moulding

Use of a pattern, hollow form, or matrix to give a specific shape to something in a plastic or molten state. It is commonly used for shaping plastics, clays, and glass. When metals are used, the process is called casting.

In injection moulding, molten plastic, for example, is injected into a water-cooled mould and takes the shape of the mould when it solidifies. In blow moulding, air is blown into a blob of molten plastic inside a hollow mould. In compression moulding, synthetic resin powder is simultaneously heated and pressed into a mould.