A study on siro-, solo-, compact-, and conventional ring-spun yarns. Part II: yarn strength with relation to physical and structural properties of yarns

The strength of siro-, solo-, compact-, and conventional ring-spun yarns has been examined with reference to yarn migration parameters, spinning-in-coefficient, number of broken fibers, and yarn hairiness. The measured results are presented in the forms of diagrams and tables. Results reveal that at various levels of gage length and strain rate, siro-spun yarns exhibit the highest tenacity, followed by compact-spun yarns, solo-spun yarns, and conventional ring-spun yarns. Analysis of the results demonstrate that the higher tenacity values of siro-spun yarns can be attributed to the higher mean fiber position, higher migration factor, greater proportion of broken fibers, and lower hairiness. It is also found that the strength of yarns to a considerable extent is governed by yarn structure, gage length, and strain rate.     

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。     

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。     

纺纱工艺对弹性转杯纱结构和性能的影响

描述了由上海东华大学开发的用以纺制不同结构性能弹性转杯纱的一种弹性转杯纱纺纱系统。研究了在改变加捻参数和氨纶丝牵伸倍数时弹性转杯纱的结构与性能。结果表明加捻参数和氨纶丝牵伸倍数对弹性转杯纱的结构和性能均有一定的影响,氨纶丝线密度也会影响纱线的性能。     

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。     

A comparative study on performance characteristics of multicomponent core-spun yarns containing cotton/PET/elastane

Abstract

This paper experimentally investigated the characteristics of different (filament and multicomponent) core-spun yarn type. Filament core-spun yarns comprised cotton covered drawn textured (DTY) polyester (PET) filaments with four different filament finenesses. Regarding the production of multicomponent (dual) core-spun yarns, both PET with four different filament finenesses and elastane with four levels of draft variable were fed simultaneously. Yarn samples were produced with modified ring spinning system at the same spinning conditions. As a control group, 100% cotton ring-spun yarn was also manufactured. Tensile properties, unevenness, imperfections and hairiness of yarn samples were determined. Also, fatigue characteristics of yarn samples were examined at two different loading of cycles. The results showed that filament fineness had a significant effect on all yarn properties being determined. Dynamic modulus and dynamic strain properties of yarns, filament fineness, elastane draft and number of cycle were found to be statistically significant at 0.05 level.     

The dimensional and mechanical properties of wool/polyester fabrics made from vortex and ring-spun yarns

Fabric woven from wool/polyester (PES) Murata vortex spun (MVS) blend yarn is a commercially viable proposition particularly on the basis of advantageous wear-resistant properties, compared with fabric made from traditional worsted ring-spun yarn. However, in some early industrial trials with fabric made from 45/55-blend wool/PES MVS yarn, significantly greater relaxation shrinkage was found relative to comparable worsted ring-spun fabric. It was noted at the time that the amount of relaxation shrinkage in MVS fabric could be reduced to a large extent by using steamed MVS yarn.

In this study, the extent of variations in the dimensional and mechanical properties of fabric samples woven from a combination of steamed and unsteamed MVS yarn and equivalent worsted ring-spun yarn is examined. In general, greater hygral expansion and relaxation shrinkage were found in loom-state fabrics made from unsteamed MVS yarns, whereas the fabric made from steamed MVS and ring-spun yarns gave relatively low levels of relaxation shrinkage and hygral expansion. Permanent setting of fabrics, by pressure steaming, was found to be more effective than yarn pre-steaming in reducing relaxation shrinkage levels of fabrics made from unsteamed MVS yarn. After pressure steaming, all fabrics showed similar levels of relaxation shrinkage and hygral expansion.

Permanent setting of the fabrics, by pressure steaming, resulted in similar levels of relaxation shrinkage and hygral expansion, irrespective of the yarn production method; relaxation shrinkage fell to around 1% and hygral expansion increased by about 1%, relative to the loom-state samples. MVS fabrics were relatively heavier and fuller and had a firmer handle than the worsted ring-spun fabrics, reflecting the greater fabric weight, thickness and shear rigidity measured on these fabrics. These attributes are associated with different structures of the worsted ring-spun and MVS yarns used to make the fabrics.     

