Thermoplastics stay waterproof but breathable

A DSM Engineering Plastics product story

Edited by the Engineeringtalk editorial team Jul 6, 2007

Skyair and Skyair XT membranes can be used in recreational, sports, medical and construction applications which are waterproof and windproof, yet remain "breathable".

Skymark Performance Films employs 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 and when laminated to fabric can be used in recreational, sports, medical and construction applications which are waterproof and windproof, yet remain "breathable".

Arnitel has successfully implemented new technologies for the Arnitel Vapour Transmission (VT) products.

These Arnitel VT products combine intelligent breathability with excellent film processing behaviour 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 nonwoven 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".

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.

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.

"We are proud to have helped Skymark meet the challenges of breathable, waterproof membrane applications with their Skyair and Skyair XT products", said Francis Aussems, Application Development and Technical Manager, DSM Engineering Plastics.

"It is particularly satisfying to work with Skymark because of their ability to seek out and use new developments".

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.

The same attribute makes nonporous 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.

The material offers elasticity over a wide temperature range, excellent chemical resistance, a high melting point, and good adhesion to substrates.

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.