赛络菲尔包缠纱结构建模分析与性能优化

为定量预测实际生产中赛络菲尔(Sirofil)包缠纱的性能,分析了其成纱加捻过程和特点。根据加捻三角区中的几何关系,推导出三角区纱线质心相对锭子偏移距离与纱线捻回角的关系,并得出半个捻回纱线质量的计算公式;对加捻三角区进行受力分析得到力矩平衡方程,解释了Z捻纱捻度由下向上的传递规律,分析了长丝与短纤须条的相对位置对Sirofil包缠纱强力的影响;最后对模型求解并进行实验验证。模型计算和实验结果表明：隔距变大纱线质心偏移距离变大,须条捻回角减小;汇聚点之上单纱捻向与汇聚点之下传递捻向相同,且短纤须条位于长丝左侧时所加的捻度较之在右侧时多。该模型和实验为Sirofil包缠纱性能和结构的分析提供了参考。     

加捻对转杯纺复合纱结构性能的影响

在2种长丝超喂率下,通过调整复合纱的捻系数使棉纤维和涤纶长丝复合以纺制不同类型的转杯纺复合纱。测量了纱线张力并研究了加捻对转杯纺复合纱结构和性能的影响。结果表明,复合纱捻系数在2种长丝超喂率下对复合纱的结构和性能都有显著的影响;涤纶长丝在复合纱中是以螺旋线形式与棉纤维纱条加捻复合,当长丝张力随着复合纱捻系数的增加和长丝超喂率的减小而增加时,长丝趋向于复合纱内层,复合纱的主要性能也会随之发生变化;与常规转杯纺纱线相比,复合纱表面较光洁,结构较紧密,主要性能得到了改善。     

Impact of high-speed draw frame and its preparatory on packing and related characteristics of ring spun yarn

Impact of draw frame delivery speed, coiler diameter of carding machine and card draft on packing density of yarn and related characteristics of ring spun yarn have been found to be very significant. With the increase in draw frame speed and coiler diameter of card, there is a decrease in helix twist, helix angle, helix diameter with the consequent increase in yarn packing density. However, with the increase in card draft, both helix twist and helix angle increase up to a certain level, whereas helix diameter increases steadily; the yarn packing density shows a decreasing trend. Yarn packing density is always higher at the middle position of the fibre than at the position of trailing or leading hooks. However, coefficient of variation (CV%) of yarn packing density at the centre position of fibre is the lowest followed by leading position and trailing position of the fibre.     

绢丝/锦纶长丝sirofil复合纱成纱性能

 以锦纶低弹丝和绢粗纱为原料,纺制不同捻度、不同喂入间距的绢丝/锦纶长丝sirofil复合纱,测试了复合纱的强伸性能、条干不匀和毛羽。通过对实验结果进行方差分析发现,在实验范围内,复合纱成纱强度和断裂伸长率均随纺纱捻度的增加而增加,但纺纱两组分喂入间距对其影响不大;成纱捻度和两组分喂入间距对成纱的条干不匀CV值影响不显著;复合纱的毛羽指数随成纱捻度及两组分在前罗拉处喂入间距的增加均呈现下降趋势。由此得到实验范围内绢丝/锦纶长丝sirofil复合纱的优化纺纱工艺参数:捻度850捻/m,前罗拉喂入间距18 mm。     

空心锭包覆纺纱的芯纱残留捻回及其应用

为探讨空心锭包覆纺纱过程中外包缠纱对芯纱的假捻作用与应用,以黑、白两色涤纶长丝纱组成双芯纱,黑色涤纶长丝纱为外包缠纱,纺制了不同纺纱工艺的包覆纱,分析了芯纱残留捻回的捻向和捻度特征以及锭速、引纱速度、芯纱张力对芯纱残留捻度的影响;对利用芯纱残留捻度纺制段彩纱的原理与段彩特征进行了探讨,并给出了应用实例。结果表明:外包缠纱对芯纱缠绕的假捻作用,会使芯纱上形成残留捻向变化、捻度不等的捻回分布;残留捻回的捻度随锭速的增大、引纱速度的降低、芯纱张力的减小而增大;利用芯纱残留捻回的片段呈色效应,可用异色芯纱纺制具有段彩外观的“纱/纱”复合段彩纱,这种段彩纱具有区别于常规段彩纱的“闪色”特征。     

加捻对不同涤纶长丝芯吸性能的影响

以毛细效应和湿蒸发原理为基础 ,对不同截面形状和加工方式的涤纶长丝在不同捻度条件下芯吸高度的变化规律进行了实验研究。结果表明 :特殊异形截面涤纶长丝较圆形截面的芯吸效果好 ,加弹丝的芯吸效果好于平牵丝 ,捻度对长丝芯吸性能的影响呈Lorentzian曲线变化规律     

