A Brief Analysis Of Cotton Color Grading Test

< p > cotton quality evaluation in China has gone through two systems. One is the "grade examination system" which is mainly implemented by sensory testing before 2013. The two is the "color level inspection system" which is mainly instrumented based on the reform of cotton quality inspection system.

"Grade examination system" is a comprehensive judgement of people's perception of cotton color characteristics, maturity, and rolling quality by hand. It is like the pulse of Chinese medicine. With a finger, it can give a comprehensive body condition evaluation simply by pulse, but it can not give a more accurate cause. In the "grade examination system", the grade represents the quality of cotton.

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In the < p > color level inspection system, the color level does not fully represent the quality of cotton. It only indicates the color condition. If combined with a series of physical indicators such as clone value and fracture strength, comprehensive evaluation can show the comprehensive quality of cotton. There is a big difference between color grade and grade in showing cotton quality.

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< p > grade test, without any instrument, the test value can be obtained. Its < a href= "//www.sjfzxm.com/news/index_c.asp" > test is based on < < /a > > based on the description of the written standard and the grade object standard made by the authoritative department each year. There is no quantitative index to measure the correctness of the test. The color level fundamentally changes the situation that the sensory test can not be measured, and the accuracy of the test is measured by the test value of the instrument.

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< p > the eyes of the grading personnel are considered to be the primary tools for measuring colors. Their sensitivity to color differences is much higher than that of HVI. However, subjective judgement of human beings has some subjective shortcomings, persistence and stability are not good, and it is not suitable for judging the absolute level of color, as well as the accuracy of instrument testing.

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The fact that "P > 200 years" has proved that cotton color not only affects the appearance of the product, but many properties of the cotton fiber are related to the color, and the color is the primary factor determining the quality of the cotton.

The "color grading inspection system" is used to determine cotton's yellowness and reflectivity by large capacity cotton rapid tester.

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The color of cotton is basically the same. The degree of yellow and shade is enough to indicate the color grade. The color level of cotton is graded by reflectivity (Rd) and divided by yellow degree (+b). P

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< p > cotton is divided into 4 types according to the Yellow degree: < a href= "//www.sjfzxm.com/news/index_c.asp" > white cotton < /a >, light polluted cotton, light yellow dyed cotton and yellow cotton. According to the reflectivity, white cotton is divided into 5 grades, the spotted cotton is divided into 3 grades, the yellow cotton is divided into 3 grades, and the yellow cotton is divided into 2 grades, 13 grades.

The color level is represented by two digits, the first is the level, and the second is the type.

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One of the tasks of the reform of the quality inspection system of < p > China a href= "//www.sjfzxm.com/news/index_c.asp" > cotton < /a > is to gradually replace the manual grade inspection by hand testing with the color level which can be quantified by the HVI test.

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< p > first, a large number of test data were obtained through instrumented notarization test, and the color grading map of cotton was established.

Secondly, some laboratories were selected to carry out the compliance verification test of color level artificial sensory test and HVI test, and the cotton classification map was adjusted to make it more suitable for the different characteristics of cotton in different parts of China.

Finally, the cotton seed processing enterprises, cotton inspection institutions and cotton textile enterprises were selected for cotton color level sensory test and instrument (HVI) test comparison and verification.

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< p > after the analysis and statistics of a large number of detailed data, the color grading map of cotton in China was finally improved and applied to complete the pition from grade inspection system to color grade inspection system, and training inspectors, reversing the concept of consistent cotton quality inspection from the personnel's thinking, understanding and mastering the relationship and difference between the color grade and grade of cotton, mastering the source of various colors of cotton, the appearance characteristics of lint and the appearance and processing characteristics of cotton in each planting area.

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