Water proof-breathable fabric has been interest in the area of protective clothing and sportswear in cold weather. For these materials, the protection level against water is known to have an inverse relationship with the vapour permeability, or breathability. That is, textile material of more open structure would show high air permeability and low water resistance, while that of compact structure would show opposite characteristics. There are could be three types of waterproof fabrics. One is impermeable fabrics that prevent all permeation of aerosols, liquids, vapours and gases. Another is water repellent fabrics that repel splash of liquids and permeate gas or vapour. The other is water-proof/breathable fabrics which can prevent liquid phases and permeate gas or vapours.

For water-proof breathable clothing, both the water resistance and the vapour transmission are very important for user comfort. The water resistant fabric with low vapour transmission would build up humidity and sweat under the garment very quickly, possibly causing the hyperthermia. Hence, there is necessity of developing a waterproof-breathable fabric that can block water while exhibiting a certain level of vapour/permeability.

Due to the inverse relationship between the water resistance and the vapour/air permeability, the protection level against water should be compromised to attain certain of vapour transmission. So this paper described about mechanism of waterproof breathable, various fabrics and its application in cold weather apparel.

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About Author:

Harun Venkatesan and V.N. Gowrishankar are students of 4th year B.Tech in Textile Chemistry in the SSM College of Engineering.