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。     

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。     

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...     

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。     

原色与脱色牦牛绒精梳纯纺纱工艺研究

针对牦牛绒纤维主体长度短、长度离散度大、含有大量粗死毛等导致无法使用现有毛精纺设备实现精梳制条的问题,通过采用便捷喂毛、高效预梳、低损伤分梳、落物充分回收装置组成高效分梳机构,将卷曲、块状绒团拉伸为基本伸直的单纤维状.在细纱工序,分别采用环锭纺、网格圈紧密纺、全聚纺纺制原色和脱色牦牛绒单纱和赛络纱,并对成纱质量进行测试...     

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.     

Mechanical analysis on constant cross-section segment of fiber band in condensing zone during compact spinning

It has been found through experiments that under the same spinning condition, the twist of the compact spun yarn is approximately and averagely 5% larger than that of traditional ring‐spun yarn. The larger part of the twist is called additional twist. Since the additional twist affects the subsequent processing to some extent, it is worth studying carefully. A theoretical model for analyzing the additional twist of a fiber band with constant cross‐section in the condensing zone of a cotton‐type compact spinning machine through a mechanical discussion is presented in this paper. Factors affecting the additional twist of the yarn, including the pressure of the profile tube, the friction coefficient between the fiber band and the lattice apron, the length of the suction slot, and the curvature radius of the profile tube, are discussed by numerical integral analysis. The experimental results verified the proposed fiber band additional twist model.     

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.     

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.     

黑牦牛绒氧化脱色工艺优化及其可纺性

针对黑牦牛绒氧化脱色对纤维性能及纺纱性能的影响,采用正交实验,对其氧化脱色条件进行了优化,得到最佳工艺条件：H2O2 浓度为25 g/L,焦磷酸钠浓度为5 g/L,温度75 ℃,时间90 min,溶液pH值为8.5。通过对比分析脱色和未脱色纤维性能,并分别采用全聚纺和四罗拉网格圈紧密纺纺制20.83 tex纱线进行性能测试,进一步研究脱色牦牛绒纤维的可纺性能。结果表明：脱色后,牦牛绒纤维的物理机械性能出现了不同程度的下降,表面鳞片结构破损;当采用同一方法纺相同支数的纱线时,脱色牛绒较原色牦牛绒纱线条干和强伸性变差;采用不同方法纺相同线密度纱线时,全聚纺纺制的脱色牛绒纱线较四罗拉网格圈紧密纺强力低、条干优。     

数值分析网孔罗拉气动式紧密纺纱纤维集聚区内的气流流动特征

采用大型流体计算软件模拟网孔罗拉气动式紧密纺纱纤维集聚区内的气流流动状态．并基于数值模拟结果分析了网孔罗拉气动式紧密纺纱纤维集聚区内的气流流动特征、分析认为由于气流吸聚槽自牵伸钳口线位置开始向纤维集聚区左侧倾斜,导致气流吸聚槽左右两侧气流流动方向不同,且气流流动速度差异显著,因此在气流吸聚槽处形成的气流汇聚线更靠近气流吸聚槽的右侧边缘,揭示了网孔罗拉气动式紧密纺纱实践中,被集聚的纤维须丛总是位于靠近气流吸聚槽右侧位置的原因。     

普适性柔顺光洁纺纱技术分析与应用

欧洲采用优化工艺、外加强制性控制力的方法降低纱线有害毛羽,最有效成熟的集聚纺技术降低细纱3 mm毛羽高达80%,但存在能耗大、成纱硬度高等问题。针对现有技术问题,本文提出在线降低纤维刚度以提高纤维加捻成纱性能的纺纱方法,研制出配套纺纱技术装备,制造出表层致密光洁、内部纤维充分转移的柔顺光洁纱线,形成柔顺光洁纱线技术,广泛适用于棉、麻、化纤纺纱领域,具有装备操作简便、性价比高、易于推广等方面的优势,实现产业化应用。     

