全聚纺集聚区吸风槽型对成纱质量的影响

探讨全聚纺集聚区吸风插件上的吸风槽型对成纱质量的影响。选取八种不同截面尺寸的吸风槽型,分别纺制20S、40S、60S精梳纯棉纱,并对所纺纱线各项成纱性能指标包括毛羽、条干、强力进行测试。结果表明:当吸风槽截面尺寸大时,气流的横向集聚作用减弱,对纤维须条的集聚效果差,成纱质量较差;相同吸风槽对不同纱支成纱质量的作用不同:随着所纺纱线支数的提高,最优吸风槽的截面尺寸相应减小。     

集聚纺纱方式对纱线性能的影响

为了探究集聚纺纱方式对纱线性能的影响,采用以传统环锭纺为基础的四罗拉网格圈紧密纺、紧密赛络纺、全聚纺及低扭矩纺四种集聚纺纱方式纺制了28.1、18.5、14.7 tex的纯棉纱。通过对纯棉纱线的断裂强度、断裂伸长率、毛羽和条干均匀度等性能进行测试分析,探究了四种集聚纺纱方式对纱线性能产生影响的原因。实验结果表明:由于不同集聚纺纱方式的成纱结构特点不同,影响了纱线的内在性能。紧密赛络纺的成纱强力最高,全聚纺的成纱有益毛羽最多,低扭矩纱在假捻器的作用下纱线品质得到了提高其纱线条干最好,紧密赛络纺的纱线总毛羽数最少。     

基于Fluent的全聚纺集聚区流场模拟与分析

全聚纺是一种新型窄槽式负压空心罗拉紧密纺系统。为全面研究全聚纺集聚区内气流的运动规律,本文采用Fluent软件模拟全聚纺集聚区内流场分布,分析了空心罗拉表面窄槽宽度分别为0.6、0.8、1.0 mm时不同位置须条的输出方向、集聚方向、厚度方向气流速度分布规律,为全聚纺系统集聚区优化设计提供理论参考。     

全聚纺纱体内纤维转移规律对成纱性能的影响

为探讨全聚纺集聚区对成纱质量的影响,在加装全聚纺装置的QFA1528型细纱机上,分别采用四种集聚负压：1600Pa、2000Pa、2400Pa、2800Pa;四种槽型的吸风插件：水滴槽、短斜槽、直槽、长斜槽;三种不同的气流导向片：A型、B型、C型,纺制线密度为9.7tex的纯棉全聚纺纱线,并对纱线的各项性能指标进行测试。采用示踪纤维方法,对纱体内纤维的内外转移系数进行测量,继而分析不同集聚区工艺对成纱质量的影响。结果表明：当负压为2000Pa时,纱线条干和强力最好,当负压为2800Pa时,3mm以上的有害毛羽最少;当吸风插件选择短斜槽时,纱线条干最好,选择长斜槽时,纱线的强力和毛羽最好;当气流导向片选择B型时,纱线的条干最好,选择C型时,纱线的强力最好。     

凹槽形状对气流槽聚纺纱集聚区流场及成纱性能的影响

针对气流槽聚纺纱不同集聚凹槽形状对成纱性能的影响,建立集聚区域三维模型,利用Fluent软件模拟不同凹槽结构的气流槽聚装置集聚区域的流场分布,比较其气流流场的特点。模拟结果表明：在相同负压条件下,非对称凹槽气流槽聚装置的气流利用率高,负压气流方向和集聚方向的速度分别为48.3、24.5 m/s,可有效握持和集聚纤维束,使得输出的须条能够最大程度地集聚,纤维也尽可能多地集中成为主体纤维束,有利于减少毛羽。通过测试所纺27.78 tex苎麻纱的成纱性能,验证非对称凹槽的集聚性能以及集聚气流对成纱性的影响。实验结果表明：采用非对称凹槽集聚装置纺制的纱线毛羽比环锭纺减少了77.58%,成纱强力比环锭纺提高了14.32%,成纱性能显著提高。     

全聚纺与四罗拉网格圈紧密纺集聚区纤维运动分析

对紧密纺集聚区集聚纤维的运动状态以及不同运动轨迹对于成纱质量的影响进行分析。选择DTM129型全聚纺细纱机与四罗拉网格圈紧密纺细纱机进行纺纱试验,分别纺制棉、粘胶、涤棉混纺3种原料的纱线。在纺制过程中,利用高速摄影机对集聚区运动须条进行拍摄,并运用AutoCAD软件获取集聚须条的运动轨迹。通过分析对比得出结论:全聚纺细纱机所纺纱线的条干性能较优,四罗拉网格圈紧密纺细纱机所纺纱线的毛羽、强力性能较优。     

