短纤纱动态拉伸性能

短纤纱的拉伸强力通常是评定纱线质量的重要指标。纱线拉伸强力在纺纱后道的大部分工序中(如整经、机织和针织)起着重要作用,因此对其精确的评定方法在工业生产中很重要。通过分析动态拉伸性能的定义和所用到的拉伸仪器,以环锭纺、转杯纺、喷气纺和摩擦纺的短纤纱的动态拉伸性能测试为例,做了几项有关理论和实验的工作,探讨了研究短纤纱动态拉伸性能在工业生产中的重要性,同时也总结出影响动态拉伸性能的因素有材料、纺纱参数和测试方法等,得出短纤纱静态和动态强力的关系。     

Dynamic failure behaviour of blended spun yarns during winding

In the present work, the initiative is being taken to study the spun yarn failure behaviour under real dynamic conditions i.e. winding. An attempt is made to study the dynamic failure behaviour of blended ring yarn in relation to yarn structure. Multi-coloured tracer fibre technique is employed to study the broken ends of yarn during the winding process in terms of proportion of fibre break/slip, configuration of yarn broken end and yarn failure length. The ring spun yarn failure during winding is basically dominated by fibre breakage. The length of broken and slipped fibres is found to be different in trailing and leading portion of the broken ends and also depends on viscose content in the blends. The failure zone length and sum of percentage of tapered and slipped broken ends are found to follow the exactly similar trend with fibre failure coefficient with the change in blend ratio. The mathematical model established to explain the spun yarn failure during winding process displays lower error%.     

The Influence of the Spinning Process,Yarn Linear Density,and Fibre Properties on the Hairiness of Ring-spun and Rotor- spun Cotton Yarns

Cotton–spun yarns from 34 staple stocks were manufactured by means of the ring–spinning process (34 yarns) and a rotor–spinning process (29 yarns) and tested for hairiness with the Shirley Hairiness Meter. For each spinning system, yarns were spun at two values of yarn linear density (15 and 30 tex for ring–spinning and 30 and 50 tex for rotor–spinning), but the twist multiplier was kept constant within the series for each spinning process.

The higher hairiness of ring–spun yarns and an increase ln hairiness with the yarn linear density were confirmed. The effect of the fibre parameters on yarn hairiness explains only about 30% of the total effect for ring–spun yarns and 40% for rotor–spun yarns. Fibre length and its uniformity are the fibre properties having the greatest influence on the hairiness of both ring– and rotor–spun yarns, the Micronaire index having only slight influence on the hairiness of ring–spun yarn.     

The Detection of Irregularity Sources by Variance–Length Curves

Abstract

The migration in ring yarn (type I and type II), rotor yarn and air-jet yarn was studied in terms of three parameters - mean fibre position (MFP), mean migration intensity (MMI) and root mean square deviation (RMSD) - using classical tracer fibre technique. The effect of various process variables on migration parameters was analysed using the Taguchi method, analysis of variance and a regression model. The trends of migration parameters in ring yarn-type I are opposite to those of ring yarn-type II. The ring yarn has the highest MFP and the lowest MMI. The rotor yarn has the lowest MFP and RMSD. The air-jet yarn has the highest MMI and RMSD. Increase in card draft increases the MMI and RMSDof rotor yarn and decreases the MMI of air-jet yarn.However, it tends to increase the RMSD of ring yarn-type II, rotor yarn and air-jet yarn. A high draft/doublings at draw frame increases MFP in ring yarn-type II, rotor yarn and air-jet yarn. A decrease in ring frame/air-jet draft or an increase in speed frame draft decreases MFP in these yarns. All the migration parameters follow almost the same trends with change in process variables in rotor yarns.     

Influence and comparison of emerging techniques of yarn manufacturing on physical–mechanical properties of polyester-/cotton-blended yarns and their woven fabrics

Abstract

In this study, the physical–mechanical properties of ring spun, ring compact, rotor and air-vortex yarns were investigated. The study was carried with yarn having linear densities of 24.4 tex and 36.7 tex, which were then converted to woven fabrics. The ring spun yarns have higher values of strength but also with higher strength irregularities. Extra-ordinarily low hairiness was observed in air-vortex yarns due to its unique yarn formation technique. The deviation rate (DR) of yarns have correlation with the mass spectrogram of respective yarns obtained from USTER Tester 5. Rotor and air-vortex yarns exhibited higher coefficient of friction. The woven fabrics made from ring spun yarns exhibited higher tensile and tear strength with higher elongation at break. The fabrics made from air-vortex yarns have very good pilling grade due to less protruding fibres on their surface and good structural integrity.     

