簇绒地毯织机提花装置的绕纱动态张力分析

簇绒地毯织机纱线张力是影响提花质量的关键因素,为对其进行有效控制,本文研究了步进电机输入对簇绒提花装置区间绕过纱线张力的动态变化情况。首先建立提花装置的步进电机的负载模型,并分析其角频率输入对输出电磁转矩的对应关系;然后,根据米纳科夫定理的原理,建立纱线段绕过提花罗拉前后纱线动态张力模型。同时,进一步分析步进电机的输入与提花装置绕纱的输出动态张力之间的数学模型,在选定提花罗拉半径r、中心距 、纱线包角 等初始条件下,利用迭代-欧拉法分析其数值变化情况,得出角频率输入与纱线张力输出之间的定量关系,并探究不同包角对纱线动态张力的影响机制,为不同绒高的簇绒地毯甚至满幅簇绒提花地毯的制造和研究提供参考。     

牵引罗拉稳定纱线张力的作用机制

由于地毯簇绒机簇绒过程中纱线张力的波动将影响簇绒地毯毯面质量,所以纱线张力的稳定十分重要。本文推导出纱线进出牵引罗拉的张力公式,得出牵引罗拉调节张力的作用机制为：牵引罗拉运动可以看成是由多个圆柱形罗拉的转动与平动的复合,其在转动过程中与纱线接触的齿数会发生变化,进而会引起纱线包角的变化,从而导致纱线张力的变化。应用三角几何方法,推导出纱线总包角与牵引罗拉中心距的关系式,应用MathCAD软件计算各个参量变化时的包角。通过计算分析,找出牵引罗拉调节张力的理论依据,为工程实践提供了参考。     

生产无条纹绒头地毯过程中的问题

在BCF纱变形、热定型及簇绒的过程中,浓色体计量的波动在单色割绒地毯中会产生可见的经向条纹,而多色割绒地毯、起圈地毯及割绒地毯的毛圈来源于短纤维,对其波动不是很敏感,造成割绒地毯的条纹有多种原因,簇绒作为最后一道工序,毫无疑问是最重要的,但问题也可能出自绒头纱的生产厂,纺丝染色过程,甚至浓色体的生产厂,造成割绒地毯条纹的两个根本原因,是在不同纱线生产过程和簇绒工序中,绒头纱的色差和纱线张力过大。     

簇绒提花地毯纱线束动态张力分析

 为控制纱线张力波动,提高毯面质量,有必要研究提花罗拉控制下纱线张力波动的形成及影响因素。本文假设地毯纱线束为线性弹性,且截面为圆形。在离合器吸合和释放瞬间,以作用在提花罗拉上的阻力矩作为输入,纱线的动态张力为输出,对提花罗拉与牵引罗拉间纱线束的动态张力进行理论分析。根据动量矩定理和纱线束质量守恒定律,建立了提花罗拉作用下纱线束动态张力模型。假设输入为阶跃信号,应用拉普拉斯变换,求出纱线张力波动的幅度、频率及阻尼比,并进行仿真。结果显示,阻力矩对纱线束张力波动有很重要的影响。因此为降低纱线张力的波动,有必要对提花罗拉的结构、离合器摩擦片进行精密设计。同时,分析了纱线束长度对张力波动固有频率和系统阻尼系数的影响。     

三圈高地毯簇绒机提花控制系统

为了在毯面上形成花型图案,设计和开发了三圈高地毯簇绒机提花控制系统。该系统采用计算机控制的伺服电磁离合器相结合的提花装置,利用工控机把工艺人员设计提花织物的花型信息转化为数字化控制信息,根据工艺参数设定,控制伺服电机按一定关系实时跟踪主轴转速,通过工控机板卡输出信号到离合器功率驱动板来控制电磁离合器的状态切换,实现送纱量的控制,进而控制每次簇绒过程中的纱线张力,并最终在毯面上形成三圈高地毯图案。     

各种不同簇绒地毯织机的喂纱系统工作原理比较

通过对各种不同的簇绒地毯织机喂纱系统的分析，比较不同的喂纱系统织机织造出地毯质量的利与弊，对手企业选购地毯织机具有借鉴意义。     

Van de Wiele公司收购Superba公司

<正>2015年5月27日,比利时地毯织机生产商Van de Wiele公司签署了收购法国Superba公司及其美国子公司的协议。Seperba公司是一家生产地毯纱热定型设备的公司,已形成了一种基于饱和蒸汽的独特的热定型系统。在高度专业的簇绒和机织地毯纱线领域,经过40多年的研究,Superba公司提供了一套完整、     

power-heat-set:采用过热蒸汽热定型

1热定型 热定型是合股纱线稳定化以及＂记忆＂捻回的工艺。 地毯纱主要由热塑性纤维制得,如聚丙烯、聚酰胺,在热塑性纤维准备簇绒/织造以及后续加工直到获得成品地毯之前,还有一些预处理工序（图1）。     

给纱系统

本专利介绍了一种新型给纱装置,此装置包括一个回转的输出罗拉(10)和一传动带(20)、纱线(30)出导纱器(40)引入至输出罗拉和传动带之间。为了使输出罗拉(10)的回转速度和传动带(20)的速度同步,从而输出控制速度和纱线(30)的张力一致这样圆形针织机上的每个系统在相同的给     

自捻纺纱技术知识问答(三)

32.自捻纺纱时卷绕张力如何确定? 可用纱线张力仪对自捻纺纱机上各根纱的张力逐个测定. 卷绕张力的数值可按下式确定: 卷绕张力=338/N_m=300/N_W=特克斯/3上式中:N_m为公制支数N~w为英制精梳毛纺支数如各根纱卷绕张力普遍偏大或偏小,可调节卷取速度.如其中个别筒子张力偏大或偏小,可先检查该根纱捻度是否与其它纱线一致,如捻度相差较多,则很可能是由于加捻罗拉间压力或间隙不一致所形成,应调整加捻罗拉.如捻度相差不多,则检查和调整加捻罗拉至卷绕槽筒间各部     

