http://www.fibre2fashion.com/industry-article/4/326/textile-photo-chromic-sensors-for-protective-textile1.asp
Laboratory Colour and Appearance Measurement
Technical University of Liberec Czech Republic
e-mail: martina.vikova@tul.cz

Abstract

Depletion of stratospheric ozone is expected to lead to an increase in the amount of UVB radiation present in sunlight. In addition to its well-known ability to cause skin cancer, UVB radiation has been shown to alter the immune system. The immune system is the body's primary defence mechanism against infectious diseases and protects against the development of certain types of cancer. Any impairment of immune function may jeopardize health by increasing susceptibility to infectious diseases, increasing the severity of infections or delaying recovery from infections. In addition, impaired immune function can increase the incidence of certain cancers, particularly cancers of the skin.

With careful use of protective clothing, skin damage can be reduced drastically. Medical experts frequently recommend the use of clothing for protection from UVR. Not all clothing, however, protects equally or adequately.

The base of solution could be SMARTtextiles with irradiance responsible fibre materials. SMART or INTELIGENT materials respond to environmental stimuli with particular changes in some variables. For that reason they are often also called responsive or adaptive materials. Depending on changes in some external conditions, adaptive materials change either their properties (mechanical, electrical, appearance), their structure or compositions, or their functions.

Mostly, SMART materials are embedded in systems whose inherent properties can be favourably changed to meet performance needs. The primary purpose of the proposed work is development of origin method and device for measurement of adaptive response on UV-VIS and NIR irradiance. This work is widely recognized as establishing the fundamental knowledge base for the creation of variety of new materials as sensors for application to basic textile structures, non-woven, and other related materials and their barrier properties against UV-VIS and NIR irradiance. Our objective is to use the special photo chromic and photo adaptive polymer, which has a response to above-mentioned part of electromagnetic irradiation.

Introduction

Reversible colour changing of some substances is well known effect. Name of this effect is chromism and if the effect is reversible colour change depending on temperature, name of this effect is thermo chromic. If is colour change affected on solution name is solvate chromism, light colour change dependence is named photo chromism, etc. This reversible colour change we can use as indicator of different stimulation and true colour measurement method we can quantify by this stimulation.

In present time we have on the market protective clothes, which give good insulation against hazardous substances and radiation. Obviously is on the market measuring systems for measuring dangerous substances and its concentration, respectively excessive intensity of radiation. On the other side we should solve transportation of these measuring systems, stress of acting persons (firemen, solders, etc.) during theirs actions from reason of weight and dimensions of measuring systems. This problem will solve integrated textile sensors, which will be flexible component of protective clothes. Potential possibilities of using textile-based sensors are now intensively studied in Laboratory Colour and Appearance Measurement (LCAM) of Department of Textile Materials of Technical University in Liberec, Czech Republic. In this study are present textile sensors with colour response on UV radiation and we will present studies of dynamic changes, stability of sensitivity these kinds of sensors. Also will be present study of moderating these sensors for different part of UV.

 
Convergence of Electronics and Textiles for Today and Tomorrow By : Mr. G. Tamilarasan


Introduction

Today, the interaction of human individuals with electronic devices demands specific user skills. In future, improved user interfaces can largely alleviate this problem and push the exploitation of microelectronics considerably. In this context, the concept of smart clothes promises greater user-friendliness, user empowerment, and more efficient services support. Wearable electronics responds to the acting individual in a more or less invisible way. It serves individual needs and thus makes life much easier. We believe that today, the cost level of important microelectronic functions is sufficiently low and enabling key technologies are mature enough to exploit this vision to the benefit of society. In the following, we present various technology components to enable the integration of electronics into textiles.

Wearable electronics go far beyond just very small electronic devices to wearable flexible computers. Not only will these devices be embedded in textile substrates, but an electronics device or system could ultimately become the fabric itself. Electronic textiles (e-textiles) will allow the design and production of a new generation of garments with distributed sensors and electronic functions. Such e-textiles will have the revolutionary ability to sense, act, store, emit, and move-think biomedical monitoring functions or new man-machine interfaces - while ideally leveraging an existing low-cost textile manufacturing infrastructure.

