Abstract:

Significance Air-jet vortex spinning machine (AVSM) is an spinning equipment with high spinning speed and efficiency in achieving high quality of multi-variety yarns, which is developed on the basis of jet spinning technology. AVSM is employed by more textile enterprises and has a profound scope for spinning of medium and long lengths staple cotton and blended yarns. But the technology of AVSM has its disadvantages and limitations of significant fiber loss, 100% short fiber loss for cotton yarn spinning. The limitation of the spinning range can be expected to overcome by the market leading enterprises of AVSM. Thus, in order to understand the current application, research development and present problems in AVSM by domestic and foreign spinning enterprises, a comprehensive analysis of the results of research and patent design achieved in AVSM is presented.

Progress Modern air-jet vortex spinning (AVS) technology is basically a new spinning technology developed on the base of the Murata AVSM. The key technologies and principle related to the AVS process include cotton guiding and feeding, sliver drafting, conveying, AVS device, yarn winding, and yarn packaging. The AVS device is the core device of AVSM, and the earliest version was manufactured by Murata. Later Gernot from Rieter proposed another AVS device, which is with different designs for the spindle, needle guider, and nozzle block. The research on in two types of AVS device have been made in the aspects of structure optimization, CFD simulation of three-dimensional air flow field inside of AVS device. Some improved structures of AVS device were proposed for reducing rate of short fiber falling, and for increasing the spinning rate. Huayan in Shaanxi designed two-split structure of AVS device controlled by pneumatic cylinder for opening and closing of the upper and the lower branches. The double AVS devices composed of the upper and lower branches was design to prevent fibers to be taken away from the airflow for improving the spinning rate. There are a few designs of the needle block with special features, i.e., the movable needle with adjustable axial position, or adjustable angle between guide hole and needle, the more guide holes and heating function. In nozzle block, some improved designs were made such as four adjacent spiral vortex grooves on chamber wall, three-stage structure, the surrounding spiral pipe on the outer surface for further improving the spinning effect.

Conclusion and Prospect For understanding the main application and research status of AVS technology, the relevant patents and research papers are reviewed. The research shows that the main research content of AVSM and its key technology are developed by some Chinese spinning enterprises and textile research institutes such as Huayan in Shanxi, Jiangyin Huafang New Science and Technology Ltd. Co. and so on with many related patents mainly focusing on the improved structural design of the AVS device and its related components. Overseas large-scale production of AVSM is mainly made from Murata and Rieter. Global research is also focused on the content of AVS of Murata, and more researches carry out simulation analysis on AVS device and on the spinning performance. In comparison with the early development of AVSM from Murata and Rieter, the relevant achievements of application and research progress of AVS technology are not noticeable. At present, the nozzle chamber of AVSM is often designed as the conical frustum model, in which the working principles of setting multiple air-jet vents in tangential direction of the chamber surface for producing the swirling air flow to make fiber false twisting has not changed. Looking forward to the future, CFD analysis and experimental research of AVS device will be needed aiming at the design of chamber structures, the production of higher strength yarn and the optimization of twisted vortex for improving the performance of AVS, meeting the production of multifunctional yarns and manufacturing yarns from short cotton fiber. In addition, with the progress of science and technology, more and more automation and intelligence control systems will be developed and applied in the AVSM such as electronic yarn cleaner, detection and control of foreign fibers, short fibers diagnosis, visualization, and others.

Key words: air-jet vortex spinning, spinning device, nozzle block, conveying mechanism, winding mechanism