毛/镀银长丝包芯纱织物的抗电磁辐射性能研究

采用赛络纺与包芯技术相结合的方式,用羊毛包覆镀银长丝纺制环锭包芯纱,选择合理的结构参数,开发抗电磁辐射精纺面料。选取纱线的捻系数、线密度及织物紧度三个因子进行正交试验,测试纱线强度和伸长以及织物电磁屏蔽效能(屏蔽效能可达50 dB)。试验结果表明,影响织物屏蔽效能的主要因素是纱线线密度,即镀银长丝绝对含量。最终确定纱线线密度为23 tex,捻系数为540,织物紧度为90%。     

旋流器对环锭纺不同线密度纱线性能的影响

采用安装在传统环锭细纱机的旋流器加工不同线密度的纱线,探讨了旋流喷嘴内部高速旋转气流对纱线加捻成形的影响。结果表明：旋流器的使用能够有效地减少纱线毛羽,但在优化纱线强力、条干不匀率等方面作用不是很明显且对不同线密度纱线质量的改善程度存在一定的差异。采用纱道为2 mm,气道为1.4 mm的旋流器,所加工不同线密度纱线的质量都有一定程度的提高,其中线密度10 tex 纱线的3 mm以上毛羽、断裂强度和条干不匀率质量指标的改善均优于其他四种纱线,为研究最好地降低纱线的成纱毛羽提高纱线质量而选择合适尺寸的旋流器提供参考。     

不同成纱系统的精纺羊毛/涤纶平行纱的纱线特征

为优化平行纱的成纱性能,分别使用花式捻线系统与环锭纺纱系统纺制2种精纺羊毛/涤纶平行纱,并对比分析这2种成纱系统所纺制纱线的结构与性能特点。其中使用花式捻线系统纺制平行纱的方法是先在环锭纺纱上分别纺制线密度为15.625 tex的深蓝、浅蓝2种颜色的细纱,再在花式捻线机上将2种细纱平行喂入,外包1根线密度为2.22 tex的涤纶长丝;使用环锭纺纱系统纺制平行纱的方法是先在环锭纺纱上间隔喂入深蓝、浅蓝2种颜色的粗纱,纺制线密度为31.25tex的细纱,再将其与线密度为2.22tex涤纶长丝在并线工序并合。对比这2种成纱系统,结果表明:使用花式捻线系统纺制的平行纱的纱线强力较使用环锭纺纱系统纺制的平行纱高出48.7%、断裂强力高出44.4%。对比2种平行纱的纱线风格,使用花式捻线系统纺制的平行纱颜色均匀,使用环锭纺纱系统纺制的平行纱呈现深蓝、浅蓝2种颜色交替的效果。     

三通道环锭数码纺纱机控制系统的开发和应用

介绍了三通道环锭数码纺纱系统的构成,构建了JWF1551型环锭数码细纱机控制系统、数控纺纱机主电路与PLC电路、PLC控制程序,设计了友好的人机交互界面。以三通道环锭数码纺纱机的数字化模型为基础讨论了成型纱线密度、混纺比、捻度的调控机理,根据数字化模型得出了该细纱机可纺以下纱线:恒定线密度和五基色纤维任意恒定混纺比纺制的混色纱;恒定线密度和分段变化色纤维混纺比的段彩纱;恒定线密度和渐进变化色纤维的渐变纱;渐进变化线密度和渐进变化色纤维混纺比的双渐变纱;恒定色纤维混纺比和分段变化线密度的竹节纱;分段变化线密度和分段变化色纤维混纺比的段彩竹节纱。     

棉/单芯涤纶长丝包芯纱的性能研究

分别对棉/单芯涤纶长丝包芯纱与纯棉环锭纱的性能进行了测试分析。结果表明对于相同线密度的纱线,棉/单芯涤纶长丝包芯纱的拉伸性能、断裂强度和毛羽均高于纯棉环锭纱,耐磨性较纯棉环锭纱高。     

线密度和组织结构对牛仔面料保型性的影响

针对牛仔服装在穿着时受到外力、环境等因素影响易变形走样的问题,通过分析5种全棉面料的松弛曲线图,研究纱线线密度和面料组织结构对牛仔面料保型性的影响。这5种面料的纱线线密度、经向密度、纬向密度和组织结构呈现出一定的规律。通过分析它们的松弛曲线图得出：牛仔面料所用的纱线线密度和组织结构对牛仔面料的保型性有较大影响,即当面料在其它规格相同的情况下,纱线线密度低的牛仔面料其保型性好于纱线线密度高的面料,组织为3/1的牛仔面料的保型性能好于组织为2/1的牛仔面料。     

