Shrinkage

Shrinkage refers to a change in the dimensions of a workpiece caused by the application of heat or the use of chemicals. The volume of the material remains unchanged, while its shape and size are affected.

This effect is often used deliberately, for example in the application of heat-shrink tubing. Heat-shrink tubing is made from materials that contract when heated, thus forming a close-fitting protective layer around cables or other objects.

However, shrinkage can also occur unintentionally and lead to unwanted changes. One example of this is the behaviour of thermoformed plastic parts. When exposed to service temperatures, such as those found in electrical appliances, or under extreme solar radiation, these parts tend to return to their original shape as a flat sheet. This unintentional shrinkage can impair the function and aesthetics of the affected parts.