赛络纺加捻三角区内纤维的受力分析

根据纤维的力学性能和赛络纺加捻三角区的特点,采用有限元分析方法对赛络纺加捻三角区内纤维受力分布进行数值模拟。对锭速、钢丝圈和捻系数对加捻三角区内纤维受力分布的影响进行具体分析。结果表明：锭速对成纱三角区内纤维受力分布影响效果最为明显,三角区内纤维的受力和纺纱张力的方向有密切关系,细纱捻系数对加捻三角区的结构有着重要影响。有限元分析结果结合纺纱理论可以实现纺纱工艺参数的优化,对纺纱实践具有一定的参考价值。     

Research on yarn qualities modified by mechanical false-twisting device

Abstract

In the ring-spinning process, the area between the front roller nip and twisting point is spinning triangle, and its geometry influences the fiber tension distribution in the spinning triangle directly and determines the properties of spun yarns. Therefore, in the paper, one kind of mechanical false-twisting device was introduced on the ring spinning, which can affect the twist propagation and change the spinning triangle geometry actively. First, the modification of the false-twisting device on the DTM129 ring-spinning frame was introduced. Taking the medium cotton yarn spinning as an example, corresponding ring yarn, Sirospun yarn, compact yarn were spun on the modified spinning frame under different designed twist factors, and the applicability of the false-twisting device on different spinning method was discussed. It is shown that comparing with the common yarn, the Hairiness and Strength of the modified yarns are all improved, and the effect of false-twisting device on yarn qualities is more effective for the low-twist yarn. Comparing with the ring spinning, the improvement degree of the modified compact spinning is a little smaller. Then, the long-staple cotton ring yarn, polyester and medium cotton blend ring yarn, polyester ring yarn were spun on the modified spinning frame under different designed twist factors, and the applicability of the false-twisting device on different fibers was discussed. It is shown that the influence of the false-twisting device on the long-staple cotton yarn and polyester yarn is little. That is, the false-twisting device given in the paper would be more applicable on the short fiber spinning under the low designed twist factor.     

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.     

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。     

不同纺纱参数对双喷嘴假捻纱成纱结构的影响

比较和分析了双喷嘴喷气纱和涡流纱的差异。纱线强度主要是包缠纤维比例的函数。试验证明纤维在第二喷嘴成纱。第二喷嘴形成的捻度向后传递到牵伸系统,并抵消了第一喷嘴造成的反向捻度。通过调整入口的几何位置、喷嘴压力和纤维喂入的设计参数,可以对加捻三角区产生积极的影响,并可达到提高输出速度的效果。通过这些方法可略微改善成纱结构及性能。     

16.7 tex纯苎麻纱线赛络假捻纺工艺研究

苎麻纤维粗硬,弹性回复性差,成纱毛羽多,且残余扭矩大,织物表面纬斜严重。为改善纱线质量,降低细纱的残余扭矩,采用赛络低扭纺纱技术试纺了16．7tex纯苎麻细纱,探究了喇叭口位置、假捻器高度、假捻器与前罗拉的速比、钢丝圈规格对成纱质量的影响．并对细纱的断头率、断裂强力、毛羽指数、条干均匀度几个指标进行了测定和对比。得出纺16．7tex纯苎麻赛络低扭纱的最优工艺参数为喇叭口位置左移0．5cm、假捻器高度为1cm、假捻器与前罗拉的速比为2．5、钢丝圈规格为G2。     

利用赛络纺纱技术提高毛单纱织造效率

介绍了赛络纺纱技术在毛单纱织造中的应用 ,并从原料选用、加工工艺研究、工艺优化与控制等方面进行了分析 ,得到了一些在生产实践中具有一定指导作用的结论。     

基于自由转子的纱线扭矩的检测方法

纺织用纱线在加捻过程中会使其内部存在一个较强的扭矩,为对纱线的扭矩进行准确的测量使其匹配准确的蒸纱定形标准,减小因纱线内部残存扭矩造成织物纬斜概率,提出了以自由转子为核心的纱线扭矩的检测方法。首先与纱线末端相连的自由转子在电磁阻尼的作用下由静止开始平稳转动,光电传感器对其转动状态进行扫描并将捕捉到的光电信号传输至计算机得到转子转过的角度与时间的数据关系,然后在Origin中对其进行二次求导拟合出角加速度与时间的关系曲线。由曲线可准确得到转子的初始角加速度,通过初始角加速度和测试所用转子转动惯量的乘积即可快速高效得到测试纱线的扭矩。实验结果表明:该方法能够准确测出各类纱线的扭矩,数据误差较小,不仅在如今的纺织业生产检测中具有广阔的应用前景,而且为纱线扭矩领域的研究提供了一种新的思路。     

Porel纤维／精梳棉赛络纺竹节纱的开发

Porel纤维是一种改性聚酯、高仿棉纤维,具有良好的亲水吸湿性和导放湿性。通过与精梳棉混纺开发的赛络纺竹节纱,满足了针织面料对吸湿、透气、柔软的舒适性要求。在生产过程中,针对纤维的性能特点,纺前对Porel纤维进行预处理,对各工序采取一系列技术措施,最终开发出符合质量要求的Porel纤维／精梳棉赛络纺竹节纱,实践证明：该产品特性既具有吸湿快干的性能,又具有竹节纱、赛络纱的风格特征,满足了市场的要求。     

