Performance evaluation of waterproof breathable fabrics

In many applications, breathable fabrics are expected to satisfy many functional characteristics other than breathability, such as fabric tear, tensile, and peel strength flex and abrasion resistance launderability tape sealability thermo-physiological comfort, etc., and perform efficiently over the lifetime of the product. - - Surface modification or stitching may also adversely affect the functionality of fabrics. 

However, the performance evaluation of waterproof breathable fabrics is done mainly by measuring three properties  

The fabric s resistance to penetration and absorption of water can be measured by two different kinds of tests simulated rain tests and penetration pressure tests. 

AATCC Test Method 35 provides a method of testing the penetration of water by impact. This method can be used to predict the rain penetration resistance of fabrics. A test specimen of 20 x 20cm backed by 15.2 x 15.2 cm blotter paper is mounted in a vertical rigid support frame, as shown in Hg. 2.11. The specimen is exposed to horizontal 

The tester consists of four specimen holders of 100 nun diameter placed over inclined cups with a rotating mechanism rubbing the underside of specimens, as shown in Fig. 2.12. Specimens are subjected to simulated rain from a height of 150cm using filtered water under pressure. Water penetrating through the fabrics is collected in the cups and is measured on mass basis. 

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