Plastics for Medical Sterilisation: Autoclave, Gamma & EtO Compatibility

Design Considerations for Repeated Cycles

· Avoid sharp internal corners — stress risers initiate crazing during thermal cycling

· Anneal machined parts before first sterilisation to release machining stress

· Specify the cycle count the device must survive, then test to 1.5× that number

· Verify that cleaning agents used between cycles are compatible with the polymer

· Consider colour shift: ambering of PPSU or PEI after gamma is cosmetic, not structural

Validation Support

NAGOMER supplies material certification and batch traceability for medical programmes, and can machine test coupons and prototype devices from the same production stock used for final parts. Combined with our ISO 9001 quality system, that gives device manufacturers a documented chain from resin lot to finished component for their own validation files.

Equally important is the total number of sterilisation cycles a device must survive in service, not merely in validation. A surgical instrument reprocessed twice a day for five years faces more than three thousand cycles; a single-use device faces one. Laying that number against the compatibility table narrows the material choice faster than any other single input. It also reframes the cost conversation: PEEK and PPSU components justified by a thousand-cycle life are expensive per part but remarkably cheap per use compared with an item replaced every hundred cycles.

Related reading: PEEK in Medical Devices, PPSU & PSU Sulfone Polymers, and Engineering Plastic Certifications Explained.