Yarn Attrition and Hairiness: A Yarn Self-rubbing Test

An investigation is reported in which hairiness was measured on 40 yarns of different types before and after a yarn self-rubbing action and hairiness and attrition parameters were analysed. It was found that the maximum hair length detected generally decreased after the self-rubbing action, but the evolution of the hair-length distribution and the increase or decrease of hairiness depended on the fibre type, the yarn linear density, the yarn structure (ring-spun or rotor-spun yarns; singles or two-fold yarns), and the tendency to form pills by attrition, as well as the fall-out of matter during frictional action. Of the attrition parameters, the loss of weight by fibre fall-out is greater in cotton yarns than in chemical-fibre staple-spun yarns; in ring-spun yarns than in rotor-spun yarns; and in singles yarns than in two-fold ones. The nap- or pill-formation tendency is greater in fine and medium singles spun yarns than in coarse and two-fold yarns, but here the nature of the fibre plays an important role.