Overview

There is an extremely wide variety of mouldings that have been produced, ranging in complexity from straightforward to highly technical, since the introduction of injection moulding. Advances in injection moulding technology, toolmaking and machining techniques have made it possible to produce mouldings of high complexity.

Not far behind these advances, the standard components industry has kept pace with an ever-increasing range of high-quality products. Making full use of these can greatly simplify designs and tool constructions and also reduce both design time and toolmaking time.

Many standard components are specifically designed to provide solutions to several different types of undercut or ejection problems. Clearly, where these can be successfully incorporated into a design, full advantage should be taken in using them. In most instances such components offer a self-contained solution for forming and releasing an undercut in the mould tool, such as collapsible cores, and are a considerable advantage for the designer and toolmaker.

Despite the wide range of geometric forms of mouldings that are produced, it is possible to classify the mould designs into two broad groups when a new component has to be moulded: those that may be based on existing proven mould designs and those that require a totally new design. It is clearly advantageous to use a previously proven design and adapt it to suit a mould design for the new part when this is possible, since with existing designs all the bugs have already been ironed out and their behaviour in production is fully...