Trends in technical textiles
Global technical textile leaders converge to discuss the industry’s future and some recent innovations.
By Adrian Wilson
How to Enter Technical Textiles Markets,” a conference held in Edinburgh, Scotland, in October 2009, was the fifth in a series arranged by International Newsletters Ltd., publisher of Technical Textiles International and technical-textiles.net. Presenters from around the globe offered manufacturers and suppliers tools to understand how to seize opportunities presented by the technical textiles market. The meeting focused on market sectors by application and by geography; speakers gave an analysis of the sectors alongside an overview of the latest developments within them and the effects these are having. Following are some high points of the conference.
Motivated by the military
Historically, military inventions often result in broader civilian applications. This is especially true of technical textiles. Smart fabrics developed by the U.S. military and the U.K. military are now entering the civilian market, providing opportunities for manufacturers. “The U.S. military has been the incubator for a wide range of smart textiles and technologies, with the drive towards developing new materials which can sense and react to environmental conditions or interact with others,” said Steve Warner, president of the Advanced Textiles Association (ATA) in Roseville, Minn., U.S.A. Driven by the military need for ballistic restraint materials and medical products, the U.S. market for smart fabrics grew by 27 percent in 2008 to reach a value of US$193 million.
Microwave grafting technology
John Almond, co-founder of Alexium Ltd., based in Cambridge, U.K., provided details of a ground-breaking and potentially disruptive reactive surface technology, developed initially in a U.S. Department of Defense laboratory. Alexium now holds the proprietary patents for the technology, which allows for the surface modification and attachment of nanoparticles or multi-functional groups to surfaces or substrates in a matter of seconds.
A unique microwave grafting technique is at the heart of the developed method for employing commercially available chemical compounds to produce multi-functional materials. In addition to being extremely fast, the technique is a low-energy treatment that involves no heat, with the microwave graft providing triple-point attachment of the silane and the ability to crosslink multiple functions simultaneously.
The initial focus of the U.S. military for the technology was the production of lightweight CBRN (chemical, biological, radiological and nuclear) suits. The Alexium shell fabric of the new CBRN suits is said to enable them to be lighter, thinner, more flexible and more breathable.
Liquid-repellent nanocoating
P2i Ltd. recently installed its latest ion-mask™ liquid-repellent nanocoating line for Adidas in Guangdong, China. The company has 15 such machines in place, primarily in Asia, but also in Europe and the United States. The proprietary lines are for P2i’s own production and also those licensed to third parties.
The technology works by applying a nanometer-thick polymer layer over the entire surface of a product. Using an ionized plasma gas, this layer is molecularly bound to the surface so it will not leach away. The process confers superior oil and water repellency by reducing the surface energy to ultra-low levels, down to one third that of polytetrafluoroethylene (PTFE). In footwear and textile applications, P2i’s technology also minimizes liquid absorption from outside elements and evaporated perspiration. P2i Ltd. was established in 2004 to commercialize the treatment, originally developed by the U.K.’s Ministry of Defence. Ion-mask is now available in a range of premium products in Europe.
Impact protection
The Dow Corning® Active Protection System (APS) was first introduced in 2007 and is based on silicone materials that are able to absorb and dissipate energy, reducing the amount of force experienced by the wearer or the object being protected. Two new versions of the APS were introduced in 2009: the S-Range, based on three-dimensional spacer fabrics, and the TP-Range of thermoplastic silicone materials.
“The first generation attracted a lot of interest, winning design and innovation awards, but certain material aspects limited their use beyond the original target of replacing rigid, hard armor in motorcycling applications,” said Liz Mallen, Dow Corning Active Protection System program leader. “Our aim now is to offer the designer more choices. The spacer fabrics in the S-Range allow great breathability and airflow, as well as softness and flexibility, while TP-Range products are supplied in sheet form, either with or without perforations, and offer even greater protection.”
Both new products are said to be effective over a broad range of temperatures from –20°C to +40°C and have the added benefit of washability.
Textiles and robotics
Intelligent textiles will have a major part to play in the rapidly advancing field of robotics, and particularly in allowing robots to take on the form and features of human skin, said David Lussey, founder and director of Peratech Ltd. in North Yorkshire, U.K. He explains that a nonlinear sensing capability can be achieved on or within a textile structure, by coating them with electrically conductive nanoparticles, or by incorporating the nanoparticles into the fibers or yarns. This new class of electrically conductive material known as quantum tunelling composites (QTC) can make fibers and yarns extremely sensitive to stimuli such as pressure, temperature, vapor or radiation.
QTC textile switch and sensor coatings are rugged, reliable and able to operate in difficult environments. They can also be washed and dry cleaned and are extremely safe. They can be employed on many host systems to make switches and sensors, such as those employed extensively in textile apparel by New York-headquartered Qio Systems. The use of QTCs in robotics in combination with textiles is already a commercial reality, with the Robonaut gloves developed by the National Aeronautics and Space Administration (NASA) and the Defense Advanced Research Projects Agency (DARPA) being employed on unmanned space missions.
Textile skin
Among the applications for QTC sensors is to provide a sensing textile skin in an autonomous or prosthetic hand. In this application, QTCs provide the benefits of durability, low cost and flexible integration with a very low sensor material profile.
“The sensor material can detect multiple gestures and functions that respond instantly to contact, and the sensitivity of the material can be customised for the individual application,” Lussey said. “We have been involved in a number of robotics projects and it’s an area where textiles are definitely going to be of great importance because of their obvious benefits and ability to become the next best thing to human skin.”
Peratech has also been involved in the EU-funded Inteltex project which has incorporated carbon nanotubes (CNTs) into polymer binders to be spun into filaments and yarns. Such materials are sensitive to heat, strain, shear, liquids and vapors.
“The project is in its final year and CNT-loaded polymer fibers and yarns have been produced and made into woven and nonwoven textiles, which are demonstrating good sensitivity and selectivity when used as sensors,” Lussey said. “Sensors have been produced in sizes ranging from a few centimetres to many meters, and Peratech has provided the necessary connectivity to take the signal from the sensor to the associated electronics.”
These new developments have inevitably faced challenges in light of the current financial downturn, but advancements continue to be made in the technical textile arena, providing opportunities for growth in this cutting-edge market segment. “CNTs are here to stay, just like the robots, and these areas are shaping the future of textiles,” said Lussey.
