TPEs are materials of choice for medical devices

Medical device manufacturers increasingly turn to thermoplastic elastomer (TPE) for applications that require flexibility or rubber-like elasticity. These compounds have replaced alternative materials like thermoset rubber and PVC in standard applications like tubing, bags, pouches, drip chambers, masks, cushions, syringe tips, ventilator bags, luers, stoppers, gaskets, seals, and dropper bulbs. And as designers have come to appreciate the value of TPEs, more and more are using these elastomers for new applications.

TPEs are excellent candidates for medical applications due to their chemical inertness or ‘clean’ ingredients. Medical grade TPEs are made with FDA compliant raw materials and are free of phthalates and latex proteins. In addition, TPEs are inherently designed to have extremely low extractables or leachables, even when in contact with aqueous based systems (like bodily fluids). Medalist TPEs are considered biocompatible per ISO 10993 testing protocols for cytotoxicity, irritation, and sensitisation. Products made from TPEs can be sterilised by e-beam, gamma, ethylene oxide, or autoclave methods.

Besides versatility, a second reason for TPE growth in medical devices involves their advantages over alternative materials. The most obvious advantages stem from the fact that TPEs are thermoplastics. They process more efficiently and economically than thermoset rubber, provide greater design freedom, exhibit a wider range of color options, and, unlike rubber, can be recycled. At the same time, TPEs provide device manufacturers with a means of obtaining comparable or even superior properties while avoiding problems associated with certain alternative materials. This has been particularly apparent in replacement of the following.

Latex. Medical manufacturers seek alternatives to latex due to protein allergies, concerns with the level of extractables or leachables from the cure system, and odor. Another factor is economics: Processing rubber is more laborious than processing TPEs, and TPE processing scrap is recyclable. Typical applications include extruded film and dipped anesthesia bags.

The move to alternative materials is also taking place among TPEs themselves. For example, the device industry is seeing a shift from thermoplastic vulcanizate (TPV) elastomers to other TPEs.