Fiber Inspection: A Brief Discussion on the Correlation between Cotton Grade and Color Grade

It is generally believed that the "quality" of cotton fiber grade represents quality and "level" represents grade. Grade level is a comprehensive indicator representing the quality and level of cotton fiber, and it also indicates that cotton fiber has different economic value and use value. The three conditions for rating grades are maturity, color characteristics, and the quality of the press.

Cotton fiber color grade: The type and grade of cotton fiber color. The type is determined according to the yellow depth, and the level is determined according to the degree of lightness and darkness. The color quality of cotton fiber directly affects the level of cotton fiber and the color level of cotton fiber. The color of cotton refers to the color and luster of the cotton. It is both a reflection of the appearance of the physical appearance of the cotton fiber and also related to the inherent quality of the fiber. The color reflects the intrinsic quality of cotton to some extent, and it is one of the main conditions for assessing the grade of cotton. It is the only condition for evaluating the color of cotton fiber.

The color of cotton is the absorption and reflection of cotton in different degrees of light at different levels. Since the absorption and reflection change the original spectral components, the three color cells on the human retina receive different stimulation and sunlight, resulting in various Color perception. The luster of cotton is reflected by the optical properties of cotton fibers. The reflection of cotton fibers on light and the strength of reflected light determine the strength of cotton luster.

The color of cotton is related to variety, soil, and climate. At the same time, it has a direct relationship with the maturity of cotton. Under normal circumstances, the maturity of cotton in the early and middle stages is very late. The maturity of cotton is poor. From the cotton growth process, the cotton husks of cotton in the early and middle stages are And cottonseed contains less tannins, late cotton contains more tannins in cotton hulls and cottonseed skin. The color of cotton fiber is related to the number of tannins. The more tannins contained in the cotton husk and cottonseed skin, the darker the color of the cotton fiber, so when we test the cotton, we see that the early and mid-term cotton color is white or milky, and late cotton. The color is yellow and red.

The luster of cotton is formed in the natural growth of cotton. It has a great relationship with the cross-sectional shape of cotton fiber. The closer the fiber cross-section is to the round, the better the luster is, and the closer the cotton fiber cross-section is to the cellulose deposited in the cell wall. The more, the crystallization degree in the fiber structure is increased, the crystal area is increased, and the alignment degree of the macromolecules is increased, and therefore, its maturation is good and the strength is high.

The luster of cotton fiber is related to the number of natural turns. Natural turns are more. The raised spherical surface on the fiber surface can enhance the reflection ability of light, and the sensory reflection on the retina of the human eye is brighter. The waxy layer on the surface of the cotton fiber is also one of the factors that reflect the gloss. The immature fiber wax layer is uneven and thick, and the reflected light is insufficient. As the maturation of cotton fiber increases, considerable cellulose is deposited in the secondary cell wall. The cross-sectional area of ​​the fiber tends to be round and has a longer circumference. It distributes the limited wax to make it The thickness is reduced and evenly distributed, and the gloss can be better reflected.

The quality of cotton fiber is mainly reflected in the degree of maturation, strength, number of turns, and other aspects of cotton. These aspects are related to the internal structure of cotton fiber. The inner structure is at a good level and its quality is good. From the aspect of appearance, the color is both white and bright. Therefore, under normal circumstances, the quality of good color cotton fiber is also good.

In the grade test, the color of cotton fiber is an important factor in assessing the quality of cotton. When the sensory method is used to identify the grade of cotton, the color can indirectly reflect the inherent quality of the cotton fiber because the color of the cotton fiber is proportional to the maturation, strength and turning of the cotton. When the color of the cotton fiber is good, the maturity and strength level of the cotton fiber are generally higher, the number of turning is more, the value of spinning is high, and the quality level is good; when the color of the cotton fiber is poor, the maturity and strength of the cotton fiber are also generally Lower, the fibers are thin, strip-shaped fibers, and the number of twists is also low. The value of spinning is low and the quality level is poor. When testing color grades, the quality of the cotton color directly determines the type and level of the color grade. According to the depth of its color to determine the type, according to the brightness of the gloss to determine the level.

Through one-year color-level pilot test, the author believes that in most cases, the cotton color grade white cotton grades 1 to 4 and the grade grades 1 to 4 correspond, and the grade grade 5 grades should correspond to the basic color gray instead of the yellow and the color grade white cotton five grades. For example, the base color yellow will correspond to the light pollution secondary cotton grade, and the grade level 6 generally corresponds to the light pollution level three.