全聚纺与四罗拉网格圈紧密纺集聚区三维流场模拟与对比分析

为了探究四罗拉网格圈紧密纺纱系统和全聚纺纱系统集聚区气流对须条集聚的影响,文章利用AUTOCAD创建了四罗拉网格圈紧密纺纱系统和全聚纺纱系统的物理模型,利用ANSYS Fluent Release 16. 0计算集聚区流场数值,表征流场分布并对比分析了两者速度分布规律。研究结果表明:两者的静压分布规律相同,气流从集聚区两侧流入内侧;两者集聚区的前区、中区、后区速度分布情况大致相同,而两者对应的三个区域的速度分布规律不同;综合分析两者静压和速度的分布规律及成纱质量分析,全聚纺具有更好的集聚作用。     

全聚纺集聚区三维流场数值模拟与分析

采用Fluent软件对全聚纺集聚区流场进行数值模拟,得到集聚区气流流动规律,给出集聚区内流场的速度分布规律及流场分布对须条结构的影响。结果表明:窄槽罗拉外表面不同高度处的气流分布规律相似,但速度值有较大差异,各轴向速度分量在h为0.5 mm处达到最大;在集聚区域的不同位置,X轴向速度分量分布规律差别较大:在集聚后区,气流辅助须条输出,在集聚前区,气流阻碍须条的输出;在整个集聚区域,全聚纺对须条均有良好的集聚作用,且集聚作用逐渐增大,到达输出钳口时集聚作用达到最大。     

基于Fluent的全聚纺不同吸风槽集聚效果数值模拟

为探讨吸风槽对全聚纺集聚效果及纺纱质量的影响,采用Fluent软件对全聚纺系统集聚区流场进行数值模拟,得到3种吸风槽集聚区的气流流动规律,并对模拟结果进行比较分析。结果表明:长、短斜槽在整个集聚区均对须条产生集聚作用,但有恶化须条条干的可能;长斜槽的Z轴向速度分量分布不利于集聚效果的产生,直型槽在集聚中区有使须条再次扩散的可能。最后进行了纺纱实验验证,证明模拟结果及分析是准确的。     

集聚纺气流导向元件的偏移对集聚效果的影响

针对立达第3代集聚系统的气流导向元件在生产中左右偏移的现象,分析了该现象对集聚效果的影响。选取气流导向元件的居中位置,以及左右各偏移1.5、2.5 mm共5个特征位置,使用Fluent软件对集聚系统流场进行数值模拟,并通过CFD软件对模拟结果进行数据分析。对比分析后发现,在发生1.5 mm和2.5 mm偏移时,集聚区均出现不同程度气流速度和静压大小的变化,包括集聚范围缩小、集聚气流速度忽高忽低和集聚处静压降低等。通过纺纱实验对模拟结果进行验证后得出:气流导向元件发生1.5 mm偏移时气流速度和静压大小改变引起的成纱质量波动较小,而当偏移量达到2.5 mm时成纱条干不匀上升3%,毛羽指数增加了8%,其影响趋势与理论研究结论相吻合。     

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 of flow field in complete condensing spinning: effects of suction unit and guiding device

Complete condensing spinning (CCS) is one kind of pneumatic compact spinning. A kind of hollow roller with strip groove structure on the surface is used to condense the fiber bundle and improve the yarn qualities. In this paper, the numerical simulation of flow field in CCS is studied using fluent software. Using AutoCAD Software, according to the physical parameters of the practical system, a three-dimensional (3D) model of the condensing zone is established firstly. Then, the numerical simulations of the flow field in CCS were presented. Three kinds of suction units, straight-type, long-skewed, and short-skewed, and three kinds of guiding devices, A-type, B-type, and C-type, were discussed. Corresponding simulations in the front, middle, and back condensing zone and arc line along the front roller surface direction were given and analyzed comparatively. It is shown that the flow field distribution in CCS is stable and can condense the fibers well. The shape of suction unit may mainly influence the output of fiber strand in the condensing zone and affect the yarn evenness. When compared with the long-skewed and short-skewed suction units, the straight-type suction unit is beneficial for the fiber strand output leading to better yarn evenness possibly. However, the distribution ranges of flow field in CCS with both long-skewed and short-skewed suction units are larger than that of the straight-type suction unit. Furthermore, comparing with that of without a guiding device, the direct transverse air condensing force in CCS using a guiding device is greatly larger, which is beneficial for reducing the yarn hairiness. However, the assisted condensing forces are smaller and make the yarn evenness possibly worse. Finally, the obtained numerical results are illustrated by spinning experiments.     

