Hairiness of staple fiber yarns Part II: model validation

An attempt is made here to verify and validate the probabilistic models of yarn hairiness reported in Part I of this work. It is shown that the double exponential model of yarn hairiness corresponds more close to the experimental results than the single exponential one. This suggests that two types of hairs of very different nature are present in yarns. The first type of hairs falls with the increase in yarn radius quickly to (practically) zero. These hairs create something like “moss” on the yarn surface. They are considered to be good as they bring pleasant handle, fullness of the fabric, etc. On the other hand, the second type of hairs falls with the increase in yarn radius very slowly. These hairs are created mostly from “long flying fibers,” which often bring difficulty in the subsequent technological processes, namely weaving as well as make the fabric look bad.     

Some studies on hairiness reduction of polyester ring spun yarns by using air-nozzles during winding

This paper reports on the hairiness reduction of polyester yarns at winding using air-nozzles. Three yarns of the same count were spun each from fibres of 1.0, 1.2 and 1.4 deniers respectively. Using a CFD (computational fluid dynamics) model, airflow inside the nozzles is simulated to explain the role of nozzle parameters viz., axial angle of air inlets and yarn channel diameter on yarn hairiness reduction during winding. Air drag forces acting on hairs are calculated. Transverse drag forces acting on hairs play a major role in bending the hairs. Vortex nature of air and air velocity profile inside the nozzle are the important phenomena in reducing yarn hairiness. Box and Behnken factorial design of experiments is used to optimize nozzles parameters, fibre denier, and air pressure to maximize the hairiness reduction. Axial angle of 45° for air inlets, 2.2 mm yarn channel diameter, 1.4 denier fibre, and 0.9 bar (gauge) air pressure are the combinations to get maximum reduction in S3 hairiness values of nozzle wound yarns. Fibre denier is a major influencing factor in reducing yarn hairiness.     

A comparative study on yarn hairiness results from manual test and two commercial hairiness metres

The true hairiness (actual hair number and length) of ring, compact and rotor spun yarns was measured by means of a tedious manual method. The hairiness results were then compared with yarn hairiness results obtained from two commercial instruments (Uster tester and Zweigle Hairiness Meter). The comparative analysis between the measurement methods has revealed very significant discrepancy between the true hairiness results and that from commercial instruments, not only just in terms of the number of hairs, but also in terms of the hair-length distribution. The hair numbers obtained from manual method are much greater than that obtained from the hairiness metres, and the true hair-length distribution does not follow the well-known exponential decay. This study shows that the two existing hairiness measuring systems, while essential for rapid assessment of yarn hairiness, are not accurately measuring the true hairiness of spun yarns.     

55—SOME FACTORS AFFECTING THE HAIRINESS OF WORSTED-SPUN YARNS

Further experiments are reported on the hairiness of worsted-spun yarns, chiefly of mohair. The effect of some fibre physical properties on the hairiness of man-made-fibre blended-fibre yarns was also studied. Leading hairs are predominant among the singles yarns spun by different drafting systems, although their proportions may vary. The hairiness of yarns spun by different drafting systems is compared. The Ambler Superdraft Uniflex spinning machine produced the least hairy Courtelle acrylic-fibre yarns from the different drafting systems studied. An increase in the drafting angle and an increase in traveller weight reduced the yarn hairiness, and there appeared to be a critical value of flume-setting, above and below which yarn hairiness increased. The Uniflex spinner appeared to produce at least equally lean, if not leaner mohair yarns, both singles and two-fold, than did the flyer system.     

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.     

38—THE HAIRINESS OF MOHAIR AND WOOL WORSTED-SPUN YARNS: CORRELATION BETWEEN THE RESULTS OBTAINED WITH THE SHIRLEY HAIRINESS METER AND THOSE OBTAINED WITH THE DIGITAL ITQT APPARATUS

An investigation is reported of the correlation between hairiness values obtained with the Shirley Hairiness Meter and those obtained with the Digital Hairiness Meter developed by the Institute of Chemical and Textile Technology (ITOT). Twenty mohair yarns and 46 wool worsted yarns processed at SAWTRI were analysed with these two instruments. For mohair, very good correlations were obtained between the number of hairs per metre, as measured by the Shirley instrument, and the average hairiness and length data obtained with the Digital Meter (correlation coefficients between 0.95 and 0.99). For wool, the agreement between the two sets of results was not as good, the ITQT parameter correlating best with the Shirley measurement being the average length, followed by the maximum hairiness. For wool, the over-all correlation coefficients—without distinguishing between the different yarn linear densities—were 0.60 for the mean length, 0.47 for the average hairiness, and 0.40 for the average hairiness and maximum length. When the results were separated according to the yarn linear density, the correlation coefficients increased to 0.80–0.88 for the average length, 0.69–0.75 for the maximum hairiness, and 0.63–0.81 for the maximum fibre length, whereas they were insignificant for the average hairiness. An attempt was made to establish a parameter known as the ‘visible’ hairiness, but this gave satisfactory results only for the finest yarns (correlation coefficient 0.80).