An improved viscoelastic model for tufted carpet yarn

To overcome the problem that the existing mathematical model cannot characterize the viscoelastic properties of tufted carpet yarn completely and accurately, an improved viscoelastic model is built using the semi-empirical method. Using the test data of creep and stress relaxation, the parameters of the improved model are determined. Through the evaluation of fitting effect, the optimal mechanical model to characterize the viscoelastic properties of tufted carpet yarn is obtained. The results show that compared with the standard linear model, the improved model is more suitable to characterize viscoelastic mechanical properties of tufted carpet yarns, such as the creep and stress relaxation properties, which provides a solid theoretical foundation for analysis of vibration characteristics and dynamic tension control of tufted carpet yarn.     

On the dynamic model of yarn with time-dependent tension

In order to control yarn vibration and improve carpet quality, it is essential to research the fluctuation of yarn tension and its influences during tufting process. Assuming the polypropylene yarn has linear elasticity with a circular cross-section, we take the dynamic tension as the output and the friction acted on yarn by Jacquard roller as the input. At the moment of clutch operation and release, the tension fluctuation of polypropylene yarn during transmission from pulling roller to Jacquard roller was theoretically analyzed. A mathematical model describing yarn tension fluctuation was derived based on the moment of momentum theorem and mass conservation. The dynamic tension was obtained by applying Laplace’s transformation, providing the input-breaking moment as a step response. The result shows that tension fluctuation has an important influence on the carpet quality; therefore, it is necessary to carefully design the Jacquard roller and the control friction plate of clutch. Moreover, the effects of the yarn length between Jacquard rollers and pulling rollers on natural frequency and damping coefficient of yarn tension fluctuation were analyzed.     

An improved method to analyze the tensile behavior of carpet yarn

Since the strain, friction, and vibration of carpet yarn have direct impact on the quality of tufted carpet, mechanical properties of yarn play an important role in carpet weaving. An improved method based on Boltzmann superposition principle for describing mechanical behavior of carpet yarn is presented in this paper, which greatly reduces the amount of calculation and further improves the fitting precision. To estimate the performance of the model, we carry out some experiments on carpet yarn specimens, and compared with a nonlinear viscoelastic model widely used in studying nonlinear material. The results showed that the improved method and the nonlinear viscoelastic model perfectly fit the stress relaxation experimental curves when the deformation of the specimens is small, however the improved method is more accurate than the nonlinear viscoelastic model based on single integral constructive equation when the models are used to predict the stress relaxation responses.     

汽车用聚酰胺纤维全球动向

现今，聚酰胺（PA）纱作为复合地面系统的一部分，为驾驶提供了舒适的环境。但受成本的驱使，新的替代品不断涌现，如聚酯（PET）或聚丙烯（PP）纱线和针剌材料，以及聚乳酸纤维（PLA）和新型聚酯纤维（PTT）等从生物中提炼出的非石油基的材料。此外，由于小汽车数量的不断增加，汽车地面系统表层材料将采用针刺地毯复合到簇绒地毯上的新型产品。     

轴向运动纱线束的非线性横向振动特性

为控制纱线张力波动,提高毯面质量,研究了建立地毯织造过程中粘弹性纱线束振动模型及其影响因素。为此,应用三参数本构关系表征纱线束粘弹性,结合轴向几何非线性变形和材料非线性因素,应用牛顿第二定律建立纱线束横向振动方程。经无量纲化和一阶Galerkin截断,应用四阶Runge-Kutta法求解常微分方程,可得纱线束喂入速度、张力波动幅度以及阻尼系数对振动特性的影响。结果显示,在纱线束材料确定下,降低纱线束振动振幅从而减少张力波动的方法主要是增加阻尼系数,如增加提花罗拉表面摩擦系数。     

Study on semi-worsted carpet yarn processing北大核心

This paper mainly discuses how to use semi-worsted system to produce machine-made carpet yarn which can be suitable for different carpet machines processing and meet the high quality requirement of machine-made carpet yarn. Semi-worsted processing includes blending, carding, gilling, spinning and doubling etc. By the study and analyses on semi-worsted processing, the advantage of low production cost, short processing, high processing yield and adaptability of semi-worsted are introduced. Blending can mix different materials evenly in order to avoid streaks, stains and dyeing problem on carpet; carding is the role of carding fiber blocks into a single fiber and further blending more evenly; gilling is making sliver carded into suitable size which is matching different yarn count of spinning delivery by drafting and gilling; spinning and doubling is just drafting and twisting to different yarn which can satisfy for different yarn specification for carpet machines processing.     

基于Rhino-Python的多圈高簇绒地毯三维仿真

为解决空间结构复杂的多圈高簇绒地毯在实现其外观三维仿真时缺乏真实感的问题,利用Rhino环境下的PythonScript实现了簇绒地毯外观的三维仿真。将绒圈中心线及截面曲线分段后局部求解相关控制点坐标,再由B样条曲线对二者进行拟合。同时考虑到地毯绒圈之间的相互挤压导致绒圈发生了随机偏转变形,通过设计算法模拟了绒圈产生形变后的状态。在此基础上添加绒圈表面纹理及光照模型,进一步渲染输出仿真结果。测试结果表明:利用B样条曲线拟合原理并借助于Rhino-Python平台的簇绒地毯三维仿真方法是可行的,且易于实现;与实际地毯样品相比,能够较为真实地模拟不同排纱规律下多种花型图案、绒圈高度变化的簇绒地毯。