Mechanical Properties of Moistened Needle-Punched Nonwoven Fabric Based on Blend of Fibers with Various Linear Densities

The effect of the degree of water vapor sorption on mechanical properties of needle-punched nonwoven fabric based on a blend of polyethylene terephthalate (PET) fibers with 0.33 and 1.7 tex linear densities in 45:55 % ratio is investigated. The fabric strength is estimated by nominal breaking stress. A parameter expressing the ratio between nominal stress and relative tensile elongation in the first stage of the process is proposed for estimation of tensile strength. The structure of the fabric based on fibers with various linear densities is studied and the mechanism of its elongation and breaking is proposed. Increase of tensile strength and strength of moistened fabric in longitudinal and transverse directions is observed at sorption degrees ranging from 0 to 4.5-5.0 kg/kg.