未知规格的机织物纱线线密度测试方法研究

已知纱线规格的机织物纱线线密度测试可依据FZ/T 01093-2008《机织物结构分析方法织物中拆下纱线线密度的测定》进行.而未知纱线规格机织物的拆下纱线线密度的测试根据以上标准无法准确测出.就未知纱线规格的机织物拆下纱线线密度的测试方法进行探索,即采用在纱长测试仪上测量其长度,测定不同规格纱线的伸直张力,再测量纱线质量及准确伸直长度,然后根据公式得出其线密度值.     

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。     

低扭矩纱性能和结构

文章对纯棉环锭纺低扭矩纱的性能和结构与传统环锭纱进行了比较研究,结果表明纯棉环锭纺低扭矩纱在纱线捻系数降低34.8%时,纱线强度高于传统环锭纱2%;纯棉环锭纺低扭矩纱的毛羽少,纱线中纤维排列更紧密。     

高速涡流对环锭纺成纱质量的影响

探讨高速涡流对环锭纺成纱质量的影响.在环锭细纱机的前钳口至导纱钩之间安装自制的高速涡流装置.分别采用5种气压纺三种不同线密度的纱,并与传统环锭纱进行质量对比测试分析.结果表明:在涡流方向与纺纱Z捻捻向相同的条件下,与传统环锭纱相比,成纱3 mm及以上毛羽可减少70.3％～82.7％,纱线强力可增加7.3％～8.0％,成纱条干随气压增高有所恶化.指出:高速涡流装置可以缩小环锭纺加捻三角区的高度和宽度,从而达到改善成纱毛羽、增加纱线强力的作用,其重点是根据纱线密度优选气压.     

The Specific Heat of Hygroscopic Textiles

A comparison between the qualities of open-end- and ring-spun yarns produced from Egyptian cottons is reported. Yarns of different counts and twist factors were produced on both the BD 200 open-end-spinning machine and a conventional ring-spinning machine, and their quality was studied by determining their strength, uniformity, and number of imperfections. The quality of open-end-spun yarn relative to that of ring-spun yarn is expressed in terms of the relative quality factor.

It is shown that the percentage reduction in strength of open-end-spun yarns compared with that of ring-spun yarns can be minimized by spinning them to coarser counts from shorter cottons. This is attributed to the different interactions between the fibre properties and the mechanism of yarn formation when different types of cotton are used.

It is also shown that the relative quality of open-end-spun yarns can be considerably increased by spinning them to coarser counts from Ashmouni cotton. The quality of open-end-spun yarn can exceed that of ring-spun yarn when Ashmouni cotton is spun to a linear density exceeding 30 tex.

It is concluded that the BD 200 open-end-spinning machine cannot be recommended for spinning fine yarns from long-staple Egyptian cottons.     

A Study of Throstle-spun-silk/Raw-silk Core-spun Yarn Part III: Yarn Appearance

Using different spinning systems, the experimental core-spun yarns are made from the same fiber material under the same yarn conditions, namely, yarn count, twist factor, and fiber composition. The shape factor is adopted to evaluate the core eccentricity expressed as the position of the continuous-filament core yarn in the cross section of the core-spun yarn. The bispectrum is applied to consider the yarn irregularity in spectral analysis. The characteristic-appearance of the throstle-spun yarn is discussed and compared with that of the ring-spun yarn.     

43—FIBRE MIGRATION IN OPEN-END-SPUN YARNS

A study of the migration of fibres in open-end-spun yarns is reported. Samples of viscose rayon yarns were produced by the drum and air-vortex methods, and the results obtained on them were compared with those for a ring-spun yarn made from the same fibre. Migration was studied by determining three parameters: the helix profile, the mean fibre position, and the r.m.s. deviation, i.e., the root-mean-square value of the radial deviation of the helix profile from the mean fibre position. The geometry of fibre-packing in the yarn cross-section and the fibre extent were also studied.

It is shown that open-end-spun yarns are somewhat different in character from ring-spun yarns and that the most basic structural differences are found in the fibre extent, fibre migration, and fibre-packing density. The fibre migration in an open-end-spun yarn is shown to be as little as one-sixth of that in a typical ring-spun yam, and the difference in structure is important in that it can affect the yarn properties. It is concluded that the observed low strength of most open-end-spun yarns can be attributed to the poor fibre extent and inferior fibre migration within the yarn body and that their relatively high elongation can be explained in terms of the folded and entangled nature of the fibres.