基于有限元方法的全聚纺集聚区流场数值模拟

利用有限元分析软件ANSYS中的FLOTRAN CFD分析功能,对全聚纺集聚区内的三维流场进行数值模拟分析。通过模拟结果的对比分析,得到全聚纺集聚区内气流速度及气流分布规律,对全聚纺工作原理进行解释。其次结合环锭纺和全聚纺纯棉纺纱实验,讨论气流全聚纺集聚区气流分布对纯棉纱质量的影响。结果表明:对于纯棉纱的纺制,全聚纺有利于改善成纱条干,提高成纱强力,减少有害毛羽的同时保留丰富的有益毛羽。     

浅谈细纱机纱线毛羽的成因及控制措施

为了减少纱线的毛羽,提高纱线的质量,简要分析在原料、设备器件、车间温湿度及人为因素等方面分析了传统环锭纺细纱机及网格圈式紧密纺细纱机上成纱毛羽形成的主要原因,并进行了相应的实验。提出了控制细纱毛羽的主要措施,即采用成熟度适中及短绒率低的原棉,注意钢领与钢丝圈的的选配及使用周期,调节好车间温湿度并加强车间管理。结果表明,采用以上措施有利于减少毛羽。     

Trajectories of fibers and analysis of yarn quality for compact spinning with pneumatic groove

To study the motion trajectory of a fiber bundle in the flow field of compact spinning system with pneumatic groove, the computational fluid dynamics model was established and resolved by numerical computation using FLUENT software. The dynamics of the infinitesimal element of a fiber in the flow zone was also established. The dynamic model was solved by utilizing the self‐designed MATLAB procedure, and the motion trajectory of the fiber in the flow zone was derived. Results of this research confirmed that before the fiber bundle reaches the groove, it is condensed only by the effect of airflow, and when sliding into the groove, it is affected by both airflow and the shape of the groove. Edge fibers of the fiber bundle are condensed by airflow, and the condensing width of fibers is dependent upon the effect of air flow. The position of fibers of different widths change as a result of airflow, and the phenomenon of migration of fibers takes place in the section of the fiber bundle. Compared with the conventional ring‐spun yarn, both the tensile strength and the breaking strength of the compact‐spun yarn are enhanced, in particular by reducing yarn hairiness.     

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.     

紧密纺普梳纱与传统环锭纺精梳纱的性能分析

为了了解紧密纺普梳纱与传统环锭纺精梳纱成纱性能的差异,在相同配棉、相同开清和梳棉工艺、同一粗纱定量条件下,利用DTM129型细纱机纺制了CJ 14.5 tex精梳纱,并加装Suessen公司Elite紧密纺装置纺制了C 14.5 tex普梳纱.通过测试对比两品种的成纱性能,结果表明:C 14.5 tex紧密纺普梳纱成纱细节、粗节和棉结指标较CJ 14.5 tex传统环锭纱差一些,但强伸性能指标较好,毛羽较少.生产中可通过加大梳棉落棉率等措施改善紧密纺普梳纱粗细节.认为紧密纺采用普梳工艺流程,相对于传统环锭纺精梳流程生产效率提高,在满足成纱质量要求的情况下紧密纺采用普梳纺纱工艺可降低生产成本.     

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.     

集聚纺气流集束原理和纱线结构——纤维集束运动学初探

为了探讨集聚纺紧密纱条干均匀度提高的原因,进一步探索紧密纱的集束原理及集聚纺的本质,详细分析了纺纱三角理论,用运动学的基本方法重点从纱路倾斜的作用、集聚区上纤维的运动以及纤维翻滚的"填谷效应"阐述了纤维的集聚过程,对比了紧密纱的特点及集聚赛络纺的优势,展望了其发展前景。指出:集聚过程中集束气流场内的纤维束经过倾斜的集聚槽时,外层纤维的翻滚、内部纤维的整体滚动形成了紧密纱独特的双层结构;机械式集聚纺研究仅着眼于消除纺纱三角即减少毛羽,在纱线结构变化方面,目前还不具备气流式集聚纺纱双层的特点。     

网格圈目数与纱线综合性能关系的研究

网格圈是紧密纺纱技术的关键部件，其空隙的大小及织造密度的高低都对纱线的性能有影响。文章分析了不同目数的网格圈对不同线密度纱线性能的影响，同时讨论了纺制不同线密度纱线对网格圈的选择。