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.     

Research on Sirospun yarn torque using airflow false twisting device

Yarn torque is one of the most important indexes of yarn quality, which is determined on the mechanical state of the constituent fibers and their configuration in the yarn. The fiber tension within a yarn was proposed to be the most influential factor governing the magnitude of yarn torque by Bennett and Postle. Therefore, the research on Sirospun yarn torque is investigated by analyzing the fiber tension at spinning triangle in this paper. Firstly, theoretical models of the fiber tension distributions at primary and final spinning triangles are presented, and corresponding residual torque within a yarn due to the fiber tension is given. The relationships between the yarn torque and the spinning triangle parameters are analyzed theoretically. Secondly, as an application of the proposed method, a modified Sirospun spinning system with an airflow false twisting device which can change spinning triangle parameters are investigated, and the properties of spun yarns produced by the modified system are evaluated and analyzed. It is shown that with the increasing airflow pressures, the Sirospun yarn shows a more and more uniform distribution of tensile and compressive stress within a yarn, and thus the yarn torque decreases correspondingly.     

旋流纺闭合式纤维集聚机构的改进及成纱性能

 为了探究旋流纺新的引纱方法,本文在旋流纺闭合式集聚装置上作了改进,将其设计成附有引纱通道和引纱罗拉的集聚装置。成纱利用引纱方法将汇聚好的纤维束引出来,再利用旋流喷嘴加捻成纱。首先分析改进前后集聚装置的区别和成纱原理,然后通过改变旋流喷嘴的气压配置,对所纺纱线的断裂强力及毛羽两项纱线质量的主要性能指标进行了测试,分析喷嘴气压配置与成纱质量之间关系,并通过扫描电镜来分析纱线结构的变化。发现：这种成纱方法可以纺制出普通纯棉纱线,加捻气压仍然对纱线质量影响较大,纱线的外观和改进前的纱线不同。本结果为研究旋流纺新型汇聚装置提供参考。     

CCZ-VI仿真型竹节纱装置的生产实践

介绍了CCZ-VI仿真型竹节纱装置的工作原理及主要特点,竹节纱生产过程中应注意的几个关键性问题,如原棉配置、粗细纱工序工艺参数的合理选择和络筒速度的合理设定,并且总结了部分工序采取的重点技术和管理措施。     

Dynamic analysis of spinning triangle geometry part 2: spinning triangle geometry and yarn quality

This paper examines empirical relationships between the geometrical parameters of the spinning triangle and the quality parameters of ring spun yarns. For this purpose, controlled variations in the geometry of the spinning triangle were induced using two existing modifications in the ring spinning process and by varying the yarn twist level. The geometrical parameters of the spinning triangle were measured using the clear rubber roller combined with digital image processing techniques as described in the first part of this study. The yarn quality parameters measured included yarn hairiness, strength, elongation and evenness. Yarn hairiness showed more noticeable sensitivity towards the physical shape of the spinning triangle than yarn tenacity, while yarn evenness and elongation were not significantly influenced by changes in spinning triangle geometry.     

改变环锭纺纱路对成纱质量影响的研究

在棉纺常规环锭细纱机和紧密纺环锭细纱机上进行了改变纱路的纺纱试验,测试对比了纱线性能指标。结果表明,在常规环锭细纱机上,采用左斜纱路与传统的直纱路比,可以较显著地减少纱线毛羽,提高纱线的强力,改善纱线的条干均匀度和降低常发性纱疵;而在紧密纺环锭细纱机上,改变纱路对成纱质量改善没有明显的影响。     

Research on pneumatic compact spun yarn quality

Compact spinning is one of the most important improvements of traditional ring spinning, which is implemented by adding a fiber condensing device to condense the fiber bundle and decrease the spinning triangle. Pneumatic compact spinning is the most widely used compact spinning method at present. Compact spinning with perforated drum and compact spinning with lattice apron are the two main kinds of pneumatic compact spinning. Therefore, in this paper, comparison analysis of yarn quality between compact spinning with perforated drum and compact spinning with lattice apron is presented. First, 9.7 tex cotton-combed yarn is spun in three different kinds of pneumatic compact spinning systems, including two kinds of compact spinning with perforated drum: Rieter’s COM4 and complete condensing spinning system (CCSS), and one lattice apron compact spinning system: Toyota’s four-line compact spinning. The test results of yarn qualities show that comparing with other two kinds of compact spinning systems, the yarn spun in CCSS has the best evenness, least long hairiness, and slightly lower strength. Then, the properties of spun yarns are analyzed using two methods. First, using Fluent Software, numerical simulations of three-dimensional flow field in condensing zone of three kinds of compact spinning system are presented, respectively. Second, the fiber movements in condensing zones are captured using high speed camera system OLYMPUS i-speed3.     

