Plastics for medical devices

In medical technology, plastics are not selected by price and processability but by biocompatibility and sterilisability. ISO 10993 sets out how a material in contact with tissue must be evaluated; how long and how intensively that contact lasts determines the scope of testing. Common choices are PEEK for loaded implant components, PSU and PPSU for autoclavable housings and sterilisation trays, POM and PC for functional parts, and TPE and silicone wherever softness and resilience are required.

The second question is sterilisation, and it rules materials out. Not every thermoplastic survives steam at 134 degrees; gamma radiation embrittles some and discolours others; ethylene oxide requires degassing times and leaves residues that must be assessed. Anyone who settles the sterilisation route only after the design is finished will design twice.

For buyers, provenance matters as well: medical-grade types with a manufacturer's declaration, documented batch traceability and ideally a drug master file or USP Class VI evidence. A standard grade bearing the same designation but from a different production line is not the same material — additives and compounds differ, and that is exactly what a notified body looks at.