TABLE OF CONTENTS Multi-shot moulding has been around for over thirty years and is used as a method of placing materials either side by side (abutting), one on top of the other within an overlap, or superimposition of one shot onto another. To do this special tooling and machinery is required. Common examples of such mouldings are keypads with the numbers made of one colour and the letters moulded-in using another colour. The advantage of this technique being the elimination of the printing processes which would otherwise be required to mark the keypads. Multi-colour automotive taillights are also made by this technology. Another common application of this technology is to combine hard and soft materials to produce a soft feel component. Handles such as on doors or toothbrushes are common products benefiting from this technology.
Multi-shot moulding techniques are well established, their growth being pushed by the development of thermoplastic elastomer (TPE) materials, enabling rigid and flexible material combinations such as those described previously to be employed. These can also be seen in a variety of other applications from automotive seals to bras.
A number of moulding methods can be employed to produce a multi-shot moulding but whilst mouldings can be produced by a variety of methods, those produced from the same material but in multi-colour multi-shot enjoy the highest market share.
Multi-shot techniques produce not only multi-colour but also multi-material mouldings. The most common methods are the use of tool rotation, the core back technique and transfer tools. Transfer...