In general, the number of hairs per metre as measured with the Shirley Meter correlated well with the average length as measured by the Digital Meter, provided that only yarns of the same linear density were compared. The correlation was lower for the maximum hairiness and maximum length and practically non-existent for the average hairiness, except for the mohair yarns.     

基于毛羽图像检测的浆纱抗起毛性能评价

为准确检测织造载荷作用前后浆纱的毛羽及有效表征浆纱的抗起毛性能,提出一种基于毛羽量图像检测的浆纱抗起毛性能评价方法.对纯棉14.5 tex的原纱和3种不同上浆率的浆纱,在JN-01浆纱耐磨性能测试仪上模拟织造载荷,并进行不同载荷次数的摩擦起毛实验.起毛后的纱线经图像采集、纱线主干分割、毛羽分割和主摩擦区间定位等处理后,...     

两种紧密纱与环锭纱的性能比较

将11.7tex纯棉精梳环锭纱、倚丽纱及卡摩纱进行了成纱毛羽、强伸性能的测试对比，分析了紧密纱与环锭纱存在性能差异的原因。结果表明：相对于环锭纱两种紧密纱长毛羽明显改善，络筒后毛羽增长率高；单纱断裂强度紧密纱较环锭纱提高，倚丽纱比卡摩纱高，两种紧密纱强度不匀率均好于环锭纱；断裂伸长、断裂功指标卡摩纱、倚丽纱均好于环锭纱。     

The Hair-length Distribution of Yarns,Measured by Means of the Zweigle G 565 Hairiness Meter

Some features of the experimental hair-length distributions obtained when yarn hairiness is measured by means of the Zweigle G 565 apparatus are described. Tests were made on a population of 85 yarns from different fibres and blends and various spinning processes. It is found fundamentally that the distribution seems to be formed by two exponential mechanisms operating, respectively, for hairs shorter than 3 mm and for hairs longer than 3 mm in most of the cases. The first mechanism is valid below the unique theoretical exponential distribution, whereas the second one tends to be placed above this theoretical distribution. Other features studied are: the role of the type of fibre or blend and the spinning processes; the percentage of hairs exceeding 3 mm calculated over the total number of hairs counted; and the effect of a yarn self-rubbing action on the hair-length distribution and yarn-hairiness parameters.     

气道位置对旋流器减少细纱毛羽效果的影响

为了进一步优化旋流器的内部结构,更好地改善成纱质量,本文在前期研究基础上设计了三种不同气道位置的旋流器,并且在加工气压分别为0-0.25MPa下加工纱线。通过测定纱线的毛羽指数,并和普通环锭纺纱线进行对比,得出：当气道直径d=1.4mm,气道在纱道上的分布位置为1:2,加工气压为0.2MPa时,所纺纱线的毛羽指数达到最低。同时,利用流体力学计算软件ANSYS CFX对喷嘴内的气流场进行数值模拟和分析,研究了气流场对纱线毛羽减少的影响机理,并进一步阐明了气道位置和加工气压对喷嘴内气流场的影响。     

苎麻纱线毛羽成因分析及改善措施

从纺纱器材和纺纱工艺出发,探讨影响纯苎麻纱线毛羽的因素。分析对比不同的钢领型号和表面状态、细纱锭子速度、导纱钩直径、细纱加捻程度、槽筒速度、络纱张力等条件下纺制的16.7 tex纯苎麻细纱,在标准状态(温度20℃,湿度65%)下采用长岭YG172A型毛羽仪测试纱线毛羽情况,了解不同纺纱条件对纱线毛羽的影响,制定改善措施,减少纱线毛羽,提高纱线质量。实验表明:细纱、络筒速度是影响纱线毛羽的关键因素;4 mm以下的纱线毛羽占80%～90%,毛羽主要在细纱工序产生,络筒工序增加较快。因此,优选合理的纺纱器材和纺纱工艺,采用新的纺纱技术和纱线后处理技术是减少纱线毛羽的重要措施。     

浅析自动络筒机对细纱毛羽的影响

基于络筒工序细纱管纱高速退绕因自身摩擦、纱线张力的影响使纱线毛羽增加的现状,提出在自动络筒机上加装气圈控制器或加装PERLA-A型涡流毛羽减少装置,不仅将使毛羽明显减少,还可提高纱线强力,并具有其它积极效果。通过在相同工艺条件下自动络筒机加工同号数紧密纱与普通纱的不同毛羽增加情况对比,分析认为产生毛羽的根源是细纱工序,并非是自动络筒机加工的原因。     

细纱工序毛羽的有效控制

为了减少成纱毛羽,针对细纱工序的工艺、器材及温湿度对细纱毛羽的影响情况进行了跟踪试验.结果表明:细纱捻系数适当增加,成纱毛羽减少;细纱毛羽随着细纱总牵伸倍数的增大呈上升趋势;前胶辊前移2 mm～3 mm对减少毛羽有一定作用;细纱牵伸工艺按照改善条干均匀度的思路进行配置,有利于减少毛羽;钢领、钢丝圈的选配和使用时间对毛羽影响较大;车间相对湿度较高有利于减少细纱毛羽.指出减少细纱毛羽要注意细纱工艺的配置、专件器材的管理以及加强各项基础性管理工作.     