并捻工艺对Coolmax复合纱性能的影响研究

研究了并捻张力、并捻捻度对Coolmax／棉并捻复合纱强伸性能、毛细芯吸效应的影响，试验结果表明Coolmax长丝与棉纱不同并捻张力搭配对复合纱强伸性能有显著影响，复合纱断裂强度、毛细管芯吸高度都有临界捻度。优选出DTY8.33tex／34f Coolmax长丝与JC9．7tex棉纱并捻复合纱线的并捻工艺为：Coolmax长丝并捻张力10eN，棉纱并捻张力20eN，S向并捻，复合纱线捻度为60捻／10cm。     

亚麻/莫代尔/棉/锦纶长丝嵌入式复合纱的纺制

选用亚麻、莫代尔、棉、锦纶为原料,在经改造后细纱机上保持其他纺纱工艺不变情况下,分别选取适当的长丝间距、长丝张力和捻系数进行纺纱,然后对所纺纱线的实际断裂强力、毛羽指数和条干均匀度3项指标进行测试与对比分析。结果表明长丝间距、长丝张力、细纱捻系数对纱线断裂强力、断裂功、纱线毛羽和条干均匀度有较大的影响,纺14.5tex的亚麻/莫代尔/棉/锦纶长丝嵌入式复合纱的最佳工艺参数为长丝间距10mm,长丝张力10cN,捻系数490。     

Yarn twist measurement using digital imaging

Digital image analysis techniques in the spatial and frequency domains for twist measurement of yarns are described. A spatial technique is developed to extract the twist angle through the analysis of the yarn core image. Then, a Fourier transformation technique is applied to yarn images to measure the orientation of the fibre on the yarn surface. Finally, a hybrid method that incorporates frequency domain filtering prior to spatial analysis is proposed. The trials show that spatial analysis is a fast method and can successfully predict the twist in the yarn. Fourier transformation technique is quite sensitive to the protruding fibres obstructing the yarn surface, which may result in measurements having high variations. For yarns having little amount of hairs protruding from the core, the results agreed reasonably well with actual twist levels. Frequency domain filtering in conjunction with the spatial analysis of the yarn surface is found to be superior in terms of accuracy. The twist values calculated using the more reliable diameter measurements with back-lit images together with twist angles from the front-lit images are found to be more accurate when compared with the actual values.     

A Study on Wicking in Natural Staple Yarns

In this study, natural staple yarns of cotton and wool were investigated for wicking properties. Fibre packing density reflected by yarn wicking rates was measured in ply cotton yarns. It was seen that with the samples measured in this work, both twist level and number of ply in a yarn can affect yarn wicking behavior. When twist and yarn count remained unchanged, wool yarns with different fibre diameters were measured for wicking rates and the best wicking was found on the yarn with the coarsest fibre diameter. Comparison was made in this work on the treatment methods, and on both synthetic continuous filament yarns and the natural staple yarns. While prewash treatment could improve yarn wicking by changing fibre surface condition, plasma treatment was a more effective way in increasing yarn wicking rate for both filament yarns and staple yarns.     

加捻方向对双股线性能的影响

加捻是制备短纤纱、股线及绳索的必备工序。加捻对纱线有两方面作用,一是通过加捻增加纤维间的抱合力,从而赋予纱线足够的强度。二是加捻增加了纤维间的螺旋角并使纤维集聚在一起,从而增加纱线的强度。采用意大利Savio公司的Sirius倍捻机制备不同捻向的双股线试样。尝试验证不仅捻度对纱线性能有重要的影响,而且纱线捻向也有很大的影响。测试结果表明,捻向与单纱捻向相同的双股线(单向捻合双股线)具有更好的断裂强力、断裂伸长率、摩擦因数与耐磨性。研究还给出了捻向对双股线及由双股线制成的织物拉伸性能的影响。     

聚丙烯长丝/芳纶包缠纱捻度的优化

利用平行纺纱技术,通过合理配置ON-SC1000型花式捻线机的空心锭转速及卷绕速度,成功研制出5中不同捻度的聚丙烯长丝/芳纶包缠纱。选取了影响包缠纱综合性能的7项指标进行测试,包括其断裂伸长CV值、断裂强力CV 值、粗节、纱结、细节、条干均匀度、耐磨性,将它们依次定义为X1、X2、X3、X4、X5、X6、X7。采用主成份分析法,对包缠纱综合性能进行分析,计算得出五种捻度的包缠纱综合得分依次为0.067、-0.818、-0.751、-1.019、1.476。结果表明：五种纱线的捻度由优到劣依次为320T/m、250T/m、300T/m、200T/m、350T/m;在250-320T/m的范围内,纱线外观优良,有利于充分发挥两种长丝的优良特性。为正确设计聚丙烯长丝/芳纶包缠纱的捻度提供了很好的指导作用。     

S捻向棉纱生产实践

棉纱常用Z捻以利于纱线断头时工人的接头操作,用S捻单纱配右斜纹组织可达到模拟股线产品的效果,且生产成本可以降低很多。在S捻棉纱整经和浆纱生产过程中更容易出现捻缩,通过降低S捻纱的捻系数可减少捻缩现象,纱线强度没有下降。     

