Abrasion Phenomena in Durable-Press Cotton Fabrics

Abstract

The abrasion characteristics of representative durable-press cotton fabrics were evaluated by selected laboratory-abrasion and laundering tests and the breakdown pattern of individual fibers was surveyed by electron-microscope photographs. Samples compared were from such treatments as wet-fix, poly-set, face-coating, fiber encapsulation, and graft polymerization. Although degree of abrasion resistance, as measured by Accelerotor weight loss or Stoll flex cycles, varied with different treatments, the damage types exhibited by individual fibers differed little from treatment to treatment. In most samples having acceptable degrees of wrinkle recovery and crease retention, the major mechanism of failure was fracture of the entire fiber in a brittle break. In untreated cotton, the characteristic feature of wet abrasion was fibrillation of the fiber surface; wet abrasion of cross-linked fibers often resulted in peeling of thick slabs and ribbons of fused fibrils from the body of the fiber. Characteristic of dry abrasion of untreated fibers was smoothing of fiber surface, general crushing of the fiber, accumulation of lumps of fiber material, and occasionally a pinching-out of wedged-shaped fragments from the side of the fiber in a typical mechanical fatigue break. In cross-linked fibers, differences between dry and wet abrasion were small. Most characteristic of cross-linked fibers was abrupt fracture of otherwise undamaged fibers and brittle shattering of the fiber as in the crushing of glass. Addition of softeners and thermoplastic polymer coatings to the cross-linking treatment improved abrasion resistance, apparently by physical protection of the fiber surface from abrassive forces, but the final mechanism of the failure was nearly always of the same type-mechanical fracture of the fiber. Observations of characteristic damage types in laundering tests in a household-type washing machine were also included. Surfaces of fibers from washed and line-dried fabrics resembled more closely those of fibers from fabrics tumble-dried than of those washed and tumble-dried.