The Effect of Strain Rate on Tensile Properties of Cotton Yarns

The effect of strain rate on tensile properties of cotton yarns is analyzed using the standard linear solid model. The tensile curve, breaking strength and work of rupture of the yarns under different strain rate are calculated. A good correlation exists between the experiment results and theoretical anticipations.     

织造前后浆纱物理机械性能变化的研究

研究织造前后浆纱物理机械性能的变化，有助于分析浆纱各种物理机械性能指标对浆纱可织性的影响及探讨经纱的断裂机理。测试了在织机上沿其横向分段获取的织造前浆纱试样和织造后浆纱试样的物理机械性能。分析表明，从织物中获取的“布纱”不能正确反映织造后浆纱的物理机械性能的衰减程度，应选用从前梭口荻取的“织纱”作为织造后的浆纱试样；织纱断裂强力降低率和断裂伸长率降低率为10％左右，耐磨次数降低率小于40％；浆纱断裂强力与断裂伸长率服从正态分布，而耐磨次数服从对数正态分布。     

The Effect of Gauge Length on Tenacity of Cotton Yarns

The tensile properties of cotton yarns are studied. A lot of data are gotten and analyzed. It indicates that the breaking strength of the yarns follows Weibull distribution. Then the effect of sample length on strength is analyzed using Weibull's statistics. The Weibull parameters are calculated through regression method. The breaking strength of the yarn at different sample length is predicted. Theoretical prediction conforms the experimental results very well.     

热处理对Tencel纱线强伸性能的影响

纱线的强伸性能极大地影响着它的加工性能和产品的穿着性能，这里测试分析了Tencel、粘胶纱线经不同条件的热处理后其断裂伸长率、断裂强度、弹性模量、断裂比功的变化，通过测试发现不同条件热处理后Tencel纱线的各强伸性能指标均比粘胶纱线的高。     

Mechanical Behavior of Soybean Protein Fibers

In order to understand the relationship between the mechanical property and the effect of bleaching and dyeing to the soybean protein fibers(SPF), four mechanical models are chosen. The tensile and relaxation property of the soybean protein fibers are analyzed. The tensile and relaxation curves are fitted with the suitable model. It shows that the relaxation property of SPF is in accordance with the standard linear solid model. Estimates of the Hookean spring modulus at 8% and at 10% are different, so some structural modifications could be produced by the strain. Bleached fibers show a higher level of relaxation than raw fibers and dyed fibers. Bleaching has a remarkable influence on decreasing tenacity at break for each test modality. Knotted and looped modalities decrease fiber tenacity remarkably in all three samples.     

实验方法研究纱线可织性

主要讨论影响经纱可织性的因素以及研究经纱可织性的实验方法。原纱质量、经纱准备、织造条件是影响经纱可织性的重要因素。经纱的可织性可通过改变纺纱参数、纺纱技术来提高，但对经纱可织性有决定性的是织前准备。通过织前准备，特别是浆纱工序可充分地提高可织性。分析表明给定浆纱的可织性可通过浆纱强伸性、浆纱耐磨性、织造模拟后浆纱毛羽变化、织造模拟后浆纱缠结分离力等指标来预测。     

织造和染整加工前后精梳毛纱拉伸性能的关系

为了根据织造前纱线的拉伸性能和织造、后整理工艺预测织物的拉伸性能,研究了织造和染整加工前后精梳毛纱拉伸性能的关系,获得了三方面的结论:(1)经常规后整理加工的各种精梳毛织物中经纱的伸长变形能力没有显著差异,但其纬纱的伸长变形能力与织造和染整工艺有关。(2)坯布染色情况下织造前纱线的伸长变形曲线在伸长率方向扩大一定倍数以后与织物中纱线的伸长变形曲线相当。纱线染色情况下织造前纱线的伸长变形曲线的某一部分与织物中纱线的伸长变形曲线相当。(3)后整理加工中的经向张力和拉幅张力对精梳毛织物中纱线的伸长变形能力的影响特别大。树脂整理有降低织物变形特别是变形回复能力的作用。     

Predicting the Tensile Curve of Polyester Twisted Ply Yarn under Large Deformation

Considering the changes of ply yarn 's structure parameters during the axial extension,a new model has been proposed for predicting the tensile curve of polyester twisted ply yarn under large deformation without the tensile strength tests.The relationships between the structural parameters and tensile properties under large deformation were considered.The feasibility and accuracy of the model were studied by comparing the predictive results and the experimental ones.The structural parameters in the model were acquired under every strain before rupture.The radial dimension and twist angle of the yarn were obtained by an observation platform and image processing technique.The true modulus of the yarn was obtained indirectly from the tensile data of the single yarn and the mathematical equations.The tensile curves of the yarns at different twist levels for predicting were plotted.The results demonstrated that the predicted curve tendency and the values were quite close to the experimental ones.The model exhibited a good applicability to predict the tensile curves for low and medium twist yarns.     

