Study On Air-jet Vortex Spinning Of Polyester And Cotton

Air-jet Vortex Spinning technology is a kind of semi-open-end spinning technologiesdeveloped on the basis of Air-jet Spinning by Murata Machinery Ltd. in Japan. It uses high-speedrotating air currents to wrap fibers into yarn. With a series of advantages such as short processingflow, labor saving, high degree of automation, high production and so on, Air-jet VortexSpinning becomes one of the most potential spinning technologies of the21st century. Manydomestic and international scholars have made a lot of researches on the principle of yarnformation mechanism, structure of vortex-spun yarn and product development of Air-jet VortexSpinning, but the raw materials are mainly regenerated cellulose fibers, and there are less researchon the design of nozzle structure. Some problems still exist when spinning polyester and100%cotton. Air-jet Vortex Spinning equipments in our country are heavily import-dependent. Besides,the spinnability and yarn quality of air-jet vortex spinning are largely affected by the environmenttemperature and humidity, but there have been short of systemic research. On the basis ofspinning nozzle designed for viscose fiber, spinning experiments were done with polyester andcotton in this paper, the main contents are as follows.(1) Spinning experiments of modal and polyester were done with orthogonal method indifferent air temperature and humidity and the moisture regain of rove. The result shows that onlywhen the moisture regain of rove and the environment temperature and humidity are within theirsuitable range at the same time can we get high quality yarns smoothly. For modal and polyester,the suitable range of moisture regain are10%~14%and0.4%~0.9%respectively. When thetemperature and humidity of compressed air as well as spinning environment are within20℃~30℃and45%~65%, the spinning process is smooth and yarn quality is good.(2) By single factor spinning experiment of polyester and cotton, the spinning air pressure,distance from front roller nip to nozzle and distance from guide needle to cone body wereoptimized. The results show that under the experimental condition, for polyester yarn,polyester/combed cotton65/35blended yarn and combed cotton yarn, the preferred processparameters are as follows. The spinning air pressure:0.55MPa,0.5MPa,0.5MPa respectively;distance from front roller nip to nozzle:14mm~16mm,12mm~14mm,12mm respectively;distance from guide needle to cone body:1.5mm,1mm,1mm respectively.(3) For each kind of yarn, the nozzle structural parameters were optimized, including guidedneedle length, the structure of the vortex chamber, jet orifice angle of vortex tube, jet orificediameter of vortex tube, jet orifice number of vortex tube, tip angle of cone body. The influencesof these structural parameters on yarn quality were studied when spinning different kinds of yarnsand the optimum parameters were obtained. Repeated spinning experiments show that the yarn quality all get different degree of improvement after optimization of the nozzle structure.(4) The test method for the twist of vortex yarn were explored. The factors that have aninfluence on the twist of vortex yarn were obtained by theoretical analysis. On the basis of theyarn ideal spiral model, the twist of vortex yarn was tested by YG002C fiber fineness analyzer.The regression equations between yarn twist and spinning pressure and spinning speed wereobtained by regression analysis and the relationship between yarn strength and twist wasdiscussed.