Investigation of fiber migration in rotor-jet spun yarn

The fiber migration in the newly developed rotor-jet spun yarn is investigated utilizing the tracer fiber technique and a proposed image analysis method. Effects of rotor-jet spinning parameters including three air-jet nozzle types of 90Z, 60Z, and 30Z (the values of 30, 60, and 90 are jet orifice angles and Z is air rotational direction identical to rotor rotational direction) at different air pressure values of 0.2, 0.5, 0.8, and 1 bar were considered. The results showed that increasing of air pressure causes the fiber to locate in the interior position of the yarn for 90Z nozzle, while for 30Z and 60Z nozzle types, the fiber is moved toward the exterior position of the yarn. Conversely, it was indicated that with increase of air pressure mean migration intensity and migration frequency increase for 90z nozzle, whereas decrease for 30Z and 60Z nozzle types. In general, the mean migration intensity and migration frequency magnitudes of rotor-jet spun yarn with 90z nozzle type are significantly higher than those of normal rotor yarn particularly at the higher air pressure. However, rotor-jet spun yarns with 30Z and 60Z nozzle types exhibited much lower mean migration intensity and migration frequency magnitudes than normal rotor yarn.     

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.     

Research on flow field in a modified ring spinning system with the air nozzle

Twisting is one of the most important steps in the yarn spinning, which influences the geometry of spinning triangle and determines the properties of spun yarns. Airflow is one of the most important measures on improving yarn spinning. In this paper, a kind of air nozzle with vortex guiding channel was designed and used on the modification of ring spinning system, and the spun yarn qualities was studied by analyzing the airflow field in the nozzle. Firstly, the three-dimensional physical model of nozzle was given using CAD software according to the geometrical size of the practical nozzle model. Then, the numerical simulations of the three-dimensional flow field in the nozzle were given using Fluent software. Finally, two different kinds of yarns 10Ne and 20Ne were spun in the modified ring spinning system with the nozzle installed. The airflow pressure 0.01 Mpa and two different swirling directions, anticlockwise and clockwise, were chosen. The qualities of spun yarns, hairiness, strength, evenness, and number of snarling were measured and analyzed. It is shown that the high vortex airflow can be produced in the nozzle, and then corresponding twist can be produced. For the Z(S) twisting spun yarn, under the effects of the clockwise (anticlockwise) vortex airflow, the pre-twisting would be produced and the yarn twist can be strengthened, while under the effects of the anticlockwise (clockwise) vortex airflow, the untwisting effect would be produced, and the yarn twist can be decreased.     

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.     

基于图像的喷气涡流纺纱线捻度测试方法探讨

为探究适用于喷气涡流纺纱线捻度测试的有效方法,在对比分析喷气涡流纺纱线与传统环锭纺纱线结构的基础上,借助扫描电子显微镜,分别通过喷气涡流纺纱线的外观图像和横截面图像,测试了喷气涡流纺纱线捻度.并采用Photoshop软件处理喷气涡流纺纱线横截面图像,探究喷气涡流纺纱线内外层纤维数量比与其捻度的关系,提出了用喷气涡流纺纱...     

转杯纺与赛络纺氨纶/棉包芯纱的性能对比

通过将转杯轴中心开孔,借助转杯负压的作用引入长丝的方法纺制了转杯纺氨纶丝/短纤包芯纱;通过在传统环锭细纱机上加装一个长丝喂入装置的方法纺制Sirofil包芯纱.测试了这两种包芯纱在相同规格和纺纱条件下纱线的纵向形态、毛羽、强力和条干等相关性能.分析得出结论为转杯纺包芯纱表面光洁,毛羽少,不易起毛起球,强力稍低,条干稍差于Sirofil纱,并分析解释了原因.     

