Injection moulding is a manufacturing process that allows for the production of parts by injecting material into a mould. This process can be performed with a wide range of materials, including many metals, glasses, elastomers, confections and most commonly thermoplastics and thermosetting polymers.
The process works by feeding your chosen material into a heated barrel. Having been mixed in the barrel it is forced into a mould cavity where it is allowed to cool and harden into the configuration of the mould.
The polymers used in this process have a long history. It was in 1847 that Jon Jacob Berzelius, a Swedish chemist, developed the first condensation polymer
. ‘Polyester’ as it became known was produced from glycerine and tartaric acid. In addition to polyester Berzelius is widely credited with originating the terms catalysis, polymer, isomer and allotrope, though those original definitions differ dramatically from the terms we would use today.
By 1861, British inventor Alexander Parkes had developed the first man-made commercial plastic
. The material, known as “Parkesine”, was publicly demonstrated at the 1862 International Exhibition in London. Derived from cellulose it could be heated, moulded and would retain its shape once cooled; though it was incredibly expensive to produce, prone to cracking and was highly flammable.
It was not until American inventor John Wesley Hyatt developed a plastic material named Celluloid in 1868 that Parkes invention was improved in such a way that it could be processed into finished form. In 1872, together with his brother Isaiah, Hyatt patented the world’s first injection moulding machine
. The machine was relatively simple in comparison to today’s machine and worked in a similar way to a hypodermic needle, incorporating a plunger that injected plastic through a heated cylinder into a mould.
World War II
The outbreak of the Second World War resulted in a rapid expansion of the industry during the 1940’s. During this period there was considerable demand for inexpensive, mass-produced products. By 1946 American inventor James Watson Hardy had developed the world’s first screw injection machine
which gave manufacturers much great control over the speed of injection and the quality of the products that were produced. The fact that the material was mixed before injection also meant that coloured and recycled plastics could be mixed with virgin material before injection.
An Evolved Industry
The plastic injection moulding industry has evolved considerably over the years. The screw injection machine now accounts for the vast majority of all injection machines and where once they were most commonly used for the manufacturing of combs and buttons, it is now possible to mass produce a vast array of products for a wide range of industries including:
Following the acquisition of a number of additional Krauss Maffei injection moulding machines, Coda Plastics have been able to dramatically increase our operating capacity. If you think that our team can assist you with the production of your next project, do not hesitate to get in touch.
You can call Coda Plastics on +44(0) 1692 501020, or drop us an email to firstname.lastname@example.org.