Development of Non-Contact Measuring Method for Final Twist Number of Double Ply Staple Yarn Keizo Koganeya 1, Youichi Yukishita 1, Hirotaka Fujisaki 1, Yasunori Jintoku 2, Hironori Okuno 2, and Motoharu Fujigaki 3 1 Graphic System Development Div., Shima Seiki Mfg., Ltd, 85 Sakata, Wakayama 641-8511, Japan 2 Mechatronic Development Div., Shima Seiki Mfg., Ltd, 85 Sakata, Wakayama 641-8511, Japan 3 Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan Abstract : The twist of yarn is one of its important properties. The amount of twist inserted in a yarn is a factor on which are dependent, not only tensile strength, but also a number of properties which contribute to yarn quality. The common method for testing final twist, an attribute of double-ply yarn generally used with flat knitting machines, consists of untwisting the yarn. We propose a method for extracting an outer profile from an image of yarn which is scanned by running the yarn in front of a CCD camera. The number of peaks in the outer profile is related to the number of final twists in the yarn. The number of final twists can be estimated by calculating their frequency in the outer profile using FFT. This paper shows the results of this new method, compared with those of the ordinary method of untwisting yarn. (Received 15 December, 2010 ; Accepted 15 September, 2011) JIS JIS L 1095 9.15.1 A 1 2 3 LED FFT Fig.1 Fig.2 LED LDL-TP- 100 100-SW CCD FLEA- HIBW-CS Point Gray Research Inc. PC 1 0.0173mm 100% 66.7tex 2/30
Fig.3 Fig.5 Fig.6 1 2 Fig.4 FFT Fig.7 13.3mm Fig.7 5.2 Hz mm100mm TW 1 Fig. 3 Original yarn image on running condition. TW = 100 / 2 1 1 2 2 1 Fig.7 w mm mm Fig. 4 Processing yarn image without hair on running condition. =11w 2 2 Fig.7 Fig. 5 Distribution of yarn width along yarn-length at one scene. Fig. 1 Experimental setup. Fig. 2 Overview of measuring setup. Fig. 6 Schematic view of distribution of yarn width.
Table 1 Test for visual check. Fig. 7 Power spectrum of yarn width for evaluating final twist. Table 2 Test for confirmation of final twist. Fig.8 Table6 +35% 25% 23m/min 49cN 5gf 0.8mm 100% 125tex 2/16 0.2mm 100% 16.7tex 2/120 Table 3 Test for influence of final twist. Z S 50% 70% Table1 Table2 Table 4 Test for tight twist yarn.
Table3 Table4 Table3 38.5tex 1/26 25tex 1/40 12.5tex 1/80 3 X2 Y2 Z2 X1 Y1 Z1X3 Y3 Z3 Table4 W Fig.3 2 FFT 10 20 Table1 1 13.3mm Table2 100mm 20 2 100m Table3 Table4 100mm 20 2 100m Table 5 Results of test for visual check. Table 6 Results of confirmation of final twist. Table 7 Results of influence of final twist. Table1 10 20 Table5 7 7 Table2 Table6 9 5% 9 13% Table3 Table4 Table7 3% X Y Z X Y
10% Z 8% 25% X3 15% X3 W 8% 9 Fig.8 Fig.6 Fig.3 Fig.8 Fig.6 Fig.9 FFT Fig. 8 Image of yarn 9, woolen yarn. Fig. 9 Cause of the error in case of yarn X3. 2 FFT 10% 1 0.8mm 100% 125tex 2 /16 0.2mm 100% 16.7tex 2/120 10% 5% 1. Y. A. Ozkayaa, M. Acara, M. R. Jacksona, Journal of the Textile Institute, 101(2), 91, (2010). 2. Y.Guo,X.M.Tao,B.G.Xu,K.F.Choi,T.Hua,S.Y. Wang, Meas. Sci. Technol., 21, 1, (2010). 3. B. G. Xu, C. M. Murrells,X. M. Tao, Textile Reserch Journal, 78(5), 439 (2008).