细纱后区牵伸倍数对成纱质量的影响

在相同工艺条件下,以5种不同后区牵伸倍数纺制了C18.2 tex和C14.6 tex纱,进行了纱线性能测试,分析了后区牵伸倍数对成纱质量的影响。结论是,后区牵伸倍数为1.38时,C18.2 tex和C14.6 tex纱质量最好,表明后区牵伸倍数趋近临界牵伸倍数时,成纱长毛羽少,条干CV值低,且粗细节、棉结少。     

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.     

Modal涤纶亚麻喷气涡流纱的开发及性能分析

探讨多组分喷气涡流纱的品种开发.利用喷气涡流纺纱机纺制Modal/涤纶/亚麻60/20/20 18tex纱,并对其成纱强度、毛羽、耐磨性和抗起球性及成纱质量作了测试,指出:喷气涡流纱毛羽少,耐磨性和抗起毛起球性较好、粗节和棉结较少,但成纱强力较低、条干较差.     

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。     

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.

     

Investigation of the concurrent sliver-opening mechanism and unveiling features of the new dual-feed rotor spinning concept

To examine the effectiveness of the new dual-feed rotor spinning system, we performed a set of experiments to assess the influence of the opening roller type, sliver feed method, and direction of fiber feeding into the rotor on the quality of a polyester/cotton blend yarn. Six yarn samples of 58tex consisting of 55/45 polyester/cotton were prepared in this study. Their respective properties, such as tenacity, elongation at break, mass irregularity, hairiness, thick (+35%) and thin (?30%) places were tested and statistically analyzed using Minitab. ANOVA analysis showed that the tested yarn quality properties were statistically significant among groups except for thick places (+35%). Tukey’s post hoc test based on the honest significant difference was performed to determine the implication of results within groups at the value of α?=?0.05. The dual-feed blend yarn (PCLR) spun with opening roller type OK37 on the left and OK40 on the right exhibited superior yarn quality characteristics compared to other samples. Dually carded slivers yielded better yarn quality compared to simultaneously carded ones. The combing direction did not produce a clear trend on the quality of yarns. The study provides important insights into the potential of the dual-feed rotor spinning concept.     

合理配棉提高转杯纺纱质量

介绍了转杯纺配棉与成纱质量的关系以及配棉特点.生产实践证明,合理配棉能够有效控制成纱中的粗节、棉结、成纱条干CV和成纱强力等指标,达到提高质量降低成本的目的.     

后区牵伸倍数对细纱前区压力棒牵伸的影响

探讨后区牵伸倍数对细纱前区压力棒牵伸成纱质量的影响.观测、分析了细纱机前区压力棒牵伸须条的形态及摩擦力界的变化;测试分析了细纱机后区牵伸倍数对成纱质量的影响.结果表明:细纱机前区加装压力棒对减少成纱的千米粗节、千米细节及千米棉结具有显著效果,但会使成纱毛羽指数恶化;适当减小后区牵伸倍数,有利于改善成纱质量.根据对成纱各项指标的综合评价结果,后区牵伸倍数在1.2以下为宜.     

双S曲线软牵伸纺纱技术

从装置结构方面阐述双S曲线软牵伸纺纱技术(简称双S软牵纺)改善纱线质量的原理,对比环锭纺和双S软牵纺纺制同规格纱线的测试数据,分析双S软牵纺的成纱质量特点,并分析原因。传统环锭纺在牵伸区由于上下胶圈表面线速度差造成摩擦和静电,影响成纱质量。双S软牵纺去掉了上下胶圈及上下销,通过S形曲线板、曲线管和网格圈实现对纤维须条的控制。分别用双S软牵纺和环锭纺纺制精梳棉/涤纶(60/40)混纺的18.4 tex纱线,测试其条干、纱疵等指标,用单因素方差分析法对数据进行分析。结果表明,双S软牵纺因可优化牵伸区摩擦力界的分布,缩短浮游区长度,因此控制浮游纤维更为有效,可较显著地改善成纱条干,降低千米棉结、千米细节、千米粗节等常发性纱疵的数量,其中粗节(+35%)纱疵改善尤其显著。     

压力棒隔距块在棉纺中的应用

为了探讨在棉纺生产中压力棒隔距块对成纱质量的影响,分析了压力棒隔距块的原理,并在FA506型环锭细纱机上加装不同型号的压力棒隔距块分别纺制出CJ9.7 tex、CJ7.3 tex纱线,测试纱线的毛羽、强力、条干等各项指标并进行对比分析。结果表明,在棉纺中使用压力棒隔距块后,成纱条干有所改善,成纱强力变化不大,成纱毛羽的变化也不明显。     

捻度对锦纶/棉混纺纱质量指标的影响

为进一步提升锦纶/棉混纺纱质量,针对捻度与锦纶/棉混纺纱质量指标的关系问题进行了分析。在其它工艺相同的条件下调整细纱工序捻度的设置,纺制了16种锦纶/棉混纺纱,对其质量指标进行测试,并通过SPSS软件对捻度与混纺纱质量指标之间的关系进行拟合与回归分析,建立了混纺纱质量指标随捻度变化的回归预测模型。结果表明,捻度与锦纶/棉混纺纱强伸性能、粗细节和毛羽指标显著相关,测试组数据与预测值间残差绝对值均在3倍残差标准差以内,验证了模型的有效性。捻度大小直接影响锦纶/棉混纺纱的强伸性能、粗细节和毛羽指标,预测模型反映了捻度对混纺纱强伸性能、粗细节和毛羽指标影响的数量相关关系,为锦纶/棉混纺纱生产中捻度设计和快速调整提供了参考依据。     

