网眼罗拉集聚纺集聚效果的影响因素

 为深入了解网眼罗拉集聚纺集聚效果的影响因素,借助CFD计算流体动力学软件及MatLab工具,探讨负压、网眼罗拉表面摩擦因数对集聚效果的影响。结果表明：在定负压条件下,随着表面摩擦因数的减小,集聚效果逐渐变好,可得出临界表面摩擦因数;在变负压条件下,网眼罗拉表面临界摩擦因数与负压存在着正相关趋势,因此,需合理选择负压与网眼罗拉表面摩擦因数,以加工低能耗、低成本、高品质的集聚纺纱线。     

集聚纺网圈的结构和制造初探

介绍了集聚纺用网圈的结构、功能和织造方法,将国产天问公司网圈和进口网圈对比试验后表明,两者的效果非常接近。网圈外表面摩擦因数大,内表面摩擦因数小,这一要求必须通过选用合适的织物结构达到。     

涤纶赛络集聚纱摩擦性能研究

探讨纯涤纶赛络集聚纱的摩擦性能。从纱线表面特征、纱线直径和可压缩性能方面评价了不同初张力条件下T14.6tex、T11.7tex和T9.7tex赛络集聚纱的摩擦性能,并与传统环锭纱、集聚纱和赛络纱进行对比分析。结果表明:纱线的静摩擦因数和动摩擦因数均随所施初张力的增加而降低;纯涤纶赛络集聚纱纵向表观结构整齐度最高,表面毛羽明显减少,条干均匀度也得以改善;赛络集聚纱表面光洁,平顺整齐,且纱线直径和可压缩变形小,摩擦时接触面积小,纱线的静摩擦因数和动摩擦因数比相同规格的其他三种纺纱方法小。认为:利用赛络集聚纺技术开发纯涤纶纱线可以改善涤纶纱线的摩擦性能,提高其织物的服用舒适性。     

集聚赛络纺纱导流装置的设计与应用

针对集聚赛络纺纱系统能耗较大的问题,设计3种导流装置,以降低集聚赛络纺纱系统的负压,达到节能降耗的效果。首先通过solidworks软件建立集聚赛络纺纱集聚区三维物理模型,利用fluent进行数值模拟,分析集聚区气流场的分布情况;然后通过纺纱实验进一步验证导流装置能够起到节能降耗的效果。结果表明：出口负压越大,集聚槽附近的速度越大,集聚槽上方的气流对须条起到挤压作用,使须条紧紧贴在网格圈表面,集聚槽侧向气流使须条宽度减小,须条表面的毛羽能够卷入到纱体表面,形成紧密的结构,从而能够减小甚至消除加捻三角区;使用所设计的3种导流装置(集聚负压1 000 Pa)纺制出来的纱线与普通集聚赛络纱(集聚负压2 000 Pa)质量相当,甚至更好。     

网格圈负压式集聚纺集聚区须条半自由端加捻机制

网格圈负压式集聚纺纱实践表明,在相同工艺条件下,纺制相同线密度的纱线,集聚纱捻度比环锭纱捻度高5％左右.为揭示此现象的形成机制,采用高速摄影技术,对直线形集聚斜槽集聚区须条的集聚情况进行拍摄,发现存在类似卷捻的现象.通过纺纱实验,对采用相同工艺纺制的相同线密度的集聚纱和环锭纱捻度进行对比,结果表明集聚区须条的附加捻度是...     

网格圈集聚纺纱系统三维流场表征与分析

通过建立流体动力学模型,利用标准κ-ε湍流模型及并行计算技术对网格圈集聚纺纱系统集聚区流场进行了模拟与表征,分析集聚区域内气流的流动状况,解析吸气斜槽入口曲面上气流的静压分布及速度分布规律,并讨论速度分布对须条的作用效果。研究结果表明：网格圈集聚纺纱系统是利用负压效应来产生集聚气流;斜槽入口曲面上的负压使网格圈向异形管内凹;X、Y、Z轴向的速度分量对须条的作用效果各不相同;集聚区产生附加捻度的区域主要靠近吸气斜槽的S1端。     

网格圈集聚纺纱系统三维流场表征与分析

 通过建立流体动力学模型,利用标准κ-ε湍流模型及并行计算技术对网格圈集聚纺纱系统集聚区流场进行了模拟与表征,分析集聚区域内气流的流动状况,解析吸气斜槽入口曲面上气流的静压分布及速度分布规律,并讨论速度分布对须条的作用效果。研究结果表明：网格圈集聚纺纱系统是利用负压效应来产生集聚气流;斜槽入口曲面上的负压使网格圈向异形管内凹;X、Y、Z轴向的速度分量对须条的作用效果各不相同;集聚区产生附加捻度的区域主要靠近吸气斜槽的S1端。     

