The Study Of Yarn Hairiness Based On High Speed Photography

Yarn hairiness is mainly produced in spinning process and increased in the windingprocess. According to this, in this paper, the process of yarn forming especially the movementof fiber in the spinning triangle and the movement of fiber in the compact field are studiedwith the help of high-speed camera. The changes of hairiness in the process of yarn formingare analyzed by observing the structure of yarns. Then, the key mechanical components inwinding process causing the growth of hairiness are studied by analyzing the dynamic changeof yarn hairiness in winding process, which proves reference for eliminating the hairiness ofyarns.In this paper, firstly, JC14.6tex,9.7tex and7.3tex combed cotton yarns are spun onring-spinning frames, compact spinning with lattice apron and complete condensing spinningframes. Then, yarns are prepared for winding, and quantitative analysis is done by the directtest of yarn hairiness. On this basis, by using a high-speed video camera, the yarn motiontracing on spinning triangle area of ring-spinning process and condensing zone of compactspinning with lattice apron and complete condensing spinning are studied. Then combiningwith the results of quantitative analysis, the relationship of yarn structure and yarn hairinesschanges in the process of spinning yarn are studied. Secondly, the hairiness variation of30tex、11.7tex、7.3tex combed cotton yarns and18.3tex、9.8tex viscose yarns spun by compactyarns with lattice apron and complete condensing spinning after winding are analyzed.Combining with fiber movement on condensing zone and yarn structure, the effect of twokinds of compact yarn structure on the changes of the hairiness were compared. Meantime,the hairiness feature of complete condensing spinning was analyzed. Finally, research on thedynamic changes of hairiness in the process of winding is done to get the key components ofhairiness increasing in the winding process.The experimental results show that:1. The yarn hairiness number of compact spinningwith lattice apron and complete condensing spinning is less than that of traditional ringspinning, and the number of1mm short hairiness with complete condensing spinning isbasically retained compared with traditional ring spinning; after winding process, the increaseof more than3mm harmful hairiness of compact spinning with lattice apron and completecondensing spinning is relatively greater than that of ring-spinning; hairiness increasing rateof complete condensing spinning is larger than that of compact spinning with lattice apron,and with the increase of linear density, growth rate of two kinds of compact yarn hairiness ismore significant difference.2. In the process of the spinning, the edge fiber at spinningtriangle area of ring-spinning is difficult to be involved in the yarn body, and short fiber isexposed to the yarn surface easily, so the yarn structure with a lot of hairiness is loose, andfiber is easy to be drawn out of yarn body in the process of winding, and the yarn hairinessincrease largely. In the spinning process of compact spinning with lattice apron and completecondensing spinning, fiber is basically involved in the yarn body, and the surface fibers withweaker force of the yarn body with less hairiness are easily pulled out to generate hairinessduring the winding. In the process of spinning with compact spinning with lattice apron, under the action of negative pressure in the airflow guide groove, fiber turn along thedirection of the airflow guide groove, and get false twist at the concentrated area, so yarnstructure is too hard-spun to be pull out. In the gathering process of complete condensingspinning, the fibers remain tight straight and shift to left along a certain angle. There is noturnover phenomenon of the gathering process of compact spinning with lattice apron. Thesurface fibers with weaker force are easily pulled out to generate hairiness during the winding.3. In the process of winding, the friction borne by the yarn is bigger through the doubletension device and drum device, so yarn hairiness is most affected here.