Mechanical Properties of Needle-Punched Polymer Nonwoven Fabrics Under Constant Load

The dependence of relative elongation of needle-punched nonwovens of various structures on the impact of a constant load is studied. The major stretching occurs in the first 20 seconds and then 5-10 % more until a constant value is attained in 30 minutes. Relative elongation under a constant load depends on the direction of cutting of the samples and surface density of the fabrics. Fabric stretching under constant load is determined by straightening crimped fibers in the punching process and stretching in the longitudinal direction depends on the reorientation of the fibers from the transverse to the longitudinaldirection.