仪纶~(TM)纬平针织物的抗起毛起球性能

本文分别选用环锭纺、赛络纺、赛络紧密纺纺纱工艺,制备了同等纱支的仪纶~(TM)纯纺、仪纶~(TM)/棉(65/35)混纺针织纱线及其纬平针织物,对比测试了纱线性能及其织物抗起毛起球性能。实验结果显示:不同纺纱工艺的仪纶~(TM)针织纱线总体性能相似,赛络紧密纺纱线纱体结构更均匀;赛络纺织物的抗起毛起球性较环锭纺织物高0.5级,赛络紧密纺织物的抗起毛起球性明显好于环锭纺织物;混纺织物的抗起毛起球等级和起球粒数均有所改善。     

皮芯结构微纳米纤维复合纱线的制备及其性能

为探究纺丝液质量分数对皮芯结构微纳米纤维复合纱线结构与性能的影响,利用双针头水浴静电纺丝法连续制备了以聚对苯二甲酸乙二醇酯(PET)长丝为芯、外包聚酰胺6(PA6)的皮芯结构微纳米纤维复合纱线,通过扫描电子显微镜、差示扫描量热仪和万能材料试验机对其形貌结构、热性能和力学性能等进行测试与表征。结果表明：不同PA6纺丝液质量分数制备的微纳米纤维复合纱线均具有良好的皮芯结构;当PA6纺丝液质量分数从10%提高到20%时,纳米纤维复合纱线的平均直径从(61.99±13.08) nm增加到(150.22±21.53) nm,结晶度由16.28%提高至20.63%;当PA6纺丝液质量分数为20%时复合纱线的结晶度达到了常规PA6纤维的结晶范围,增加纺丝液质量分数一定程度上可提高复合纱线的力学性能。     

环锭纺和紧密纺纱线的比较研究

比较研究了以棉、聚酯纤维为原料、在不同的紧密纺系统上纺制的相应的 环锭纺和紧密纺纱线.结果表明紧密纺纱线与环锭纺纱线相比,弹性、拉伸性、耐磨性、刚度和紧密度较高,毛羽、条干不匀率和疵点较少,纱线直径较小.而且,紧密纺的弹性恢复参数比环锭纺要好得多.从改变比例的方面来说,RoCoS系统纺出来的纱线与Zinser和Suessen紧密纺系统纺出来的纱线相比较时,表现出弹性、直径和紧密度的改变量小,但是拉伸性变化大.     

复合纱体中长丝分布形态对纱线性能的影响

为研究长丝复合纺纱过程中由长丝与短纤维须条复合产生的不同纱线内部结构对纱线性能的影响,设计并建立了6种长丝复合纺纱线结构模型,分析和预测了模型对应的成纱性能,并进行实验验证,对比分析了各复合纺纱形式所得纱线的毛羽、条干、强伸性能。结果表明：相比单独的包芯结构和长丝单侧包缠结构,长丝由两侧对须条进行包缠优化了纱线结构,表现出更佳的复合纱拉伸和成纱条干性能;同时拥有长丝双侧包缠和包芯结构的复合纱,表现出最优的成纱强力和条干;较大的长丝与须条隔距与张力更有利于长丝束缚和控制纤维外露,有效降低成纱毛羽。     

Wicking and drying properties of conventional ring- and vortex-spun cotton yarns and fabrics

This study investigated the vertical wicking, water absorption and drying properties of vortex- and ring-spun combed cotton yarns and knitted fabrics comparatively. The yarns were produced in three different counts as 30 Ne, 40 Ne and 50 Ne. The experimental results revealed that vortex-spun yarns had lower yarn and fabric wicking and water absorption values than ring-spun yarns. In addition, it was observed that yarn type did not have a significant impact on the drying time of the fabrics.     

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。     

环锭纺纱和紧密纺纱罗纹针织物性能及其他物理性能

所有数据显示紧密纺纱织物的性能及其他物理参数优于精梳纱织物。相对于传统的环锭纺,紧密纺纱的毛羽指数低、强度高、条干均匀。紧密纺和环锭纺纱线结构上的差异明显地影响其织物性能、因此,尽管所有其他织物参数都相同,紧密纺纱生产的针织物相对于环锭纺纱针织物还是有着较短的线圈长度、较高的面密度、断裂强度、断裂伸长、顸破强力,以及更少的起毛起球。紧密纺纱线生产的针织物仅耐磨性稍差于环锭纺纱针织物．     

Analysis of spinning process using the Taguchi method. Part IV: Effect of spinning process variables on tensile properties of ring,rotor and air-jet yarns

Abstract

The yarn samples prepared for migration study were tested for tensile properties. Furthermore, the effect of drafts of the spinning machines on yarn strength and breaking elongation (%) was studied. The effect of spinning position, doff position and material conditioning during testing on yarn tensile properties were also accounted for. The ring yarn was seen to have the highest tensile properties, whereas air-jet yarns the lowest. The low elastic recovery of viscose fibres is the cause of weakest and least extensible air-jet yarns.     

