Advancement in Sport textiles by vignesh dhanabalan

Advancement in Sportech

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ADVANCEMENTS IN SPORT TEXTILE

Abstract

As we all know that sports textiles holds a great potential in the textile sector, it has

proved its dominance by the incorporation of smart textiles into ultimate goal of providing

comfort, protection, thermal insulation, moisture management and heat regulation to the

wearers. Smart textiles are inheriting of artificial intelligence into the sportswear. To simply

say smart textiles sports wears are to be under stood as self-thinking garments. It is of at most

important that we discuss and know about active smart textiles that are dominating in the

sports textiles. The prime objective of this paper to bring out the importance of active smart

textile materials like phase change material, shape memory material, auxetic materials,

holofibeand d3o materials. These material‟s principal, working mechanisms, properties,

methods of incorporation in textiles and its application in sports textiles are highlighted in

this paper. More over smart textiles in sportswear has played its key role in the London

Olympics 2012, which is also clearly proved in this paper, which gives clear evidenceof the

contribution of textiles for technology and development of standard of human life. Smart

textiles have come out with solutions for various researches carried out by the scientists and

multinational companies investing millions of dollars in it. The phase change materials are

used in wears of athletes, football, mountain climbing and snow skiing, where extreme

climatic conditions are to be tackled. The d3o materials are used in bike race, jumping events

and rugby where high impact forces are involved.

Introduction

The sports textile has taken its place from the floor (Ex. Artificial turf)

to the roof (Ex. PTFE roofing). The consumption of textile material used in sports was

1382000 tons in 2010. This figure itself shows the potential of the textile in sports sector

Sportech segment comprises of technical textile products used in sports (sportswear, sports

equipment and sports footwear)

Examples of sportswear are: aerobic clothing, athletic clothing, football clothing,

cricket clothing, games shorts, gloves, jackets, pants, shirts, shorts, socks, swimwear and

tennis clothing. Examples of sport equipment are: sails, trampolines, camping gear, leisure


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bags, bikes and rackets. Examples of sports footwear are: athletic shoes, football boots, gym

shoes, tennis shoes and walking boots.

Basically Textile materials were designed for having protection against extreme

natural condition of heat and cold, then gradually the purpose of clothing until it took a new

face (In the name of trend , ascetic use , and many more)now a days they are designed for

specific purposes and tasks.

In earlier days mostly cotton was preferred, with innovations and raise in requirement

blends of fibre like cotton/polyester, cotton/viscose and polyester/viscose were used. Smart

textile is expected to solve all the demands and the shortcomings of the sportsman like

moisture level maintenance, heat regulation, comfort, protection from UV rays and protection

against various impact forces.Smart textile materials readily interact with

human/environmentalconditions thereby creating changes in the material properties. For

example, thephase-change materials and shape-memory polymers embedded in fabric

layerswill be able to interact with a human body and produce thermoregulatory controlby

affecting the microclimate between the clothing and the human skin. Inaddition to the two

dimensions of functionality and aesthetics, if `intelligence'can be embedded or integrated into

clothing as a third dimension, it would leadto the realization of protective and safety clothing

as a personalized wearableinformation infrastructure.

Properties required for Sportswear

The clothing should be capable of protecting the wearer from external climatic

conditions such as wind, sun, rain and snow, extreme temperatures.

Good tactile properties

Thermal insulation

Good stretch ability

Being capable of transporting perspiration from skin and then quickly dispersing it.

Fabric should be capable of protecting the wearer from any impact forces.

Good energy storing/ absorbing capacity

The fabric should be designed in such a way that the wearer should experience less

drag (due to air or water).

Fabric should provide psychological comfort to the wearer.

Maintain the body temperature by thermoregulation.


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Necessity in advancement (up gradation) of materials

High strength

Flame and heat resistance.

High specific strength and modulus

High chemical resistance and high abrasion resistance.

High resistance to acid, solvents, steam, chemicals and fuels.

Moisture regain and soft hand (comfort).

Present scenario of sportswear market

As Olympics being the biggest recognition of the sports activity throughout the world,

it is considered as the biggest stage to exhibit the innovations of the sportswear companies. In

London Olympics 2012 one of the clear favourites to be benefit will be one of the main

sponsors, Adidas of Germany, which anticipates £ 100 million in directly related sales of

merchandise alone. It is also seeking to use the games to overtake its rival Nike (U.S.A), as

the biggest sportswear company in the UK. Nike is currently the market leader with an 18%

share of the UK‟s £ 4.3 billon sportswear markets, with Adidas in second place with 15%

share.

