An Experimental Study of the Needled Nonwoven Process

This part of the series deals with the measurement of fiber damage caused by needle punching. A critical step in the experimental determination of fiber damage is to unravel fibers from needled nonwoven fabrics. This is achieved by using a feed web containing water-soluble fibers and a small percentage of wool. After needling, the fabric is put in hot water to dissolve the water-soluble fibers, leaving unconnected loose wool fibers. Damage due to needling may be in two forms, complete fiber breakage and fiber weakening. Fiber breakage is measured in terms of fiber length reduction, while fiber weakening is measured in terms of the reduction of fiber bundle strength. Needle-loom and feed web conditions, such as needling density, depth of needle penetration, needle design, web thickness, and methods of feeding the web to the needle loom, are investigated for their influence on fiber damage.