正反捻双股线结构及其拉伸性能的研究

探讨正反捻双股线结构及拉伸性能。分别使用棉纱和涤纶长丝制成正反捻双股线并对其进行加捻、结构扫描和拉伸试验。结果表明:随着捻度的增加,纱线中的一股因同向加捻而收缩成为芯纱(丝),另一股因退捻而伸长成为包缠纱(丝),其捻缩率主要取决于芯纱(丝)的捻缩率,包缠纱(丝)对芯纱(丝)的包缠角取决于两根纱(丝)的捻缩率差异;正反捻双股线的强力低于同号的普通双股线,存在两个临界捻系数峰值;其拉伸断裂曲线在捻系数较小时会出现双峰现象,当捻系数足够大时,则呈现单峰状态。认为该研究结论可为花式纱线和复合纱线的生产与研究提供一定的实践与理论支撑。     

双股线几何强力模型的建立与其影响因素

 股线的强力增强效应一直都还停留在定性描述上,作为组成纱线强力的两大因素,纤维性能和纱线结构对强力的贡献情况尚不明朗。为了量化这两部分,从建立双股线模型的几何配置出发,分析了单纱短片段在拉伸载荷下轴向和径向的力学状态对拉伸行为的影响,体现在拉伸模量与单纱性能参数和捻回角的关系;并且考虑了单纱之间的抱合力作为组成股线强力的一部分,推导了单纱在无滑移情况下的股线强力表达式,并定量分析讨论了单纱性能参数与纺纱参数对股线最大强力的影响情况,其结果符合一般认识,可用于开发纱线新产品的强力预测。     

The effect of yarn twist direction on the formability of woven fabrics

This experimental work examines the influence of the yarn twist on the formability of a woven fabric. Consideration is given to the phenomenon of bedding between warp and weft yarns, as affected by the local helix angles of bent yarns. A total of 28 plain weave woven fabrics (four groups, each with seven samples) were produced, using Solospun? yarns as warp and weft threads. The fabric bending length and the initial modulus of each sample were measured from which the formability was calculated. Results indicated that the fabrics in which the warp and weft twists are unidirectional (Z &; Z) have higher formability in comparison to those fabrics in which the warp and weft twists are opposite to each other (Z &; S). In addition, among the former fabrics the highest formability belongs to those in which the total helix angle of the warp and weft is close to 90 degree whereas the lowest formability belongs to the latter fabrics with least amount of twist.     

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。     

Development of mathematical model to predict vertical wicking behaviour. Part I: flow through yarn

Theoretical models have been proposed in this article (Parts I and II) to predict the vertical wicking behaviour of yarns and fabrics based on different fibre, yarn and fabric parameters. The first part of this article deals with the modelling of flow through yarn during vertical wicking, whereas the second part deals with the modelling of vertical wicking through the fabric. The yarn model has been developed based on the Laplace equation and the Hagen–Poiseuille’s equation on fluid flow; pore geometry has been determined as per the yarn structure. Factors such as fibre contact angle, number of filaments in a yarn, fibre denier, fibre cross‐sectional shape, yarn denier and twist level in the yarn have been taken into account for development of the model. Lambertw, a mathematical function, has been incorporated, which helps to predict vertical wicking height at any given time, considering the gravitational effects. Experimental verification of the model has been carried out using polyester yarns. The model was found to predict the wicking height with time through the yarns with reasonable accuracy. Based on the proposed yarn model, a mathematical model has been developed to predict the vertical wicking through plain woven fabric in the second part of this article.     

含PET/PTT聚酯弹性长丝的毛织物弹性控制因素

研究了在织物紧度相同的情况下,纱线捻度、纤维细度、织造方式、染整方式等因素对含PET/PTT聚酯弹性纤维的毛混纺织物弹性的影响.过大的长丝捻度会降低织物的变形和弹性回复性能;长丝细度增加,使得织物在小外力下不容易变形,回复性能较好.将长丝和毛涤纱并线作为纬纱和将1根长丝、1根毛涤纱间隔作为纬纱的方式织造,织物弹性变形能力没有差异.经过拉幅定形的织物弹性变形能力小于经过松弛定形处理的织物.原色着色丝和白丝均能很好的实现织物弹性,但染色丝织物的变形能力要好于原液丝和白丝织物.     

环锭纺竹节纱捻度分布及其对强力的影响

根据环锭纺竹节纱在加捻过程中的扭应力分布状况,采用杆件扭转模型,建立了竹节纱加捻扭转的数学模型。借助这一模型分析了竹节纱的4个参数(基纱直径、竹节直径、竹节间隔以及竹节长度)对捻度分布的影响。分析表明,竹节部分的捻度总小于设计捻度,主要受竹节直径与基纱直径比值的影响,比值越大,减少越明显;基纱部分的捻度总大于设计捻度,主要受竹节长度与竹节间隔比值的影响,比值越大,增加越明显。在捻度分布研究的基础上,分析了竹节纱捻度分布对强力的影响,并进行了实验验证。一般情况下,竹节部分的捻度下降对强力的影响不及竹节部分纱线截面内纤维根数增多的影响,因而竹节部分的纱线强力高于基纱部分的强力,竹节纱强力的大小与捻度和基纱捻度相同的普通纱强力极为接近。