
The Beginnings
It all started back in 1868 when a billiard ball making company, Phelan and Collander, advertised a $10,000 reward, a serious sum in 1868 for a suitable replacement for expensive ivory, not only was ivory expensive but it very nearly wiped out the African elephant at that time. Cue (no pun intended) an inventive-minded young printer by the name of John Wesley Hyatt seeing the contest announcement. Hyatt’s persistence in answering its call would eventually open the floodgates of synthetic plastic consumer goods. With no formal training in chemistry, Hyatt spent a dangerous year experimenting with various materials in his shed. Eventually, he found that a particular preparation of guncotton mixed with camphor oil resulted in a strong, lightweight material that could be ‘moulded’ into almost any shape and dyed any colour. He patented this and shortly after Hyatt and his brother trademarked the name ‘celluloid’.
John Wesley Hyatt
With his brother, Isaiah, in 1872 they created what would be the first injection moulding machine. The machine, whilst pretty basic, worked perfectly for the purpose. Consisting of a ‘plunger’ style part that injected ‘plastic’ into the mould this was the birth of what today we all know as injection moulding. Hyatt’s invention did have some faults. Most notably the design didn’t take into account plastic’s poor ability to conduct heat. This fact often results in the plastic not being a consistent temperature or consistency when injected into the mould.
Evolution
The war and the demand for inexpensive mass-produced items led to a revolution in manufacturing methods, and the biggest was James Hendry's screw injection moulding machine in 1946 using an augur design instead of a plunger. This revolutionised the industry. The augur screw is placed inside the barrel. Because the screw runs through the centre of the barrel, it displaces the inner core of raw material, thereby eliminating one source of unequal heating. Today, almost all injection moulding machines use this technique.
In the 1970s James Hendry developed the first gas-assisted injection moulding process. This new development allowed for the production of complex, hollow articles that cooled quickly; thereby improving design flexibility and the strength and finish of manufactured parts while also reducing production time, cost, waste and weight.
Modern Incarnations
Picture of a simplified injection moulding machine
Today, the product design of injection moulding machines is much sleeker, although the technology itself has not changed very much. With computer technology we are able to achieve more specificity through injection moulding, which is why it accounts for such a large range of products on the market today. In almost any shop or home in the world, you would be hard-pressed not to find at least something that was created through the process of plastic injection moulding. It forms an integral part of today’s design and manufacturing industry, which is quite a large claim to fame from a technique that developed because of billiard balls.
Today other injection moulding variations include gas-assisted, metal injection moulding, thin-wall injection moulding, liquid silicone rubber injection moulding and reaction injection moulding. Die casting is often mentioned alongside them but it is a metal casting process, not a variant of injection moulding
Plastic-IT Ltd has an ISO 9001:2015 certified in-house injection moulding facility in Shropshire so if you have a new project, or are looking to relocate existing tooling, we can assist with the whole process. We work closely with a selected group of suppliers to ensure project success and customer satisfaction.
From low volume production to 24/7 lights-off operation, from tool try-outs to one-off production runs, our goal is to provide you with the most cost-effective solution to your injection moulding requirement.