Studies on the Pilling Tendency

Abstract

(1) PHENOMENA OF THE PILLING For the purpose of studies on the pilling tendencies of the textile fabrics, the polyethylene-, terephthalate and viscose fibers blended fabrics are subjected to the constant rubbing action by using the Random Tumble pilling tester.The mean number of pills on the surface of fabric against the rubbing time are evaluated, and pilling tendencies which correlated with them are discussed. Futhermore, the formative process and the grown state of pills are experimentally confirmed by the microscopic examinations.1) If a curve of the mean number of pills against the rubbing time is divided off the several regions according to the changing propensities of the curve, the tendencies from the formation to the wear-off of pills can be perceived.2) By the microscopic examination, the formative process of a pill is accurately seen. It is found that the grown pills consist of a body and leg parts.3) The polyethylene-terephthalate fibers are apt to make more pills as compared with the viscose fibers.4) It is found that some of pill bodies contain a node or the assembly of nodes, that is, they contain so-called "pill nucleus".In this parer, the growth mechanism of pills are especially investigated by the microscopic examination, and the pilling tendencies are discussed in detail.The results obtained are as follows :1) The mechanism of a pill body such as the fullness and the motion on the growing process of pilling are expressed by the model.2) The changes of pill size against the rubbing time are evaluated with the apparent volume of the pill body, and several propensities by changing the volume are discussed.3) Effects of the legs on the growth of a pill body play a more important role in such a growing process.

A Mathematical Model of Pilling Mechanisms1

“…Averages for seven pills/sample are given in Table I I I. The order of magnitude is sin~ilar to range of data reported by Tsujimoto [13]. …”

“…Their higher strength prevents pill wear-off and their electrostatic property attracts foreign matter which can act as pill nuclei [i, 13]. In this connection, two types of pills have been distinguished, one whose nucleus is formed by foreign matter and the other where the nucleus is formed by an irreversible tangle of the fihers themselves [13]. Qualitatively, pilling proceeds as follows E2, 6]: fuzz forls, fuzz entangles to pills, and .pills wear off.…”