超喂率对空气变形纱的成纱结构、性能及其织物的影响

超喂率是影响空气变形纱(以下简称空变纱)及其织物结构性能的一个重要参数。本文就超喂率对空变纱的形态结构、光泽、强伸度、摩擦等性能以及对空变纱织物性能的影响进行了较全面的实验研究,给出了实测数据,并通过分析而引出了重要结论。     

Study on the Bending Properties of Woven Fabrics and Its Yarns

A theoretical analysis on the two extreme cases of yarn bending rigidity as well as the relationship between them is proposed. The significant influence of fiber-to-fiber interaction on yarn bending rigidity is revealed. Experimental observation on the relationship between fabric/yarn bending property and fiber fineness, yam structure, fabric structure is given as well. Three problems are discussed and the following conclusion is thus obtained. There exists, similar to a rigid engineering rod, a linear relationship between yarn bending rigidity and the square of yarn fineness (expressed as yarn count in tex), but the increasing speed is much lower. Yarn bending rigidity in the fabric also to a great extent depends on the fabric density and yam twist factor, and so on. Fabric's bending hysteresis primarily depends on its bending rigidity.     

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.     

Influence of Wires Properties on Warp-Knitted Loop Geometry in Plane Based on Theory of Elastic Rod

Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.     

管道纺包芯纱的研究

本文研究了在管道纺纱机上不添加构件而进行包芯纱的纺制。分析了其包芯纱的成纱机理。观察了实际成纱的横截面,证实了棉纤维能够均匀地、完全地包覆在芯丝的周围。也对不同性质的芯丝所纺包芯纱的结构作了观察,并对不同成纱的性质随速度增加而变化的规律作了研究。     

喷气变形纱单丝轨迹及转移机理

喷气变形是一项新型成纱技术。碍于喷嘴精小而复杂,喷嘴中紊流及单丝的运动还不甚清楚,这给喷气变形纱成纱机理的分析研究带来一定困难。作者采用有色单丝立体示踪和显微测试等手段,对喷气变形纱中单丝的运动和转移进行探讨,大量观察了单丝在喷气变形纱中的各种形态,并找到了单丝轨迹的一般规律。这对于喷气变形纱成纱机理的分析推测,对于喷气变形纱拉伸断裂机理的研究等,提供具有一定价值的参考和依据。     

赛络纺技术纺毛氨包芯纱初探

将赛络纺新技术应用于毛氨包芯纱的纺制,并对纱的结构及性能进行测试。通过实验表明,赛络纺技术在纺弹力纱上具有明显的优势,产品的综合性能指标均优于传统的环锭纺弹力纱。     

TENSILE BEHAVIOUR OF ROTOR SPUN YARNS

This paper deals with the tensile behaviour of rotor spun yarns. Having regard to the spe-cial construction of rotor spun yarn, some modifications for Hearle's theory have been made inorder to apply Hearle' s theory to rotor spun yarn. The paper then goes into calculating thetensile curve and investigating the effect of main parameters and spinning conditions on thetensile behaviour of rotor spun yarn. It was found that the following facts are noteworthy forimproving the mechanical properties of rotor spun yarn: (1) Selecting suitable navel so as tocontrol the P. T. E. length within a reasonable range. (2) Improving the design of single fibresupply device to decrease the amount of spoiled fibre and hence increase the effective fibrelength. (3) Increasing spinning yarn tension without yarn break to enhance the fibre migrationratio. (4) For the rotor spun yarn of industrial use, it is the way to increase the yarn strengththat the rotor groove should be designed with the groove angle beneficial to decrease the yarnspecific volume.     

管道纺成纱结构的研究

本文对管道纺纱的加捻过程作了分析,得出成纱的外层纤维捻度较大和内层纤维捻度较小的结论。然后,通过受力分析,从理论上加以证实,并采用电子显微镜等实验手段,对管道纺和摩擦纺两种成纱实物的外部结构和内部结构作了同样的观察和计算,从实验方面也证实了管道纺成纱结构是内松外紧,与摩擦纺成纱结构内紧外松正好相反,有利于提高成纱强力。     

玻璃纤维/聚丙烯长丝喷气混纤纱力学性能研究

利用电镜观察玻璃纤维／聚丙烯长丝喷气混纤纱的结构，并通过对单纱热压，分析纱结中玻璃纤维的状态；在DCS500岛津试验机上测试了喷气混纤纱的性能。通过研究得到：喷气混纤纱的拉什强度和模量、纱线断裂伸长率受玻璃纤维／聚丙烯丝的混合程度、玻璃纤维在纱线中的状态、纱干表面聚丙烯纤维丝圈状态影响。     

