1. The strength and elasticity of fibers with poor maturity of raw cotton are worse than those of mature fibers. They are easy to break and produce neps when stress is generated due to ginning and blowroom processing during production and processing.
A foreign textile research institute divided the proportions of different mature fibers in the raw materials into three groups, namely M1R=0.85, M2R=0.75, M3R=0.65 for spinning tests. The test results, the number of spun yarn neps are listed in Table 1
The above table shows that the proportion of immature fibers in raw cotton is getting higher and higher. The larger the yarn, the more the neps content in the spun yarn increases.
Using these three groups of raw cotton yarns to weave cloth, although no problem can be seen on the gray cloth, after dyeing, it was found that the white spots of the final product of raw cotton with a large content of immature fibers were higher than those of mature fibers. The white spots of fabrics woven with high raw cotton content increase significantly.
2. The fineness and maturity of raw cotton are generally expressed by the micronaire value. The better the maturity of the raw cotton, the higher the micronaire value. High, different raw cotton varieties have different micronaire values.
Fine velvet raw cotton with high maturity has good elasticity and high strength. Few neps are produced during the spinning process. Low-maturity fibers have poor rigidity due to thick fibers. , low single strength, easy to produce neps and short fibers under the same impact conditions.
For example, when the blower speed is 820 rpm, due to the different micronaire values of cotton fibers, the neps and linters produced are also different, but the beater speed is correspondingly reduced. , the situation will improve, see Table 2
The above table shows: the fiber is fine Different degree and maturity, and different micronaire value, have different effects on the nep content of the yarn.
3. When selecting raw cotton and designing the cleaning and carding processes, the length, impurity content, and In addition to short staple and other indicators, special attention should be paid to the selection of the micronaire index of raw cotton. Especially when producing and processing fine-staple cotton and long-staple cotton, the size of the micronaire is more important. The selection range of the micronaire is generally 3.8- 4.2. When blending cotton and designing spinning processes, attention should also be paid to the maturity of cotton fibers to ensure that sliver neps are reduced and the quality of spinning, weaving and dyeing is steadily improved. </p