Research On The Effects And Countermeasures On Testing By HVI Of The New National Standard Of Cotton

As a representative of cotton fiber testing instruments,Uster's HVI has been widely used in cotton testing organizations and cotton spinning enterprises because of its advantages such as accuracy,high speed,comprehensive and high efficiency.With the implementation of the new national standard of cotton,the color grade has replaced the cotton grade and the test of cotton has come into a new instrumentation times.HVI will not only play a more important role in the process of public prosecution of cotton but also play a positive role in the cotton spinning enterprises to optimize the distribution of cotton and reduce the cost of production.It puts forward higher requirements on the rationality,accuracy,science and other aspects of the quality indexes of cotton with HVI.This paper will study on how to make HVI satisfy these requirements and propose some corresponding countermeasures.The main contents of the paper are as follows:(1)The relationships between the two indicators like yellowness and reflectance of cotton and other indicators were analyzed and the test results of cotton color grade tested with HVI were discussed on whether they were accurate,scientific and reasonable or not.(2)Also,the significancy of the factors affecting the test results of cotton Micronaire with HVI were analyzed and studied,and the levels of influence of various factors were determined by combining the analysis method of uncertainty.In addition,the levels of influence and the significance of the factors affecting the long and strong module test results of cotton with HVI were analyzed and studied,and uncertainty evaluation were done by combining the analysis method of uncertainty.(3)In this paper,the differences and relationships of the test results with HVI and AFIS were compared and analyzed by testing the short fiber content of cotton with the two instruments and the test results of the length uniformity and the short fiber content of cotton were discussed on if there's a relationship as well.(4)This paper aslo studied on the measures and countermeasures to the cotton new national standard with HVI.The research results of this paper are as follows:(1)The results showed that the reflectance of cotton had a statistically significant positive correlation with the upper half length,breaking strength,Micronaire and the length uniformity of cotton but the yellowness of cotton had a opposite correlation with those indicators.HVI had a good stability and accuracy in the process of detecting the color grade of cotton.(2)When testing Micronaire of cotton fiber with HVI,the effect of the test results on Micronaire caused by the operators was more significant,by two different sample delivery techniques was significant,by the quality of sampling was more significant,and by the test number was not significant.By combining the analysis method of uncertainty,the degree of influence of the four factors on the test results was identified as follows,sample delivery method>operator>sampling quality>number.(3)The degree of influence of various factors on the test results during testing the strength,length uniformity and the upper half length as follows,sampling quality>operator>number and the three factors didn't have a significant effect on the three indicators.Calculating the factors uncertainty of components by combining the analysis method of uncertainty,and we can know the temperature and humidity of the environment,the operators,the system calibration and the performance of the instruments had a certain effect on the test results during the process of testing with HVI.(4)Through the introduction of uniformity,the linear regression equation between the short fiber content and the length uniformity of cotton was determined.(5)Based on the changes of the new national standard and the testing demands of HVI,the specific response measures and countermeasures of HVI were provided.