网格圈型集聚纺集聚区纤维运动轨迹模拟分析

为获得网格圈型集聚纺集聚区的纤维运动轨迹,首先由流场模拟获得了集聚区的速度场,然后建立了纤维微元在气流场中动力学模型,最后通过Matlab编程模拟了不同初始位置的单纤维运动轨迹。研究结果表明：不同初始位置的纤维在气流作用下的运动轨迹不同,纤维之间发生相互穿插现象;纤维在Y轴向气流作用下逐渐靠近并贴伏在网格圈表面;不同初始位置的纤维运动轨迹反应出集聚区须条集聚过程可分为快速集聚区、调整集聚区和稳定集聚区。     

气流槽聚型紧密集聚纺纱装置试验设计与结果分析

本文主要针对气流槽聚型紧密集聚纺纱装置,通过改变不同负压值和钢丝圈的大小进行纺纱试验,并根据纺纱试验的结果讨论负压大小和钢丝圈大小对纱线质量的影响,选择最优的负压和钢丝圈参数。研究结果表明:环锭纺与集聚纺纱线的毛羽、强力和条干存在明显差异,集聚纱的毛羽数与环锭纱相比明显减少,并且结构紧凑、条干光滑;随着吸气负压的增加,集聚纱线的紧密程度也相应增加。     

集聚纺工艺对三通道数码纺细纱质量的影响

探讨在三通道数码纺环锭细纱机上应用集聚纺工艺时对细纱质量的影响。介绍了配置集聚纺装置时牵伸区的牵伸集聚原理,分析了不同槽形的集聚纺负压工艺片对纤维产生集聚时所能发挥的作用,并分别以细纱和织物为对象,测试并分析不同工艺片对细纱质量指标的影响和对织物表面色彩分布的影响。结果表明:不同槽形的负压工艺片导致三束纤维的集聚状态不同,对细纱表面特征影响大。认为:选择合理的集聚纺配件是提高三通道耦合纱质量的有效手段。     

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.     

网格圈式紧密纺集聚负压对成纱性能的影响

探讨网格圈式紧密纺集聚负压对成纱性能的影响规律.在细纱机紧密纺改造机台,通过不同负压条件下分别纺制3种纱号的紧密纱,研究分析了集聚负压对成纱毛羽、强力和条干的影响.结果表明:3 mm以上有害毛羽随着负压的增大呈现逐渐减少的趋势;对成纱强力而言,采用较大的负压时提高中号紧密纱强力有利,而细号紧密纱则应选择适宜的负压;对条干而言,纺制较粗纱号的紧密纱负压应适当偏大;而纺制较细纱号的紧密纱负压则应该适当降低.     

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.     

Numerical simulation on the condensing effect of suction slot in compact spinning with lattice apron

In this paper, a geometrical model is built by the actual structure of a condensing zone in compact spinning with lattice apron, and a fluid dynamics model is designed by FLUENT to study the numerical simulation of flow field in the condensing zone of straight, oblique, and deformed suction slots. The result shows the laws of airflow static pressure and velocity distribution of three kinds of condensing zones. The difference of distribution between compact direction and adsorption direction of strand is stressed on, which is helpful to make a deeper study on the mechanism of compact spinning with lattice apron and provide a theoretical support for the optimal design of suction slot.     

钻孔皮圈集聚纺纱系统三维流场的模拟与分析

为研究钻孔皮圈集聚纺纱系统气流对须条的集聚效果,采用3D CFD技术建立了钻孔皮圈集聚纺纱系统集聚区域的计算流体动力学模型,应用软件Fluent 6.3对集聚区域内流场进行并行计算,表征了集聚区域流场的流动情况,解析集聚区域内流场的静压分布及速度分布规律。研究结果表明：气流速度沿不同的轴向分量对须条的集聚作用不同;集聚区静压与流速沿Z轴向的分布规律相似;该系统集聚机制以气流集聚为主,椭圆孔与圆孔处的静压与速度分布规律存在差异,椭圆孔比圆孔具有更佳的集聚效果。     

集聚纺纱线结构对成纱质量的影响

为探讨紧密纺纱线的结构对成纱质量的影响,采用示踪纤维方法,在梳棉工序制得含有示踪纤维的生条,然后通过后道工序纺制成需要的纱线。在视频显微镜下通过观察纤维在成纱中的转移,来对比分析全聚纺与普通环锭纺、三罗拉网格圈紧密纺和四罗拉网格圈紧密纺4种纱线的结构特点。结果表明：全聚纺纱线中纤维平均径向位置最小,但纤维内外转移系数最大。在此基础上,根据所得数据给出纤维的包络线,并借助纤维的内外转移系数等特征参数,从理论上分析了不同纺纱方式下纱线结构对纱线强伸性能的影响。