In the following, various technology components to enable the integration of electronics into textiles are discussed. Key elements are Photonic textiles using LED fabrics, a silicon-based micro-machined thermoelectric generator chip for energy harvesting from body heat, presented in Section 2, an interwoven antenna concept for RFID labels for the identification of textiles described in Section 3, application of nanotechnology in the development of CNT yarns and bio-sensing textiles.

http://www.fibre2fashion.com/industry-article/22/2119/convergence-of-electronics-and-textiles-for-today-and-tomorrow1.asp
 
Self Cleaning Garments By : S. Parthiban

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Abstract

Water and soil repellency has been one of the major targets for fiber and textile scientists and manufacturers for centuries. Nano science is employed for this type of problems. From the nano science self cleaning is the wonderful technology for dirt-free with other functional finishes. So, through this paper we deals with various mechanisms of self-cleaning and the coatings, manufacturing methods, and also various functional finishes like antimicrobial; UV ray finishes which can be imparted with the major advantages than the other conventional finishes and application area of this technique. Connection to this limitation, problems with this technique and recommendations for the purpose of bringing out new ideas which is incorporated in the self cleaning garments.

Introduction

Nature has already developed an elegant approach that combines chemistry and physics to create super repellant surfaces as well as self cleaning surfaces. "Lotus leaves" is the best example of self cleaning surfaces. The technology of self-cleaning coatings has developed rapidly in recent years. As a commercial product, their potential is huge and their market truly global. Because of the wide range of possible applications. The concept of self cleaning textiles is based on the lotus plant whose leaves are well-known for their ability to self-clean by repelling water and dirt. Now day's peoples are very busy in their work that they do not have time for clean their daily wear cloths also people who are working in kitchens having headache to wash their garments. Also military peoples have to survive in such drastic condition that they cannot wash their cloths. Nano technology provides a new concept self cleaning textiles which gives self cleaning as well as fresh cloths every day, this not only technically benefited but techno economically also benefited. The field of self-cleaning coatings is divided into two categories: hydrophobic and hydrophilic. These two types of coating both clean themselves through the action of water, the former by rolling droplets and the latter by sheeting water that carries away dirt. Hydrophilic coatings, however, have an additional property: they can chemically break down adsorbed dirt in sunlight.

About the Author
The author is associated with PSG College of Technology.





Advanced Protective Textiles By : Shweta S. Joshi

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The definition of technical textiles adopted by the authoritative textile Terms and Definitions, published by the Textile Institute is textile materials and products manufactured primarily for their technical and performance properties rather than their aesthetic or decorative characteristics.

12 main application areas of technical textiles are:

• Agrotech: agriculture, horticulture and forestry
• Buildtech: building and construction
• Clothtech: technical components of footwear and clothing
• Geotech: geotextiles and civil engineering
• Hometech: technical components of furniture, household textiles
• Indutech: filtration, conveying, cleaning and other industrial uses
• Medtech: hygiene and medical
• Mobiltech: automobiles, shipping, railways and aerospace
• Oekotech: environmental protection
• Packtech: packaging
• Protech: personal and property protection
• Sporttech: sport and leisure

Protective and Safety clothing and textiles:

Textiles for protective clothing and other related applications are another important growth area which has attracted attention and interest somewhat out of proportion to the size and value of the existing market. The variety of protective functions that needs to be provided by different textile products is considerable and diverse. It includes protection against cuts, abrasion, ballistic and other types of severe impact including stab wounds and explosions, fire and extreme heat, hazardous dust and particles, nuclear, biological and chemical hazards, high voltages and static electricity, foul weather, extreme cold and poor visibility.
 