New innovations by Market leaders

Nike (U.S) has recently introduced series of light weight performance sportswear,

designed for such as athletics and basketball, including its Nike Flyknit and Nike Pro Turbo

speed uniforms. Nike‟s Pro turboSpeed suit (based on AeroSwift technology), which Nike

claims enables an athlete to run 0.023sec faster over 100m than when wearing previous best

running kit.

This suit is based on polyster fabric approximately 82% of the raw material being

derived from recycled plastic bottles(13 bottles are needed for each garment on average).

Smart Textile in Sports Wear

The smart textile in the sports clothing industry has resulted in the use of engineered

textiles for highly specialized performances in different sports. Smart materials providing

such a strong focus in the textile industry generally, companies are increasingly looking for

„value added‟ textiles and functional design in sportswear as well as intelligent textiles which


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monitor performance with in-built sensors. In this paper we are mainly concentrating on the

second level of smart textile that is the active sports textile which consists of the materials

like phase change material, shape memory material, auxetic materials, chromic material.

Classification of Smart Textile

Smart textiles are classified into three categories depending on functional activity, as follows:

Passive smart textiles: -The first generation of smart textiles, which can provide additional

features in passive mode that is not concerning with alteration in environment are called

passive smart textiles. Optical fiber embedded fabrics and conductive fabrics are good

examples of passive smart textiles.

UV protective clothing, multilayer composite yarn and textiles, plasma treated clothing,

ceramic coated textiles, conductive fibers, fabrics with optical sensors, are some examples of

passive smart textiles.

Active smart textiles:- The second generation of smart textiles have both actuators and

sensors and tune functionality to specific agents or environments, are called active smart

textiles. These are shape memory, chameleonic, water resistant and vapor permeable

(hydrophilic/ non porous), heat storage, thermo regulated, vapor absorbing, heat evolving

fabric and electrically heated suits.

Phase change materials and shape memory materials, heat sensitive dyes etc. in textiles form

active smart textiles.

Ultra smart textiles:-Very smart textiles are the third generation of smart textiles, which can

sense, react, and adapt themselves to environmental conditions or stimuli. They are the

highest levels of smart textiles. These may deal actively with life threatening situations

(battlefield or during accidents) or to keep high levels of comfort even during extreme

environmental changes. These very smart textiles essentially comprise of a unit, which works

like the brain; with cognition, reasoning and activating capacities.Ultra smart textiles are an

attempt to make electronic devices a genuine part of our daily life by embedding entire

systems into clothing and accessories. Though the entire potential has not been completely

realized, the developments so far can be termed as only rudiments of very smart textiles.

For example, spacesuits, musical jackets, I-wear, data wear, sports jacket, intelligent bra,

smart clothes, wearable computer etc.


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Passive smart textiles are lifeless but very smart textiles, are the most dynamic levels

of artificial intelligence in textiles5. In fact, passive textiles may not be termed as really smart

since they do not think for themselves. Nevertheless they perform special functions in the

passive mode and hence the term passive smart textiles.

Phase Change Material for Sports Wear

Phase change materials

Phase change material (PCM) the has a inherent property of lateral heat that can be

stored or released from a material over a narrow temperature range. These materials absorbs

energy (latent heat) during the heating process as phase change state takes place and release

energy (latent heat) to the environment in the phase change range during a reverse cooling

process.

Phase change process

In general the phase change material is that they change between solid and liquid state

in the temperature range where the material in used. A change from solid to liquid (melting)

involves the absorption of heat, and similarly a change from liquid to solid (crystallisation)

involves the release of heat. A melting heat absorption temperature of 20 to 40oc and the

crystallisation heat releasing temperature of 30 to 10oc are effecting in clothing. PCM‟s

currently used in textile structures are in the most cases different types of paraffin. Phase

change temperatures (solid and liquid) and the heat of melting depends on the chain length of

the linear hydrocarbon paraffin.

