Reforming ProcessesInjection Moulding

What is It?

The Process by which liquid plastic is forced into a mould and then allowed to cool in order to produce a wide range of products such as casings for electronic products and closures for packaging.

The Machines

The Machines continued …….

Diagram

The Process

The hopper is filled with granules. The granules are heated by an element in

the machine. A screw thread turns and pushes the

softened material forward. The plasticized material is then injected into

the mould by a hydraulic arm.

The process continued……

Time is allowed for the material to cool and harden inside the mould.

The ram is withdrawn and the mould opens.

The moulded product is ejected from the mould by ejector pins.

The mould closes ready to make another product and the cycle continues.

The Mould

Moulds are usually made from steel.

The Mould continued………

The Products

The Products continued……

The plastics

Most plastics can be injection moulded. Best suited to thermoplastics although

thermosetting plastics can be used. With thermo plastics the waste can be

reused. A wide variety of colours available.

Injection Moulding - Advantages

Intricate details and textures can be produced.

Moulds produce accurate products. Highly automated process. Products require very little finishing. Suitable for high volume production. Low unit cost for long production runs.

Injection Moulding - Disadvantages

Moulds are very expensive to develop and produce.

Not suitable for small production runs.