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.     

应用图像处理的纱线黑板毛羽量检测与评价

针对目测法检测纱线黑板毛羽效率低、主观性强等问题,提出一种新的基于图像处理的毛羽检测方法。纱线黑板经扫描仪采集图像,然后进行中值滤波、二值化、形态学运算、局部阈值等处理,得到黑板毛羽图像,统计出毛羽像素点个数,提出评价黑板毛羽量的指标--M指数。采用原料、线密度和纺纱方式各不相同的纱线进行实验,测得18种纱线的毛羽M指数,与乌斯特仪得到的毛羽H值建立回归模型,两种测试结果之间的相关系数为0.975。6种纱线的验证结果表明,本文提出的毛羽检测法和建立的毛羽M指数能较完整地提取和评价整块纱线黑板毛羽,算法精度高、评定结果可信度好。     

纱线毛羽图像的二值化处理及其Matlab实现

文章利用CCD扫描来采集纱线灰度图像，运用计算机快速处理数据的能力以及Matlab强大的图像处理功能，采用适当的方法对纱线毛羽图像进行消噪、灰度变换、二值化处理。通过分析二值化图像的特征，分别得出带毛羽纱线和不带毛羽纱线的图像面积，进一步计算出纱线相对毛羽率。结果表明，该方法分割效果好，运算速度快，不需要购买专门的仪器，具有较高的实用价值。     

基于数字图像处理的纱线毛羽检测

为了更准确地检测出纱线毛羽长度及其根数,在结合视频显微镜和图像处理技术的基础上,提出一种新的毛羽检测方法。首先采用MOTIC SME-140视频显微镜采集纱线图像,然后经过灰度变换、图像分割、形态学开运算、图像细化处理,得到完整的纱线条干图像和细化后的毛羽图像,接着以纱线条干边缘为基准线,对毛羽分割点进行判断,最后得出不同长度的毛羽根数。图像法检测结果表明各纱线片段的毛羽根数值较为稳定,并且检测结果与目测图像计数的结果非常接近。因此,本文所提出的毛羽检测方法较现有的光电检测方法更为准确、可靠。     

Measurement of long yarn hair based on hairiness segmentation and hairiness tracking

For the problem of hairiness information missed in existing hairiness measurement method, the goal of this work is to accurately measure the length of long yarn hairiness and obtain the path over every hairiness point of the whole hairiness. To achieve this goal, the yarn images were captured by the video microscope (MOTIC) and the thinned hairiness images were obtained by a series of image processing. The different measurement baseline and step value were choose to segment long hairiness in the method of hairiness segmentation, and the different hairiness lengths were obtained, the results of length show that the length of 0.5mm (baseline)and 3 pixels (step value) is closest to hairiness real length. And then, the more accurate lengths of the hairiness were calculated by the method of hairiness tracking. The lengths of the two new methods are longer than the length of the method of fixed length (1mm), but the lengths of hairiness tracking is longer than the longest lengths of hairiness segmentation. The compared results show that the method of hairiness tracking can record the information of every point in hairiness and calculate the pixels of a hair fiber, and acquire more complete information of full hairiness then hairiness segmentation.     

粗纱机半封闭锭翼提高纺纱质量的实践

论述了半封闭锭翼与全封闭锭翼在同等条件下的长期对比试验结果，不同季节、不同品种精梳和普梳纱条件下，全封闭锭翼产生的纱疵和毛羽各不相同，而半封闭锭翼则有效解决了普梳纱纱疵问题和精梳纱毛羽问题。     

梳针分梳板与锯齿分梳板对涤纶纱毛羽的影响

研究梳棉机刺辊下加装梳针分梳板、锯齿分梳板对涤纶纱毛羽的影响.用YG172型纱线毛羽仪对隔距为0.3 mm、0.5 mm和1.0 mm时梳针分梳板和锯齿分梳板加工涤纶纱时2 mm和3 mm及以上毛羽进行了检测.结果显示:两种分梳板均在隔距为0.3 mm时最有利于毛羽的减少.两种分梳板对比,总体上以加装梳针分梳板更有利于减少涤纶纱毛羽.