纱条中纤维排列状态与纱条不匀的关系

为研究短纤维纱条中纤维的排列状态与纱条截面纤维根数分布不匀的关系,采用几何概率方法建立了等分区间内纤维左头端数分布与纱条截面纤维根数的期望之间的数学模型,并定义了表征纱条中纤维排列状态的参数。运用蒙特卡罗方法模拟了纱条截面根数不匀随排列参数变化的关系曲线。结果表明:短纤维纱条截面纤维根数的CV值与纱条中短纤维排列参数呈负线性关系,与纤维长度分布和模拟区间大小的划分无关;且当排列参数接近1时,即纤维左头端数在所划分区间中为固定值时,纱条截面纤维根数不匀最低,而当排列参数趋向于0时,即纤维左头端数在所划分区间中呈泊松分布时则不匀最大。     

纱条中纤维的分布对其不匀率影响与检验方法

纱条中纤维的分布对其不匀率影响与检验方法棉纱的重量不匀率是衡量其质量优劣的重要指标之一。棉纱条中纤维的组成结构，如纤维平均长度，长短纤维比例，以及排列状态等都对纱条不匀率有影响。所以，可以经过其抽样检验法，了解、掌握纱条中纤维的分布情况。并进一步分析...     

聚丙烯腈纤维拉断法制条工艺探讨

腈纶长丝束多区拉断法直接制条工艺要保证出条重量、收缩率及条干达到膨体纱的成纱要求,工艺配置复杂,受下列因素的影响：纤维的断裂伸长率、加热板温度、热牵伸倍数、存放时间、各区牵伸搭配等。根据以上各因素的不同的变化规律,相应调整制条工艺。     

生条中短纤维含量与成纱指标的相关性分析

为探索生条中短纤维含量对纱线指标的影响,更好地通过短纤维含量指标对纱线指标进行预测,通过在不同锡林刺辊速度条件下对棉纤维进行梳理,并采用相同的后序工艺进行纺纱,将生产的生条取样,借助USTERAFIS 测试仪检测纤维的长度分布,分别统计出10、12、14 和16 mm 以下4 种短纤维的含量,同时借助条干、毛羽和强力测试仪分别检测各种实验条件下生产纱线的条干、强力和毛羽等指标,最后使用SPSS 统计软件计算出4 种短纤维含量指标与成纱各指标之间的相关系数。结果表明：当梳理工艺变化时,生条中短纤维含量指标与条干部分指标有较高的正相关性,与成纱强力指标不存在显著的相关性,与毛羽指标甚至是负相关。     

仿羊绒腈纶纤维条的开发

研究以0.88dtex细特腈纶丝束为主要原料在Seydel-679型拉断机上生产细特腈纶正规条,并与3.33 dtex腈纶收缩条混纺,开发生产仿羊绒腈纶条.结果表明,生产仿羊绒腈纶纤维条的适宜工艺为:拉断工序拉伸倍数6.05～6.27,再割区隔距比常规工艺大5mm,卷曲箱压力略大,汽蒸压力为0.15～0.3 MPa;针梳工序正规条与收缩条配比为52:48,降低针板号数,退卷曲区牵伸倍数1.15～1.3,梳箱喂入区牵伸倍数0.98,主牵伸倍数6～8,前罗拉隔距45mm.     

也谈毛纱截面内的纤维根数

与传统的计算方法不同，本文用六方密堆积结构导出了毛纱截面内的纤维根数及其可纺支数之间的计算公式。     

牵伸对纱条条干不匀影响的模拟研究

牵伸时纤维运动引起其排列变化是影响牵伸后纱条条干不匀的关键.为探究纤维变速点分布对牵伸后纱条条干不匀的影响,通过计算机模拟了实际纱条中的纤维排列(实际纱条),分别对理想纱条和实际纱条牵伸过程中的纤维运动进行了模拟,计算了在不同变速点分布下牵伸后纱条的条干不匀,并进行实验验证.结果表明:与理想纱条相比,实际纱条的条干不匀...     

电容式条干均匀度仪上纱条离散特征数方差σ^2的研究

本文研究了在电容式条干均匀度仪上把现在反映内不匀的变异系数，改用反映内外不匀的总变民系数来表征纱条均匀度，用上述方式计算总变异，大大提高了测量精度。     

聚丙烯腈纤维拉断法制条缩率控制的探讨

本文结合我公司生产实际,并借鉴原料厂家生产经验,就腈纶膨体纱生产过程中的主要质量指标──收缩率的控制进行探讨。     

关于Tencel纤维在制条过程中毛粒的形成及其改善措施的分析

本文提出了国内Tencel纤维条生产中常见的质量问题，并通过Tencel纤维条的生产实例，对加工过程中毛粒的形成及其改善措施进行了具体的分析，为国内Tencel纤维条的生产提供一份实际资料。     