一种新型窄槽式负压空心罗拉全聚纺系统

本文给出了一种新型窄槽式负压空心罗拉紧密纺系统-全聚纺,并对该系统的结构组成、成纱特性进行了全面分析,最后通过在三家不同纺纱企业进行纺纱实验对全聚纺与网格圈型紧密纺成纱质量进行对比,指出：与网格圈型紧密纺相比,全聚纺成纱条干有所改善,在有害毛羽减少效果基本相同的前提下可保留丰富的短毛羽,成纱强力稍有降低,即成纱综合质量较好。同时,全聚纺系统运行维护成本低、能耗小,具有良好的市场推广应用价值。     

全聚纺涤棉混纺纱内纤维的径向分布

为研究全聚纺混纺纱中纤维的径向分布情况,采用环锭纺、网格圈型集聚纺和全聚纺3种方法纺制28.1tex涤棉混纺纱线,运用哈氏切片器切取三种混纺纱线样本,借助MOTTC B1型显微镜观察并采集样本中两种纤维的分布状况图,结合汉密尔顿（Hamilton）指数的方法分析,得到全聚纺混纺纱内涤纶纤维和棉纤维在纱截面内的内外转移趋势及分布规律。结果指出：利用传统环锭纺纺制的涤棉混纺纱,涤纶纤维有明显向纱芯转移的趋势,而网格圈型集聚纺,涤纶纤维向纱芯转移的趋势较传统环锭纺弱,全聚纺相对于网格圈型集聚纺而言,涤纶纤维分布更加随机,并且涤纶纤维有向纱外转移的趋势。     

集聚槽倾角对紧密纱质量的影响

探讨集聚槽倾角对紧密纱质量的影响。分析了紧密纺异形管集聚槽的形态与作用,并采用集聚槽倾角为5°、7°、9°3种不同的异形管,分别纺制5种不同线密度的紧密纱,进行纺纱质量对比试验。结果表明:随着集聚槽倾角的增大,单纱强力降低,有害毛羽数减少;集聚槽倾角的增大对29.2tex和19.4tex纱条干CV值影响规律不明显,但14.6tex、11.7tex与9.7tex纱线的条干CV值则随着集聚槽倾角的增大而升高。     

Influence of condensed spinning method on yarn property北大核心CSCD

In order to explore the effect of condensed spinning method on the yarn properties, the pure cotton yarn with 28. 1, 18. 5 and 14. 7 tex was spun by four kinds of condensed spinning methods based on traditional ring spinning such as four, roller lattice apron compact spinning, compact siro spinning, complete condensed spinning and low torque spinning. The breaking strength, breaking elongation, hairiness and evenness of the pure cotton yarn were tested and analyzed, and the reasons for the influence of four kinds of condensed spinning methods on yarn performance were explored. The experimental results show that the characteristics of the yarn structure by different condensed spinning methods will influence the inner properties of the yarn. The yarn spun with compact siro spinning has the highest strength, the yarn spun with complete condensed spinning has the most beneficial hairiness. The yarn quality of the low torque yarn is better under the effect of the false twister. It has the best evenness, and the yarn spun with compact siro spinning has the lowest total hairiness. © 2018 China Silk Association. All rights reserved.     

有机棉紧密纺纱线的生产实践

为了提高有机棉纱线的品质,采用紧密纺纱技术对其进行纺纱,并对比纺制所得紧密纱和环锭纺有机棉纱的性能指标结果表明,通过紧密纺纱工艺可以有效提高有机棉纱强力并降低毛羽量。     

紧密纺纱技术与毛羽问题

针对传统纺纱前钳口处加捻三角区形成毛羽的基本规律，在该钳口出口处采取消除加捻三角区的纺纱方法即紧密纺纱方法，将纱线表面长毛羽在须条离开握持钳口时就贴向纱干，有效降低了纱线毛羽。采用自行研制的紧密纺装置对棉和毛进行纺纱试验，结果表明紧密纺对降低纱线毛羽效果明显。