转杯纺复合纱与sirofil复合纱的性能对比分析

纺纱方式的不同使得纱线的结构和性能也不同。通过将转杯轴中心开孔,借助转杯负压的作用引入长丝的方法纺制转杯纺复合纱;通过在传统环锭细纱机上加装1个长丝喂入装置的方法纺制sirofil复合纱。测试分析这2种复合纱在相同规格和纺纱条件下其纵向形态、起毛性、毛羽、纱线表面纤维抽拔力和强力等相关性能。研究结果表明,转杯纺复合纱表面光洁,毛羽少,不易起毛起球,耐磨性能好,其强力稍低于sirofil复合纱。     

Some studies on hairiness reduction of polyester ring spun yarns by using air-nozzles during winding

This paper reports on the hairiness reduction of polyester yarns at winding using air-nozzles. Three yarns of the same count were spun each from fibres of 1.0, 1.2 and 1.4 deniers respectively. Using a CFD (computational fluid dynamics) model, airflow inside the nozzles is simulated to explain the role of nozzle parameters viz., axial angle of air inlets and yarn channel diameter on yarn hairiness reduction during winding. Air drag forces acting on hairs are calculated. Transverse drag forces acting on hairs play a major role in bending the hairs. Vortex nature of air and air velocity profile inside the nozzle are the important phenomena in reducing yarn hairiness. Box and Behnken factorial design of experiments is used to optimize nozzles parameters, fibre denier, and air pressure to maximize the hairiness reduction. Axial angle of 45° for air inlets, 2.2 mm yarn channel diameter, 1.4 denier fibre, and 0.9 bar (gauge) air pressure are the combinations to get maximum reduction in S3 hairiness values of nozzle wound yarns. Fibre denier is a major influencing factor in reducing yarn hairiness.     

Analysis of spinning process using the Taguchi method. Part V: Effect of spinning processvariables on physical properties of ring,rotor and air-jet yarns

Abstract

Effect of lap hank and drafts, of various spinning sequence of machines, was studied on physical properties of different yarns using Taguchi method and analysis of variance. The ring yarn is highly even and has the least number of thin places and neps but thick places are the least in rotor yarn. The air-jet yarn is the least even and has the highest number of thin places, thick places and neps. The total hairiness is the least on rotor yarn and number of hairs =3 mm (S3) the least in ring yarn. In air-jet yarn the total hairiness and S3 are the highest. The finer lap hank and higher card draft in preparatory process produces even ring and rotor yarns with lower hairiness. However, the higher speed frame draft improves the evenness of yarn produced from coarser lap hank and lower card draft. Lower ring frame, rotor and high air-jet draft improves the properties of the respective yarns. Increase in ring/air-jet draft increases S3.     

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.     

Research on spun yarn qualities in a modified ring-spinning system using airflow-twisting device

In this paper, a kind of airflow-twisting devices which can produce the twist by the high vortex airflow is employed for improving the twist propagation process of ring-spinning system. Firstly, three different kinds of yarns Ne20, Ne40, and Ne60 are spun in this modified ring-spinning system with five different airflow pressures and two different swirling directions, including anticlockwise and clockwise, and the qualities of spun yarns, including hairiness, strength, evenness, and number of snarling characterizing the yarn residual torque, are measured. Secondly, the images of spinning triangles are captured by using a high speed camera system OLYMPUS i-speed3, and the mechanism of the effects of vortex airflow on yarn qualities is discussed by analyzing the fiber tension distributions in the spinning triangle. It is shown that for the ‘Z’ twist spun yarn, the spinning triangle decreases with the increasing of clockwise airflow pressures, whereas the triangle becomes more and more symmetrical with the increasing of anticlockwise airflow pressures. Meanwhile, the comprehensive qualities of spun yarn are improved with the increasing of both directions of airflow pressures to a certain extent. However, the hairiness and strength of spun yarn will be mainly improved with clockwise airflow, whereas yarn residual torque mainly reduced with anticlockwise airflow.     

丽赛纤维喷气纺纱性能研究探讨

文章采用丽赛、天丝、粘胶、棉、涤棉为原料分别进行喷气纺纱，并将喷气纱线性能进行比较，研究丽赛喷气纺的纱线强力、条干、毛羽、弯曲刚度等性能。     

涡流纺纱线性能分析

研究涡流纺成纱性能.采用相同熟条纺制了CJ 20 tex涡流纺纱线、传统环锭纺纱线、紧密纺纱线和喷气纺纱线,通过分析对比了这4种纱的成纱结构、毛羽、耐磨性及强伸性能,认为涡流纱成纱强力虽低于紧密纺纱线和传统环锭纱,但强力不匀较好,毛羽大幅度降低,耐磨性能很好,抗起毛起球性能好.     

