Waterproof breathable fabrics for protection

Breathable films and coatings are useful for designing fire fighter dress material, feel Subhasish Pal, Sagarika Pal and Syamal Maity.

A continuous progress in technology demands smart garments for different uses. Waterproof breathable fabrics – which use smart technology – are designed for use in garments that provide protection from the weather that is from wind, rain and loss of body heat. Clothing that provides protection from the weather has been used for thousands of years. The term ´breathable´ implies that the fabric is actively ventilated. Breathable fabrics passively allow water vapour to diffuse through them yet still prevent the penetration of liquid water. Sportswear is not used only for actively sporting activities, but also worn as casual wear, so it needs to fulfill the fashion and functional demands of this area. With the increase in leisure activities and new consumer buying behaviour – the right outfit for the relevant sports activities – other requirements on textile material and manufacturers have been added, like hygiene aspect and protection from ultra-violet radiation, for example. In order to be able to meet these growing requirements, fabric manufacturers and chemical industry are continually offering new materials and finishing products. For sportsman who engage in swimming, running, cycling, gymnastic or ski it is more important, in functional clothing buying behaviour, that if the textile material meet the expected requirements rather than which material it is made of. With the development of high-tech textile products, advantage of performance has been finished the traditional hesitant behaviour in clothing and has been changed demands of consumers. Waterproof breathable fabrics are designed for use in garments that provide protection from the weather that is from wind, rain and loss of body heat. The fabric is actively ventilated which gives breathability. Breathable fabrics passively allow water vapour to diffuse through them yet still prevent the penetration of liquid water.

Breathable films and coatings are useful for designing fire fighter dress material; it should permit the escape of body perspiration efficiently and reduce the incidence of heat stress which is a major cause of death due to fire fighting. One of the commonest causes of occupational deaths amongst firefighters is heart failure due to heat stress (hyperthermia) caused by loss of body fluid required to produce perspiration. In submarine suits wearer needs protection against drowning and hypothermia for long periods under severe weather condition. Breathable fabrics are also very important for the personnel working at temperatures well below 30 deg C in wind, rain, and snow. For military foul weather clothing û is produced to the highest standards of performance.

Breathablility is meaningless without a high standard of waterproofness and initial hydrostatic head of 500 cm of water (50 kPa) for high quality products to 130 cm of water (13 kPa) for lower grade products. Garments, which are both waterproof and breathable, help to provide the wearer with a greater level of comfort in many adverse situations. Waterproofing and moisture permeability are two mutually contradictory functions. Consequently, producing a material which has both these properties has proved to be a major challenge for manufacturers of waterproof performance fabrics. The introduction of new waterproof breathable fabrics has greatly increased the range of choice for consumers. It has also led to a higher degree of segmentation in the market.

Breathable vs non-breathable fabric

The human body strives to keep its core temperature at 37ºc. During physical activity, extra body heat is produced causing the nervous system to react by sweating. Sweat glands pump perspiration through pores, body heat is transferred to the sweat, causing i