大豆油丙烯酸酯改性双酚A型环氧树脂的研究

以丙烯酸和环氧大豆油（ESO）为原料合成了大豆油丙烯酸酯(AESO).通过红外光谱、示差扫描量热法、热重分析、力学性能测试及硬度测试,研究三乙烯四胺作为固化剂时大豆油丙烯酸酯改性双酚A环氧树脂（DGEBA）的热学性能、力学性能以及硬度. 结果表明:三乙烯四胺固化大豆油丙烯酸酯的焓变（?H =28.63 J/g）远小于三乙烯四胺固化双酚A环氧树脂的焓变（?H=428.25 J/g）;随着混合体系中大豆油丙烯酸酯质量分数的增加,焓变、玻璃化转变温度(Tg)、拉伸强度、拉伸模量以及硬度都会减小,峰值固化温度（Tp）、冲击强度、断裂伸长率会逐渐增加,改性的双酚A型环氧树脂逐渐变为韧性断裂,证明大豆油丙烯酸酯对双酚A环氧树脂有优良的增韧作用.     

转杯纺复合纱的结构与性能

在经过改装的转杯纺纱机上，通过调整涤纶长丝的超喂率生产不同结构和性能的转杯纺复合纱。长丝超喂率对复合纱的外观、结构和性能均有较显著的影响。当长丝张力随长丝超喂率减小而增加时，长丝从复合纱表面逐渐趋向于分布在纱线内层。复合纱的拉伸性质、条干、毛羽等性能与长丝超喂率有密切联系。与纯棉转杯纱相比，复合纱的外观和性能均有较大程度的改善。     

纤维弱节的力学特征与判定

纤维弱节是造成纤维力学性能退化和纤维品质下降的主要原因。这里采用单纤维拉伸和形态轮廓观察结合的方法，对羊电纤维弱节的力学行为进行表征。提出了用纤维细节处的平均断裂应力σ^-和断裂应变ε^-，作为纤维弱节的判断的依据。并对羊电的细节断裂、弱节断裂，非弱节(正常)断裂的概率作了实到和理论计算，其结果分别为印％、奶％和印％。这征明作者采用的单纤维性能分析仪(SIFAN)法和显微图像加单纤维强力仪(OM XQ)法的实用性与有效性。     

双组分纤维混纺纱强伸性能的研究

从双组分纤维纯纺纱的拉伸性能和断裂过程出发，对双组分纤维的混纺纱的断裂特性进行了分析，建立了双组分纤维混纺纱的伸长率与各组分纤维本身的拉伸性能，混纺比之间的理论关系式，并用几种双组分纤维及其混纺纱的实验拉伸结果与所推出的理论关系式做了验证对比，证明所建立的理论关系式是可靠的。该式对于预测混纺纱的拉伸性能，从而正确选择混纺纤维及其混纺比有理论指导意义。     

Prediction Method for Tensile Property of Woven Fabrics in Lower Loads

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BALANCING TORQUE OF SINGLES COTTON ROTOR YARNS

This paper reports a recent development of a yarn modification process to produce torque balanced singles spun yarns. Taking advantages of the core-sheath structure of unconventional spun yarns, we have developed a yarn modification process and applied it to singles yarns spun by rotor spinning. Torque free singles yarns have been produced from 100% cotton fibers. The spirality of resultant single jersey knit fabrics has been greatly reduced or, in some cases, completely eliminated. Properties and performance characteristics of both parent and modified yarns as well as their resultant fabrics have been evaluated including the yarn tensile properties, surface properties, handle, air permeability, burst strength, and pilling resistance of the fabrics.     

