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| Issue date:01/10/2007 |
| ATA Journal for Asia on Textile & Apparel - Oct 2007 Issue |
| Source:Journal for Asia on Textile & Apparel |
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| Whether offering protection from simply inclement weather or the heat and danger of desert wars, function is increasingly being built into garments, Adrian Wilson reports |
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| David Beckham models the new LA Galaxy strip featuring advanced Adidas technologies |
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Garments can now be engineered to carry out a range of functions depending on their intended end-use and/or environment.
In active sportswear, breathability is the key, and sophisticated moisture management systems have been developed by a number of manufacturers. Aligned with lightweight comfort and engineered fit, clothing can make a significant contribution to sporting performance.
Sportswear for play
David Beckham, for example - arguably right now the most well known footballer on the planet -recently unveiled the new kit of his US team LA Galaxy.
The latest in Adidas apparel technology is featured in the Galaxy kit, including ClimaCool and FlowMapping technologies designed to allow heat and sweat to escape the body and also proven to reduce fatigue and dehydration. The football top also features ForMotion technology, engineered to fit an athlete's body in motion through three-dimensional design and by flattening the seams to reduce irritation.
For the hottest Olympics ever, in Athens, Greece, in 2004, Adidas created its Climacool Olympic apparel technology, engineered to keep an athlete's body at the optimal body temperature at all times, regardless of the heat.
Together with Dr George Havenith of Loughborough Sports University in the UK, Adidas studied human thermal physiology, or how people react to heat stress. Body maps for both male and female athletes were created to precisely identify where the human body produces sweat at different exercise levels, in different climatic conditions as well as considering different athlete types, body types, genders and age.
Based on this research, Adidas applied moisture-wicking fabrics, conductive fibers consisting of silver-coated yarns and three-dimensionally structured fabrics, to key heat and sweat zones. The X-Static conductive fibers were located down the back of the shirt in a chimney construction to conduct heat, and conductive tape was applied along the inside of the neck, both to draw heat away from critical heat zones and send cooling signals to the brain. The 3D fabrics, located in key places on the garment, consisted of hundreds of small indents on the body-side of the fabric. These sat off of the body, stopping the garment from clinging and maximizing ventilation.
Water repellancy for outerwear has now been combined with breathability, in the latest nanocoating treatments developed by companies such as Nano-Tex and Schoeller.
The range of nano-enhanced treatments marketed by Nano-Tex called "Resists Spills", "Repels and Releases Stains", "Coolest Comfort" and "Resists Static" are now used by over 100 of the leading global brands.
These treatments all comply to the criteria for nanotech products as defined by the National Nanotechnology Initiative in the USA, in that they consist of ordered assemblies of particles of between 1 and 100 nanometers that can be structured and manipulated, resulting in their novel properties.
They are also said to be both more durable and efficient than conventional coating. The nanoparticles are attached into the fibers without affecting the feel of the fabrics, and their engineered purpose is permanent.
NanoSphere is a finishing technology offering many types of textiles a high level of protection from soiling, soaking, wear and tear. The basis of this consumer-friendly, environmentally-compatible innovation by Schoeller is a resilient micro-rough surface structure, created at chemo-physical levels in nanometric dimensions. Even very oily and greasy substances running off astonishingly do not affect the look, feel or properties of the textile material.
Despite the lengthy development times involved in creating such products, it is likely that their performance will quickly come to be taken for granted and expected at consumer level, yet they represent a truly scientific breakthrough in fabric technology.
Protective wear
Generally speaking, the more hazardous the situation, the more the functionality in clothing becomes critical.
This is certainly true for the military.
TenCate Protective Fabrics USA has recently secured contracts worth well over US$50 million to supply FR (flame-resistant) camouflage fabrics to the US military.
Defender M to be used in the latest US combat gear |
The company has developed a new, highly functional fabric called Defender M, involving both knitted and woven materials, will be used in the latest US combat gear.
This is not only a significant boost for TenCate, but also its fiber suppliers - the fabric is composed of blends of Teijin Twaron para-aramid, nylon and Lenzing FR.
Head of the Lenzing FR team Oliver Spöcker said the TenCate contract represented "the biggest sales story in Lenzing FR's history" and as a consequence, manufacturing would be doubled to 6,000 tonnes annually by April 2008 as a result of constant debottlenecking.
