| Currently ring spinning is the commonly used spinning method in the world, which hasadvantages of mature technology and versatility. However, the spun yarn has too muchhairiness, leading to lower the efficiency of the post processing. Attaching a swirl nozzle onthe traditional frame ring is not only convenient, but also can reduce hairiness remarkably.Some research, such as the airway angle, spindle speed, distance between swirl nozzle to thefront roller had been carried out. In this paper, we focused on the configuration of swirlnozzle(airway diameter and airway position), and made an optimization of swirl nozzlestructure.We carried out the experiment on CZJF-5Intelligent Multifunction Spun Frame.First,we investigated the effect of swirl nozzle on the performances of various fineness yarn. Under0.05~0.25MPa air pressure, we spun10tex,20tex,30tex,40tex,50tex yarn. Test resultsshowed that swirl nozzle could reduce S3(length≥3mm hairiness index) remarkably, andreduce yarn density and increase twist slightly.30tex yarn had a less density reduction, a littleevenness increased rate, twist and intensity almost were changeless, therefor30tex was theoptimal linear density.In order to study the influence of airway configuration on swirl nozzle, we arrangeddiameter group and position group swirl nozzles.(1)In the diameter group: CFX simulationfound that, swirl nozzle which airway diameter was1.2mm had a low flow velocity along theyarn channel center line, the yarn were not bent easily, thereby reduced the probability ofhairiness wound into the yarn body. Flow rotation inside1.6mm swirl nozzle was too weak towound hair into the yarn body, and it had a strong lateral pressure along the yarn channelcenter line, causing the yarn running unstably.1.4mm swirl nozzle had a large flow velocityalong the axis, moreover, its helix was regular. Therefore CFX simulation deduced1.4mmwas better than1.2mm and1.6mm. Spinning experiments showed that1.4mm swirl nozzlewas always superior to1.2mm and1.6mm as of S3values, breaking strength,unevenness.(2)In the position group, CFX simulation found,the change of airway positioncouldn’t affect air pressure, flow velocity, but the twisting area.Swirl nozzle with air positionA(the distance between the intersection of airway and yarn channel to yarn entrance was7mm)> air position B(the distance between the intersection of airway and yarn channel toyarn entrance was10.5mm)> air position C(the distance between the intersection of airwayand yarn channel to yarn entrance was14mm), Then from CFX simulation,we found A wasbetter than B and C. Spinning experiments showed that airway position A had a slightly betterresults than B and C on every aspect. Therefore, on one hand, spinning results confirmedsuccessfully the CFX simulation inference, on the other hand the experimental results explained theoretically the reason that the various airway diameters and airway positions haddifferent results.Finally, according to the above conclusions, we selected30tex yarn to do orthogonalexperiment.Results showed that the significant of three factors was air pressure> airwaydiameter> airway position. The optimal process parameters was air pressure0.25MPa,airway diameter1.4mm, airway position A. Considering the thick and thin, the best pressurewas0.15MPa, under this condition, comparing with the traditional spun yarn, the yarnproduced with swirl nozzle, the S3value was decreased74.2%, breaking strength wasdecreased0.5%, evenness was decreased2.6%. So it clearly showed that swirl nozzle had anadvantage on reducing hairiness. On fabric hand aspect, comparing the ordinary fabric, theswirl nozzle fabric felt more stuff. When the external force acted on two fabrics, the structureof swirl nozzle fabric was more easily changed, its recovery performance and anti-wrinkleability were stronger. |
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