Phase change

material

Melting

Temperature

(degree celsius)

Crystallisation

Temperature

(degree celsius)

Heat

storage

capacity

(J/g)

Eicosane 36.1 30.6 247

Nanodecane 32.1 26.4 222

Octadecane 28.2 25.4 244

Heptadecane 22.5 21.5 214

Phase change paraffin and their properties


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The phase-change effect occurs in transient wear situations, when the meltingor

crystallisation temperature limit is crossed. Situations where this can beoptimally utilised are,

for example, when a person is moving frequently betweenwarm and cold environments or

handling cold pieces, or when the physical stressis changing frequently between hard work

and rest. The absorption and releaseof heat is a repeatable cycle, which takes place at the skin

temperature withoutunpleasant low and high temperatures.Incorporation of PCM into textile

fibres and structures is done throughencapsulating the paraffin in microcapsules (diameter

10±50 _m), to preventleakage in the liquid phase. The microcapsules are then incorporated in

eitherthe spinning dope, in insulating foams or in coating paste. As the textilecharacter of the

structure has to be maintained (mechanical strength, handle,etc.), only a fraction of the

product will actually be PCM, the main part being thematrix material. Scientists are therefore

somewhat sceptical about the truethermo physiological benefits of PCMs integrated in textile

materials.

Classification of phase change material

The materials used for the thermal energy storage are classified by the A.Abhat

.These materials are classified on the base of Thermal energy storage type and phase change

states.


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Phase Change material for Sportswear

Phase change materials have the potential to change the state at constant temperature and

store large quantity of energy. One of the most efficient uses of phase change materials can

be done in textiles by choosing materials that have large Thermal Energy Storage (TES) and

melting point from 15°C to 35°C.The required properties of Phase Change Material (PCM)

for the sportswear are mentioned below:

Large heat of fusion

Melting point temperature between 15°C to 35°C

Low toxicity

Non-flammability

Ease of availability

Low price

For effective heat transfer, large thermal conductivity

Harmless to environment

Little temperature difference between the solidification and the melting temperature

Stability for repetition of solidification and melting point

On the bases of the heat storage capacities, phase change temperature and properties

mentioned above the types of materials suitable for textiles especially sportswear are

given below with brief description.


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a. Hydrated Inorganic Salt

Hydrated salts are significant importance to use in Thermal Energy Storage (TES) due

to relatively high thermal conductivity (~0.5W/m°C), high volumetric storage density

(~350MJ/m3) and moderate costs compared to the linear chain hydrocarbons.

Hydrated inorganic salts with “n” water molecules are very important due to the heat

absorbing and heat releasing temperature interval is from 20°C to 40°C.

b. Linear long chain hydrocarbon

Hydrophobic linear hydrocarbons are the by products of the oil refinery and have the

general formula CnH2n+2. These materials are inexpensive, having no toxicity and

bigger source of raw materials available at different melting temperature ranges

according to the no. of carbon items present in the Paraffin. The mostly suitable linear

chain hydrocarbons have temperature -5.5°C and 37.5 °C. The phase change

temperature can be chosen for the specific applications by selecting the no. of carbon

atoms of the hydrocarbons. These are the most important materials used thermal

energy storage (TES) and the thermo regulated textiles such as sportswear. The

melting temperature of n-Eisocane is 37.5 °C which is about human body and heat

emission of the hydrocarbons.

c. Poly Ethylene Glycol

One of the important PCMs for the textile applications is Poly Ethylene Glycol (PEG). The

commercially available paraffin is cheap which contains a moderate thermal storage density

of (~200kJ/kg) and wide range of melting temperatures. The repeating unit of PEG is ox

ethylene (-o-CH2-CH2-) n. The melting temperature of the PEG is usually proportional to the

molecular weight.

PCM working in sports wear

The phase change materials could be encapsulated in the form of liquid before

applying to the textile structure. The capsules diameter varies between 1Om to 30 Om. The

benefits of applying the PCMs in the capsule form are these are resistant to the mechanical

actions, heat and chemical resistant. These materials reply to the changing environment in the

following manners.


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The temperature rises: When the temperature of the body raised due to the higher

ambient temperature more than the melting temperature of the PCM, the core material (Phase

change material) reacts accordingly and absorbs heat. By absorbing heat chemical bonds are

broken and phase change material is started converting from solid to liquid state. During the

melting process PCMs absorbs heat energy from the surrounding and stores extra energy.

