1 Quality index of combed sliver
Combed cotton yarn is used to spin high-end products, so the quality of combed sliver is Quality requirements are extremely high. Due to the different spinning varieties, raw cotton conditions and production conditions of each factory, the quality index control range of combed sliver is also different. The general control range is shown in Table 5-2.
▲Combed sliver quality index
2 Reduce neps and combed yarn defects
The quality requirements of combed cotton yarn are higher. The number of neps and impurities in combed cotton yarn is more than half less than that of carded cotton yarn with the same linear density, because the combing machine can remove a considerable amount of neps and impurities. In particular, the impurity removal rate reaches 50% ~ 60%, and the neps can be removed 10% ~ 20%.
To reduce nep impurities and yarn defects, in addition to rationally selecting raw cotton, giving full play to the impurity removal function of the cleaning and carding processes and preventing the generation of neps, in the combing process The following points should be noted:
(1) Improve the roll preparation process, improve the quality of the rolls, and strive to improve the longitudinal and transverse uniformity of the rolls and the straightening and parallelism of the fibers, To give full play to the combing function of the combing machine.
(2) Improve the mechanical condition of the carding machine, especially the condition of the combing needles, which is the key to improving the carding effect. For example, the comb needle specifications and needle planting density of the cylinder and top comb should be reasonably adjusted to prevent needles and needle shortages, keep the comb needles in good working condition, trim the brushes in a timely manner, improve the flatness of the brushes, and maintain the elasticity of the bristles to improve The working efficiency of the brush ensures that it can clean the cylinder needle surface, etc.
(3) Correctly master the combing process, and reasonably adjust the timing of the separation roller’s forward rotation, the positioning of the cylinder bow plate, the timing of the closing of the nip plate, and the combing distance.
(4) Reasonably grasp and control the combing noil rate. According to the quality requirements of the spun cotton yarn, reasonably determine the noil rate, pay attention to the status of the noil at any time, and reduce the table difference and eye difference of the noil.
(5) Strengthen operational management. During operation, attention should be paid to the sticking of small rolls to prevent unclear layers or damage to the combing needle when feeding thick layers, which will affect the quality of the cotton web. At the same time, the cleaning cycle of various parts of the combing machine is correctly formulated and implemented, and better pile board structures and materials are used to reduce combing yarn defects.
3 Reduce the evenness of combed sliver
Due to the periodic separation and combination of the cotton web output from the combing machine, the combed sliver has Larger periodic segments are uneven. After the combination of subsequent processes, the periodic unevenness of the combed sliver can be greatly reduced, and because the fibers in the combed sliver have better separation and straightening parallelism, there are less short lint and defects, which is beneficial to Due to the drafting process in the subsequent process, the combed sliver has better evenness.
There are many factors that affect the evenness of combed sliver. On the basis of improving the quality of small rolls and maintaining normal organizational status, the following points should also be paid attention to:
(1) Reasonably adjust process parameters and correct timing positioning;
(2) Correctly control the tension draft of each part to reduce accidental stretching long;
(3) Keep the passage through which cotton webs and cotton slivers pass through smooth and clean;
(4) Strictly control the temperature and humidity of the workshop , control the temperature and humidity of the workshop within the specified range, that is, the temperature is 20 to 30 degrees Celsius, and the relative humidity is 55% to 60%, so as to avoid improper temperature and humidity control, which may cause winding rollers, winding rollers, cotton web edges, and coil strips to be tilted Pipe blockage and other problems.
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