Structures and Properties of Composite Yarns of Filaments and Wool Staple Fibers

More and more composite yarns of filament and wool staple fiber have been applied to develop the new type of fabrics. However, the great difference in yarn structures between the composite yarns and conventional staple yarns does affect the properties of yarns and fabrics. In this paper, it has been studied that the differences of the composite yarn properties of tensile, bending rigidity, torsional rigidity, the hairiness and irregularity etc.     

大豆蛋白纤维膜代尔混纺针织物力学性能分析

采用多功能织物强力机等实验仪器对5种不同混纺比例的大豆蛋白纤维／莫代尔混纺针织物的性能进行了测试分析．结果表明，随着大豆蛋白纤维含量的增加，大豆蛋白纤维混纺针织物的断裂强力有增加的趋势，断裂伸长率也随之增加；大豆蛋白纤维／莫代尔混纺针织物的项破强力随大豆蛋白纤维含量的增加而下降；大豆蛋白纤维混纺针织物的撕破强力逐渐下降，尤其是在大豆蛋白纤维质量分数为100％时，织物的撕破强力最小；大豆蛋白纤维混纺针织物的纵向、横向弯曲长度逐渐下降，而其柔软性提高；大豆蛋白纤维／莫代尔混纺针织物的起毛起球性逐渐增加，织物磨损时的质量损失率逐渐增大，说明大豆蛋白纤维混纺针织物的耐磨性逐渐下降，在大豆蛋白纤维含量为100％时，即纯大豆蛋白纤维织物的耐磨性最差．     

大豆蛋白纤维/莫代尔混纺针织物力学性能分析

采用多功能织物强力机等实验仪器对5种不同混纺比例的大豆蛋白纤维/莫代尔混纺针织物的性能进行了测试分析.结果表明,随着大豆蛋白纤维含量的增加,大豆蛋白纤维混纺针织物的断裂强力有增加的趋势,断裂伸长率也随之增加;大豆蛋白纤维/莫代尔混纺针织物的顶破强力随大豆蛋白纤维含量的增加而下降;大豆蛋白纤维混纺针织物的撕破强力逐渐下降,尤其是在大豆蛋白纤维质量分数为100%时,织物的撕破强力最小;大豆蛋白纤维混纺针织物的纵向、横向弯曲长度逐渐下降,而其柔软性提高;大豆蛋白纤维/莫代尔混纺针织物的起毛起球性逐渐增加,织物磨损时的质量损失率逐渐增大,说明大豆蛋白纤维混纺针织物的耐磨性逐渐下降,在大豆蛋白纤维含量为100%时,即纯大豆蛋白纤维织物的耐磨性最差.     

单梳经平织物增强复合材料拉伸性能试验研究

在拉舍尔舌针经编机上编织了6种玻璃纤维单梳经平织物,采用手糊工艺将其与不饱和聚酯树脂复合.在万能材料试验机上测试了单梳经平织物增强复合材料试样的拉伸性能,并对其纵向、横向与斜向应力-应变曲线、弹性模量、断裂强度等进行了分析.结果表明,单梳经平织物增强复合材料的拉伸性能具有明显的正交各向异性特征;织物结构参数的变化,导致了线圈形态、延展线的长度和取向等的差异,使复合材料的拉伸性能不同.     

涤/棉混纺股线拉伸力学性能与捻度关系的研究

对13.1tex设计捻度为85.6捻/10cm的涤/棉(65/35)混纺环锭纱,用退捻、加捻的方法获得5种不同捻度的单纱.对同一捻度的单纱合股后反向加捻成不同捻度的合股线,测量了合股线的断裂强力、伸长、初始模量,发现同一单纱捻度的涤/棉股线,随着合股捻度增加,其断裂比强度出现4个极大值,且其分布有一定的规律.     

Pre-drafting Multiple of Spandex for Spandex/cotton Core-spun Yarns

The factors that influence the properties of spandex/ cotton core-spun yarns are introduced. The pre-drafting multiple of spandex is an important parameter that influences the yarn properties such as elasticity, breaking force, breaking elongation and costs. The experiment with different pre-drafting multiple is designed. The effects of pre-drafting multiple on yarn properties are evaluated by fuzzy mathematical decision. 3.3 is the optimum pre-drafting multiple for 14.6tex + 40D spandex/cotton core-spun yarns. At this multiple, the spandex content is proper and the spandex core is less prone to breakage. The cotton fibers wrap spandex more closely and transfer more frequently between inside and outside.