DuPont's resin has been used in microtweezers for non-invasive surgery

DuPont's resin has been used in microtweezers for non-invasive surgery

Glass-reinforced nylon resin has been used in microtweezers for non-invasive surgery. ERBE Elektromedizin in Germany used DuPont’s Zytel nylon resin to mould the handle and integrated lever in microtweezers developed for keyhole surgery.

ERBE and system supplier PEZET chose Zytel 70G30HSL in place of the Peek material originally planned for the handle. The resin was modified, through the incorporation of a masterbatch, to accept laser-marking. ERBE development engineer Achim Brodbeck told PRW.com: “All the parts meet standard requirements for medical equipment.”

The material is also less expensive than Peek. DuPont’s Bernd Muskat adds: “There’s a factor 30 [price differential] between Zytel and Peek – 85-90 euros [per kg] – based on my market knowledge.” The handle’s individual parts included a main housing, a cable channel and a holder for a 1.5mm-diameter metal tube, through which the wires for operating the tweezer’s jaws pass. The lever to open the jaws is mounted on the handle.

DuPont said very precise parts can be moulded with the resin that keep their functionality even after sterilisation in an autoclave, where temperatures can reach 134°C. Zytel also provides long-term resistance to cleaning agents used in hospitals.

PEZET head of design and development Jakob Mesam says: “As long as the correct mould temperature, injection speed and injection pressure are strictly adhered to, the parts of Zytel are of very high quality and show no post-shrinkage.”