Fibres & Yarn Processing

Saurer GroupITMA ASIA Hall 1 Stand No. B84At the joint exhibition stand,you can have a look at all theinnovations from Allma, Barmag, Hamel, Neumag, SaurerCzech, Saurer Embroidery,Schlafhorst, Volkmann and Zinser.BarmagA focus will be Barmag's high-performance texturing machineAFK2 with automatic package transfer for highest productiv-ity and quality of the texturized yarns. The newly developedtake-up device ATT (Advanced Take-up Technology)allowsproduction speeds of more than 1,…     

Molecular Modelling of the Structure of Polyacrylonitrile Fibres

In spite of considerable effort, attempts to explain the physical structure of fibres based on atactic polyacrylonitrile have so far met only with limited success. This paper shows that molecular modelling, used in conjunction with X-ray diffraction, provides an essential additional input for explaining the nature of the ‘ordered regions’ in these fibres. It is suggested that these ordered regions, consisting of regularly assembled irregular helices, should be viewed as ‘configurationally disordered crystals’.     

The Simulation of the Geometry of a Two-component Yarn Part II: Fibre Distribution in the Yarn Cross-section

This paper considers the distribution of fibres in yarns and discusses the development of a model for the simulation of fibre distributions; the concept of ‘virtual location’ within the cross-section domain, which may contain a fibre, is introduced. The distribution of fibres in real yarns is compared with computer-generated distributions. The distributions predicted by using the model demonstrate all of the properties of the real yarns considered.

The change in the fibre distribution caused by compressive forces is considered, and a model to describe the behaviour of real yarns is proposed.     

纱线毛羽的分布及络筒工序对纱线毛羽的影响

叙述了国内外对纱线毛羽的研究状况,阐述了评价纱线毛羽分布的方法,同时指出络筒张力、速度对涤、棉筒子纱线毛羽的影响,发现并分析了涤纶纱毛羽指数着络纱速度提高而先增后减的特殊现象。     

Study of Yarn Snarling Part II: Mathematical Modelling

In the previous paper the experimental study of yarn twisting and snarling was reported and the application of theoretical criteria for predicting the critical parameters of snarling was discussed. This paper deals with modelling of snarling in textile yarns. The twisted textile yarn is modelled as an elastic rod subject to torque and tension. A unified model of snarling/kinking is developed which takes account of geometrical non-linearity. The sequential stages of loop/snarl formation and elimination are studied. The critical parameters of loop/snarl formation and elimination are obtained and the theoretical model compared with experimental results. The changes in yarn torsion, torque and tension which accompany loop formation and elimination are discussed.

The modelling results provide an insight into the snarling mechanism and can be used both to enhance efficiency of twisted yarn production by elimination of snarling and to simulate the fancy loop/snarl yarn appearance. The present model may serve as a basis to develop more sophisticated models.     

Fibres from Thermotropic Polyesters: The Use of Chain Modelling in Structural Characterization

Some rigid-chain aromatic polyesters form a ‘liquid-crystal’ nematic mesophase on heating, i.e., they are thermotropic, and exhibit ‘self-reinforcing’ properties when used for specialist mouldings. In contrast to the expanding commercialization of this class of plastics, the utilization of thermotropic polymers for the production of high-performance fibres is in its infancy. This paper illustrates the versatility of a chain-modelling approach, in conjunction with X-ray diffraction, for structural characterization of fibres from the thermotropic poly(p-oxybenzoate-co-p-phenylene isophthalate)s. The models were also used to evaluate the effect of polymer composition on chain stiffness, which is one of the major factors limiting the achievable tensile modulus of such fibres.     

PTT长丝/天丝短纤复合纱面料的热加工设计

为了充分发挥PTT长丝和天丝短纤各自的优良特性,形成优势互补,将PTT长丝和天丝短纤通过空心锭包覆和网络加工开发复合纱面料.本文针对PTT长丝/天丝短纤单纱空心锭包覆复合纱和PTT长丝/天丝短纤单纱网络复合纱面料的开发,探讨了PTT纤维的热加工性能及其与PTT长丝/天丝短纤复合纱面料设计的关系.结果表明,充分利用PTT纤维热加工对织物结构及性能变化的作用,优化面料设计方案,是实现PTT长丝/天丝短纤复合纱面料设计目标的关键,从而开发出了手感柔软滑爽、光泽柔和、弹性足且悬垂感强的新颖面料.     

