Following the resounding success of breathable functional textiles for sport and leisurewear, the development of fabrics for these purposes is said to be entering a new phase. Experts at the internationally renowned textile research centre, the Hohenstein Institute in B�nnigheim, Germany, have analyzed the heat and moisture management specifications for fabrics worn on different parts of the human body and in a process called 'body mapping with comfort zones' or simply 'comfort mapping', the scientists say their findings should make it possible in the future to use different textile materials for different parts of a garment, making sportswear significantly more comfortable to wear.

"Until now, sports clothing were usually made entirely of a single type of textile material. In many cases, this proved unsatisfactory in terms of comfort. In order to meet the various different requirements for moisture wicking, insulation, and weatherproofing, sportsmen and women often had to wear several layers of clothing on top of each other, on the 'onionskin' principle," the Hohenstein experts say. "Now, innovative textile structures should make this unnecessary in the future. As well as providing the best possible temperature and moisture regulation, in relation to the ambient climate and the activity, now textiles should also take skin sensory aspects into account in the interests of comfort."

Principles of comfort mapping

Comfort mapping is said to take account of the spatial distribution of heat and moisture production in different parts of the body by using different textile materials. For example, a windproof textile material on the chest and back would keep the cold wind out, while a particularly breathable and moisture-wicking textile material under the armpits would keep it dry under there. The institute says the principle of body mapping is based on findings about human thermoregulation.

"The term thermoregulation refers to a complex, interconnected system of the body's own reactors, which trigger certain physical reactions when they receive messages from the brain. These control mechanisms are set in motion in conditions of either heat stress or cold stress. Under extreme heat stress, for example when cycling in summer, the sweat glands are activated, but these are not evenly distributed over the whole body. So different quantities of sweat are released in different parts of the body," says lead Hohenstein researcher Dr. Jan Beringer.

"With cold stress, for example when skiing, the control mechanism automatically triggers a protective function. This prevents the body core, i.e. the essential organs in the torso and the brain, from losing too much heat. Consequently, the skin and the extremities, especially the hands and feet, cool down. There are specific cold receptors in human skin that are responsible for detecting cold stress," Dr. Beringer says, adding:

"However, these cold receptors are not evenly distributed over the surface of the skin, with relatively more on the torso and head, and fewer at the extremities. This is why we are generally more sensitive to low temperatures around our trunk than at our extremities. Based on these findings about thermoregulation, it makes sense to develop clothing, especially for sportswear, that is adapted to meet the needs of different parts of the body, to make it comfortable to wear.


Sportswear with comfort zones


"If sportsmen and women are to be able to concentrate fully on their sporting activity, it is essential that their clothing is comfortable to wear. Making sure they feel nice and dry and comfortable in every situation is the best way of giving their individual performance an extra boost" Dr. Beringer adds. With this in mind, experts in his research team have now developed a sample prototype of a sports top with comfort zones based on the principle of body mapping, for the high-intensity sports of cycling and running.


Alongside the criteria for temperature and moisture control, skin sensory aspects such as softness and suppleness are also said to have played a role in the quest for the ideal product. The scientists say they were by no means satisfied with purely qualitative or subjective assessment criteria, but were looking for quantifiable, objectively verifiable benchmarks based on absolute criteria.


"With this project, we entered new territory, scientifically speaking. Because of the complexity of the task, absolute criteria for thermo physiological and skin sensory investigations had never been formulated in this way before," says Dr. Beringer, explaining the scope of the project.


Which properties should the ideal sportswear fabrics have?


In the first stage of the project, the researchers identified which properties the materials should have for use on the different parts of the body. To do this, specific property profiles were produced for the various materials, combining thermo physiological and skin sensory criteria. The researchers had to bear in mind that these requirements differ depending on the type of sport, the garment or part of the body involved and the weather conditions.


"Of critical importance here was the composition of the materials, i.e. where would it make sense to use synthetic fibres, where hygroscopic natural fibres (natural fibres such as wool, which can absorb a great deal of moisture without making you feel wet), and where a mixture of fibres? How do the so-called regenerated fibres such as viscose, modal or lyocell, that are made of sustainable raw materials, behave, "Dr. Beringer asks.


According to the results of the investigation, Dr. Beringer says, the greatest benefit is gained from using innovative fabric structures where the surface of the fibre can be modified depending on the requirement. "However, at the scientific heart of this project was the way that the results of thermo physiological studies, in terms of specific criteria such as heat insulation, breathability, moisture management and drying time, were combined with the results of skin sensory investigations. The context for this was the requirement that sportswear worn next to the skin should offer not only good thermo physiological properties but also excellent skin sensory comfort," he says.

 

According to the researchers, what was needed therefore were textiles which feel soft and supple and do not cause any irritation on the skin such as scratching or itching. Even when the skin is wet with sweat, the clothing should not stick to the skin, they established. The specific parameters measured in the tests therefore, were: sticking index, wetting index, surface index, number of contact points between textile and skin, and stiffness. The skin sensory investigation also took account of the different requirements depending on the type of sport, garment/body area and weather conditions.


Measurable pinnacle of comfort


According to Dr. Beringer, in the process of producing a profile of clothing physiology requirements, the next stage was to calculate exactly which specific properties a ready-made sports textile would have to have to be best suited for a particular purpose, depending on the type of sport, climatic conditions and the garment in question.


To do this, the experts at the Hohenstein Institute, working with partner companies in the textiles industry with an interest in the project, developed a prototype of a short-sleeved sports top with comfort zones, for running and cycling. With the help of the thermal articulated manikin Charlie, developed at the Hohenstein, which simulates the thermoregulatory system of a human, the scientists were able to obtain the information they needed to design this top in advance, by carrying out appropriate tests. For this purpose, the thermal articulated manikin was divided into 16 segments, such as the chest, back and upper arms.


A computer-controlled heating system was attached to each segment, which could be used to regulate the heat production for each section of the body separately. The tests were carried out when the manikin was both stationary and in motion, and using a wind machine which simulates the movement of air or turbulence. The findings made in the laboratory tests were backed up by wear tests conducted with volunteers in controlled conditions in the climate chamber.


The volunteers were fitted with sensors in the relevant places and had to test various fabrics in defined climatic conditions during a sporting activity such as running on a treadmill or riding on an exercise bike, and also using a wind machine. The data obtained in this way was fed directly into the development of the prototype.


Future trend


Building on the idea of the prototype sports top, the concept of comfort zones could, according to Dr. Beringer, be applied in future to nearly all sports and to all kinds of garments. Dr. Beringer says: "Together with our partners from the German textile and clothing industry, we have created a starting point for innovative products with tremendous customer benefits and well thought-through functionality. Furthermore, the sports sector has traditionally served as a test-bed for everyday clothing, because consumers increasingly want the comfort of sports and functional clothing in their everyday clothes. "

 

"The principle of so-called body mapping was an invention of the company W.L.Gore & Associates in 2006. Since then, some manufacturers of sports articles have adopted this procedure in producing their textiles, but have so far each worked in their own way and to their own standards. Consumers have to rely on the manufacturer's information, "Dr. Beringer says, adding that, in the case of body mapping with comfort zones:


"The main advantages here are that the textile can be more exactly adapted to meet the needs of the sportsman or woman. If sportswear is now designed to be perfectly suited to the particular sport, climate conditions and garment, and complies with specific property profiles, consumers can always be sure they are buying the best possible products, with improved comfort for a more efficient performance. "


(Courtesy: Industrial Community Research and Development (IGF), Germany)


Originally Published in New Cloth Market, April-2011