The temperature falls: when the temperature of the body decreased due to lower ambient

temperature less than the crystallization temperature of the PCM, the core material (phase

change material) reacts accordingly and releases the previous stored heat. By releasing heat

the chemical bond are formed and the core phase change material started converting from

liquid to the solid phase. During the crystallization process releases heat to the surrounding

and wearer feels thermal comfort.

Microcapsules have the following benefits when applied to the garments:

A Cooling effect due to the heat absorption of the Phase change materials

A heating effect due to the heat emission of the phase change materials

A thermo regulating effect for the body by heat absorption or heat emission of the

PCMs which keeps the temperature nearly at the constant level.

As an active thermal barrier effect that is resulted by the heat absorbed or released by

the PCM which helps in regulation of the heat flux generated in the garment, from

human body to the environment and make it suitable according to the thermal needs(

ambient temperature, humidity, pressure of air and physical activity performed).

The fabrics treated with micro capsulated PCMs can absorb 4.44 J/g of heat if it contained

about 23% of the capsule material melamine formaldehyde during the melting process. The

heat absorbed by the capsule material 4.44J/g delayed the increase of temperature on the

clothing. In this manner it helped in increasing thermal comfort and reduced heat stress.

Incorporation of PCM’s in textile

The design and development of PCM have an ability to maintain the thermal energy

storage at worse and normal condition. They are incorporated in textile through

microencapsulation that are consisted on shell and surrounded core material. They are applied

through coating, melt spinning, fiber extrusion method, injection moulding, foam

manufacturing. PCM have linear hydrocarbon chain known as paraffin waxes, hydrated salt,


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polyethylene glycol, fatty acid and mixture of organic and non organic compounds.

Microcapsule application in textile has an advantage that encapsulation prevents the PCM

dispersion in structure, minimizes its evaporation and reduces the reaction of PCM with

environment, provides by increasing heat transfer area and constant volume and permits easy

application without any side effect. In fiber 5-10% microcapsule are incorporated without

effecting softness, drape and strength and no need of processing or washing.

Microcapsules are particles with thickness may be less than one Om and particle size

are vary within the range of less than 1Om and more than 300Om depends on the method of

encapsulation and diameter vary in between 20 to 40 Om. Microcapsules can be produced by

physical and chemical method that are limited to the cost of processing, regulatory affairs and

the use of organic solvents that are concerning to environment and health. Physical

techniques are employed through spray, centrifugal and fluidized bed process and the

chemical are employed through polymerization techniques.

The Cooperation is a miscible process in which the material in dispersed form is

added to the polymer solution and then suspended in aqueous phase condition containing

surface active agent. Micro capsulation is possible by mixing both water in oil or oil in water

method. In this case paraffin/wax in encapsulatation has high energy storage about 145 to

240j/g.

In situ polymerization two liquids water and organic solvent are bringing together to

react each other and form a solid pre condensate. The situ polymerization has the ability to

form a microcapsule with the best ability of diffusion tightness of their walls. In the Micro

capsulation study the situ polymerization methods, effect of stirring rate, ph of reaction

mixture, content of emulsifying agent, capsule diameter etc. in all these study our purpose is

to build a manufacturing that have based on situ polymerization in order to form a

microcapsule of PCM that is used in textile application. Second thing is to make it suitable

for laboratory scale and industrial scale work to save the energy and time.


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It’s Application in Sports Textile

During the sports activity the heat generated by the body can‟t be released properly

into the environment, this is the main cause of increasing thermal stress. But the when the

wearer uses the PCM active garments, the heat is released when it is necessary. In snow

skiing, mountain climbing, cycling and running are the sports where PCM active textile is

widely used.

D3o(de-three-oh)

A new material for different types of impact protection has been introduced under the

trade name d3o. In the normal state, the molecules flow past each other at low rates of

movement, but when they are subject to an impact that would require them to move very

quickly they instantaneously lock together to form a rigid protective barrier. As soon as the

impact has passed, they unlock to provide normal flexibility. Thus the garment does not

restrict body movements as conventional body armour products but give protection when it is

needed. Two versions are described: the three-layer d3o flex where the impact protection is

situated between a stretch outer layer and a moisture wicking inner textile, and the four-layer

d3o armour with an additional armour layer to provide penetration resistance. The base

material for d3o is generally polyurethane, but other polymers are also used. Applications are

foreseen in head, foot and body protection for motorbike riders, downhill skiers, etc.To the

question what does this mean to the average person walking down the street? Basically d3o

offers superior lightweight, flexible impact protection which when integrated into apparel

maintains style, comfort and practicality without compromising mobility. This integration

offers individuals "the edge" through increased control with flexible yet highly effective

protection.