The effect of air-jet nozzle structural parameters on new cotton rotor-jet spun yarn properties

In this paper, a hybrid spinning system the so-called “rotor-jet spinning method” which utilizes the air-jet nozzle in rotor spinning process is presented. Thus, air-jet nozzles with different structures of 90S, 90Z, 60Z, and 30Z (the values of 90, 60, and 30 are orifice angles and S and Z are air rotational directions) were designed and constructed and then mounted between the take-up nozzle position and doffing tube in a rotor spinning machine. The air-jet pressure was changed at 0.2, 0.5, 0.8, 1, 1.2 and 1.5 bar values. The physical properties of cotton rotor-jet spun yarns with yarn count 20 Tex and nominal yarn twist of 938 TPM were investigated and compared with that of normal rotor-spun yarn. The experimental results indicated that by utilizing a 90Z air-jet nozzle at 1 bar air pressure, the highest yarn tensile strength, abrasion resistance, and twist, and lowest elongation are obtained compared with those of normal rotor as well as rotor-jet spun yarns with 30Z, 60Z, and 90S air-jet nozzle types. However, the rotor-jet spun yarn irregularity produced with 90Z air-jet nozzle is almost identical to normal rotor-spun yarn. It is also shown that the rotor-jet spun yarn hairiness properties which were produced with a 90Z air-jet nozzle at air pressure values of 0.2, 0.5 and 1 bar is almost similar to normal rotor-spun yarn while the lowest yarn hairiness is achieved at air pressure value of 0.8 bar. The experimental results of this paper suggest that the newly developed rotor-jet spun yarn is superior to normal rotor-spun yarn from the point of view of yarn tensile, abrasion resistance, twist, and partially hairiness properties.

     

Prediction of spun yarn strength at different gage lengths

In this article, the influence of tensile tester gage length on ring, rotor and air-jet spun yarns tenacity and its coefficient of variation have been investigated. A statistical model has been presented that correlates yarn tenacity and coefficient of variation of yarn tenacity to gage length. The model is based on Peirce model and assuming the three-parameter Weibull distribution of yarn strength values. A reasonable agreement has been shown between the experimental and predicted values. The model successfully captured the change in yarn strength and its coefficient of variation at different gage lengths. Results showed that at longer gage lengths, yarn strength decreases and its coefficient of variation decreases as well.     

喷气涡流纱及其织物性能分析

文章对竹浆纤维和莫代尔纤维两种原料的喷气涡流纱与环锭纱及其织物进行了测试分析和比较,得出喷气涡流纱制成的织物与环锭纱制成的织物相比具有更加柔软,强度较低,表面光滑,耐磨,透气较好的特点。     

Tensile behavior of staple fiber yarns part III: comparison of mathematical models

Despite the development of artificial neural network and computer simulation models that predict yarn tensile properties, the mathematical model is still very important being the base for all models. In this research, three mathematical models have been applied for evaluation of coefficient of fiber strength utilization in staple spun yarns before break at same value of yarn strains. The experiments were conducted on cotton, viscose and polyester fibers, and yarns. The results indicated that our model exhibited least prediction error followed by Pan’s and Frydrych’s models for cotton and viscose but for polyester, Pan’s model produced least error followed by Frydrych’s model and our model. The superiority of our model might be resulted from the introduction of the phenomena of fiber directional distribution in the staple spun yarns.     

