Variation in imperfections level due to winding of ring yarn

Transcription

1 Indian Journal of Fibre & Textile Research Vol. 32, September 2007, pp Variation in imperfections level due to winding of ring yarn S Subramanian a, P S Karthikeyan, M Ragu Ramachandran & A Velmurugan Department of Textile Technology, A C College of Technology, Anna University, Chennai , India Received 14 April 2006; revised received 17 July 2006; accepted 1 September 2006 The variation in imperfections level due to winding of carded and combed ring yarns and the effect of foreign matters, such as black specks of broken seeds, lead bits and trashes present in the ring cop yarn, on imperfections during winding process for carded cotton ring yarn has been studied. The results show that the thin places increase, and thick places and neps decrease due to the fall of foreign matters during winding in the carded yarn. In the combed yarn, the thin places, thick places and neps increase during winding. Keywords: Broken seeds, Cotton, Fibre cluster, Foreign matters, Imperfections, Winding, Yarn hairiness IPC Code : Int. Cl. 8 D02G3/00 1 Introduction Yarn hairiness is one of the essential parameters, which influences the performance of yarn in the subsequent processes. All the hairs, which protrude from the yarn, do not present a problem during further processing. Normally, the hairs of the length 1-2 mm give wear comfort. However, all the hairs of the length 3 mm and above may cause considerable problems in subsequent processes. 1 During winding, the yarn gets abraded with the guiding elements of the winder. It has been found that the hairiness parameters increase during winding and repeated rewinding due to raising of hairs. 2,3 The abrasion causes the surface hairs in the yarn getting rolled up together and tend to form fibre clusters and nep like defects. 4,5 The effect of winding parameters on change in yarn imperfections has been studied by many researchers. 6,7 The thin places are due to the removal of protruding surface fibres from the yarn body. During winding, the yarn imperfections increase to a fold of % for the combed yarn and this increase in imperfections is greater for yarns with higher level of hairiness. 8 In the present work, the change in imperfections level due to winding of carded and combed ring yarns and the effect of foreign matters, such as black specks of broken seeds, lead bits and trashes present in the ring cop yarn, on imperfections during winding process for carded yarn has been studied. a To whom all the correspondence should be addressed. ssubbu@annauniv.edu 2 Materials and Methods 2.1 Materials Carded cotton yarn of tex (30 Ne) & 9.85 tex (60 Ne) and combed yarn of tex (50Ne) were produced with the process parameters and experimental arrangements as given in Tables 1 and 2 respectively. To get the yarns with different levels of hairiness and imperfections, the process parameters, viz. spindle speed, use of anti-balloon control ring and traveller mass, have been selected. 2.2 Test Methods The yarn samples were tested using a Uster UT3 tester for hairiness, unevenness and imperfections. The imperfections were measured at following sensitivity levels, viz. thin places 30%, -50%, -60%; thick places +35%, +50%, +70%; and neps +140%, +200%, +280%. The tests were carried out using the specifications: test speed, 400 m/min; test time, 1 min; and number of tests, 10 per sample. Table 1 Material and process parameters used for the production of yarn samples Parameter [50 NeC] (I) (II) (III) 9.85 [60 NeK] Material MCU 5 S4 Average S4 Good LRA +JKHY MCU 5 +S6 Roving hank Break draft Yarn TM Spacer, mm C Combed, and K carded.

2 SUBRAMANIAN et al.: VARIATION IN IMPERFECTIONS LEVEL DUE TO WINDING OF RING YARN 291 Table 2 Experimental arrangements for producing yarn samples Yarn sample Yarn count tex Spindle speed rpm Usage of ABC ring Traveller [50 NeC] No 12/ [50 NeC] Yes 12/ [50 NeC] No 12/ [50 NeC] Yes 12/0 5 [30 NeK(I)] No 4/0 6 [30 NeK(I)] Yes 4/0 7 [30 NeK(I)] No 4/0 8 [30 NeK(I)] Yes 4/0 9 [30 NeK(II)] No 4/0 10 [30 NeK(II)] Yes 4/0 11 [30 NeK(II)] No 4/0 12 [30 NeK(II)] Yes 4/0 13 [30 NeK(III)] Yes 2/0 14 [30 NeK(III)] Yes 2/0 15 [30 NeK(III)] Yes 2/0 16 [30 NeK(III)] Yes 1/0 17 [30 NeK(III)] Yes 3/ [60 NeK] Yes [60 NeK] Yes 11/ [60 NeK] Yes 11/ [60 NeK] Yes 12/ [60 NeK] 16,000 Yes 13/0 Table 3 Effect of foreign matters on yarn imperfections due to winding Yarn sample Foreign matters, mg/ 3000 m Ring Cone Difference The microscopic study was carried out to determine the presence of kitties, i.e. black specks of broken seeds, lead bits and trash. The kitties were taken out by untwisting the yarn composite with the help of forceps and miniature pluckers. Due to the complexity involved in the segregation of kitties, only the kitties with appreciable size were segregated out and weighed. Very small kitties could not be taken out without the sticking fibres. The weight of kitties present in the cop and cone yarn per 3000 m is given in Table 3. As the kitties and foreign matters of appreciable size were not present in the combed yarn, the studies were conducted for the carded yarn only. 3 Results and Discussion 3.1 Change in Yarn Hairiness due to Winding Tables 4-6 show that there is significant increase in hairiness due to winding in most of the cases owing to the abrasion of yarn against the guiding elements of winding machine. The increase in hairiness due to winding is higher in the case of 50 Ne combed yarn than in carded yarns. In the case of combed yarn, the increase in hairiness during winding is greater for the ring bobbins having less hairiness at the spinning stage (correlation coefficient 0.89). The findings for the combed yarn are in agreement with the findings of Moraye et al Variation in Yarn Imperfections due to Winding Combed Yarn The imperfections and hairiness of ring cop and cone yarn are given in Table 4. It is observed that there is significant increase in imperfections due to winding in most of the cases. The increase in neps can be attributed to the conversion of hairs into neps due to abrasion of yarn against the guiding elements of Parameter Table 4 Imperfections and hairiness of ring cop and cone yarns (50 NeC) Sample 1 Sample 2 Sample 3 Sample 4 Cop Cone Cop Cone Cop Cone Cop Cone U% Imperfections level -30% % % % % % % % % Hairiness index