压力棒隔距块在棉纺中的应用

为了探讨在棉纺生产中压力棒隔距块对成纱质量的影响,分析了压力棒隔距块的原理,并在FA506型环锭细纱机上加装不同型号的压力棒隔距块分别纺制出CJ9.7 tex、CJ7.3 tex纱线,测试纱线的毛羽、强力、条干等各项指标并进行对比分析。结果表明,在棉纺中使用压力棒隔距块后,成纱条干有所改善,成纱强力变化不大,成纱毛羽的变化也不明显。     

喷气涡流纺工艺对粘胶/涤纶包芯纱性能的影响

为获得更高强力的喷气涡流纺纱线,通过引入涤纶长丝制备喷气涡流纺粘胶/涤纶包芯纱。采用统计分析等方法研究了芯丝线密度、纺纱速度对喷气涡流纺粘胶/涤纶包芯纱强伸性、条干不匀和毛羽的影响规律,同时对比分析了不同纺纱条件下包芯纱的结构外观。研究结果表明：芯丝线密度、纺纱速度对喷气涡流纺粘胶/涤纶包芯纱各性能响应值有不同程度的影响;纺纱速度过高或过低均不利于包芯纱成纱的强伸性提高和条干均匀性改善,纺纱速度的增加会使毛羽H值增大;在一定范围内,增加芯丝线密度有利于包芯纱强伸性的提高,随芯丝线密度的增加,包芯纱毛羽H值减小;此外,选用较大的芯丝线密度和较高的纺纱速度时,纺制的包芯纱芯丝外露现象越明显。     

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。     

喷气涡流纱及其织物性能分析

文章对竹浆纤维和莫代尔纤维两种原料的喷气涡流纱与环锭纱及其织物进行了测试分析和比较,得出喷气涡流纱制成的织物与环锭纱制成的织物相比具有更加柔软,强度较低,表面光滑,耐磨,透气较好的特点。     

乌拉草/棉/维纶复合纱线的开发与性能

针对乌拉草/棉/维纶赛络纺包芯纱存在毛羽较多和条干较差等问题,加装导纱器引入外包缠纱,设计一种改善其条干和减少毛羽的新型纺纱方法:改进型赛络菲尔纺。对影响纱线性能较大的纱线捻系数与导纱间距进行了实验,并以断裂强度、断裂伸长率、毛羽指数和条干均匀度为性能评价指标,对改进型赛络菲尔纺制备的乌拉草/棉/维纶复合纱的工艺进行模糊综合评价。结果表明:捻系数对纱线性能影响顺序依次为400、380、360、340;改进型赛络菲尔纺在单纱间距为10 mm,捻系数为400时,复合纱的综合性能最好,与传统赛络菲尔纺工艺制备的包芯纱对比,毛羽指数下降了73.49%,条干不匀率减小了29.05%。     

旋流器对环锭纺纱线性能的影响

在传统环锭细纱机的前罗拉与导纱钩之间安装旋流器进行纺纱,能够较好地改善环锭纺纱线的性能。通过正交试验的方法,考察了气压、锭速、捻系数和旋流器到前钳口的距离对纱线质量的影响,得出优化的参数组合。结果表明：气压为0.25 MPa、旋流器到前钳口的距离为6.5 cm、捻系数为330、锭速为9000 r/min时,所纺纱线质量最好;与传统环锭纺纱线相比,这种纺纱方法所纺得的纱线毛羽减少量达到97％,断裂强度提高了9%,条干不匀降低6%,为研究提高纺纱性能的新型纺纱方法提供参考。     

喷气纺纱喷嘴气压的工艺研究

为提高喷气纺纱的强力,分析探讨了喷嘴气压对成纱结构和性能的影响,选取第一喷嘴气压和第二喷嘴气压分别进行单因子五水平试验,运用直观分析法分析喷嘴气压及其差值对成纱性能的影响.试验结果表明:两个喷嘴气压差值较大时对纱线的强力、伸长和毛羽有显著影响,对纱线的条干、粗细节影响不明显.在以强度为主要参考指标时,较理想工艺为第一喷嘴气压0.35 MPa,第二喷嘴气压0.43 MPa.