A Study On The Testing Of Cotton Short Fiber Content

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...