An examination of the fibre geometry in the yarn shows that the design features of drum spinners are important with regard to the determination of the fibre extent, a tangential feed being preferable to an axial one.

The yarn cross-sections demonstrate that open-end spun yarns generally have a lower fibre-packing density than ring-spun yarns, which tends to give the yarn a more bulky nature; this is consistent with what might be expected from an assembly of tangled fibres.     

A study on siro-, solo-, compact-, and conventional ring-spun yarns. Part I: structural and migratory properties of the yarns

Properties of spun yarns are mainly affected by fiber properties and yarn structure. Yarn structure is principally influenced by the spinning system. In fact, each spinning system tends to produce a distinctive yarn structure. Recent refinements in spinning technologies have yielded significant improvement in yarn structure. Siro, solo and compact spinning are the new spinning systems to have made a breakthrough until recently. Of the various structural parameters for staple yarns, fiber migration has a crucial influence on the yarn mechanical properties. Thus, the need for precise and concise information about fiber migration becomes important for better understanding of yarn structure and hence yarn mechanical behavior. The work presented here aims to analyze fiber migration in siro-, solo-, compact-, and conventional ring-spun yarns by varying the twist factor. The results demonstrate that the siro-spun yarns exhibit the highest fiber migration parameters, followed by compact-spun yarns, solo-spun yarns, and conventional ring-spun yarns.     

20—FIBRE MIGRATION IN JUTE YARN. PART I: THE EFFECT OF TWIST

Fibre-migration studies show that, in sliver-spun jute yarn, fibres reside nearer to the surface, and thus its structural features differ from those of ring-spun yarns. A wrapped-ribbon structure is suggested for sliver-spun jute yarn. Long-term migration is practically absent. Migration increases with an increase of twist as in typical ring-spun yarns.     

Study of fiber packing density of lyocell ring‐spun yarns

The study of yarn structure and related yarn properties has been the subject of much research. However, the study of the fiber packing density, which has practical significance for a number of yarns and their characteristics, has been limited to circular yarns because of the disordered yarn structure. In this paper, the fiber packing density of lyocell ring‐spun yarns is determined with the image analysis method. This method does not have any limitation with regard to the fiber cross‐sectional shape. The effect of yarn count, twist factor, spindle speed, traveler weight and front roller diameter on the fiber packing density in the yarn cross‐section is analyzed. The results of this paper and the data published in other scientific works are in good agreement.     

Geometry of fiber distribution in Marl yarn using the computational method

In this research, the structure of a type of bi-component composite yarns so called Marl yarn was studied. Fibers packing density factors within the yarn cross section as well as the effect of twisting on the resultant yarn were investigated. Samples of Marl acrylic yarns were provided using different twisting levels. Images of the cross sections of the produced yarn were obtained using the transverse sectioning method. The images were captured using the optical microscopy. The prepared images of the yarn cross section were then analyzed using image processing methods. In the first stage, yarn central coordinates and radiuses were calculated. In order to investigate the uniformity of fibers distribution and packing density within the yarn cross section, the fiber distances from the yarn center within the small radial and polar elements were calculated and the coefficient of variations (CV %) was determined. The maximum value of the fibers packing density was determined. The results showed that the fibers were mostly concentrated within the central region of the yarn; this was followed by the decrease in the fibers packing density while moving into the yarn’s outer layers. It was also concluded that increasing the intensity of the applied twist would result in higher fibers packing as well as the decrease in the yarn radius.     

The Air-permeability Measurement of Open Fabrics by Using Superimposed Fabric Layers

An account is given of an investigation of the dimensional properties of a series of plain weft-knitted fabrics produced from open-end-spun yarns. The results are compared with those for similar fabrics knitted from ring-spun yarns.

It is shown that fabrics knitted from the two types of yarn possess different properties and particularly that the amount of relaxation shrinkage observed in fabrics knitted from open-end-spun yarns is greater than that which occurs in fabrics knitted from ring-spun yarns. The aesthetic properties of fabrics made from open-end-spun yarns are inferior to those of fabrics made from ring-spun yarns, particularly with regard to a lack of stitch clarity and a somewhat harsher handle, although the latter effect is shown to be apparently unrelated to differences in the frictional properties of the two types of yarn.     

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.     

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.