Dimensional Effect of Abrasion Head on Wear Resistance of Spun Yarns

Abstract

The abrasion resistance of spun yarns has been evaluated by the modified criterion which takes into account the geometrical relationship between the frictional pin and the yarn. When the yarn is in contact for the length H with the frictional pin of diameter D and the pin is reciprocating with a stroke S, the yarn is abraded most severely at the central portion S* =|S-H| of the contact area. Therefore, it is reasonable to suppose that the yarn breakage depends on the wear of the portion S*. The frictional energy dissipated within the region S* is given by Eb* =Eb·|S-H|/S, where Eb is the frictional energy dissipated by the whole yarn up its breakage.The dependence of Eb* on D (0.6mm-10mm) and S (7mm-40mm) has been investigated experimentally for the spun yarn of 63tex made of polyester staples of 51 mm length and 2 denier. When S is smaller than 12mm, the yarn breakage is dominated by the fiber cutting and Eb* increases extraordinary provided that D is larger than 2.5mm. It is considered because the pin of large diameter is not effective to cut the fiber.It has also been found that Eb* does not substantially depend on S under the condition of 15.5mm ≤S≤ 40mm and D=2.5mm-5.0mm, where the yarn breakage is dominated by the fiber pull out. The mechanism of the frictional fatigue behavior of spun yarns and its dependence on D and S can be more clearly understood by the use of the modified criterion Eb*.