There are many ways of processing plastic from raw material to finished product. Different products require different processing methods. Below are a few common processing methods.
A barrel with a reciprocating screw that injects molten plastic into a mould. The melted plastic is cooled and solidifies, after which the mould is opened to reveal the hardened end product. Example: caps.
The plastic material is melted in a barrel. The plastic is then forced through a nozzle to form a stiff tube. Once this tube comes into position between two mould halves under the barrel, the mould is closed around an extruded tube (injection blow moulding) or hollow preform (injection stretch blow moulding). In the following step, a pipe inserted into the tube via the mould blows compressed air into the tube thereby forcing the tube up against the contours of the mould. Examples: bottles, cans.
Extruding involves pouring molten plastic into a barrel that contains a so-called reciprocating screw. This screw rotates and forces the molten plastic through a nozzle at the end of the barrel, where the plastic is cooled and attains its final shape. Examples: pipes, hoses and tubes.
Compression moulding uses two compression plates between which a moulding tool is placed. The material is placed in the cavity of the moulding tool, where it is pressed together and a vacuum ensures that the material fills the cavity.
In moulding the molten plastic is poured into moulds that give the plastic the desired shape. This is one of the simpler methods for processing plastic.