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About D3O

D3O Labs is the name of the company that manufactures and markets their d3o

protective material. The name d3o is basically a mystery - the manufacturers have only given

vague speculations of its origin, that d3o came from the name of the room it was invented or

it's a secret chemical compound that is used in its manufacture, D3O Labs will only say "No

comment".

D3O Labs is the provider of solutions for impact protection material. They

manufacture and license their unique patented material, which combines enhanced chemistry

and engineering to produce a high performance shock absorbing protective system. It is a

high-tech material, in D3O Lab's own words, "intelligent molecules", so for lightweight top-

quality protective material, built into BMX, mountain bike, ski and snowboard body armor,

you ARE getting what you pay for. Material that is as comfortable as, for instance, a soft

knee pad but with intelligent molecules that react to impacts, tightening and reflecting the

force throughout the material allowing d3o to protect as well as any hard shell knee pad.

D3O Material Development

D3O is comprised of a polymer composite which contains a chemically engineered

dilatants, an energy absorber. This basic material has been adapted and enhanced to meet

specific performance standards and applications. Initially d3o is formed as a gel, almost like a

Silly Putty, except that it's, well, bullet proof. The d3o material used in protective gear

applications is almost taffy like, softer and a bit stiffer then any regular foam rubber, a

consistency like unto an old foam camping pad, but it doesn't feel like you could pull chunks

off (because you can't).


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Partner d3o Materials

D3O has patented a unique polymer composite which contains a chemically engineered

dilatant so that it functions as an energy absorber. This basic material has been chemically

enhanced to allow the material to be adapted to meet specific performance applications and

typically is offered in three solutions: ST, XT and SHOCK+.

ST is a lightweight material formulation typically applied to components in the

automotive market. It‟s flexible and high performing so you can feel safe when you

use it. It is Lightweight, Flexible and Strong performance at ambient temperatures.

The XT material is our newest formulation and the best performing shock absorber

across a wide range of temperatures. It is lightweight and particularly impressive at

high temperatures. The material is temperature stable, lightweight and high

performing shock absorber.

Shock+ is extremely durable. It performs particularly well at cold temperatures and

can be used in a wide variety of products. The material has great shock

absorption,durable, andideal for extreme environments.

Application of d3o

A few examples of d3o's use to date can be seen in a vast range of products such as

GS race suits from Spyder as worn by the US ski team in the 2006 Winter Olympics; Sell's

Contour goal keeper gloves for football (soccer) and Pro Pad shinguards; Racer MCR

motorcycle gloves; ski and snow apparel manufacturers such as Schoeffel, Reusche, Kjus

and Sessions have all adopted d3o, Sessions producing the world's first base layer combined

with the impact protection technology and finally the 07/08 winter season is set to introduce

Quiksilver and Ignite beanies containing d3o to the market for soft headwear with added

protection, not a replacement to a helmet but better than a beanie!


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Shape Memory Materials

Shape memory materials (SMMs) react to changing environmental conditions

generally increasing and decreasing temperature by changing their geometrical shape. Shape

memory materials are smart materials that have the ability to return from a deformed state

(temporary shape) to their original (permanent) shape induced by an external right stimulus

(trigger), such as temperature change.This phenomenon is known as the shape memory effect

(SME), and it has been found in a number of material systems, including some alloys,

polymers and ceramics etc. Shape memory effects can also be utilised in several types of

functional textile and clothing products:

· Variable thermal insulation through SMM spacer elements between liner and outer fabric.

· Variable moisture permeability membranes.

· Shock damping materials.

Shape memory alloys (SMAs) were first developed where the transition is due to a

phase change between austenite and martensite. In shape memory polymers (SMPs) the

change occurs as glass transition or melting. SMPs have several advantages over SMAs,

which are valuable in the textile applications: low density, good mould ability, low cost, glass

transition temperature variable between 30oc and .70

oC, potential biocompatibility and

biodegradability, high capacity for elastic deformation.