浆纱耐磨寿命统计分布规律的研究

通过测试和分析浆纱的耐磨寿命,发现浆纱的耐磨寿命较好地服从对数正态分布,故应使用耐磨次数的几何均值代替算术平均值来评价浆纱的耐磨性。     

蚕丝／其它天然纤维复合丝织物前处理加工性能研究

本文主要研究蚕丝．棉、蚕丝／羊毛复合丝织物前处理工艺与产品性能关系。     

竹节纱织物竹节分布CAD系统的开发

文章提出了针对竹节纱竹节分布CAD系统的总体结构和功能开发,详细介绍了在竹节分布模拟过程中各个影响参数在竹节分布计算过程中的计算方法,利用计算机图形图像技术,将竹节纱织物的竹节分布逼真地再现于计算机之上。实验证明,该系统可以准确地模拟竹节纱织物的竹节分布,可以指导实际生产,大大缩短竹节纱织物的生产开发周期,提高企业的反应速度。     

含疏水纤维的纱线对单层织物吸放湿性的影响

在不同含量表面疏水纤维的纱线织成的平纹织物的基础上,探讨了该织物的吸湿性和放湿性变化规律,研究证实当构成织物的纱线中加入少部分表面疏水纤维后,织物具有良好的吸放湿性能.     

喷水织机上纬纱速度在梭口中的分布规律

提出用喷水冲量来衡量喷水引纬力，采用传感器测试了喷水冲量，分析了喷水参数对喷水冲量的影响以及喷水冲量在梭口上的分布规律。     

Evolution of Moisture Distribution During Storage in a Composite Food Modelling and Simulation

In order to predict moisture transfer in a composite food, a mathematical model was developed and tested on a 2‐components system constituted of a sponge‐cake in contact with a fresh wet filling. Using independent sorption kinetic experiment, a power law was found as representative of the effect of moisture content on water effective diffusivity of sponge‐cake. The parameters of power law was then adjusted using the model optimization procedure on moisture profiles measurements of sponge‐cake in contact with a 0.99 water activity agar gel at 20°C. The model was validated with 0.95 and 0.90 water activity agar gels and successfully used to predict moisture transfer in a real food (processed cheese/sponge‐cake system).     

超大牵伸中区牵伸分配对成纱质量的影响

探讨四罗拉三区超大牵伸中区牵伸分配对纺纱质量的影响。在加装集聚纺装置的TH558型超大牵伸细纱机上分别纺制11.8tex、9.8tex、7.4tex粘胶赛络集聚纱和14.8tex、11.8tex、9.8tex莱赛尔赛络集聚纱,分析了中区牵伸分配对成纱质量的影响。结果表明:纺制赛络集聚纱中区牵伸倍数应控制在1.2倍~1.6倍间,其中纺莱赛尔纱采用1.3倍、纺粘胶纱采用1.5倍时成纱综合性能较优。认为:中区牵伸分配对超大牵伸装置的纺纱质量有着显著影响,应根据纺纱原料通过试验,优选中区牵伸倍数,以获得较优的纺纱质量。     

大豆蛋白涤纶混纺纱纤维分布探讨

通过切片等方法对不同混纺比大豆蛋白纤维与涤纶混纺纱纤维分布规律进行了分析和比较,得出Hamilton和Onion指数.结果表明:大豆蛋白纤维含量为40%时,大豆蛋白纤维与涤纶混纺纱的实际分布与均匀分布Onion指数差异率最大,大豆蛋白纤维有效利用率最高.大豆蛋白纤维和涤纶纤维在混纺纱中的转移规律并不完全符合传统的转移规律.     

实际生产中零疵纱的控制

文章分析了毛纺企业零疵纱产生的主要原因,并且提出了在实际生产中控制零疵纱的措施,引入了无效量的概念,对实际生产有指导作用.     

Sirospun 纺单纱纱线结构和捻度分布的分析

通过对Ｓｉｒｏｓｐｕｎ纺股线中单纱结构的研究认为Ｓｉｒｏｓｐｕｎ纱两根单纱上存在着假捻现象。若导纱钩与单纱间摩擦力增大,单根纱段上的假捻现象增强,假捻捻回增多,则单根纱段上的捻回角将增大,外层纤维对纱线内层纤维的向心压力相应增大,纱条结构更紧密。     

转杯纱中纤维转移与捻度分布的规律

利用科视达公司生产的手持式视频显微镜可以对转杯纱中的示踪纤维的三维空间位置作较准确的测量,发现示踪纤维在转杯纱中也存在内外转移现象,得出捻度沿转杯纱径向分布的二次抛物线型分布规律。