浅析化纤清梳联清棉流程对生条棉结的影响

介绍了采用全套国产设备和采用德国特吕茨勒开清设备的两条化纤清梳流水线对生条棉结的影响。     

梳棉机给棉板与刺辊隔距对梳棉质量影响

用AFIS单纤维测试仪对不同的给棉板与刺辊隔距生产的生条质量情况做了检测,结果显示：（1）给棉板与刺辊隔距愈小,对纤维,尤其是长纤维损伤愈严重;（2）单纯以短绒率来表示纤维损伤可能是不全面的;（3）给棉板与刺辊隔距愈小,对棉结和杂质去除越为有利,但对带籽屑棉结去除以隔距较大时比较有利。     

提高A186系列梳棉机生条质量的工艺措施

针对A186型梳棉机的特点,在原有纺纱工艺的基础上对各部位隔距、速度等采取了部分改进措施,生产实践表明,生条质量得到了显著提高。     

Modeling roller drafting based on fiber arrangement in the sliver

The variation of fiber arrangement caused by fiber motion during roller drafting process contributes greatly to the sliver properties, especially to the irregularity. In this study, a model of roller drafting based on fiber arrangement in the sliver was developed to calculate sliver irregularity. This proposed new method was capable of tracing the motion of individual fibers during the whole drafting process from the first floating fiber accelerating being accelerated to the last floating fiber being accelerated. The additional irregularity caused by the characteristic of accelerating in different cross-section was also calculated and analyzed by this simulation. The obtained simulation results were highly in accordance with empirical conclusions by the displacement deviation theory. Besides, the output fiber arrangement could be recorded and saved in order to be further regarded as the input fiber arrangement of the next following drafting process. The simulation results of three drafting zone were highly corresponded to the previous experimental research. Therefore, the as-developed model was proved to be useful and accurate to explore roller drafting and predict sliver irregularity.     

Analysis of ramie fiber length changes during the stretch-breaking process

Stretch‐breaking is a recent new technology proposed for ramie fiber processing. By analyzing the fiber motion and its breaking point pattern in the stretch‐breaking zone, the distribution of the fiber breaking point was estimated, and the relationship between fiber length parameters, such as average length, length irregularity, and short fiber content, and stretch‐breaking settings was constructed quantitatively. Furthermore, the factors affecting fiber length changes are discussed. In addition, the distribution of the fiber breaking point in the fiber is experimentally determined. It can be concluded that the stretch‐breaking gauge presents high correlation with the length parameters of the treated fiber. These conclusions are profoundly instructive to the practice of the stretch‐breaking technique.     

Simulation on fiber random arrangement in the yarn part II: joint effect of fiber length and fineness distribution

Simulation on fiber random arrangement in the yarn has been studied in our previous research, where only fiber length distribution was considered. In this study, fiber fineness distribution was also taken into account in order to study the joint effect of fiber length and fineness distribution on fiber arrangement in the yarn. Eight-millimeter term limit irregularity of simulated yarn can be re-expressed by calculating the irregularity of the total weight of fibers within each yarn subsection. It can be seen from the results that the calculated irregularities considering fiber fineness distribution are closer to tested values compared with those without considering fiber fineness distribution. Besides, when the variance of fiber fineness gets greater, the difference between the calculated values with and without considering fiber fineness distribution becomes more obvious. For fiber length, the effect of average fiber length on yarn limit irregularity is very little, while its distribution has no significant effect on yarn limit irregularity. The improved simulation on fiber random arrangement in the yarn is more reasonable and can be applied for the prediction of yarn qualities.     

A mathematical model of fiber orientation in slivers

The directional arrangement of fibers significantly determines the internal structure and the mechanical properties of the slivers and the ultimate yarns produced from such slivers. In order to evaluate the directional arrangement of fibers in slivers, the experimental method according to Lindsleys’s idea, based on the weighing of suitable combed-out and cut-out fringes, is most frequently used in practice. But, the traditional Lindsley’s evaluation takes on some empirical ratios of fringe weights only. In this work, the experimental method according to Lindsley’s idea is analyzed and a set of relevant equations are derived for the theoretical determination of the measured fringe weights. The new characteristic of fiber orientation represents the harmonic mean of cosines of angles among the short fiber segments and the longitudinal direction of the sliver. The probability density function of the directional arrangement of fibers in a sliver is also estimated. The experimental data obtained on polyester-drawn sliver is compared with the theoretical results and a satisfactory correspondence between them is observed. The fiber orientation function reported in this article can be used in practice as a new quality parameter for the slivers and also to judge the effectiveness of the fiber preparation processes.     

Effect of accelerated point distribution on sliver irregularity. Part II: optimization of draft settings in two-zone roller drafting system

Accelerated point distribution plays a dominant role in discussing sliver irregularity in drafting. This paper, which is based on a theory developed in an earlier publication, proposes a new method to optimize the draft settings using the minimum coefficient of variation (CV) of fiber accelerated point. The new approach offers advantages over the traditional regressed optimal drafted settings (to yield the least weight variation in drafted slivers) and does not need extensive laboratory trials.     

并条工序中精梳产品皱褶条的控制

棉条皱褶如果不及时解决会直接影响成纱质量和后工序生产效率。通过对皱褶条的形态、成因进行分析,指出要合理配置并条工艺,保持设备运转状态正常,控制好车间温湿度,尤其是出条速度的选择、托棉板喂入宽度、集束器的位置及通道的光洁度。调整后,生产中近一年来未出现皱褶条现象。