It is generally believed that

Grade "quality" represents quality and "grade" represents level.

The grade is a comprehensive index representing the quality and grade of cotton fiber. It also indicates that cotton fiber has different economic value and use value.

The three conditions for grading are maturity, color characteristics and rolling quality.

Color grade of cotton fiber: type and grade of cotton fiber color.

The type is determined by yellow depth, and the level is determined by the degree of brightness.

The color of cotton fiber directly affects the grade of cotton fiber and the color level of cotton fiber.

The color of cotton refers to the color and luster of cotton. It is not only a reflection of physical appearance of cotton fiber appearance, but also an intrinsic quality of cotton.

To a certain extent, color reflects the inherent quality of cotton, and is one of the main conditions for evaluating cotton grade. It is the only condition for evaluating the color level of cotton fiber.

The color of cotton is the absorption and reflection of cotton samples to different wavelengths of light. Due to absorption and reflection, the original spectral components are changed, and the stimulation of three kinds of color sensitive cells on human retina is different from that of sunlight, resulting in various color vision.

The gloss of cotton is reflected by the optical properties of cotton fibers. The reflection of cotton fibers on the light and the intensity of reflected light determine the strength of the cotton gloss.

The color is directly related to the varieties, soil and climate, and is directly related to the maturity of cotton. Under normal circumstances, cotton matures well in the early and middle stages of cotton. In the process of cotton growth, there is less tannin in the cotton hull and cottonseed epidermis in the early and middle stages.

The color of cotton fiber is related to the amount of tannin. The more tannin the epidermis of cotton hull and cottonseed is, the more darker the cotton fiber is. Therefore, when we examine cotton, we see that the color of early and middle cotton is white or milky white, and the color of late cotton is yellowish and dark red.

The lustre of cotton is formed in the natural growth of cotton. It has a great relationship with the shape of the cotton fiber. The closer the fiber section is to the circular shape, the better the gloss. The closer the cotton fiber section is to the circle, the more cellulose is accumulated in the cell wall, and the crystallization degree of the fiber structure increases and the crystalline area increases. The waxy layer on the cotton fiber surface is also one of the factors reflecting the gloss.

The distribution of limited wax can be reduced, and the uniform distribution can be achieved. The gloss can be better reflected.

The quality of cotton fiber is mainly reflected by cotton maturity and number of turns. These aspects are related to the internal structure of cotton fiber.

The inner structure is at a better level, its quality is good, and its appearance is white and bright.

Therefore, under normal circumstances, the quality of cotton fibers with good color will be good.

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In testing, the color of cotton fiber is an important factor to evaluate cotton quality.

When the color of cotton fibers is poor, the maturity and strength of cotton fibers are generally low. The fibers are banded thin fiber, with little rotation, low spinning value and poor quality.

When testing the color level, the color and quality of cotton directly determine the type and level of color.

Determine the type according to the depth of the color, determine the level according to the brightness of the luster.

Through a year's color level pilot test, I believe that most of the cotton color grade white cotton grade 1 to four and grade one to four are corresponding, grade five, if the base color is gray instead of yellow and color grade white cotton five grade corresponding, such as the basic color yellow will correspond to the lighter spot cotton grade two, grade six is generally corresponding to the lighter grade three.