自捻纱的捻度分布特征分析

重点讨论了同相纱和相位纱的捻度结构特征以及两种自捻纱线的性能差异。从自捻纱线的结构特征来看,自捻纱线一个周期长度上存在三种纱段：有捻-有捻纱段,有捻-无捻纱段和无捻-无捻纱段。相位差的存在就是使得无捻-无捻纱段的长度减小。相位差的大小c值接近或等于无捻区长度b值时,无捻-无捻纱段长度最小,所形成自捻纱线均为有捻-有捻纱段和有捻-无捻纱段,是自捻纱线结构中性能最好的纱段。实纺相位纱和同相纱的性能比较结果表明,相位差c值约等于无捻区长度b值时,自捻纱线强度和伸长性能较好。     

假捻对低捻环锭纱结构的影响

 针对传统低捻纱强度低,影响其应用的问题,在环锭细纱机前罗拉和导纱钩之间安装1个专门设计的假捻装置,增加纺纱三角区内纤维的转移和纱线纤维间的抱合力,使纱线在具有较低捻度的同时拥有较高的强度。检测纱线的内部和外部结构,对比改良纱、普通捻度环锭纱和低捻度环锭纱的截面内纤维分布规律、纱线内的纤维轨迹以及纱线的表面结构。实验结果表明,经过改进的低捻度环锭纱与普通环锭纱具有不同的结构。     

自捻纱线的结构和性能方面的一些问题

自捻纱线由于加捻方法、加捻机构以及加捻原理和传统的环锭纺纱有本质的区别,因此有对自捻纱线的结构进行深入分析的必要.本文从自捻纱及自捻股线的结构、追加捻度、捻度的合理配置等方面,对捻度分布、“相位差”、“对偶”过程以及自捻股线的强力、布面质量等问题,进行了较详细的分析和探讨.     

自捻纱的拉伸力学性能

针对自捻纱断裂强力和断裂伸长率较低的问题,通过对同种原料自捻纺纱线和环锭纺纱线的拉伸力学性能进行对比,讨论了适合自捻纺纱的纤维和必须经过复合才能进行自捻纺纱的纤维以及对纤维配比的要求。与环锭纺纱线相比,羊毛、腈纶、涤纶自捻纱的断裂强力依次降低81.25%、49.33%、31.39%。涤纶、腈纶等纤维能直接采用自捻纺加工方式,而羊毛和苎麻不能直接采用自捻纺纱,必须和其他原料复合自捻。分别对毛/涤纶、麻/涤纶、腈纶/涤纶双组分复合自捻纱进行拉伸力学性能分析,结果表明,要使纱线拉伸性能符合要求,2种原料的组分中涤纶纤维含量需满足：毛/涤纶纱中占60%以上,麻/涤纶纱中占71%以上,但腈纶/涤纶纱的纤维配比不受限制。     

喷气交缠自捻纱

自捻纺纱工艺生产率高、生产成本低.但是,由于在纱线结构中存在无捻区,使得纱线的强力降低,在机织布面上会出现条痕,而在针织布面上会产生线圈歪斜,这些都会影响这种工艺的广泛使用.加捻自捻纱(STT纱)作为一种单向复捻纱,它是在自捻纺纱工艺后增加一道加捻工序,然后用汽蒸使加上的强捻固定下来.然而,这种方法     

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...     

自捻纺精纺毛织品产品设计与研究

自捻纺纱是新型的无锭纺纱技术,它用假捻为原理,将两根单纱捻合成结构稳定的股纱,即所谓自捻纱(也叫ST纱)。在毛精纺上为了产品与后工序需要,还须对自捻纱追加以单向的捻度,成为加捻自捻纱(也叫 STT纱)。加捻自捻纱的结构区别于环锭纱,但又比较接近环锭纱,因此通过几年来自捻纺精纺毛织品的设计与试制的实践,认为自捻纺产品既能做内销品种,又能做外销品种;不但基本上能做环锭纺的品种外,又能做环锭纺比较难做的如:高支纱和低支纱、三股纱和疙瘩纱等品种。我们前后共试制的自捻纺精纺毛织品有:70S/2纯毛单面花呢、纯毛粗平花呢、毛腈法兰…     

自捻纺纱机结构介绍

本文简要介绍了自捻纺纱与环锭纺纱相比的优缺点,详细介绍了自捻纺纱机的结构。     

自捻纺纱技术知识问答(四)

41.自捻纺纱机纺纱速度和自捻纱的捻度有关系吗? 出条速度和自捻捻度有着十分重要的依赖关系.在其他条件都相同的情况下,纺纱速度越高,自捻纱得到的捻度越小;速度越低,自捻纱得到的捻度越大(见图13)因此,自捻纺纱机在时行(慢速)或正常运行时纱线捻度就有差异,直接影响纱线的质量,应当用其他方法补救. 由于速度增加捻度降低,因此自捻纺纱机速度的提高受到一定限制.     

