The diameter and number of carding neps will directly affect the number of neps and yarn defects in the yarn, especially the number of A1 and A2 yarn defects, while the short staple rate of the card sliver will directly affect the yarn strength, minimum strength, and hairiness. Index H and weaving warp breakage. Cleaning and carding must not only control AFIS neps and short staple rate in the traditional sense, but also consider the carding state of the fibers, the diameter of the neps and the uniformity of the fibers.
01 Frequently Asked Questions about Cotton Cleaning
The cotton picking parameters of the cotton picking machine are frequently adjusted, and the operating efficiency of the cotton picking machine is low. The operating efficiency of the reciprocating cotton picking machine is controlled above 90%. The grabbing depth and speed can be determined according to the operating efficiency of the cotton picking machine, and the descending depth can be adjusted reasonably to achieve gripping and loosening of raw cotton by the beaters and ribs, further improving the opening effect of the cotton picking machine. It is necessary to strictly implement the grabbing speed and depth determined by the process, and prevent arbitrary adjustment of cotton picking parameters. Cleaning and continuous feeding of cotton is a key factor to ensure uneven sliver weight and raw material mixing effect. It is also conducive to ensuring the stability of the cotton flow, ensuring the opening effect and the removal efficiency of cotton impurities and foreign fibers. According to the cotton composition and seasonal changes, the beater speed and noil distance of each cotton cleaning machine are timely adjusted to control the growth rate of neps and short lint at a low level to ensure the effective removal of neps, impurities, short lint and foreign fibers. , ensuring the raw cotton opening effect and mixing effect.
02 Frequently Asked Questions about Carding
Nowadays, spinning mills often focus on the removal efficiency of neps and short lint, but not much Pay attention to the degree of carding of the fibers. Although carding neps and short lint are better, fiber damage may be caused by excessive carding, and the quality of the yarn is not satisfactory. Carding is accomplished by carding elements. If the carding elements are not in good condition, the ideal carding effect cannot be achieved. The movable cover chain is elongated, the chain is inflexible, the heel and toe surfaces of the movable cover are worn and the cover is undulating, which are common management problems in enterprises. Wear of the heel and toe surfaces of the cover plate and undulation of the cover plate often result in inaccurate spacing, which occurs in both sliding friction and bearing-type rolling friction. When maintaining the cover chain and the movable cover frame, pay attention to the following points:
1) The length of the cover chain must be ensured that the entire extension is within 76 mm, and the root difference on both sides is Control it within 3 mm. Secondly, it must be ensured that the star guide plate is not worn, not twisted, and intact.
2) Clean and refuel the chain regularly, measure the length periodically, and install the short chain on the main drive side to eliminate the length difference and prevent the cover plate from running in parallel.
3) Correctly adjust the chain tension, focusing on the middle footrest and the rear footrest as a supplement. Pay attention to the horizontal condition of the top surface of the movable cover after adjustment to ensure that the tension on both sides is consistent and prevent both sides of the chain. The cover is uneven and the tension is too high or too low.
4) Pay attention to the lubrication effect of the lead powder block of the movable cover plate to ensure good lubrication and prevent excessive cover plate resistance and chain elongation caused by poor lubrication.
It is necessary to strengthen the management of card clothing. The card clothing of each part of the card is both a periodic part and a wearing part. In terms of card clothing management, general enterprises have the following problems.
1) The replacement cycle of the card clothing is not clear, the card clothing is seriously overused, or even used for more than 6 years, and the carding quality is not paid attention to. It is recommended to set the card clothing usage cycle based on actual output and card clothing quality, and observe the card clothing status and carding quality on the machine at any time to ensure the card clothing usage time and finished product quality. For example, when 100% pure cotton long-staple cotton is combed 7.4 tex and the carding table output is 24 kg/h, the service life of the imported first-tier brand cylinder card clothing is 3 years, the imported ordinary brand is used for 2 years, and the domestic first-tier brand card clothing is used The cycle is 1.5 years and can meet the quality requirements of USTER 2013 Bulletin.
2) The card clothing is damaged or sick while the machine is running. When card clothing is replaced due to unexpected reasons, strict review must be carried out. For accidentally damaged card clothing, the cause must be found to prevent secondary damage after the machine is put on the machine.
3) There are no complete card clothing management regulations and usage records, and the card clothing is used loosely and replaced at will. It is recommended to establish a card clothing replacement ledger, continuously conduct optimization and selection tests of card clothing models, and select brands and models that are suitable for the company and have high cost performance. If the variety changes frequently and the raw materials change greatly, it is recommended to choose a universal card clothing to take into account the yarn quality level between different raw materials.
According to AFIS test verification, when the carding machine suction duct is clogged, neps will increase by more than 2 times. Ensuring the smoothness of the carding machine’s suction system will also help ensure the quality of carding slivers. The key to ensuring the smoothness of the carding machine’s suction system is that the dust filter air volume is appropriate, and the operating personnel check and eliminate it in a timely manner. </p
