Machining Plastics

Abstract

Although the ease with which plastics can be moulded and formed frequently offers a major advantage in manufacturing processes, it is often more desirable, or even necessary to machine. The decision to machine can be based on a variety of factors, for example:

• i. For economy, where the quantity involved does not warrant large expenditure on moulds or forming tools. When a particular component could be easily machined from available stock sections of sheet, rod or tube, careful costing of quantities and potential may be necessary before embarking on moulding tool costs, always provided of course that suitable moulding machinery is available.

• ii. Where the geometry of the component involves difficult undercuts or other features requiring complex inserts or collapsible moulds which would make moulding impracticable.

• iii. Where the required degree of accuracy or quality can only be achieved by machining.

• iv. Where the nature of the plastics material being used does not permit moulding, eg in the case where laminated plastics are chosen.