Lenzing FR's inclusion in the project was initially surprising, since the US Berry Amendment called for all military clothing to be US-made. However, Mr Spöcker explained that the US army had recently had problems with the intense heat in countries like Iraq, with temperatures often rising to over 40℃.
"In addition to protection, what soldiers were requesting was additional comfort, which can only be supplied by Lenzing FR," he said. "Moisture management is the key."
TenCate Protective Fabrics USA (formerly Southern Mills) has developed a patented process called "disruptive infrared reflective printing" for its camouflage fabrics.
Traditional garments have been based on pigment-printed aramid fabrics, which are very susceptible to abrasion. The two-stage TenCate process involves a combination of dope dyeing the aramid and vat dyeing the Lenzing FR, so that the print goes into the fabric and the flame retardancy is overprinted.
Meanwhile, over Hellendoorn in the Netherlands, new turnout clothing, distinguished by a striking sandy color, has been handed over to the local fire service.
The clothing is made from the new Millenia Light, a special inherent heat and flame-resistant fabric from the TenCate Tecashield collection.
The Millenia Light fabric was developed based on tried and tested technology that TenCate has already been using for a number of years in the United States. Over half of the fire services in the US own a suit made from TenCate materials. By using the suits, however, the Hellendoorn corps has set a national and European precedent. The Hellendoorn fire service opted for the Fireman Tiger Twente model, supplied by the company Nijhof Safety.
TenCate's Millenia Light |
Millenia Light, offering superior comfort, is exceptionally strong and durable. It is also said to remain in tact for far longer under exposure to fire and heat than other fire-resistant materials. Additionally, the fabric is extremely lightweight and, combined with the special layers and inner shell, superior to other materials in its use.
The turnout clothing is only available in the sandy color because the fibers employed-a blend of Polybenzimidazole (PBI) and para-aramid-cannot be dyed.
DuPont's heat-resistant para-aramid fiber, Nomex is employed in a wide range of protective apparel.
Inherently flame-resistant, it does not melt, drip or support combustion in air and also resists a broad range of chemicals.
The Nomex fiber is perhaps best known as a critical component in protective apparel. Today, more than three million firefighters around the world are protected by turnout gear, stationwear and accessories made of it. It is also used in apparel worn by military pilots and combat vehicle crew, racing drivers, pit crew members and track officials, and industrial workers at risk from flash fire to electric arc hazards.
US troops in Iraq are being outfitted with Nomex apparel to protect them from burns caused by roadside bombs.
DuPont last year announced a US$100 million global expansion plan to increase worldwide capacity for Nomex. It would build a new facility in Asturias, Spain, to produce isophthaloyl chloride, one of the main ingredients of Nomex, and would also add equipment to its existing Asturias manufacturing site to increase Nomex capacity by more than 30%.
Medical clothing
The protection of medical personnel from viral exposure, particularly in surgery settings, has never been more important, with incidents of viruses and other contagious diseases such as HIV, MRSA, CJD, Hepatitis and SARS increasing throughout the world.
This has given nonwoven fabrics something of a boost.
Nonwoven fabrics have excellent liquid resistance, tensile strength and hydrophobic/hydrophilic properties, pointed out by European industry body, Edana.
One of the leading manufacturers of medical protective gowns and drapes is Ahlstrom, whose multifunctional Breathable Viral Barrier (BVB), for example, is designed not only to protect medical personnel from viral infections, but also provide a high level of breathability and comfort, even as the wearer's temperature rises.
Ahlstrom's Breathable Viral Barrier (BVB) is designed to protect medical personnel from viral infections |
This triple-layered fabric features a responsive, monolithic membrane sandwiched between inner and outer fabrics made of continuous fine filaments. The inner layer provides a soft touch to the wearer's skin while the outer layer provides additional repellency and strength.
The inner membrane of BVB "breathes" as a result of the molecular diffusion of water vapour through the thickness of the film. The membrane automatically responds to rising body temperatures that doctors, nurses and other medical personnel experience in high-stress situations, especially in the operating theater, by increasing the rate of moisture transfer.
The BVB fabric allows the wearer to perspire without being trapped inside a non-breathable shell. Many other gown fabrics currently on the market use micro-porous films, which by definition have holes and cannot provide the same protection.