3 292 INDIAN J. FIBRE TEXT. RES., SEPTEMBER 2007 winding machine and the same may also be responsible for some near thick places, which were not counted as thick place, to increase its thickness and becoming thick places. The increase in thin places is significant at higher sensitivity level (thin -30%). This may be due to the removal of fibres during winding which cause smaller reduction in yarn diameter, measurable only at higher sensitivity levels Carded Yarns Tables 5 and 6 show that there is reduction in thick places and neps though statistically not significant in most of the cases. The reduction in thick places and neps may be due to the fall of foreign matters, though some neps may have been formed due to rolling of protruding fibres. In some cases, there is small increase in thick places and neps. This may be due to the measure of imperfections in other categories. The tables also show that, in most of the cases, thin places increase after winding, though statistically not significant. In the carded yarn, the foreign maters are loosely held or embedded on the surface of the yarn. These loosely held foreign matters come off the yarn, predominantly before the fibres, during abrasion of yarn with the guide elements of the winder and this has more effect on the reduction of thick places and neps compared to increase in thin places. Moreover, with hairy yarns the surface of the yarn body is well buried under the hairs and therefore does not get abraded during winding. 10 As the number of imperfections in the ring cop yarn measured at 60% and +70% levels are less, the percentage changes are varying between 0% and 200 %. 3.3 Effect of Foreign Matters on Yarn Imperfections due to Winding The foreign matters, like black specks of broken seeds, lead bits and trash particles, present in the carded ring cop and cone yarns measured by microscopic method are given in Table 3. The effect of (i) reduction in foreign matters present in the yarn due to winding and (ii) foreign matters present in the ring cop yarn on the decrease in thick places and neps due to winding are shown in Figs 1 and 2 respectively. For the analysis, the difference in the sum of thick places and neps of ring cop and cone yarn measured at medium and lower sensitivity levels, i.e. + 50%, +200%, +70% and +280% is considered. Since the foreign matters of appreciable sizes were only measured during analysis, the imperfections measured at higher sensitivity levels are not included.

4 SUBRAMANIAN et al.: VARIATION IN IMPERFECTIONS LEVEL DUE TO WINDING OF RING YARN 293 Parameter Table 6 Imperfections and hairiness of ring cop and cone yarns (60 NeK) Sample 18 Sample 19 Sample 20 Sample 21 Sample 22 Cop Cone Cop Cone Cop Cone Cop Cone Cop Cone U% Imperfections level -30% % % % % % % % % Hairiness index Fig. 1 Effect of difference in foreign matters present in ring cop and cone yarns on decrease in thick places and neps due to winding Figure 1 shows that the reduction in thick places and neps is higher for more decrease in foreign matters present in the yarn due to winding for both 30 Ne and 60 Ne carded yarns. The decrease in thick places and neps may be due to the fall of foreign matters, exceeding the neps created by the rolling of protruding surface fibres. Figure 2 shows that the more amount of foreign matters present in the ring yarn results in higher reduction in thick places and neps. The more amounts of foreign matters present in the ring cop yarn result in greater dropping while abrading with the guide elements and hence greater reduction in thick places and neps. Since the foreign matters of appreciable size are not present in the Fig. 2 Effect of foreign matters present in ring cop yarn on decrease in thick places and neps due to winding combed yarn, it has no influence on imperfections due to winding. 4 Conclusions 4.1 The hairiness of the yarn increases during winding; the increase is, however, greater for the less hairy ring cop yarn. 4.2 In 50 Ne combed yarn, the thin places, thick places and neps increase significantly after winding. 4.3 In 30 Ne and 60 Ne carded yarns, the thin places increase due to winding in most of the cases though statistically not significant. The thick places and neps reduce due to winding because of the fall of foreign matters during winding as the yarn is having more

5 294 INDIAN J. FIBRE TEXT. RES., SEPTEMBER 2007 number of foreign matters loosely held on the surface. The reduction in thick places and neps due to winding is greater for more amounts of foreign matters present in the ring yarn. References 1 Olbrich A, Melliand Int, 81 (2000) E25. 2 Barella A & Vigo J P, J Text Inst, 65 (1974) Barella A & Vigo J P, J Text Inst, 66 (1975) Chellamani K P, Chattopadhyay D & Kumarasamy K, Indian J Fibre Text Res, 25 (2000) Salhotra K R, Ishtiaque S M, Agrawal A K, Ajay Gupta, Debashis Ghosh & Arghya Talukdar, Proceedings, 41 st Joint (NITRA, Ghaziabad), 2000, Arindam Basu & Rajanna Gotipamul, Proceedings, 45 th Joint (SITRA, Coimbatore), 2004, Kathirvel M, Karthikeyan S & Chellamani K P, Asian Text J, April (1997) Desai A N, Patil V K & Balasubramaniam N, BTRA Scan, March (1994) 5. 9 Moraye S S, Raje S S & Sivakumar T S, 19 th Joint (BTRA, Bombay), 1978, Krishnaswamy R, Paradkar T L & Balasubramanian N, BTRA Scan, June (1990) 8.