Investigation On Yarn Structure And Fabric Properties Of Ai-jet Vortex Spinning

Air jet vortex spinning is utilizing high-speed rotary air to twist the strand of fibers.Its feature is that the open end is formed during the process of twisting. More and moreattention were paid to this spinning method by people because of its high-speed and lesshairiness, pure cotton yams with medium yam count can be spun by this spinningmethod.High-speed air flow is used to assist roller drafting, which straightens fibers andmakes fibers easy to control. Compared with ordinary open-end spinning, it improves thestrength of yams and the alignment of fibers in yarns; fibers get less damage during theprocess. In addition, it can spin very quickly because it uses high speed rotary air flowinstead of cursors to twist the strand of fibers.No. 861 spinning machine produced by Chitin Company is based on this kind ofspinning technique. Less than 10 machines of this kind were introduced in China till now,so the spinning technique of this method has not been matured in China. The spinningprocess and mechanism of air-jet vortex system were described in this paper. The motionmodality of fibers in nozzle were simulated and validated. Methods of fiber tracing andchips were used to investigate and model the structure of the air vortex yams. Fibers inthe center of yams have no or less twists, which account for about 30ï¼…. Fibers in theouter layers have the shape of spirality, which consist of two sub-layers. The fibers insideare twisted in the core with the shape of straight, while fibers outside are wound on thesurface of the yam with the shape of hooks. Both sub-layers account for 50ï¼…separately,and they have large numbers of closed fibers. Fibers twisted in the surface layer areoriented, but there are no significant transfers between the inner-part and the outer-part.Due to the overlaps of fibers in the helical structure, hairiness is directional and the longhairiness only occupies small amount. Characteristics of yams and fabrics obtained fromAir-jet Volute Spinning and Ring Spinning are compared here by experiments. Thestrength of MVS yams is slightly lower than that of ring spinning yams; the strength ofpure cotton yams is generally at about 90ï¼…of ring spinning yams; the strength of yamsmade from pure man-made or blended fibers can reach and exceed the strength of normalring spinning yams, and the other indexes are superior to normal ring spinning yams,especially, it has less hairiness than that of ring spinning yams, some yams can reach thelevel of compact yams. The properties of knitted fabrics which are produced by MVSyarns are close to fabrics made by traditional ring spinning yams. The strength of purecotton fabrics made by MVS yams drop to some extent, however T/C fabrics almostmake no differences; its abrasion resistance and drapability are superior to the ringspinning fabrics; it has less pilling and hairiness, but the wrinkle resistance is not as goodas fabrics with ring spinning yams; its permeability and heat resistance have no bigdifferences. Five parts are included in this paper: The first part has a brief introduction about thedevelopment and the classification of new spinning methods, the development andresearch in home and abroad of air vortex spinning, purpose, significance and content ofthis research; the second part mainly describes the spinning process and principle of airvortex spinning; the third part compares the yam performance of air vortex spinning andother spinning methods; the fourth part mainly focus on the yam structure and the effectson yarn performance of air vortex spinning; and the last part compares the fabricperformance of air jet vortex spinning and ring spinning.