moulding and forming

The choice of the moulding and forming technology will often be determined by the shape, cost and number of parts to be produced.

compression moulding

The simplest process is compression moulding where the compound is placed into a mould and the product shape is formed under heat and pressure in a press. Typical moulding times depend on the thickness, geometry and materials and may vary from 5 minutes to 20 minutes.

Small amounts of scrap material are produced, typically as flash along the mould join.

injection moulding

Injection moulding is used to rapidly reproduce large numbers of components accurately and repeatedly. Compound is injected into the mould through gates. 

Whilst a good process for large volumes of cheap (and often relatively small) components, injection moulding can produce a large amount of scrap material, sometimes as much as is used for the component itself.

extrusion

Extrusion lines usually consist of an extruder together with feed systems, haul-offs, trimming, cooling and cutting stations and packaging systems. In some cases, extrusion lines can be hundreds of metres long.

Any changes to the line, including during start-up and run-out, can generate large amounts of scrap material and off-spec product. 

overview