Wetting behaviour of raw and water-repellent cotton fabrics using wetting kinetic measurements

An electrical resistance technique has been developed to study the rate of horizontal wicking of different liquids into untreated and finish treated cotton fabrics by estimating the critical surface tension of both the fabrics and equivalent capillary spaces of fabric samples from the experimental work based on Washburn derivation. The finishing agents, namely Perlit based on modified fatty acid derivatives and Baygard 430 AFF with a fluorochemical base, have been used. It is observed that the penetration rate and wicking distance of finish treated samples reduce as compared to those of untreated samples. The results confirm different solid-vapor surface tension of the two types of samples due to the changes in surface characteristics of fabrics after finishing treatment. The radii of open channels which act as capillary tubes tend to decrease, leading to blockage of the tube during water-repellent finishing treatments.