New Thermoplastic Elastomers for Breathable Membranes

Skymark Performance Films Limited (Scunthorpe, U.K.), has employed Arnitel® VT thermoplastic ether ester block copolymer elastomer (TEE-E) film technology materials from DSM Engineering Plastics, in Skymark's breathable SKYAIR® and SKYAIR® XT membranes. SKYAIR® and SKYAIR® XT membranes offer different levels of moisture vapour transmission rate and when laminated to fabric can be used in recreational, sports, medical and construction applications which are waterproof and windproof, yet remain "breathable". Because there are no pores in membranes made from the Arnitel® material, SKYAIR® and SKYAIR® XT membranes retain their waterproof qualities even when water drops hit at high speeds, as on a motorcycle jacket worn while riding in the rain. Other attributes especially fitting for the SKYAIR® and SKYAIR® XT usage of Arnitel® include the material's elasticity over a wide temperature range, excellent chemical resistance, high melting point, and good adhesion to substrates. Arnitel® has successfully implemented new technologies for the Arnitel® Vapour Transmission (VT) products. These unique Arnitel® VT products combine intelligent breathability with excellent film processing behavior and are specially designed for applications in breathable membranes. Arnitel® VT products also exhibit excellent draping and soft touch, making it especially useful in layered fabric and non-woven constructions. Unlike many earlier waterproof yet breathable film types, films made from Arnitel® elastomer contain no micropores. Water vapour transmission is accomplished by diffusion through the film itself. SKYAIR® and SKYAIR® XT membranes are the first commercial applications of the new Arnitel® VT technologies. "We chose Arnitel® VT for its excellent processability and level of breathability," said Paul Glover, Group Technical Director at Skymark. "DSM's engineering staff went out of their way to aid us in the many development and production elements involved in the commercialisation of SKYAIR® and SKYAIR® XT using the new Arnitel® technology material, the most recent being the launch, of the higher MVTR, SKYAIR® XT membranes. The result has allowed Skymark to offer alternative breathable membranes at a competitive level into the price driven textile market and we look forward to continued developments with DSM in the future." In medical applications, pore-free SKYAIR® and SKYAIR® XT membranes block bacteria and viruses in addition to body fluids. Breathability is not affected by repeated washing, where pore-based materials tend to clog with detergents or particulate lifted during washing. In textile-based uses, the breathability of SKYAIR® and SKYAIR® XT membranes affords comfort to wearers engaged in performance recreation and sports activities, even in extreme weather. In a completely different vein, the same attribute makes non-porous fabric made from Arnitel® VT elastomer good for use as a roofing membrane in building construction, where it allows water vapour from the inhabited side to disperse into the outside air. In addition to film applications, Arnitel® is extensively used in automotive components designed for human touch, such as armrests and steering wheel covers; for components requiring exceptional fatigue resistance and resistance to oil and greases, including rack and pinion bellows, constant velocity joint (CVJ) boots, and air brake tubing. In the electronic and consumer goods industries, Arnitel® is widely used for mobile phone antennas, cable insulation, flexible tubing, handles, and pads. The range of Arnitel® is exemplified by its use both in tiny, low-noise gears, and in large, energy- and sound-absorbing railway pads.