Shape memory Polymer

Shape memory polymers are polymers whose qualities have been altered to give them

dynamic shape "memory" properties. Using thermal stimuli, shape memory polymers can

exhibit a radical change from a rigid polymer to a very elastic state, and then back to a rigid

state again. In its elastic state, it will recover its “memory” shape if left unrestrained.

However, while pliable it can be stretched, folded, or otherwise conformed to other shapes,

tolerating up to 200% elongation.While manipulated, the shape memory polymer can be

cooled and therefore returned to a rigid state, maintaining its manipulated shape indefinitely.

This manipulation process can be repeated many times without degradation. Word done on

the polymer to solidify gets stored in the polymer as latent strain energy. Shape memory

polymers (SMP) can be stimulated by temperature, pH (the level of acidity or alkalinity),

chemicals, electrical energy and light. They are able to sense and respond to external stimuli

in pre-determined shape.


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In terms of chemical structure, SMP's can be considered as phase segregated linear

block co-polymers having a hard segment and a soft segment. The hard segment acts as a

frozen phase and the soft segment acts as the reversible phase. The ratio by weight of the

hard segment: soft segments are between about 5:95 and 95:5, preferably between 20:80 and

80:20. The reversible phase transformation of the soft segment is responsible for the shape

memory effect.The polymer materials have various characteristics such as from hard glass to

soft rubber. Shape memory polymers however, have the characteristic of both of them and

their elasticity modulus show reversible change with the transition temperature.

Most of the thermally induced shape memory polymers (SMP‟s) have a one-way

shapememory effect: they remember one permanent shape formed at the higher temperature,

while many temporary shapes are possible at lower temperatures for which the systems do not

haveany memory. A two-way thermally induced SMP will remember two permanent shapes,

one formed at higher temperature and one formed at lower temperature. Bythermally cycling

the system, these types of polymeric materials will take two different shapes depending on the

temperature. These shape memory systems areengineered at the molecular level for the

requiredbehaviour.

Bi-component fibres with substantially different coefficients of thermal expansion

(CTE) can also produce thermally-induced shape memory effects viaone structurally

engineering the fibre rather than engineering the polymer. Bi-component fibres also havetwo

distinct phases,one with the high CTE component and one with the low CTE phase. The net

thermal and elasticity effects on the fibre, resulting from the competition of thermally

induced expansions, result in the system remembering all of the temperature dependent

“permanent” shapes, and thus providing a multitude of permanent shapes or two-way

variablememory effects.


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Features of Shape Memory Polymers:

Super elasticity (high deformability) above the transition temperature to avoid

residual strain (permanent deformation).

Rapid fixing of temporary shape by immobilising the polymeric chains without creep.

SMPs possess two material phases. The glass and the rubber phases. In the glass

phase, the material is rigid and cannot be easily deformed.

When the temperature is greater than "Glass transition temperature", the material

enters the soft rubber phase and becomes easily deformable.

Properties of SMP

Extent of deformation (%) = up to 200%

Density / g cm3 = 0.9 to 1.1

Critical temperature / °c = -10°C to 100°C

Recovery speeds minutes = <1second to several min.

Corrosion performance = excellent

Processing conditions = < 200°C , low pressure

Can be biodegradable

Application of SMP in Sportswear

It can be used to provide thermal insulation in both hot and cold climatic situations. In

cold protective clothing, a high thermal insulation is generally achieved by using a low-

density wadding or similar material between the outer shell and the lining fabrics. The air

content of the wadding provides most of the insulation. A bi-material laminated film

consisting of a layer of SMP and a layer of a compatible film can be used as a substitute for

the wadding. With a glass transition temperature of, say, 25oC, the SMP will shrink by some

3% and become rigid at that temperature, with an out-of-plane deformation (Fig). The

increased distance y between the fabric layers gives increased thermal insulation at the lower

temperature.


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Fig .The SMP component of the laminated film shrinks at 25oC and causes anincreased

distance y between the two clothing layers.

Actuation for heat protection at elevated temperatures (steam, boiling water, hot

fluids, etc.) is achieved with a thin film that has been pretextured with an embossed pattern.

A temporary flat shape is achieved by calendaring the embossed film, and this flat film will

be used in the clothing. On exposure to high temperatures of 55oC and above, a reversion of

the textured shape occurs and provides heat protection.

