Stress cracking in root of fins. Poor surface finish blocks light transmitting through material.
Stress relieving of material and custom designed cutting tool eliminates machining stress. Clear finish accomplished through vapor polishing.
Instrument shield stress cracks in service.
Machine components while maintaining low stress levels. Final stress relieving cycle eliminates future stress cracking.
Washer requires heat treatment for 4 days at 600 degrees while maintaining flatness.
PPS Machined Component
Component must be machined with low to no stress. Part requirements dictate a final stress test for lot acceptability.
Polysulfone is very susceptible to stress cracking over time. Annealing cycle after machining removes material and machining stress. Components pass final stress test 100% of the time.
Sample of Vapor Polishing on a Polycarbonate component.
Proper machining and stress reliving of a vapor polished polycarbonate part versus stress cracked polycarbonate component.
Polysulfone benefits from post machining stress relieving. Polysulfone is stress sensitive and unannealed components can fail in service from thermal and mechanical loading. Parts that are stabilized will survive 3 second submersion in acetone without failure.
Examples of Parts Machined in Polysulfone
PPS material annealed for 4 days to improve performance in high end device application
Stress lines in an acrylic manifold.
Analysis of stress in an ultem component. Part used in the semiconductor industry.
Annealing or stress relieving of plastics can be an important step in plastic machining.
While not all components require annealing, there may be advantages for some materials and part configurations. Please contact our engineering department to discuss your particular application. Depending on material choice and target performance, we choose from multiple approaches to ensure long term success for the plastic component.
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.
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.
Please consider the above as a brief summary of our technical plastic capabilities. Stress relieving and annealing, stress testing and measurement are topics that can be best covered by speaking with our engineering department. Please call for more information.