Outer space expeditions
Nowhere perhaps, could the functionality of an outfit be considered more critical than in the outer space, yet space clothing has changed little since the first Moon Landings of the late 1960s and 1970s.
While bulky, gas-pressurized outfits provide astronauts with the necessary protection, their significant mass and the pressure itself severely limit mobility.
Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT (Massachusetts Institute of Technology), is working to change this, and has designed a sleek, advanced suit of nylon and elastane.
"Traditional bulky spacesuits do not afford the mobility and locomotion capability that astronauts need for partial gravity exploration missions," she says. "We really must design for greater mobility and enhanced human and robotic capability."
Newman and her team have been working on the project for about seven years. Their prototypes are not yet ready for space travel, but demonstrate what they are trying to achieve-a lightweight, skin-tight suit that will allow astronauts to become truly mobile lunar and Mars explorers.
Newman anticipates that the BioSuit could be ready by the time humans are ready to launch an expedition to Mars, possibly in about 10 years.
Her prototype suit is a departure from the traditional model. Instead of using gas pressurization, which exerts a force on the astronaut's body to protect it from the vacuum of space, the suit relies on mechanical counter-pressure, which involves wrapping tight layers of material around the body. The trick is to make a suit that is skin-tight but stretches with the body, allowing freedom of movement.
Over the past 40 years, spacesuits have actually become progressively heavier, and they now weigh in at about 300 pounds. That bulk - mainly due to multiple layers and the life support system coupled with the gas-pressurization - severely constrains astronauts' movements. About 70% to 80% of the energy they exert while wearing the suit goes towards simply working against the suit to bend it.
"You can't do much bending of the arms or legs in that type of suit," Newman says.
When an astronaut is in a micro-gravity environment (for example, doing a spacewalk outside the International Space Station), working in such a massive suit is manageable, but, as Newman says: "It's a whole different ballgame when we go to the moon or Mars, and we have to go back to walking and running, or loping."
Another advantage to her BioSuit is safety - if a traditional spacesuit is punctured by a tiny meteorite or other object, the astronaut must return to the space station or home base immediately, before life-threatening decompression occurs. With the BioSuit, a small, isolated puncture can be wrapped much like a bandage, and the rest of the suit will be unaffected.
Newman says the finished BioSuit may be a hybrid that incorporates some elements of the traditional suits, including a gas-pressured torso section and helmet. An oxygen tank can be attached to the back.
The MIT researchers are focusing on the legs and arms, which are challenging parts to design. In the Man-Vehicle Lab at MIT, students test various wrapping techniques, based on 3D models they have created of the human in motion and how the skin stretches during locomotion, bending, climbing or driving a rover.
Key to their design is the pattern of lines on the suit, which correspond to lines of non-extension (lines on the skin that do not extend when you move your leg). Those lines provide a stiff "skeleton" of structural support, while providing maximal mobility.
To be worn in space, the BioSuit must deliver close to one-third the pressure exerted by Earth's atmosphere, or about 30 kPa (kilopascals). The current prototype suit exerts about 20 KPa consistently, and the researchers have got new models up to 25 to 30 KPa.
The suits could also help astronauts stay fit during the six-month journey to Mars. Studies have shown that astronauts lose up to 40% of their muscle strength in space, but the new outfits could be designed to offer varying resistance levels, allowing the astronauts to exercise against the suits during a long flight to Mars.
The project was initially funded by the NASA Institute for Advanced Concepts.
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| Copyright © Adsale Publishing Limited. Any party needs to reprint any part of the content should get the written approval from Adsale Publishing Ltd and quote the source "ATA Journal for Asia on Textile & Apparel", Adsale Textile English Website - www.AdsaleATA.com. We reserve the right to take legal action against any party who reprints any part of this article without acknowledgement. For enquiry, please contact Editorial Department. |
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| Copyright © Adsale Publishing Limited. Any party needs to reprint any part of the content should get the written approval from Adsale Publishing Ltd and quote the source "ATA Journal for Asia on Textile & Apparel", Adsale Textile English Website - www.AdsaleATA.com. We reserve the right to take legal action against any party who reprints any part of this article without acknowledgement. For enquiry, please contact Editorial Department. |
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