Annealing/Stress Relieving

Ultem machining

Vapor Polished Polycarbonate

Annealing or stress relieving of plastics is an important step in plastic machining.

While not all components require annealing, there can be important advantages for some materials and part configurations

Many manufacturers believe that their own internal annealing process is sufficient. However, in practice, batch processing can yield inconsistent results.

Connecticut Plastics has multiple programmable ovens for precise control of the stress relieving process. Our own annealing process allows us to create highly consistent material qualities from one rod to the next.

Advantages of stress relieving of the material include:

Most consistent material
Most stable material
Lowest stress possible
Better machinability of the material
Better flatness control

In addition, post-machining annealing can improve the properties of some components, especially those in the harder materials. These materials are sensitive to stress cracking, accumulated from the rod stock or machining. To achieve the lowest possible stress and the most stable component, consider stress relieving after machining. This operation is a must post polishing. Plastic components polished without annealing will likely crack in operation.Stress tests are available for the various plastics to check for this condition.