Cotton, as the main raw material for textile mills, accounts for a large proportion of the total textile cost. Research has proven that cotton fiber quality is directly related to the quality of textile products. Cotton fiber length, length uniformity, short fiber content, moisture regain, harmful defects, foreign fibers, specific strength and cotton fiber fineness are the most important indicators that determine the quality of cotton yarn.
Cotton fiber length
Cotton fiber length is an important physical indicator of raw cotton quality and a major factor in the value of textile use. When longer cotton is used for spinning, the overlapping parts of the fibers in the cotton yarn are also longer, and the strength of the spun yarn is greater. When other conditions are the same, the longer the fiber, the higher the strength of the yarn. The yarn count is finer. The fibers are long and well-organized. After the yarn is formed, the friction between the fibers is large and it is difficult to slip off. The yarn is even and dry. When spinning fine yarns with fibers with high strength and long length, it has a significant effect on improving the strength of the yarn. Therefore, cotton fiber length is closely related to yarn strength. In the spinning process, the determination of process parameters such as adjusting the roller gauge and the twist coefficient of thick and thin yarns are all related to the length of the cotton fiber. Since fiber length is the main basis for determining the spinning process and equipment, spinning process coefficients such as roller spacing, pressure, draft multiple, and twist all have an impact on the yarn evenness.
Moisture regain rate
Moisture regain rate is the main factor affecting the quality of cotton processing. factor. The moisture regain rate of processed lint also has a great impact on the spinning of textile mills. The moisture regain rate of raw cotton is high, the cotton pieces are not easy to open, and the layers are bonded, which can easily cause uneven cotton rolls. The carding machine has low carding and impurity removal efficiency, the cotton web is easy to sag, the card sliver uniformity is poor, the moisture regain of the raw cotton is too low, and the fibers are easily interrupted and damaged during the processing, resulting in an increase in short fibers and an increase in static electricity. , rollers, rubber rings and other parts produce “dry winding” phenomenon. Therefore, the moisture regain rate of textile cotton is generally controlled at 7% to 9%.
Raw cotton contains impurities
Raw cotton contains impurities which affects the quality of yarn one of the main factors. There are three categories of impurities in raw cotton. The first category is impurities that are easy to remove, such as leaf sediment and cotton seeds; the second category is impurities that are easily broken, difficult to remove, and have a greater impact on gauze, such as infertile seeds, Fiber stem chips, broken seeds, etc.; the third category is harmful defects that are difficult to remove and have obvious harm to the quality of gauze, such as soft seed skin, stiff flakes, yellow roots, foreign fibers, etc. The quality of the rolling process is also a factor that affects the quality of the yarn. Cotton with poor ginning will produce cords and neps, especially tightly wound cords and neps, which are difficult to remove by carding, resulting in an increase in neps and impurities in the yarn.
Other fibers are thin, long and light. Not only are they difficult to remove during the spinning process, but they will also be broken or combed into shorter and finer fibers during cleaning, combing and other impurity removal processes, which can easily cause yarn defects during spinning. Color defects are easily formed during bleaching, printing and dyeing, seriously affecting the quality of cotton yarn and fabrics, and causing huge economic losses to textile enterprises.
Cotton fiber strength
Cotton fiber strength is the key factor in spinning An important indicator that is crucial to improving the quality of textiles. When other conditions are the same, the higher the specific intensity, the higher the quality index of spinning yarn. Fiber strength also affects spinning production efficiency. When fiber strength is low, it is easy to break during the spinning process, which increases the end-break rate and affects the yarn evenness. In addition, the amount of cotton used increases, which increases production costs and reduces production efficiency.
Cotton fiber fineness
The fineness of cotton fiber directly affects the Yarn quality. The fiber is fine, soft and elastic to the touch. After the yarn is formed, the fiber cohesion is good and the strength is high. If the fiber is not mature well, although the fiber is thin, the elasticity is poor, and short lint and neps are easily formed during the yarn forming process, which affects the quality of the yarn. However, cotton fiber that is too thick has poor toughness, which will increase the breakage of cotton yarn and reduce the strength of cotton yarn. The finer and stronger the fiber, the higher the textile value.
Cotton fiber maturity
Cotton fiber maturity can be used as an assessment A comprehensive indicator of the intrinsic quality of cotton fiber. It directly affects the color, strength, fineness, natural twist, elasticity, moisture absorption, dyeing and other properties of cotton fiber. Therefore, the quality of cotton fiber can be estimated or measured based on the maturity of cotton fiber. Other physical performance indicators. Mature cotton fibers naturally have more twists, good elasticity, and good color. They are not suitable for forming neps and cords during the spinning process. The fibers have good cohesion and spinnability, and the yarn is even and has few defects. The yarn strength is also high. When the fiber maturity is too poor, the fiber strength is low, the fineness is fine, and the elasticity and toughness are poor. It is easy to form kinks during the spinning process, which increases the appearance of fiber defects and increases neps and impurities. However, the fibers of over-mature cotton are thick, and the number of fibers in the cross-sectional area of the yarn is relatively reduced, which also affects the strength of the yarn. </p