Indian Journal of Fibre & Research Vol. 29, December 2004, pp. 480-482

Pilling of / blends China. Except that the polyester fibresreplaced by modi­ fiedpolyester fibres,the specifications of fabrics 2 and 4 Li Long" Zhou Wei & were the same as those of fabrics 1 and 3 respectively. School of Textile & Materials, Xi' an University of Engineering The fabric details are shown in Table 1. Science and Technology, Xi' an 710048, P R China The polymer for modified polyester fibre process­ Received May 2003; revised received and accepted ing was modified. So, the properties of modified 5 November 2003 5 polyester fibre and normal polyester fibre were differ­ ent. The strength and modulus of modified polyester The pilling of Ii series of worsted fabrics made- from fibre were 2.5cN/dtex and 26cN/dtex respec­ wool/polyester fibres has been tested using circular locus pill tively. Elongation at break of modified polyester fibre tester and the mechanism of pilling studied. The process and the mechanism of pilling have been studied through the observation was 30 %. The strength and modulus of normal poly­ of fibre morphology on fabric surface by using scanning electron ester fibre were 3.8cN/dex and 50cN/dtex respec­ microscope. It is observed that the conditions of test, structure of tively. Elongation at break of polyester fibre yam, wool content and property of polyester fibres affect the was 40 %. pilling of worsted fabrics. The pilling test was done on a circular locus pilling

Keywords: Pilling, Polyester fibre, Wool fibre,Worsted fabric tester (YG502). The samples were brushed using ny­ lon brush and then abraded using the same fabric. The 7 IPC Code: Int. Cl. D06H 3/00, GOIN 33/36 experimental conditions are shown in Table 2. The Pilling is an undesirable phenomenon that affects pilling of fabrics was evaluated accord­ the hand and the appearance of garments. The pill ing to pill number on the fabrics. formation on fabric surface follows four stages 1: (i) Under the conditions of 0.5min brush time and fuzz forming, (ii) fuzz entanglement, (iii) pill form­ 0.9min abrading time, the fabrics 1 and 3 show few ing, and (iv) pill wear-off. Pilling on wool knitted fab­ pills, whereas fabrics 2 and 4 show no pills at all. rics has been a problem for a long time. Most of the Thus, the brushing and abrading at a short time have studies about pilling involve knitted fabrics contain­ little influence on pilling of samples. 2 3 ing wool fibres . Ginits and Mead ranked the fibres Table 1- Fabric specifications according to their fuzz tendency from minimum to Specification Fabric I Fabric 2 Fabric 3 Fabric 4 maximum for acetate, wool, PES (Dacron), viscose L-l and PA () fabrics. However, man-made fibres, Wool:polyester 45:55 60:40 especially the blends of polyester and wool, are Yarncount, tex 12.5/2x 1 1 .4/2 I 112 x 112 widely used because of their cost efficiency and suit­ I able end-use possibilities. Thus, suitable yarnand fab­ twist 800x880 880x960 ric parameters should be chosen to reduce the pilling twists/m tendency of these synthetic fibres. Fabric texture Sateen Sateen A considerable degree of success in controlling Warp density 505 541 pilling has been achieved through studies on the ef­ /lOcm fects of yam and fabric variables on pilling of knit­ Weft density 325 330 goods 1-4. l;;Iowever, relatively little attention has been devoted on the pilling of worsted fabrics. The present yarns/lOcm work was, therefore, aimed at studying the pilling per­ Fabrics 1 and 3 are made of wool/polyester fibres formance of wooUpolyester worsted fabrics. Fabrics 2 and 4 are made of wool/modified polyester fibres The worsted fabrics used in the study were ob­ Table 2- Experimental conditions for pilling tained from Lanzhou Wool Textile Corporation of Pill No. 2 3 4 5 6' 7 8 9 aTo whom all the correspondence should addressed. Brush time, min 0.5 3.5 3.5 3.5 3.5 3.5 1.7 1.7 1.7 be Phone: 3257226; Fax: +86-29-3235130; Abrading time, min 0.9 3.5 7 14 21 28 7 14 21 E-mail: [email protected] SHORT COMMUNICATION 481

