Study on a reducing-hairiness nozzle attached on the winding machine

A special hairiness-reducing nozzle was attached on a winding machine. The design and attachment of the nozzle should not change the yarn twist and strength. The hairiness-reducing mechanism of the nozzle was analysed, which utilised an air-jet to produce the rotating air stream to perform false twisting, detwisting and wrapping of the yarn so as to wrap the hairiness onto or twist it into the main yarn body, thus reducing the yarn hairiness. The position and method for attaching the nozzle were introduced. The hairiness index, hairiness appearance, twist and strength of the yarn, which was produced by the winding machine attached with the nozzle were examined. The results indicated that the processed yarns have their hairiness index lowered, hairiness appearance improved, and the twist and strength remained unchanged, which verified the hairiness-reducing effect of the nozzle. Fabric pilling property and surface features were measured for fabrics in which the filling yarns were through the winding machine with the nozzle. The results showed that the fabrics had less pilling and a smoother surface.     

Application of air‐jet nozzle in short staple Siro spinning system

With the objective of reducing the hairiness of Siro spun yarns, two types of air‐jet nozzle differing in the angle of sub‐holes and suitable for an air vortex ring spinning system were designed and fabricated. The performance of the JetSiro spinning system on short staple fiber materials and the effects of the different parameters on the hairiness of JetSiro spun yarns, such as nozzle pressure of compressed air, distance between front roller nip and inlet of nozzle, and nozzle structure, were investigated using the Taguchi method. The physical properties of JetSiro spun yarns with those of conventional Siro spun yarns were compared. The results show that the parameters, air pressure and distance between front roller nip and inlet of nozzle have the strongest and weakest effect on yarn hairiness. In addition, the optimum spinning conditions were determined. The application of the air‐jet nozzle exhibits significant reductions in yarn hairiness of 40%. The results revealed no significant effect of the air‐jet nozzle on the yarn tensile properties and evenness.     

气道位置对旋流器减少细纱毛羽效果的影响

为了进一步优化旋流器的内部结构,更好地改善成纱质量,本文在前期研究基础上设计了三种不同气道位置的旋流器,并且在加工气压分别为0-0.25MPa下加工纱线。通过测定纱线的毛羽指数,并和普通环锭纺纱线进行对比,得出：当气道直径d=1.4mm,气道在纱道上的分布位置为1:2,加工气压为0.2MPa时,所纺纱线的毛羽指数达到最低。同时,利用流体力学计算软件ANSYS CFX对喷嘴内的气流场进行数值模拟和分析,研究了气流场对纱线毛羽减少的影响机理,并进一步阐明了气道位置和加工气压对喷嘴内气流场的影响。     

旋流喷嘴对不同线密度纱线的作用机制

为研究旋流喷嘴纺纱方法对不同线密度纱线的减羽效果,借助计算流体软件模拟旋流喷嘴内部气流特性及不同线密度纱线在气流作用下的压强与速度分布,并用纺纱试验进行验证。模拟结果表明,进入纱道后的气流沿顺时针方向分别朝纱道入口及出口方向运动,纱线表面毛羽主要受到气流的包裹力和由于纱线自转而产生的相对包裹力作用。气流的旋转特性使得纱道管壁附近的压强高于轴线附近,因此不同线密度纱线的表面所处涡流的位置不同,受到的气流包裹力也不同。纱线线密度较小,表面受到的压强分布密集,x、y、z 向速度波动较大,其中20 tex 纱线表面的压强和速度分布情况优于10、30、40 tex 的。研究结果表明,旋流喷嘴压强在0.2 MPa 下,对20 tex 大麻/ 棉（40/60）的减羽效果最优,达到了87.6%,与数值模拟结果一致。     

55—SOME FACTORS AFFECTING THE HAIRINESS OF WORSTED-SPUN YARNS

Further experiments are reported on the hairiness of worsted-spun yarns, chiefly of mohair. The effect of some fibre physical properties on the hairiness of man-made-fibre blended-fibre yarns was also studied. Leading hairs are predominant among the singles yarns spun by different drafting systems, although their proportions may vary. The hairiness of yarns spun by different drafting systems is compared. The Ambler Superdraft Uniflex spinning machine produced the least hairy Courtelle acrylic-fibre yarns from the different drafting systems studied. An increase in the drafting angle and an increase in traveller weight reduced the yarn hairiness, and there appeared to be a critical value of flume-setting, above and below which yarn hairiness increased. The Uniflex spinner appeared to produce at least equally lean, if not leaner mohair yarns, both singles and two-fold, than did the flyer system.     