假捻集聚纺纱线的特征分析

探讨假捻集聚纺纱线的性能特点.测试了不同捻系数假捻集聚纱线的各项主要性能,并与同捻度的传统环锭纱线进行了对比试验分析.结果表明:捻系数为280的假捻集聚纱线.其条干CV值均比同捻系数的传统环锭纱差,而纱线的毛羽指数、断裂强度和断裂伸长率也只有在假捻器转速比适当的条伴下才好于传统环锭纱.而当捻系数为360时,假捻集聚纱线的条干CV值和断裂强度只有在假捻器转速比较低时才好于传统环锭纱,而毛羽指数和断裂伸长率则可在较大的假捻器转速比范围内优于环锭纱.     

纤维力学性能对自捻纱线自捻程度的影响

为研究纤维力学性能对自捻纱线自捻程度的影响,根据自捻形成过程的总应变能守恒推导出自捻捻回角和纤维抗弯刚度、扭转刚度的关系。结果分析表明：纤维抗弯刚度越大,自捻纱线的自捻捻回角越小;纤维扭转刚度越大,则自捻纱线的自捻捻回角越大;自捻捻回角的大小和纤维的扭转刚度和抗弯刚度之比成正比,即随着纤维扭转刚度和抗弯刚度之比的增大,自捻捻回角增大,所加自捻捻回数增多。通过对苎麻、涤纶、腈纶、羊毛 4 种纤维所纺的自捻纱线的半周期捻回数进行测试,验证了上述关系并得出结论：羊毛和腈纶纺纱时所得自捻捻回数较多,较适合采用自捻纺纱方式进行纺纱;而涤纶和苎麻所加自捻捻回数较少,不太适合采用自捻纺纱方式开发纺织品。     

21—STT YARNS: TECHNOLOGICAL ASPECTS OF TWISTED SELF-TWIST YARNS

The STT system is one in which unidirectional twist is added to self-twist yarns to produce two-ply weaving yarns. The added twist required for the elimination of fabric patterning due to cyclic twist variation in the yarn has been determined and has been expressed in terms of the amount of self-twist in the yarn. Fabrics woven from STT yarns have been evaluated, and the dependence of fabric properties on initial self-twist and on added-twist levels has been investigated. This has resulted in recommendations for the spinning and twisting of STT yarns for use in making high-quality worsted fabrics.     

几种自捻纺纱的加捻方式分析

自捻纺纱机的加捻方式直接影响其生产效率.文章对往复搓辊自捻罗拉、摩擦盘式、喷气式以及皮圈式自捻方式分别从加捻装置、加捻过程、特点、适用性和发展前景等方面分别作了阐述.综合分析表明,喷气自捻有很好的发展前景,在喷嘴部位的改进和生产速度提高后有可能超过往复搓辊自捻罗拉的加捻方式,但往复搓辊自捻罗拉仍将会在一定时间内以其稳定性和高效率稳步发展.     

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.     

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。     

棉纺赛络纺工艺研究和实践

探讨棉纺赛络纺纺纱工艺。分析论述了棉纺赛络纱的特点及赛络纺改善成纱强力、条干和毛羽的工艺原理,对赛络纺粗纱定量、粗纱捻系数、细纱罗拉隔距,喇叭口中心距、后区牵伸倍数、钳口隔距、导纱动程、细纱捻系数及钢领钢丝圈、胶辊选用、络筒速度、清纱门限等进行了试验分析。指出:通过合理配置工艺参数及纺纱专件,能够充分发挥赛络纺的优点,实现强力高、毛羽少、条干好的纺纱效果。     

Effects of directed movement of fibres in a twist triangle on yarn quality

This work investigates the effect of directed flow of the fibres in a twist triangle on yarn properties. This is done using different clip‐on attachments positioned on the front rollers of a ring spinning frame. Seven sets of rollers (plain non‐grooved; 75°‐biased left‐to‐right grooved; 75°‐biased right‐to‐left grooved; 15°‐, 45°‐ and 75°‐biased grooved from both sides towards the centre and solo) are made and positioned immediately below and parallel to the top front draft rollers of the laboratory ring spinning frame (tester model 82 KA) so that they can interact with the emerging drafted fibre strand before twist insertion. Afterwards, a 0.495‐ktex (2.02 Nm) finisher worsted roving composed of 55% polyester and 45% wool is fed into each unit of the ring spinning frame to produce a yarn with a yarn count of 30 Nm and a twist factor of 125. The rollers affect the flow of the fibres in the triangle zone and, as a result, the quality of the yarns is affected. A comparison of the yarns produced shows that directing the fibres in the triangle zone could improve the yarn quality. The results indicate that the 75°‐biased grooved (from both sides towards the centre) rollers improve the yarn quality in terms of hairiness, elongation and imperfections.