Analysis of spinning process using the Taguchi method. Part V: Effect of spinning processvariables on physical properties of ring,rotor and air-jet yarns

Abstract

Effect of lap hank and drafts, of various spinning sequence of machines, was studied on physical properties of different yarns using Taguchi method and analysis of variance. The ring yarn is highly even and has the least number of thin places and neps but thick places are the least in rotor yarn. The air-jet yarn is the least even and has the highest number of thin places, thick places and neps. The total hairiness is the least on rotor yarn and number of hairs =3 mm (S3) the least in ring yarn. In air-jet yarn the total hairiness and S3 are the highest. The finer lap hank and higher card draft in preparatory process produces even ring and rotor yarns with lower hairiness. However, the higher speed frame draft improves the evenness of yarn produced from coarser lap hank and lower card draft. Lower ring frame, rotor and high air-jet draft improves the properties of the respective yarns. Increase in ring/air-jet draft increases S3.     

Development of biodegradable conductive cotton yarns by in-situ polymerisation of pyrrole

Cotton yarns were modified with pyrrole in the presence of ferric chloride following a dip-nip-dry technique. Treatment of cotton with 23.4% aqueous pyrrole followed by treatment with 40.6% aqueous ferric chloride and subsequent drying in atmospheric air produced balanced improvements in the properties of the yarn such as conductivity, tensile strength and extensibility. Among the three types of yarns such as ring spun, rotor spun and friction spun considered for such treatment, ring spun yarn performed best in respect of conductivity and retention of strength. Examination of surface morphology of yarns by scanning electron microscopy revealed a common discontinuity in the growth of polypyrrole along the length of the yarns spun using friction spinning and rotor spinning systems. Such discontinuity was caused by the wrapper fibres. Ring spun yarn, on the other hand, allowed a continuous spiral growth and deposition of polypyrrole in the inter-fibre space and on the surface of the yarn. Study of pyrrole modified ring spun yarn in a typical photoluminescence system indicated photoluminescence property of such pyrrole-treated cotton yarn.     

异形涤仿麻喷气纱的纺制及工艺研究

利用异形仿麻涤纶与普通涤纶混纺，结合喷气纱特有的手感风格开发生产了异形涤仿麻喷气纱，针对纤维的性能特点，探讨了纺纱各工序工艺和关键技术，指出生产过程中的注意事项。同时，对不同混纺比的喷气及环锭纱以及它们的织物进行了性能测试和分析，测试结果表明，喷气纱与环锭纱相比，具有更加逼真的仿麻效果。     

聚丙烯腈预氧化纤维阻燃产品加工技术

为提高聚丙烯腈预氧化纤维的可纺性,改善其纱线性能,采用转杯纺纱技术纺制纱线,通过各方案试纺对比,研究了转杯纺主要工艺参数与成纱质量的关系,合理选择工艺参数,提高了聚丙烯腈预氧化纤维的成纱质量。采用PANOF转杯纱开发的织物在阻燃性、耐磨性方面明显优于环锭纱织物。     

Analysis of spinning process using the Taguchi method. Part IV: Effect of spinning process variables on tensile properties of ring,rotor and air-jet yarns

Abstract

The yarn samples prepared for migration study were tested for tensile properties. Furthermore, the effect of drafts of the spinning machines on yarn strength and breaking elongation (%) was studied. The effect of spinning position, doff position and material conditioning during testing on yarn tensile properties were also accounted for. The ring yarn was seen to have the highest tensile properties, whereas air-jet yarns the lowest. The low elastic recovery of viscose fibres is the cause of weakest and least extensible air-jet yarns.     

Investigation of the quality properties of open-end spun recycled yarns made from blends of recycled fabric scrap wastes and virgin polyester fibre

Recycled fibre obtained from fabric scrap wastes is characterized by its low quality properties in terms of inhomogeneous fibre type and non-uniformly distributed short fibre lengths, both of which negatively influences the production process and the quality of the recycled yarns made from it. One of the common ways to utilize recycled fibre in yarn production is to blend it with virgin fibres. In this research article, the quality properties of the open-end spun recycled yarns produced in different material and spinning parameters from blends of recycled fabric scrap wastes and virgin polyester fibres are investigated. As material and spinning parameters, yarn count, blend ratio, waste type, waste origin, twist coefficient and rotor diameter are selected and their effects on the quality properties of the recycled yarns are evaluated through statistical methods. Statistical results reveal that especially blend ratio, yarn count and twist coefficient significantly affect the quality properties. In general, incorporation of virgin polyester fibre to recycled fibre tends to bring about improvement in yarn quality.     

