Injection Moulding is the most widely used plastics processing method. The process consists of clamping two moulds together into which a molten polymer is injected. High pressure is used in order to obtain fast filling speeds and in order to stop the mould being over filled. The mould is held at a temperature below the melt temperature. This is commonly achieved by circulating water at a specified temperature through the cooling channels in the mould. Once the polymer melt has been set to the shape of the cavity, the mould is opened, the moulded part is ejected, and the process recommences. Injection moulding is the process of choice for producing precision parts in medium to high volume. 

AMI estimates that there are in excess of 13,000 injection moulders in Europe and AMI publishes a variety of directories on this process.