An SMP membrane with flexible moisture barrier property has beenpresented with

the trade name Diaplex by Mitsubishi Heavy Industry. The function is based on a change in

the micro-Brownian motion in the segmental polyurethane structure. The molecular structure

is rigid at temperatures below the activation point and prevents permeation of water

molecules. When the temperature rises above the activation point the thermal vibration of the

softmolecule segments creates gaps between the membrane molecules, thusincreasing the

moisture permeability. The activation temperature can betailored by changing the polymer

structure.

A drysuit (developed by U.S army) keeps the wearer dry in cold water and which can

also be worn in a warm air environment without causing discomfort from sweating can be

used as sportswear.

For clothing applications, the desirable temperatures for the shape memory effect to

be triggered will be near body temperature. In practice, a shape memory alloy is usually in

the shape of a spring. The spring is flat below the activation temperature but becomes

extended above it. By incorporating these alloys between the layers of a garment, the gap

between the layers can be substantially increased above the activation temperature.

Consequently, considerably improved protection against external heat is provided.


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The SMP membrane can be applied on to the sportswear, due to which when the

temperature raises above certain critical temperature the intermolecular rupture of membrane

takes place which increases the pores due to which breathability, moisture and heat regulation

of the body increases.

Auxetic material

When stretched in the longitudinal direction, auxetic materials get fatter rather than

thinner, in contrast to conventional materials. Poisson's ratio, which is defined as the ratio of

the lateral contractile strain to the longitudinal tensile strain for materials undergoing uniaxial

tension in the longitudinal direction, is in the region of 0.2±0.4 for most solids. Auxetic

materials have a negative Poisson's ratio.

Auxetic materials have previously been utilised, for example as graphite core

structures in nuclear reactors. Polymeric and metallic auxetic foams with convoluted cell

structures were developed in the 1980s and found various uses in packaging, sound

insulation, filtration, shock absorption and sponge materials. As a result of more recent

research work, production of auxetic polymers with specifically tailored properties is now

possible, and fibres of auxetic polypropylene have been produced at the Bolton Institute in

the UK. Currently, the use of auxetic materials in textiles is limited to the expanded PTFE

membranes, where the auxetic property is not really utilised. However,there is a growing

interest in future clothing applications for personal protection (energy absorption and impact

resistance) and supportive garments (constant pressure structures). Other auxetic fibre

applications are expected in fibre-reinforced composites (fibre pull-out resistance, tough

fracture, energy absorption and impact resistance), filtration (release of entrapped particles,

microporous structure), medical bandages (wear resistance, constant pressure).


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Conclusion

The possible use of smart materials and wearable technologies opens new

perspectives in the field of functional clothing for sports textile.

Extensive research activities in universities and research institutes as well as in

companies worldwide had proceeded and brought new solutions to the market.

The applications that have been presented here are just the tips of the eyesberg of

products that would become a commercial product in the nearby future.

Sportswear is the one of the most promising applications for SFIT (smart fabrics and

intelligent textile).

Products which change their properties according to the physical performance and/are

the environmental conditions are practically obtaining more focus in the sports wear

market.

Through the presentation of the paper we find ourselves proud to show the future of

sports textile.

At this stage we cannot describe it completely because this technology is in the

developing stage.

References

Textile in sports edited by R.Shishoo

The Indian Textile Journal (December 2010) Page no. 11

Technical Textile International (July/August 2012) Page no. 9

Wikipedia

http://www.crgrp.com/technology/portfolio/veriflex.html

http://www.azom.com/article.aspx?ArticleID=6038

http://www.gzespace.com/gzenew/index.php?pg=shape_memory_polimer&lang=en

http://www.ntcresearch.org/pdf-rpts/AnRp05/M05-GT14-A5.pdf

University of Boras ( Application of Ultra Smart Textiles in Sportswear and

Garments) 26.05.2010

World Active Sportswear Journal (June 2011) Page no. 20

Textile Asia Journal (January 2009) Page no. 12

Texincon (1991 to 2010)

Textilveredlung (1993, April) Page no.5

www.fibresource.com

http://www.crgrp.com/technology/portfolio/veriflex.html

http://www.azom.com/article.aspx?ArticleID=6038

http://www.gzespace.com/gzenew/index.php?pg=shape_memory_polimer&lang=en

http://www.ntcresearch.org/pdf-rpts/AnRp05/M05-GT14-A5.pdf

Advancement in Sport textiles by vignesh dhanabalan

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