玻璃纤维长丝纱机械性能的研究

本文对玻璃纤维长丝纱的机械性能做了较全面的讨论。文中着重探讨了玻璃纤维长丝纱在静负荷作用下的松驰性能以及反复循环负荷作用下的疲劳性能,同时设计了测定玻璃纤维长丝纱弯曲性能的试验方法——套环法,并提出了相应的指标——抗弯系数W。试验结果表明,玻璃纤维长丝纱有较明显的应力松驰现象,反复循环负荷作用对玻璃纤维长丝纱的强伸性能有较大的影响。     

高层筒中筒结构的整体稳定分析

将筒中筒结构的外框筒视为具有弯曲变形和剪切变形，并受剪力滞后影响的等效实腹筒体，视内筒只受弯曲变形。根据内外筒的变形协调条件，建立了整体结构稳定微分方程，用Ｇａｌｅｒｋｉｎ法求解方程并获得了整体结构的最小临界荷载。     

巨型钢框架结构动力分析的简化计算模型探讨

为了减小动力分析时结构的自由度数量,本文对常用的某结构形式的巨型钢框架结构体系,首先推导巨型构件的等效抗弯刚度和等效剪切刚度而得到其等效模型,并通过自振特性分析和地震作用时程分析,对等效模型和精确杆件模型的计算结果进行分析和比较.计算结果表明,等效模型具有较好的计算精度,可满足工程实际初步设计的要求.     

RELATION BETWEEN STRUCTURE OF PP DRAWN FILAMENT AND TEXTURING EFFECT

The relationship between the structure of PP drawn filament and the crimp elasticity of tex-tured yarn is investigated.It is found that orientation,crystallinity,and especially,crystalline formof drawn filament are related to crimp property of textured yarn.Lower crystallinity,moderateorientation and unstable para-crystalline structure are necessary for increasing crimp elasticity.Inaddition,the filament structure and properties before and after texturing are compared.     

未起绒1:3衬垫针织物的线圈几何结构性能

本文的目的主要是讨论未起绒1∶3衬垫针织物的线圈几何结构性能。文中先提出了一个把机号、纱支、地纱和衬垫线线圈长度、以及它们之间的比值等因素进行综合考虑的实验计划,然后分析讨论这些因素在洗涤松弛状态下对织物纵横向密度以及平方米克重的影响;同时还对这种组织结构进行了一定的理论分析,以便得到更精确的计算公式。实验结果和理论分析表明,地纱线圈长度是影响织物线圈几何尺寸的主要因素,这对实际生产有一定的指导意义。     

层状岩体抗弯刚度及其软弱夹层效应

本文应用梁的弯曲理论,在对层状岩体特性较全面认识的基础上,给出了层状岩体抗弯刚度的一般计算公式.通过实例计算发现,层状岩体抗弯刚度不仅与各层岩石的力学参数有关,而且与各层的组合方式有关.此外,顺层软弱夹层对层状岩体抗弯刚度的降低尤为显著,应予充分考虑.本文的分析计算为层状岩体顺倾边坡弯曲剪切机制及陡倾边坡倾倒机制研究,以及它们的稳定性评价建立了基础.     

转杯纱缠绕纤维对成纱强力的影响

本文提出用缠绕纤维角度分布、松紧度、稀密度、重量百分率等,作为缠绕纤维结构模式的特征量;并通过对不同工艺参数生产的转杯纱,进行缠绕纤维和成纱强力的测试与分析。最后得出不同工艺参数与缠绕纤维结构模式特征量的关系,及其对成纱强力的影响具有明显的规律性。     

REPORT ON A PROJECT AIMED AT INCREASING THE STRENGTH OF FRICTION SPUN YARN BY USING A FALSE TWIST PROCESS

The lower strength of friction spun yarns has became a key problem that hinder the develop-ment of friction spinning,especially in high speeds and fine yarns.In this paper a project aimed atincreasing the strength of friction spun yarns by using a false twist process has been made.In re-ported experiment false twist was inserted into the yarn which has been formed on a friction spin-ning machine,so that it made the yarn untwist at first,then regain the twist.In the meantime draftwas applied to generate more tension than that which had been experienced during yarn formationon the friction spinning machine.It made the yarn reforming and the loosely bound fibres in thefriction spun yarn formed due to extremely low tension on the friction spinning machine becametighter.Results indicate that with the proper draft,tension and false twist the tenacity of processedyarn will increase more than 10%.This project is an attempt to discover whether improvements can be made and whether it isworth pursuing research into modifications of yarn structure.The results imply that if the yarntension can be raised during yarn formation on the friction spinning machine or a chance is offeredto the yarn to reform after the yarn formation the yarn tenacity will be increased obviously.     

聚丙烯拉伸丝结构和加弹丝变形效果的关系

本文研究了聚丙烯拉伸丝结构与高弹丝卷曲弹性的关系,发现拉伸丝的取向、结晶度以及结晶型式均与高弹丝的卷曲性能有关,其中尤以晶型更为重要。较低的结晶度、适中的取向和不稳定的酝晶结构是提高卷曲弹性的必要条件。同时,还对加弹前后的纤维结构和性能作了分析比较。