Bayer MaterialScience (Leverkusen / Germany; www.bayerbms.com) has added three new grades to its series of medical TPUs, extending the hardness range it offers. “Texin” RxT70A, RxSTX120 and RxHM125 resins can be processed by injection moulding or extrusion and meet test requirements of the widely accepted standards for biocompatibility of the US Food and Drug Administration (FDA, Washington, DC; www.fda.org).

“Texin” RxT70A TPU is a plasticiser-free resin with good hydrolysis, low temperature flexibility, and high moisture vapour transmission rates for applications including catheters and catheter balloons, speciality tubing and profiles. It is the softest TPE in the company’s range and can also be used for gaskets and soft overmoulding applications, such as grips.

“Texin” RxHM125 is a clear TPU with a Rockwell hardness of 125 (87 Shore D) – the hardest of the new grades – and a flexural modulus of 330,000 PSI, while RxSTX120 is an opaque, high-performing TPU that offers improved impact properties. Both of these high-modulus TPU grades are claimed to offer high heat and chemical resistance, low moisture absorption, low mould shrinkage, a low coefficient of thermal expansion and good abrasion resistance, and have been developed for a number of medical applications, including connectors, clips, luer connectors, equipment housings, stopcocks and fittings.