Torsional properties of staple fibre plied yarns

A mathematical analysis of the mechanical governing equations applying to the torsional behaviour of multi-ply yarns under tension has been carried out. This analysis clearly shows that there are two components, a geometric component that determines the slope or gradient of the torque due to tension and a component that determines the yarn torque at zero applied tension (intrinsic torque) that depends on the fibre number, fibre moduli and diameter as well as the strand structural geometry. The effect of the ratio of the ply twist to the spinning twist on the two components of yarn torque has been numerically analysed for two-, three- and four-ply yarns prepared from singles 31 yarns spun with different spinning twists and for two different fibre diameters. Other comparisons are made for two-ply yarns prepared from 40 and 80 tex singles yarn. The model allows the effects of the various yarn and fibre parameters to be assessed and compared with experimental data. Experimental torque data for a range of two-ply yarns plied at different percentages of the singles spinning twist and also with different yarn histories and test environments are consistent with the trends identified by the model.     

环锭纺及转杯纺和喷气涡流纺混色纱的纤维混合效果研究

为研究环锭纺、转杯纺和喷气涡流纺3种不同成纱方法对混色纱中各色纤维混合效果的影响,分别使用3种成纱方法、2种条混方式(1道并条工序、3道并条工序)纺制6种混色纱,并制作6种混色纱的横截面切片样本,通过计算汉密尔顿指数,表征混色纱中各色纤维径向分布的均匀程度,分析不同成纱方法的纤维混合规律;同时测试6种混色纱的成纱性能,分析不同成纱方法混色纱的成纱质量。结果表明:转杯纺混色纱纤维混合效果优于环锭纺和喷气涡流纺,环锭纺次之,喷气涡流纺纤维混合最不均匀;经过3道并条工序的混色纱纤维混合效果优于经过1道并条工序的混色纱;环锭纺混色纱的强度最高,喷气涡流纺混色纱的毛羽最少。     

Elastic Recovery and Performance of Denim Fabric Prepared by Cotton/Lycra Core Spun Yarns

ABSTRACT

Elastic performance coefficient (EPC) and recovery behavior of denim fabrics prepared with cotton/lycra core spun stretch yarns have been presented in this article. The denim fabrics are woven as broken twill weaves in an air-jet weaving machine by the insertion of core spun yarns (lycra filament in core, cotton fiber on sheath) as weft and using 100% cotton yarns as warp. The effect of linear density and stretch percentage of the core spun weft yarns on tensile and recovery behavior of denim fabric have been investigated by employing full factorial design of experiments. It has been observed that the tensile strength and EPC of fabric increase with decrease in linear density and stretch percentage of the core spun stretch yarn. The immediate elastic recovery and delayed elastic recovery increase with decrease in linear density and stretch percentage of the yarns.     

喷气涡流纺工艺对粘胶/涤纶包芯纱性能的影响

为获得更高强力的喷气涡流纺纱线,通过引入涤纶长丝制备喷气涡流纺粘胶/涤纶包芯纱。采用统计分析等方法研究了芯丝线密度、纺纱速度对喷气涡流纺粘胶/涤纶包芯纱强伸性、条干不匀和毛羽的影响规律,同时对比分析了不同纺纱条件下包芯纱的结构外观。研究结果表明：芯丝线密度、纺纱速度对喷气涡流纺粘胶/涤纶包芯纱各性能响应值有不同程度的影响;纺纱速度过高或过低均不利于包芯纱成纱的强伸性提高和条干均匀性改善,纺纱速度的增加会使毛羽H值增大;在一定范围内,增加芯丝线密度有利于包芯纱强伸性的提高,随芯丝线密度的增加,包芯纱毛羽H值减小;此外,选用较大的芯丝线密度和较高的纺纱速度时,纺制的包芯纱芯丝外露现象越明显。     

丽赛纤维喷气纺纱性能研究探讨

文章采用丽赛、天丝、粘胶、棉、涤棉为原料分别进行喷气纺纱，并将喷气纱线性能进行比较，研究丽赛喷气纺的纱线强力、条干、毛羽、弯曲刚度等性能。