Assessment of porosity of flat textile fabrics

An immersion method for measuring parameters of porosity in woven and knitted fabrics and even thin non-woven fabrics is presented in this paper. The experimental results correlated to the theory to a great extent. The method is based on selectively squeezing out the fluid from the pores of wet fabrics by air pressure. We were able to estimate the porosity parameters such as the hydraulic diameter of pores, the distribution of pores, the open area for the fluid flow and the number of hydraulic pores. The parameters were estimated based on the measurement of the air volume velocity through dry and wet samples as a function of the air pressure. All measured data were fed into the computer program developed for that purpose. The whole procedure took about 20 minutes and the results obtained by this method were in good agreement with those gained optically.