赛络纺纱成纱机理探讨

通过静态模拟及动态实验,研究了赛络纺纱股线捻度,粗纱间距及纱支变化对纱条捻度、“Ｖ”形区几何形态的影响,并研究了赛络纺纱线的单纱捻度的结构。所得结论对赛络纺纱工艺制定、成纱结构研究及产品开发提供有益的参考     

基于ANSYS的加捻三角区内纤维变形数值模拟

根据纤维力学性质建立加捻三角区有限元模型,利用ANSYS13.0软件对加捻三角区纤维变形进行模拟,结合纺纱实验分析了纤维变形对纱线性能的影响。以JC14.6tex环锭纱和赛络纱为例,得到了相同条件下,环锭纱和赛络纱纺制过程中加捻三角区内纤维的变形规律和实际纺制的两种纱线的性能指标,结果表明：加捻三角区内纤维变形沿着三角区中心线呈对称分布;纤维变形与加捻三角区的形状有密切关系;与环锭纺相比,赛络纺加捻三角区内纤维变形明显较小且变形一致性好;纤维变形对纱线的毛羽和强力有着重要影响。     

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。     

聚乳酸纤维赛络纺工艺研究

通过改变粗纱间距、粗纱捻系数及细纱后区牵伸倍数研究了聚乳酸纤维赛络纺工艺,分析了不同纺纱工艺对纱线断裂强力、条干不匀率及毛羽指数变化的影响,得到了聚乳酸纤维赛络纺的较优纺纱工艺.在同一台细纱机上,采用相同的粗纱捻系数及牵伸工艺,同时纺制了23.9 tex聚乳酸纤维环锭纱和赛络纱.两种纱线的断裂强力均呈正态分布,两者波动性无明显差异,且前者断裂强力显著高于后者;聚乳酸赛络纱的毛羽有明显改善;两种纱线的条干差异不大,环锭纱略好于赛络纱.     

Predicting torque of worsted singles yarn using an efficient radial basis function network-based method

The torque in single-spun yarns is an inherent property of the twisting and bending of staple fibres during the formation of yarn combined with the effect of applied tension on the yarn. The consequences of yarn torque are well known and are widely observed as yarn instability, e.g., yarn rotation under tension; local snarling and entanglement at low loads, and as distortion in fabric, i.e., edge-curl and skewing in knitted fabric. In this paper, a method for predicting the yarn torque based on the radial basis function networks is presented and evaluated. This method uses a “universal approximator” based on neural network methodology to minimize noise during training of the network and to approximate the yarn torque as a function of the geometrical and physical parameters of yarns (twist, linear density) and the applied load. The current method is an integral radial basis function network-based approach suitable for textile engineering and gives very good prediction of yarn torque across a range of yarn structural parameters and test conditions.     

14.6tex50/50Modal/CJ赛络纺针织纱的生产

利用Modal纤维与棉混纺,纺制14.6 tex 50/50 Modal/CJ赛络纺针织纱。阐述了赛络纺纱的原理及成纱特点,概述了Modal纤维纺纱的主要技术措施。介绍了原料选择与工艺流程设计,并对纺纱工艺进行研究,给出了各工序的工艺参数设置。最终,纺纱效果理想,纱线强力高、毛羽少、条干好。     

含纱疵纱线的气流引纬牵引特性分析

为探究纱疵对气流牵引纱线的影响,根据纱疵在流体中的形状特性,提出以球体或圆柱体模型化短粗节纱疵新设想。基于Fluent的流场分析结果,对短粗节纱疵牵引力进行了数值计算,通过自行设计的主喷嘴气流引纬牵引力测试装置,测定了短粗节纱疵模型球体在0.3 MPa供气压力下的气流牵引力大小,并对前述数值计算结果的合理性进行了验证,得到较好的一致性。同时,探究了纱疵对纱线牵引力系数的影响效应,结果表明：随着纱疵直径增大,纱线牵引力系数的变化率呈先上升,随后逐渐趋于平缓现象;而随着纱疵数量的增多,牵引力系数的变化率呈逐次下降态势。     

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。     

低扭矩环锭纺纱原理及其单纱的结构和性能

本文主要回顾了低扭矩环锭纺纱技术的发展。通过讨论其纺纱三角区的特点,利用高速摄影技术对纺纱区捻度和张力分布的观察分析,系统地介绍了低扭矩纱的成纱原理。此外,结合示踪纤维技术,利用纱线结构连续测量分析系统对低扭矩环锭单纱和传统环锭单纱的内部结构进行分析,揭示了低扭矩纱独特的结构特点,如非同轴异形螺旋线结构,纤维片段局部反转现象等。这些特点解释了低扭矩纱及其织物具有优良物理性能的原因。同时,通过多个生产厂家提供的测试数据,对比分析了几代低扭矩环锭纱与传统环锭纱及其织物的物理性能,结果表明低扭矩环锭纱具有低捻高强、低残余扭矩和毛羽少等特点,其针织物经多次水洗后歪斜变形小和手感好,机织物具有较好的撕裂强力,断裂强力和耐磨擦性。最新一代低扭矩环锭纺纱技术显著地改善了高支纯棉纱的物理性能。     

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.     

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。