应用STAR-CCM+的旋流喷嘴内部三维流场数值模拟与分析

在环锭细纱机上安装旋流喷嘴,能较好地减少细纱毛羽。应用软件STAR-CCM+对旋流喷嘴内部流场进行数值模拟,表征了喷嘴纱道流场的分布情况,解析喷嘴纱道中径向、切向、轴向三向速度分布规律。当喷嘴气道与纱道相交方向和相切点不同时,结合气流对纤维的作用,分析旋流喷嘴纱道中的气流分布规律。从模拟结果得出：旋流喷嘴纱道与气道相切点沿X轴负方向长度为14mm,且喷嘴气道与纱道相交方向向上时,所形成的气流可以减少占大多数的顺向毛羽。     

旋流器对环锭纺不同线密度纱线性能的影响

采用安装在传统环锭细纱机的旋流器加工不同线密度的纱线,探讨了旋流喷嘴内部高速旋转气流对纱线加捻成形的影响。结果表明：旋流器的使用能够有效地减少纱线毛羽,但在优化纱线强力、条干不匀率等方面作用不是很明显且对不同线密度纱线质量的改善程度存在一定的差异。采用纱道为2 mm,气道为1.4 mm的旋流器,所加工不同线密度纱线的质量都有一定程度的提高,其中线密度10 tex 纱线的3 mm以上毛羽、断裂强度和条干不匀率质量指标的改善均优于其他四种纱线,为研究最好地降低纱线的成纱毛羽提高纱线质量而选择合适尺寸的旋流器提供参考。     

Dynamics of the Ramie Yarn Hair in the Nozzle of the JetWind Process and Effects of Some Nozzle Parameters

The technique of reducing yarn hairiness using an air-jet nozzle on the winder (JetWind) is a combination of the ring and air-jet spinning technologies. The dynamics of the hair inside the nozzle plays an important role in the JetWind process. In this study, a dynamical model for the coupling between a protruding surface hair on the ramie yarn and the airflow in the JetWind process is developed. Based on the model, numerical simulation of the dynamics of the hair in the nozzle is performed and the principle of reducing yarn hairiness is theoretically shown. The simulation result is validated by the experimentally captured motional configurations of the hair in the nozzle using high-speed photography technique. The effects of two nozzle parameters—the injector angle and yarn passage diameter on the dynamics of the hair and in turn, yarn hairiness are investigated by both numerical simulation and experiments.     

The effect of air-jet nozzle structural parameters on new cotton rotor-jet spun yarn properties

In this paper, a hybrid spinning system the so-called “rotor-jet spinning method” which utilizes the air-jet nozzle in rotor spinning process is presented. Thus, air-jet nozzles with different structures of 90S, 90Z, 60Z, and 30Z (the values of 90, 60, and 30 are orifice angles and S and Z are air rotational directions) were designed and constructed and then mounted between the take-up nozzle position and doffing tube in a rotor spinning machine. The air-jet pressure was changed at 0.2, 0.5, 0.8, 1, 1.2 and 1.5 bar values. The physical properties of cotton rotor-jet spun yarns with yarn count 20 Tex and nominal yarn twist of 938 TPM were investigated and compared with that of normal rotor-spun yarn. The experimental results indicated that by utilizing a 90Z air-jet nozzle at 1 bar air pressure, the highest yarn tensile strength, abrasion resistance, and twist, and lowest elongation are obtained compared with those of normal rotor as well as rotor-jet spun yarns with 30Z, 60Z, and 90S air-jet nozzle types. However, the rotor-jet spun yarn irregularity produced with 90Z air-jet nozzle is almost identical to normal rotor-spun yarn. It is also shown that the rotor-jet spun yarn hairiness properties which were produced with a 90Z air-jet nozzle at air pressure values of 0.2, 0.5 and 1 bar is almost similar to normal rotor-spun yarn while the lowest yarn hairiness is achieved at air pressure value of 0.8 bar. The experimental results of this paper suggest that the newly developed rotor-jet spun yarn is superior to normal rotor-spun yarn from the point of view of yarn tensile, abrasion resistance, twist, and partially hairiness properties.

