{"id":39685,"date":"2021-09-10T14:18:01","date_gmt":"2021-09-10T14:18:01","guid":{"rendered":"https:\/\/xometry.asia\/?p=39685"},"modified":"2025-05-30T18:10:58","modified_gmt":"2025-05-30T10:10:58","slug":"injection-moulding-technology-overview","status":"publish","type":"post","link":"https:\/\/staging-wp.xometry.hk\/en\/injection-moulding-technology-overview\/","title":{"rendered":"Injection Moulding: Technology Overview"},"content":{"rendered":"\n

Injection moulding<\/a>, a modernised and far more advanced form of casting, is one of the manufacturing methods developed through the years that allows to speed up and enhance the production of different products. Speed and ease of production are critical considerations in manufacturing, especially bulk production, as these bring about numerous advantages. These advantages include lower development costs, greater forecasting accuracy, faster innovation, and larger market share.\u00a0<\/p>\n\n\n\n

What is injection moulding? <\/h2>\n\n\n\n

Injection moulding is a manufacturing process in which molten material is injected into an already prepared mould and left to cool. Upon cooling, the material solidifies and takes the shape of the mould, before being ejected. While this process may be used for one-off productions, it is usually used in the mass production of identical parts. Materials most commonly used in injection moulding are plastics<\/a> or elastomers<\/a>.<\/p>\n\n\n\n

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Injection moulding system<\/em><\/figcaption><\/figure>\n\n\n\n

Due to its high output rate and consistency of quality, injection moulding is widely used across different industries to create parts such as electrical components, automotive parts, basic consumer plastics, furniture parts, and many others.<\/p>\n\n\n\n

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Mould for injection moulding<\/em><\/figcaption><\/figure>\n\n\n\n

How does injection moulding work?<\/h2>\n\n\n\n

A special-purpose injection moulding machine carries out injection moulding. The manufacturing process is divided into the various steps listed below:<\/p>\n\n\n\n

Step 1 – Creation of the mould<\/h3>\n\n\n\n

The first step in injection moulding is mould creation. The mould for the part to be manufactured is designed according to the specifications of the part’s 3D model, using computer-aided design, following several injection moulding guidelines. It is then manufactured in two parts, usually using CNC machining<\/a>. Moulds are made from metals (mainly steel or aluminium).<\/p>\n\n\n\n

Step 2 – Injection<\/h3>\n\n\n\n

The separate halves of the mould are placed in and held together tightly by the clamping unit of the injection moulding machine. In the form of granules or pellets, the raw material is introduced into a barrel where it is heated at a high temperature and pressure till it melts. Now in molten form, the material is immediately injected into the mould cavity, filling the entire space in the mould. It then cools down and solidifies, forming the shape of the mould.<\/p>\n\n\n\n

Step 3 – Ejection and finishing<\/h3>\n\n\n\n

After the material has completely cooled and solidified, the mould is opened by the clamping unit and the solidified finished part is ejected. The finished part is subjected to some post-processing operations<\/a>. These operations include removing excessive material and support structure, surface finishing, and, if required, painting, electroplating, heat treatment, etc.<\/p>\n\n\n\n

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Other injection moulding processes<\/h2>\n\n\n\n

There are other forms of injection moulding that vary from the process described.<\/p>\n\n\n\n

Over moulding<\/h3>\n\n\n\n

Over moulding is an injection moulding process that allows a part to be created from two different materials. The first material is moulded and, before cooling down, the overmoulding material is introduced, creating strong bonds between the substrate and the overmoulding material. This technique is used to create multi-material objects with improved aesthetics and functionality, while eliminating the need for secondary operations.<\/p>\n\n\n\n

Insert moulding<\/h3>\n\n\n\n

Insert moulding is similar to over moulding. In this injection moulding technique a preformed object is inserted into the mould before the molten material is poured. With the point being to have the preformed material inserted into the moulded object. An application of insert moulding is inserting metal screw holes into plastic parts.<\/p>\n\n\n\n

Metal injection moulding<\/h3>\n\n\n\n

In this process, finely powdered metal is combined with wax, polypropylene binders, or other polymers to form a feedstock mix. It is then injected into the mould and left to cool. Once it solidifies, a portion of the blinder is removed using methods such as the catalytic process and the use of solvents.<\/p>\n\n\n\n

Die casting <\/h3>\n\n\n\n

The die casting process, also known as high-pressure die casting, is the forcing of molten metal under high pressure into a mould cavity. The process is as follows:<\/p>\n\n\n\n