Infrared Heat Increases Productivity of Flameproof Textiles

Source : New Cloth Market

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High-quality home textiles for curtains, armchairs and sofas should not only look decorative, they also have to be hard-wearing and flameproof. Textiles usually get flame-retardant by a coating with special chemicals or saline solutions.

By retrofitting a new, Heraeus medium wave infrared system at their South Ockenden factory, Essex Flameproofing have been able to treble the capacity of the drying process used in the production of fire retarding upholstery and curtains. At the same time, they have also significantly reduced energy consumption. Forgotten candles or a short circuit in the toaster - just at home it can burn fast if one does not pay attention. Curtains and home textiles should not contribute to the spreading of a fire and therefore they . have to be equipped with flame-retardant properties.

Essex Flameproofing is a long-established company which works with designers and specifiers, fabric manufacturers, major retailers and upholsterers to impart fire-retarding properties to furniture and fittings. This is achieved by treating the fabric of the upholstery or curtains with flame-retardant chemicals to . comply with British and foreign standards and flame retarding regulations. The application of the relevant chemicals/coatings is a wet process and drying is, necessarily, an important production stage.

Upholstery is made fire-resistant by spraying the back of the upholstery cloth with a latex flame-retardant coating, which must then be dried. Previously this was achieved by heating the coated upholstery web with a long wave infrared system. However, to meet increasing demand for the company's expertise, it was decided to investigate ways of speeding up the drying process.

As a result, a new Heraeus medium wave infrared system was retrofitted at the Ockenden factory. This consists of an aluminium framework, which houses 21, 4.5kW emitters, which are arranged to be switched on and off in seven banks of three emitters, to match the heating profile to the product to be dried. Such has been the success of the new system, which is ready to run within one minute of switch-on, that .coated upholstery fabric can be dried in a single pass whereas three passes were often required with the previous system. This is partly due to the efficiency of medium wave infrared in water removal, as radiation at medium wave frequency is readily absorbed by water molecules and the energy is rapidly converted into heat.

The new system also finds further employment when it is used to provide extra capacity to dry treated curtains. Curtains are made fire-retardant by spraying them with a salt-based solution, which soaks into the fibres. When curtains come Scotch guarded, or when fabrics have low permeability, the uptake of the solution needs to be assisted by passing the wetted curtain through nip rollers. Normally, curtains are dried on their own line, but when there is capacity on the new Heraeus system, they are passed through for drying, again at twice to three times the speed.

Thermo-regulated Fibres-Concept and Virtue Source : New Cloth Market

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By: Xing-Xiang Zhang and Na Han

Abstract

Thermo-regulated fibres can response to ambient temperature and maintain the microclimate equilibrium. They can be applied in wide variety area, such as aerospace, military and medical etc. Many processing technologies for producing thermo-regulated fibre have been developed since 1971. There are still some defects and deficiencies in each method, however. With the aim at producing a environment friendly, high efficient and low costly thermo-regulated fibre, the scientists all over the world are exploring constantly.

Introduction

Thermo-regulated fabrics are a kind of functional textile containing low temperature phase change materials (PCM) or microencapsulated phase change materials (MicroPCMs) [1], or a kind of block copolymer product with segments that change phase at low temperature [2].

The thermo-regulated fabric absorbs heat energy when the ambient temperature is higher than the melting temperature of PCM and slows down the temperature rise of the fabric. The fabric releases heat energy when the ambient temperature is lower than the crystallization temperature of PCM and slows down the temperature descending of the fabric. This cycle process of absorbing, storing and releasing latent heat maintains comfortable temperature equilibrium within the microclimate between the fabric and the skin.
Thermo-regulated fibres (TRF) have attracted more and more attention recently [1, 2]. Several manufacture processes, such as impregnating hollow or non-hollow fibres with PCM solution, wet-spinning, melt-spinning and electro-spinning, etc. were used to fabricate the thermo-regulated fibres. The benefits and drawbacks of every process were not reported, however. The structures and properties of these fibres were reviewed in this paper.