     

环锭旋流喷嘴纺麻混纺纱的性能

为改善麻纤维因自身性能缺陷与传统纺织工艺局限性所导致的成纱毛羽问题,将旋流喷嘴纺纱技术应用于精细化亚麻/长绒棉/天丝和大麻/棉/粘胶2种混纺纱的纺制,选择适当的细纱工艺参数并测试成纱后的主要性能指标。结果表明:当旋流喷嘴中通入的气流压强为0.1 MPa时,亚麻混纺纱的有害毛羽数量相对于传统环锭细纱降低了89.9%,压强为0.05 MPa时,大麻混纺纱的有害毛羽数量降低了99%;显微镜下2种混纺纱线的纱体结构紧密,纤维排列整齐,纱线表面光洁,大麻混纺纱中的黑色粘胶长丝均匀包裹在纱体表面,使得纱线色泽更为均匀;纱线断裂强力与条干不匀率稍有降低,但变化不明显。     

旋流喷嘴气道配置对环锭细纱性能的影响

为研究旋流喷嘴不同气道配置对减羽效果的影响,本文设计和使用了两组不同气道直径和气道位置的旋流喷嘴进行纺纱实验,并对普通纺、紧密纺和旋流纺的综合性能进行了比较。实验结果表明：气道直径为1.4mm的旋流喷嘴减羽效果优于1.2mm和1.6mm的旋流喷嘴,气道位置为A的旋流喷嘴优于位置为B和C的旋流喷嘴。对于30tex的Z捻纱,旋流喷嘴最佳尺寸参数为气道直径为1.4mm,气道位置为A,最佳气压为0.15MPa,在此条件下,旋流纺比普通纺S3值(≥3mm毛羽数之和)降低了74.2%,断裂强度增加了5.4%;比紧密纺S3值降低了59.5 %,断裂强度降低了4.0%,减羽效果显著。     

络筒机上减少毛纱毛羽装置的研究

络筒工序会增加羊毛纱线毛羽,制约了轻薄高精羊毛纺织品的开发.文章针对改善羊毛纱线的毛羽,研制了一种气流喷嘴装置,应用旋转气流使纱线退捻-加捻的原理,进行了减少羊毛筒子纱毛羽的研究,研究重点放在解释气流喷嘴装置的设计理念,讨论管纱不同部位、不同规格羊毛纱线的毛羽减少效果,并且指明了项目的不足和进一步的研究方向,最后得出了实验装置能有效地减少毛纱毛羽尤其是长毛羽的结论.     

络简新技术应用探讨

围绕现代高速整经机和高速织造技术不断发展对棉纱质量提出的高要求,通过应用新型空气捻接器、喷气式毛羽减少装置、智能型槽筒、跟踪式气圈控制器和栅栏式张力器相结合的开环式张力控制系统等各种络筒新技术,表明其有利于提高各种无结纱的捻接强力、减少强力不匀率和纱线表面毛羽,且筒子成形良好,可以提高无结纱的质量和可织性.     

Yarn evenness parameters optimization in jetring spinning process

Abstract

In this study, the effects of air nozzles called jetring or nozzlering, on yarn quality which is used as an additional process in conventional ring spinning machines have been investigated. The response surface methodology (RSM) was used to investigate the yarn properties value. In the experiment, Ne30/1 100% cotton fibers were used. In all jetring yarn productions, the air pressure was kept at 125?kPa (gauge). In all samples, the nozzle length was kept 27?mm and twisting chamber diameter was kept Ø2mm. The number of injectors has been kept constant as 4 pieces. Giving the best yarn quality as a result of RSM, injector diameter Ø0.5?mm and injector angle 35° as determined. With this nozzle structural configuration, yarn hairiness values were reduced by 9.2% but yarn irregularity values were increased by 0.7%, yarn elongation values were decreased by 6.2% and yarn tenacity (cN/tex) values decreased to 5.6.     

芳砜纶阻燃纱线设计

将芳砜纶纤维分别与高强涤纶纤维、阻燃粘胶纤维按照不同比例混纺,测试混纺纱的强伸性能、外观质量和阻燃性。结果表明:芳砜纶/高强涤纶混纺纱中芳砜纶强力的临界混纺比为92.3%。随着高强涤纶比例的增加,混纺纱的断裂强力增加,断裂伸长率降低,条干不匀率及毛羽指数减少,阻燃性能下降且出现熔融现象。芳砜纶/阻燃粘胶混纺纱中阻燃粘胶强力的临界混纺比为73.8%。随着阻燃粘胶比例的增加,混纺纱的断裂强力及断裂伸长率降低,条干和毛羽有所改善,阻燃性能下降。     

34—A CONTRIBUTION TO THE STUDY OF THE INFLUENCE OF THE DESIGN OF THE YARN-WITHDRAWAL TUBE ON THE DIAMETER AND HAIRINESS OF OPEN-END-SPUN ACRYLIC-FIBRE YARNS

An investigation is reported in which factorial experiments were conducted to study the influence of the design of the yarn-withdrawal tube (or nozzle) on the diameter and hairiness of open-end-spun acrylic-fibre yarns. Three nozzle types, combined with three values of yarn linear density and five values of twist multiplier, were studied for four different (but equal-diameter) rotor types. lt is shown that the nozzle type has very little influence on yarn diameter but has a more significant effect on yarn-hairiness parameters. As the nozzle diameter increases, yarn hairiness also tends to increase, but, when the nozzle is grooved, an interaction is produced between yarn friction and the false twist generated that leads to a yarn that is less hairy when tested on the Digital ITQT Hairiness Meter. The principle of measurement of the apparatus used can lead to different results and trends when applied to this problem.     

