Plastic Stress Test Protocols

High stress levels in plastic are a common cause of component field failures. Stress cracks or surface crazing near stress concentrators like threads can be a sign of future problems. Sometimes stress is not visible until the component is subject to loading or exposure to chemicals by the end user.

Connecticut Plastics has protocols for testing components for stress after machining. These range from total destructive testing to optical stress measurement. While not all components require annealing, there may be advantages for some materials and part configurations. Materials most sensitive to field failures are Acrylic, Polycarbonate, Ultem, Polysulfone and Noryl.

Failures arising from hasty material selection are not uncommon in the plastic industry. Careful consideration of your application and target performance is crucial to choosing the right plastic material.

Polycarbonate Machined Components - One showing Stress Cracks

Residual stress in machined or molded plastic parts is often a concern for engineers determining life span of a device. In conjunction with annealing, Connecticut Plastics offers stress testing and measurement. We can provide either optical or chemical testing to detect stress concentration after plastic machining. This approach takes into account both material and configuration effects.

Connecticut Plastics has multiple programmable ovens for precise control of the stress relieving process. We can anneal components that are manufactured by us or by our customers. Injection molded blanks also may benefit from a stress relieving process.

Stress relieving and annealing, stress testing and measurement are topics that can be best covered by speaking with our engineering department. Through special processing, Connecticut Plastics can produce a very low stress plastic component. Customers can request a lab stress test along with a production run to ensure suitability for their application. For help with material selection and testing of your prototype please contact Connecticut Plastics. Call Pete Poodiack at 203-265-3299 X 20, or email at pete@connplastics.com.