转杯纺精梳纱棉结产生规律探讨

应用aQura仪分析了转杯纺精梳纱生产中从原料到末并条棉结数量、棉结直径的变化规律,得出开清棉工序的打手数量是影响成纱棉结的主要因素以及打手数量与开清棉棉卷的二次相关关系。探讨了依据精梳条棉结数量计算转杯纺精梳纱棉结数量的方法以及转杯纺对不同线密度纱线棉结的去除能力。利用MatLab数学软件中的函数polyfit求解最小二乘曲线拟合,得到精梳棉条棉结数与转杯纺成纱各分档棉结数的回归关系,对生产质量控制及工艺优化具有参考价值。     

Influence of fibre strength and yarn structural characteristics on tensile failure of blended spun yarns: a prediction model

The study reports on the static failure behaviour of P/V blended ring, rotor and air-jet spun yarns explained on the basis of fibre failure coefficient. Fibre failure coefficient is an index introduced to represent fibre break and slip in combination occurring during tensile failure. Fibre break/slip during tensile failure is found dependent on fibre strength, fibre cohesiveness and internal structural developments in yarns. Tensile failure behaviour of ring, rotor and air-jet yarns found to be different owing to their difference in fibre consolidation mechanism. The contribution of individual components towards fibre failure coefficient varies with the spinning technology. An attempt has been made to develop mathematical models to explain the spun yarn failure behaviour under static condition. The developed mathematical models have incorporated the fibre property (fibre strength) and few structural characteristics of yarns which are strategically selected to justify the essence of models to enhance the prediction capability. Individual models are developed for ring, rotor and air-jet yarns owing to their structural changes caused by their inherent fibre consolidation mechanism. The developed mathematical models are free from assumptions and based on pure applied mathematics and have very high potential for prediction of spun yarn failure behaviour.     

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.     

基于图像的喷气涡流纺纱线捻度测试方法探讨

为探究适用于喷气涡流纺纱线捻度测试的有效方法,在对比分析喷气涡流纺纱线与传统环锭纺纱线结构的基础上,借助扫描电子显微镜,分别通过喷气涡流纺纱线的外观图像和横截面图像,测试了喷气涡流纺纱线捻度.并采用Photoshop软件处理喷气涡流纺纱线横截面图像,探究喷气涡流纺纱线内外层纤维数量比与其捻度的关系,提出了用喷气涡流纺纱...     

紧密赛络纱与赛络纱、紧密纱的性能对比分析

介绍了紧密赛络纺、赛络纺、紧密纺3种相近纺纱方法的纺纱原理,分别纺制9.7tex、7.3tex、5.9tex的紧密赛络纱、普通赛络纱、紧密纱,通过对3种纱线质量对比分析,表明:紧密赛络纱性能最好。进一步从理论方面对于紧密赛络纱的强力增加、条干改善、毛羽减少的原因作了分析。     

应用给湿装置改善环锭纺成纱毛羽

为减少成纱毛羽,在环锭纺细纱机前钳口与导纱钩之间加装接触式给湿装置,对出三角区后的低捻段纤维须条给湿。借助高速摄影拍摄纱线与导纱轮接触所产生的水雾三角区长度发现,导纱轮直径越大,水雾三角区长度越长。通过测试一落纱平均耗水量,纱线细度相同条件下,随导纱轮直径增大,耗水量增多;同时,纱线细度增大也会增加纺纱耗水量。在上述条件下进行纺纱试验并测试成纱毛羽,14.6 tex 精梳棉管纱3 mm 及以上有害毛羽较普通环锭纺降低了35.9%,19.5 tex精梳棉纱有害毛羽降低了41.1%。14.6 tex 精梳棉管纱络筒后3 mm 及以上有害毛羽较普通环锭纺筒纱降低了41.6%。结果表明,对环锭纺须条给湿可大幅度减少成纱有害毛羽,从而提高纱线品质。     

Dynamic analysis of spinning triangle geometry part 2: spinning triangle geometry and yarn quality

This paper examines empirical relationships between the geometrical parameters of the spinning triangle and the quality parameters of ring spun yarns. For this purpose, controlled variations in the geometry of the spinning triangle were induced using two existing modifications in the ring spinning process and by varying the yarn twist level. The geometrical parameters of the spinning triangle were measured using the clear rubber roller combined with digital image processing techniques as described in the first part of this study. The yarn quality parameters measured included yarn hairiness, strength, elongation and evenness. Yarn hairiness showed more noticeable sensitivity towards the physical shape of the spinning triangle than yarn tenacity, while yarn evenness and elongation were not significantly influenced by changes in spinning triangle geometry.     

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。     

旋流器降低环锭纺纱线毛羽的研究

在环锭纺细纱机上安装旋流器,利用旋流器内部的旋转气流对纱线的加捻成形过程产生影响,以达到提高纱线质量的目的。介绍旋流器的结构以及在环锭纺细纱机上的安装位置,实验并分析旋流器中的空气压力以及旋流器的结构对纱线毛羽的影响。对安装旋流器前后纺制的纱线的毛羽、断裂强力以及条干不匀率进行对比实验。结果表明,安装旋流器后,纱线表面的毛羽降低,纱线的断裂强力提高,纱线的条干均匀度也有所改善。