Effect of nozzle size on texturing performance: comparison between air-jet and steam-jet texturing

The objectives of this research work were to investigate the use of steam in order to replace air in the production of spun-like textured yarn and to investigate the optimum nozzle size for steam-jet textured yarn for the application of sewing thread. An existing air-jet texturing machine was modified to supply either air or steam to the texturing nozzle. Using four texturing nozzles, both air-jet and steam-jet textured yarns were manufactured. The effect of nozzle size on process and yarn parameters has been studied and compared with air-jet textured yarns. The results show that spun-like textured yarn manufactured using steam has lower loop instability and higher tensile properties than air at comparable fluid pressures. SEM image analysis shows that the entangled structure of the steam-jet textured yarns is similar to air-jet textured yarns. Further, sewability results show that steam-jet textured yarns are suitable to manufacture sewing threads.     

The Influence of the Spinning Process,Yarn Linear Density,and Fibre Properties on the Hairiness of Ring-spun and Rotor- spun Cotton Yarns

Cotton–spun yarns from 34 staple stocks were manufactured by means of the ring–spinning process (34 yarns) and a rotor–spinning process (29 yarns) and tested for hairiness with the Shirley Hairiness Meter. For each spinning system, yarns were spun at two values of yarn linear density (15 and 30 tex for ring–spinning and 30 and 50 tex for rotor–spinning), but the twist multiplier was kept constant within the series for each spinning process.

The higher hairiness of ring–spun yarns and an increase ln hairiness with the yarn linear density were confirmed. The effect of the fibre parameters on yarn hairiness explains only about 30% of the total effect for ring–spun yarns and 40% for rotor–spun yarns. Fibre length and its uniformity are the fibre properties having the greatest influence on the hairiness of both ring– and rotor–spun yarns, the Micronaire index having only slight influence on the hairiness of ring–spun yarn.     

38—THE HAIRINESS OF MOHAIR AND WOOL WORSTED-SPUN YARNS: CORRELATION BETWEEN THE RESULTS OBTAINED WITH THE SHIRLEY HAIRINESS METER AND THOSE OBTAINED WITH THE DIGITAL ITQT APPARATUS

An investigation is reported of the correlation between hairiness values obtained with the Shirley Hairiness Meter and those obtained with the Digital Hairiness Meter developed by the Institute of Chemical and Textile Technology (ITOT). Twenty mohair yarns and 46 wool worsted yarns processed at SAWTRI were analysed with these two instruments. For mohair, very good correlations were obtained between the number of hairs per metre, as measured by the Shirley instrument, and the average hairiness and length data obtained with the Digital Meter (correlation coefficients between 0.95 and 0.99). For wool, the agreement between the two sets of results was not as good, the ITQT parameter correlating best with the Shirley measurement being the average length, followed by the maximum hairiness. For wool, the over-all correlation coefficients—without distinguishing between the different yarn linear densities—were 0.60 for the mean length, 0.47 for the average hairiness, and 0.40 for the average hairiness and maximum length. When the results were separated according to the yarn linear density, the correlation coefficients increased to 0.80–0.88 for the average length, 0.69–0.75 for the maximum hairiness, and 0.63–0.81 for the maximum fibre length, whereas they were insignificant for the average hairiness. An attempt was made to establish a parameter known as the ‘visible’ hairiness, but this gave satisfactory results only for the finest yarns (correlation coefficient 0.80).

In general, the number of hairs per metre as measured with the Shirley Meter correlated well with the average length as measured by the Digital Meter, provided that only yarns of the same linear density were compared. The correlation was lower for the maximum hairiness and maximum length and practically non-existent for the average hairiness, except for the mohair yarns.     

降低络筒纱毛羽的机理及实践

在络筒机上安装特制的减羽喷嘴,其设计和安装不应改变纱线的设计捻度和成纱强力。分析了减羽喷嘴的减羽机理,说明减羽喷嘴是利用旋转气流对纱线毛羽进行假捻→解捻→包缠,使其包缠到纱线主体上或捻入纱线中而实现减羽。介绍了减羽喷嘴的安装原则和安装位置。对经加装减羽喷嘴络筒机处理后纱线的毛羽指数、毛羽外观、捻度和强力进行了实验分析。结果表明,经减羽后,络筒纱线的毛羽指数下降,毛羽外观得到改善,捻度和强力没有改变,验证了减羽喷嘴的减羽效果。