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About the Authors

The authors are associated with Tianjin Municipal Key Lab of Fibres Modification and Functional Fibres, Institute of Functional Fibres, Tianjin Polytechnic University, China

The paper was presented at the 2008 International Scientific Conference on Smart Textiles. Courtesy: The University College of Boras, (CTF, The Swedish School of Textiles)

Originally published in New Cloth Market; May 2009






 
Visual assessment UV radiation by colour changeable textile sensors By : Martina VIKOVA

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Laboratory Color and Appearance Measurement,
Faculty of Textile Science, Technical University of Liberec

ABSTRACT

Sunburn, skin cancer, premature aging, and suppression of the immune system are some of the harmful effects of acute and cumulative exposure to ultraviolet radiation (UVR). A decrease of 1% in ozone would lead to increases in the solar UVR at the earths surface and may eventually lead to a 2,3% increase in skin cancer. Wearing clothing, hats, and other protective apparel during sun exposure may reduce risks associated with overexposure. However, fabrics used in summer time apparel often provide poor protection against solar UVR, because they are usually made from light to medium weight fabrics.

Our contribution is not to develop of new UV protective materials, but with advantage use well-known photo chromic dyes or pigments for constructions of new textile based sensors as integrated parts of summer clothes. In our study we would like detect not only UV radiation with sensors as indicators, but also detector of quantity UV radiation dose. We have prepared for this study concentration scale of different UV absorbers and different photo chromic dyes. We will show comparison of sensitivity modulation of our UV textile based sensors with measuring units (spectroradiometers) and reproducibility.

Key words: UV radiation, textile-based sensor, photochromism

INTRODUCTION:

In present time become worse living conditions and increase harmful pollutants in environment, which can non-reversible damage our health and jeopardize full quality our life. Big attention is given in research area respectively in development and perfection of protective clothes specially their barrier features. Protective barriers we understand how the clothes or textiles protects wearer against above mentioned dangerous conditions and if the protection is only partial or the protection is time limited by ambient conditions. Most of protective clothes are not developed for long time wearing. During development of these barrier structures we have to keep in our mind full comfort of acting persons without limitation. Some of protective clothes are equipped by electronics, respectively other sensors or devices, which monitoring and quantify dangerous substances in environment. In present time is big attention given to miniaturization of electronics and also flexibility their connection with computing units [1].

Above mentioned describe concept of protective clothes we call as intelligent structure. Disadvantage of this intelligent structure is no adequate response on the external stimulus, there is only monitoring of external dangerous conditions. This structure we call as passive intelligent textile structure.

Sensors and textile structures, which react adequate response and they are able modulate protective degree in accordance on the external stimulus (change of intensity UV, temperature, press, electrical field etc.) is called as SMART textile. As example of passive intelligent textiles are optical fibres, which leading the not only signal, but they are also sensitive on the deformation, concentration of substances, press, electric power etc. As example of active intelligent textiles could be textiles which react by change own colour in dependence on external stimulus (light, temperature) and called as a chameleonic textiles or heat containing textiles, which are able to store or slack energy according external temperature.

Moreover textile based sensors and active protective textiles has advantages that textile structure is easy customizable by sewing, thermal bonding or gluing. Also there are advantages of easy maintaining (washing, chemical drying) and low specific weight with good strength, tensibility and elasticity. Good features are also workability without change of technology of production and extremely large specific surface. Big advantages are possible integration these types of sensors into system of protective clothes and also their price availability. From these reason is this article directed to research of textile-based sensors with photo chromic behaviour, respectively to study of dynamic behaviour and modulation of sensitivity photo chromic sensors.

In this work is described new definition of colour reversible hysteresis, which is described by hysteresis of colour change curve. This colour hysteresis curve is described by kinetic model, which defines the speed of colour change initiated by external stimulus UV light. Kinetic model verification is done for textile sensors with photo chromic pigment applied by textile printing, fibre mass dyeing.

http://www.fibre2fashion.com/industry-article/4/323/visual-assessment-uv-radiation2.asp
 
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