The pill numbers for four kinds of fabric under the in brush time, so that much fuzz is formed on the sur­ conditions of different brush time are shown in Table face of fabrics. Thus, the pill numbers increase. 3. It is observed that the pill numbers of all the sam­ The pill numbers for four kinds of fabric under dif­ ples increase with the increase in brush time. The pill ferent abrading time are shown in Fig.2. With the in­ numbers of wool/modified polyester fibres are fewer crease in abrading time, pill numbers change. Moreo­ than that of wool/polyester fibres under the same fab­ ver, it is observed that the pill resistance for worsted ric specifications. Fig.1 shows the structures of yam fabrics of wool/modified polyester fibres (Fabrics 2 at different brush time. It is observed that the fibres on and 4) is better than that of wool/polyester (Fabrics 1 yam surface are pulled out or broken with the increase and 3) under the same fabric specifications. The pill structure on the fabrics is shown in Fig.3. It is observed that the fuzz entanglement is a complex structure. There are some broken wool fibreends in the pill and the fibres consisting of the pill are mostly polyester (Fig.4). Moreover, the pill is hold by anchor fibres. Fig.S shows that the anchor fibres are polyester fibres. The pill is removed from the fabric surface dur­ ing normal wear by breakage or pull-out of the anchor fibre. Thus, the properties of polyester fibres affect pill wear-off. Because of low strength and low modulus of modified polyester fibres under all the conditions of test, the structure of yarn, wool content and fabric tex­ ture are the same. The pill numbers on fabrics 2 and 4 are fewer than those on fabrics 1 and S respectively.

Table 3-Pill numbers" on fabrics Fabric Pill number b 3.5 1.7b e e c 7 14 21c 7 14c 21e Fabric 1 30 34 49 19 20 3 Fabric 2 15 10 6 3 2 4 Fabric 3 23 30 35 6 2 Fabric 4 9 4 0 0 0 0 "A verage of three tests for each fabric bBrush time in min Abrading time in min c

60 40 Fabric 3 Fabric -+- -+- I b' 50 (a) ( 30 40 30 20 � 20 10 10 Q ::: 0 ..0 0 5 10 15 20 25 5 10 E 30 15 20 25 30 ;:> " 20 ;=: "- (C) ) 20 -- Fabric 3 Cd 10 15 --- Fabric 4 10

o o'--'-----'---=....--'----' 10 15 20 25 Abrading lime, min Fig.I-Structures of yarn before and after test [a-Original, Fig.2-Pill numbers on fabrics at different brush time b- 1.7min brush time, and c-3.5min brush time] [a-3.5min , b-3.5min , c-1.5min and d- 1.5min ] 482 INDIAN J FIBRE TEXT. RES., DECEMBER 2004

Fig.3-Fuzz entanglement (3.5min brush time and 7min abrading time)

Fig.6-The structure of yarn [a-Fabric 2 and b-Fabric 4]

Fig.4-The structure of pill (3.5min brush time and 7min abrad­ fore, the structure of yarn of wooVpolyester is related ing time) to pill on the fabric. The pilling of worsted fabric is related to the ex­ perimental conditions. With the increase in brush time, much fuzz is formed on the surface of fabrics. The increase in fuzz on the fabrics will lead to the iRcrease in pill number on the fabrics. The fabrics of wool/modified polyester fibres have a high pill resis­ tance because the low strength and modulus of modi­ fied polyester fibres lead to pill worn-off easier. Moreover, the wool content on the surface of yarn also influences pilling on fabric.

Acknowledgement Fig.5-Anchoring fibre holding the pill The authors would like to thank the Economic Trade Commission of China for the financial sup­ For fabrics 2 and 4, the difference in yarn structure port. and wool content may lead to less pill number on fabric 4. Fig. 6 shows the structures of two kinds of yam. It is observed that the surface of yarnfor fabric 2 References 1 Williams V A, Text Res J, 55(1985) 312. has less wool, while that of yarn for fabric 4 has much 2 Goktepe Ozer, Text Res J, 72 (2002) 625. wool. During testing, the pills made of wool are re­ 3 Gintis D & Mead E, Text Res J, 29 (1959)578. moved easily due to the low strength of wool. There- 4 Alston P V, Text Res J, 62 (1992) 105.