Effects of lattice apron density on yarn qualities in Four-line compact spinning system

In the paper, using finite element method (FEM), the effects of lattice apron density on yarn qualities in Four-line compact spinning system were studied by analyzing the numerical simulations of the airflow velocity. Firstly, three different kinds of yarns, 18.2tex (32^S), 9.7tex (60^S), and 5.8tex (100^S), were spun on FA507B spinning frame equipped with lattice aprons of mesh size 150, 120, and 100, respectively. The hairiness, breaking strength, and evenness of spun yarns were tested and comparatively analyzed. Secondly, using FEM, the numerical simulations of the airflow velocity in the condensing zone were presented. The finite element model of condensing zone was constructed according to the physical parameters of the practical system. Then, the simulation of airflow velocities on five straight lines located in the front, middle, and back of condensing zone were given. It is shown that, in the whole condensing zone, for the lattice apron with mesh size 100, the direct transverse condensing force is high, but the assisted condensing force is low and disorder, which is not beneficial for yarn qualities. Compared to the lattice apron with mesh size 150, the usage of lattice apron with mesh size 120 may be beneficial for the high-count yarn condensing or the yarn condensing under the relatively lower negative pressures. Furthermore, taking the 9.7tex as an example, the trajectory of yarn movement in the condensing zone was given using high-speed camera system OLYMPUS i-speed3. Corresponding airflow velocities along the yarn movement path were presented.     

新型包绕纺包芯纱的开发与研究

文章介绍了一种新型包绕纺纱新技术的纺纱设备、适纺原料以及具体的纺纱方法等,论述了纺纱过程中应采取的措施,详细分析了纺纱的特点以及用此种方法生产的纱线结构特点和后续的产品延伸与开发.     

应用给湿装置改善环锭纺成纱毛羽

为减少成纱毛羽,在环锭纺细纱机前钳口与导纱钩之间加装接触式给湿装置,对出三角区后的低捻段纤维须条给湿。借助高速摄影拍摄纱线与导纱轮接触所产生的水雾三角区长度发现,导纱轮直径越大,水雾三角区长度越长。通过测试一落纱平均耗水量,纱线细度相同条件下,随导纱轮直径增大,耗水量增多;同时,纱线细度增大也会增加纺纱耗水量。在上述条件下进行纺纱试验并测试成纱毛羽,14.6 tex 精梳棉管纱3 mm 及以上有害毛羽较普通环锭纺降低了35.9%,19.5 tex精梳棉纱有害毛羽降低了41.1%。14.6 tex 精梳棉管纱络筒后3 mm 及以上有害毛羽较普通环锭纺筒纱降低了41.6%。结果表明,对环锭纺须条给湿可大幅度减少成纱有害毛羽,从而提高纱线品质。     

新型带子纱与睫毛纱的纺纱研究

主要介绍了应用小针筒织带机采用不同工艺开发生产一些新型花式纱线，如睫毛纱、包芯带子纱、彩色麦穗纱等，并详细介绍了纺纱工艺过程。同时指出小针筒织带机的调节方法，提出了生产新型花式纱时应注意的问题。     

半精梳棉纱的生产实践

探讨了半精梳棉纱的原料选配、工艺参数、质量控制以及在生产实践中采取的技术措施等关键性问题,对同配棉的同支精梳纱和半精梳纱的质量作了对比,分析了其质量特征。     

Real-time yarn evenness investigation via evaluating spinning triangle area changes

This paper examines the relationship between changes in the spinning triangle dimensions and evenness of the finally produced yarn. Three kinds of yarn (in different twist levels) were produced and during the spinning process a digital camera was used to record the production process and the triangle behaviour in front of delivery rollers. Using image-processing techniques, three parameters of the triangle (width, length and area) were measured. Then, the correlation between yarn irregularity and changes in the triangle dimensions (with regard to wavelength changes) were evaluated. The acceptable correlation between yarn irregularity and dimension changes indicated that this novel image-processing approach can be implemented in measuring yarn irregularities during the spinning process.     

