【作者】 刘若华；

【导师】 李汝勤；

【作者基本信息】 东华大学 ， 纺织材料， 2002， 博士

【摘要】 本论文在研究现有的原棉长度测试方法基础上，进一步探讨了快速测试原棉短纤维含量的取样及测试方法。应用数学工具从理论上探讨了纤维长度的取样分布、影响测试的因素、照影机曲线的修正模型及短纤维含量指标的求取方法；提出了新的取样方法并研制了相应的取样器；制作了适于测试原棉短纤维含量的纤维长度照影机样机。通过实验，对所研究的理论、方法及仪器进行了分析和验证，得到了一系列有关原棉短纤维含量测试的结论。 论文首先指出原棉短纤维含量对工商贸易、纺织工艺及产品质量的影响，阐明了快速测定这一指标的重要意义；回顾了棉纤维长度分布理论的发展；并结合国内外棉纤维长度测试技术的现状，特别是在短纤维含量测试方法上存在的问题，对棉纤维长度的测试原理、取样方法、仪器特点及其发展等进行了综合论述。 论文的主要工作是在微量取样的研究基础上，研究了采用钩夹从各种状态下的棉纤维集合体中取样时，夹子上试样的分布特点；分析了钩夹的几何形状及纤维的存在状态对取样分布的影响；研究结果指出，从非均匀分布散纤维中取样时若要得到分布比较理想的试样，应采用微量、多点、随机分散及无滑移、无纠缠的取样方式，为此取样夹子应具有较窄的宽度和较短的长度以使取样量控制在较小值，夹子的夹持力要足够大。由此出发并结合理想取样的要求，提出了一种新的取样方法——钩夹取样法，即用多只以一定方式组合，能方便快速排列开启的小钩夹夹取棉样。取样时，各钩夹彼此间的相互影响很小，每个钩夹夹取的试样量是可控的、微量的，夹取到的纤维少有滑移、丢失及相互纠缠等现象的发生。整个取样器取到的总体试样是随机、大量且有代表性的，取样分布在两侧是对称的且与原棉的原分布之间有比较明确而稳定的关系。论文在理论上研究了这种新的取样方法的性质特点及可行性，还通过大量实验探讨了对各种不同状态棉纤维所取试样的实际分布与理论分布的差异，进而分析了影响取样效果的因素，并根据研究结果制作了钩夹取样器。 由于目前使用的各种类型纤维照影机的结构、光电信号处理方式对原棉短纤维含量测试结果有影响，论文在第三章中首先从理论上研究了照影机扫描线宽度对棉纤维长度测试的影响，得出了测试原棉短纤维含量时应采用窄宽度扫描线的结论。但是由于窄宽度扫描线照影机的扫描透射光较弱，无法利用常规照影机的检测方式，所以论文对开发应用调制光来进行检测的窄宽度扫描线照影机作了一些探讨。根据在短纤维含量测试中出现的一些实际情况，不仅探讨了光电转换部分的元器件选择、使用等方面的问题，还针对由于透射光较弱而使光电信号易受环境温度及外界光线干扰的现象，在照影机上应用了稳功率光源及相干检测技术，使得仪器具有较高的稳定性和灵敏度。 为利用新的取样方法和测试装置准确、快速地测得原棉短纤维含量及其它各种长东华大学博士论文摘要度指标，论文提出了用“当量须片”研究试样量与光电输出之间的关系，并应用灰色数学模型对照影机曲线进行线性修正，梳理修正及对扫描起始点处进行修补，得出扫描曲线的修整参数。由于这些修整方法是从实际情况出发来进行的，因而比以往的从某种假设或理想条件下出发的修正及修补方法更具有优越性。 在此基础上，论文研究了利用照影机曲线求取原棉短纤维含量的方法。主要作了两方面工作，一是通过理论分析认为可以从钩夹取样法的扫描测试曲线上用切线作图的方法求取这一指标，并通过实际测试与罗拉法及HVI的测试结果进行分析比较，发现论文研究的方法具有较好的可行性。另一方面，论文还研究了运用灰色数学模型利用积分性变量求取原棉短纤维含量的方法，实验证明，这种方法不仅可避免测试结果受照影机曲线微量变化的影响，也可减少梳理带来的误差。 论文对原棉短纤维含量的测试进行了全面综合的研究，其探索的新的测试方法，克服了目前 HVI纤维长度测试仪由于梳夹取样根部纤维杂乱而无法正确测试短纤维含量，而罗拉式纤维长度仪测试速度慢，取样量不足的问题，对纺织工业生产具有应用价值。更多还原

【Abstract】 This article researches into testing technology of cotton short fiber content (SFC) based on the existing ways of cotton fiber length testing, theoretically studies sample length distributions, factors affecting the testing and calculating, adjusting model of figrogram and methods of getting SFC by virtue of mathematics, then finds a new sampling method, contrives hock-grip type sampler and makes new fibrograph. On the basis of a large amount of experiments, analyses and identifies about these theories, methods and devices are done by using modern mathematics. In addition, a series of conclusions relating to the SFC testing are drawn.This paper accounts for the sense of the testing of SFC by way of pointing out the influences of SFC on marketing, spinning process and quality of end textiles items, reviews the studying history of the theories of cotton fiber length distribution and comprehensively relates, combining the present testing situations of cotton fiber length at home and abroad, especially that of the SFC, the testing mechanism, instrument properties, sampling characteristics and developing direction in the future.The primary work done in this article on the base of the microsample is to study properties and characteristics of length distribution of samples taken by hock-grip sampler from various forms of cotton fiber and to find the influences of sampler geometry and fiber existing forms to the distribution in order to look for a new sampling way suitable to testing SFC. Accounting to these work the paper point out that an approaching ideal distribution samples can be got from nonuniform scattered fibers on condition that the sampling takes a scattered multipoint, stochastic, nonslip and nonsnarl mode, the hope-gripper are of narrow in width and short in length for sampling a pinch of fibers, and that the hold force of sampler must be big enough. Combining these with the requests of the ideal sampling, a new kind of sampling method, hope-grip sampling, is suggested, that is, using sampler with many little hope-grippers whose open space can be controlled on it to grasp cotton fibers, the sampler can be opened or closed easily and rapidly and there is less interfere between each grippers. The total took samples are characterized by less slippage, less loss and less tangle, and are large quantitative and randomly, also, there is positive and stable mathematical relationship between the sample distribution and the original’s. This paper theoretically studies the reasonable of the new sampling method, researches not only the realistic distributions of the held samples but also some factors influencing the examinations and designs a new sampler in its entirety in light of the outcomes concluded above.In order to make use of the new type sampler best, it is necessary to develop advanced fibrograph which meets with needs for the testing of SFC, because constructions and detection mechanism of varieties of fibrograph used now have great influences on thedraws a conclusion that narrow scanning line is necessary for the SFC testing. The testing principle of normal fibrograph is no more competent for the narrow scanning devices for its transmitted light is too week to be detected, so the focus of this part is developing modulating light instrument specialized for the SFC testing, concerning situations in actual examination, this paper explores not only the choosing and using of optical-electric elements but the applying of stable power light and mutual identifying technology aiming at transmitted light be faint after the narrow scanning line being used, all of these are good for enhancing stability and sensibility of the instrument. In addition, function of sample’s thick and the output is reached for adjusting the fibrogram.To measure the SFC and other length index directly, exactly and rapidly based on the new sampling technique and the specific experimenter, methods which can be used to gain length parameters from fibrogram more efficiently are studied. There are two aspects on this subject, t更多还原