How The Process of Plastic Injection Moulding Works

One of the most commonly used processes in the production of plastic items is the process most often referred to as ‘Injection Moulding’. There are several reasons as to why the process of plastic injection moulding is very popular, however one of the most common reasons given as to its popularity is the fact that as a means of goods production, the process can be used to produce enormous quantities of identically shaped plastic items of a variety of purposes. The goods produced by this process range from simple and disposable consumer goods to essential engineering components of high precision.

The Basic Process

In the most basic terms, the process of Plastic Injection Moulding involves the introduction of a certain material into the moulding machine (most typically via a ‘hopper’). The moulding machine is most commonly made up of a heated barrel (equipped with a reciprocating screw, usually driven by a hydraulic or an electric motor, which usually then feeds molten plastic into a temperature controlled split mould via a comprehensive network of gates and runners).

The polymer is melted by the reciprocating screw, which also then acts as a ram during the injection process. The shearing action of the rotating screw on the plastic assists in providing even more heat that can be utilised in this part of the process before the polymer is then injected into a mould which has been created in accordance to the required dimensions of the finished product desired by the client or customer. The pressure involved in the production process when the polymer is injected into the mould is extremely high, possibly even reaching 1000 atmospheres depending on the material being used in the process.

There are many companies and firms who specialise in producing important components and items made from plastic via the process of injection moulding. There is also a large number of companies which specialise in the production and supply of the moulds used in the injection moulding process.

The importance of the process of Plastic Injection Moulding is demonstrated by the fact that the service provided by the companies practising the process is in great demand by a considerable number of customers, including those in specialist industries such as aerospace and defence which require necessary specialist plastic goods and items produced by this process. The process is most commonly used in the production of the majority of thermoplastics such as polystyrene and nylon.