赛络菲尔包缠纱结构建模分析与性能优化

为定量预测实际生产中赛络菲尔(Sirofil)包缠纱的性能,分析了其成纱加捻过程和特点。根据加捻三角区中的几何关系,推导出三角区纱线质心相对锭子偏移距离与纱线捻回角的关系,并得出半个捻回纱线质量的计算公式;对加捻三角区进行受力分析得到力矩平衡方程,解释了Z捻纱捻度由下向上的传递规律,分析了长丝与短纤须条的相对位置对Sirofil包缠纱强力的影响;最后对模型求解并进行实验验证。模型计算和实验结果表明：隔距变大纱线质心偏移距离变大,须条捻回角减小;汇聚点之上单纱捻向与汇聚点之下传递捻向相同,且短纤须条位于长丝左侧时所加的捻度较之在右侧时多。该模型和实验为Sirofil包缠纱性能和结构的分析提供了参考。     

利用紧密纺纱技术提高亚麻/棉混纺纱的质量

在自行改装的EJM128K型紧密纺细纱机上试纺了27．8tex亚麻／棉紧密纱和环锭纱,并对比了两种纱线的性能,分析研究了紧密纺纱技术在亚彬棉混纺中的可行性。结果证明,紧密纺纱技术适用于亚彬棉的混纺,能够有效提高成纱质量。     

7.3 tex纯棉精梳纱的工艺实践

对7.3 tex纯棉精梳纱的纺纱工艺进行了探讨分析,针对长绒棉细度细、长度长、含杂少,以及特细纱纺纱难度较大的特点,合理配置纺纱工艺流程,优选各工序工艺参数。加强管理,正确选择锡林、盖板针布。细纱工序是纺特细纱的关键工序,采用低锭速、小钢领、轻钢丝圈及与前区紧隔距、强加压的工艺原则,最终使成纱质量超过乌斯特25%水平。     

用赛络纺纱技术减少芳砜纶纱线毛羽的研究

通过试验研究了赛络纺纱技术对芳砜纶纱线毛羽的减少情况。结果认为,赛络纺纱技术能够明显地减少芳砜纶纱线的成纱毛羽数量,尤其是4mm以上的长毛羽数量;并且发现,对试验的芳砜纶纤维来说,当喇叭口中心距为11mm时,成纱点稳定,成纱毛羽数量较少。文章给出了合理的工艺措施。     

转杯纺纱法加工Lyocell针织纱

Lyocell纤维具有优良的物理机械性能,其针织面料在手感和外观等方面的多功能性使其开发应用前景非常广阔。由于转杯纱自身的特点,其针织品品质优越。采用转杯纺纱技术加工28 tex的Lyocell针织纱,探讨前纺工艺及技术措施;通过对各方案试纺对比,研究转杯纺主要工艺参数与成纱质量的关系,为合理选择工艺参数,提高Lyocell转杯纺针织纱的成纱质量提供参考。     

粗纺纯羊绒针织纱的质量控制和成纱要求

粗纺纱的质量问题一直是影响针织企业生产效率和产品质量的关键因素.文章分析了工艺流程的每道工序的工艺设计和质量控制的要点,论述了粗纺羊绒针织纱的常见质量问题和实际生产中的控制措施,介绍了在国家标准下鄂尔多斯集团企业内部对纱线质量指标的控制水平,并对粗纺针织纱的成纱性能做了介绍.     

阻尼牵伸纺纱技术及其对成纱质量的影响

从纺纱牵伸装置结构和牵伸机制方面,阐述了新型环锭纺阻尼牵伸系统提高成纱质量的原理及应用效果。分别采用传统环锭纺和阻尼牵伸纺技术纺制羊毛/羊绒混纺纱,并对成纱均匀度和强力指标进行测试,采用差异率进行对比分析。结果表明:阻尼牵伸系统可以显著改善成纱条干均匀度,降低粗节、细节、棉结、毛羽量等指标,其中粗节(+50%)数量降低41.0%,最为显著;成纱的强力、断裂伸长率和断裂功等力学指标有所提高,其中断裂伸长率提高23.1%,阻尼牵伸技术对提高毛纱的成纱质量具有良好的效果。