Application of an Automatic Yarn Dismantler to Track Changes in Cotton Fiber Properties During Processing on a Miniature Spinning Line

This paper reports on the application of a newly developed automatic yarn dismantler for dismantling short staple ring-spun yarns, to track changes in cotton fiber properties from lint to yarn, during processing on a miniature spinning line. The results obtained on different Upland cottons have clearly demonstrated the practical value of the yarn dismantler in enabling yarns to be automatically dismantled into their constituent fibers. Based upon Advanced Fiber Information System (AFIS) fiber tests, miniature opening and cleaning, on a Shirley Analyzer, increased fiber neps and short fiber content and decreased fiber length, whereas the miniature card did not have a consistent effect on mean fiber length, but decreased neps substantially. The first miniature drawframe passage resulted in a significant increase in mean fiber length, fiber linear density, and maturity ratio and a decrease in short fiber content, immature fiber content, and neps. The mean length of fibers from the dismantled yarn tended to be slightly longer than that of the fibers just prior to the miniature spinning frame, while the immature fiber content tended to be slightly lower and the maturity ratio slightly higher.     

Torsional properties of staple fibre plied yarns

A mathematical analysis of the mechanical governing equations applying to the torsional behaviour of multi-ply yarns under tension has been carried out. This analysis clearly shows that there are two components, a geometric component that determines the slope or gradient of the torque due to tension and a component that determines the yarn torque at zero applied tension (intrinsic torque) that depends on the fibre number, fibre moduli and diameter as well as the strand structural geometry. The effect of the ratio of the ply twist to the spinning twist on the two components of yarn torque has been numerically analysed for two-, three- and four-ply yarns prepared from singles 31 yarns spun with different spinning twists and for two different fibre diameters. Other comparisons are made for two-ply yarns prepared from 40 and 80 tex singles yarn. The model allows the effects of the various yarn and fibre parameters to be assessed and compared with experimental data. Experimental torque data for a range of two-ply yarns plied at different percentages of the singles spinning twist and also with different yarn histories and test environments are consistent with the trends identified by the model.     

静电纺纳米纤维纱线研究进展

为拓展静电纺纳米纤维的应用领域,提高静电纺纳米纤维的力学性能,对国内外近期静电纺纳米纤维纱线的研究进展进行了综述。按照加捻方式的不同,将纤维加捻方法分为流场加捻、电场加捻和机械加捻,详细介绍了几种加捻方法,并对这些方法制备的纱线的性能参数以及方法的优劣进行了对比;讨论了静电纺丝工艺参数对纱线力学性能的影响,并介绍了几种提高纳米纤维纱线力学性能的方法;对静电纺纳米纤维纱线在智能化织物、生物工程以及电子器件领域的应用进行了总结;最后针对静电纺纳米纤维纱线中存在的问题以及未来的发展趋势进行了分析。     

亚麻长麻/涤纶长丝复合纱的纺制及其性能比较

为比较不同复合加工方法所纺亚麻长麻/涤纶长丝复合纱的性能,通过现有纺纱设备改造设计了纺纱工艺,纺制了具有相同捻度的5种复合纱;对复合纱的外观特征、拉伸性能和毛羽进行了测试与分析。结果表明:采用不同成纱方法的复合纱均具有明显的捻度分布不匀特征;包缠结构复合纱相对于捻合结构复合纱具有更好的包覆效果;相对于断裂强力而言,复合加工对亚麻纱最小强力的提高效果更好,并可显著降低强力不匀率;除同捻向包缠纱外,各复合纱均可实现免浆织造;赛络菲尔纺和并捻复合对提高成纱断裂伸长率效果显著,而包缠复合降低亚麻纱毛羽的效果最好。     

转杯纺纱法加工Lyocell针织纱

Lyocell纤维具有优良的物理机械性能,其针织面料在手感和外观等方面的多功能性使其开发应用前景非常广阔。由于转杯纱自身的特点,其针织品品质优越。采用转杯纺纱技术加工28 tex的Lyocell针织纱,探讨前纺工艺及技术措施;通过对各方案试纺对比,研究转杯纺主要工艺参数与成纱质量的关系,为合理选择工艺参数,提高Lyocell转杯纺针织纱的成纱质量提供参考。