There are many yarn defects in carded cotton yarn, which not only affects the cotton yarn rating, but also affects the appearance of the cloth, the intrinsic quality and use value of the cotton cloth. This not only brings disadvantages to the yarn mill, but also brings disadvantages to the weaving production and operation. Directly affects the vital interests of manufacturers. Based on the production practice of our company’s carded cotton yarn, we now summarize three common causes and solutions of yarn defects in carded roving.
1. Thick and thin weft yarn defects
(1) When joining thick joints, the lap is too long, too short or wrapped Too tight or too loose, resulting in thick and thin wefts.
(2) The parts that the cotton sliver and yarn sliver pass through (such as the bundler, the bell mouth, the flyer channel, etc.) are not smooth, resulting in hanging slivers and bringing the yarn or sliver into the transportation During the process, the lint or the mouth of the sliver barrel is damaged, resulting in uneven thickness and weft.
(3) When the roving is broken, the whiskers float into the adjacent yarn strips and the double yarns are fed to form a thick weft.
(4) When processing and roughly winding rubber rollers and rollers, the thin strips are not pulled clean or the end-breaking automatic stop device fails and a few strips continue to form, resulting in thin wefts.
(5) After the roving frame, the sliver is hung with wool and the batch is dropped. The lathe on duty did not find it in time and fed the roving to form a fine weft.
(6) Improper operation when changing the teeth of the roving frame, movement of the rubber roller when unloading and applying pressure, or transmission inertia when turning on and off the machine, etc., resulting in fine weft.
2. Slub yarn
(1) Do not follow the operation According to the method, the pile board flowers in the carding, combining and roughing processes, the short velvet at the bell mouth and various accumulated flowers are brought in, flying flowers are moved, etc. to form the pile board slub yarn.
(2) The drawing pressure rod is in an improper position, and the coarse transmission gear is too loosely meshed. The keyway or shaft hole is worn out and loose, resulting in intermittent cotton webs and slub yarn.
(3) The surface of the thick rubber roller is rough, the roller groove is not smooth and has burrs, and the yarn passages in each part are not smooth and have sticking and blocking phenomena, forming bamboo Festival yarn.
(4) The coarse cleaning device fails, the pile loops do not rotate, the suction force of the suction device is too small, the pile board under the roving does not contact the roller, or the pile board is not cleaned, causing the pile board flowers to adhere. , forming slub yarn.
(5) After carding, the bottom of the car belly is not cleaned in time, causing the pile yarn on the card sliver to enter, forming pile yarn.
(6) During the flat-wiping process, oily slub yarn is formed due to poor work or careless cleaning work.
3. Uneven yarn defects
Uneven yarn defects can be divided into regular uneven evenness and irregular uneven evenness. Regular and uneven evenness are sudden yarn defects, mainly caused by defective mechanical parts, improper process parameters, raw material fluctuations, and sudden changes in workshop temperature and humidity. Irregular unevenness is mainly caused by the drafting force being greater than the control force. The main reasons are:
(1) The draw bundler is damaged, the opening is too small, not smooth, and the guide The width of the rack is too large and the pressure of the rubber roller fails.
(2) The rubber roller or apron core is short of oil, and the suction force of the draw air suction device is too large.
(3) The distance between the coarse rollers is improper, the rollers are tangled, the transmission gears are poorly meshed, and the gears are non-standard parts.
(4) There is a large difference in the distance between the swing pin jaws of the roving frame, slippage or loosening of the positioning screws, deviation of the lower apron, etc.
(5) The roving pressurization fails, there is pile pattern in the bundler or the whiskers are not in the central area bundler.
(6) The roving guide frame is not functioning properly, turning and stopping, causing unexpected elongation of the sliver.
◆Solutions
In view of these three types of defects that often occur in pure cotton carded varieties, Through observation and analysis, we took corresponding measures from the aspects of operation management and equipment to effectively solve such problems.
1. Operational management
(1) Patrol workers on duty to strengthen picking and catching Improve work enthusiasm and sense of responsibility.
(2) Put an end to barbaric operations such as “fanning, blowing, slapping, and beating” by on-duty lathes to avoid flying flowers when moving.
(3) Strengthen carding and cleaning work, and clean the rear car belly and leaky bottom in time.
(4) The accumulation of roving coils should be removed in time.
(5) Regularly check whether there are white flowers in the draw frame bellows. If white flowers are found to be sucked in, repair them promptly.
(6) Strengthen the inspection of the automatic stop-stop device by quality inspectors and on-duty workers. If it is found that it is not working or does not stop, it must be repaired before driving.
(7) After the drawing machine pressurizes the sliver manually, he must rub the sliver to check whether the sliver is normal.
(8) Combing, combining, and roughening are supplied to the station, problems are solved promptly, and the transportation route of the full barrel of sliver is shortened as much as possible. The sliver must be handled with care and avoid touching the sliver.
(9) Carry out technical training activities before and after work and on rest days to improve the operational level and ensure the quality of joints and joints.
(10) Eliminate sugar from raw cotton with a sugar content exceeding 3%.
(11) Strengthen the temperature and humidity control in the workshop, record the work of air conditioners, and make timely adjustments.
(12) Replace damaged or rotten sliver barrels in a timely manner; make sure the springs in the sliver barrels are soft and hard, and replace unqualified springs in a timely manner.
2. Equipment aspects
(1) Flat wiper car insurance Quality and quantity are guaranteed, each yarn channel is truly smooth, the pile loops rotate flexibly, and the cleaning device is in good condition.
(2) Maintenance workers regularly check rollers, rubber rollers, and transmission gears to ensure they are in good condition and refuel in time. Timely use a wiping cloth dipped in gasoline or alcohol to clean the cotton wax, dirt, rust spots, etc. on the surface of the roller groove to prevent the roller from getting entangled.
(3) Optimize the process and select the process for loading. For example, the distance between the rollers in the middle and rear areas of the FA31l draw frame should be appropriately enlarged. Under the condition of ensuring supply, the vehicle speed should be appropriate. slow.
(4) Ensure and coarsen the transmission teethThe wheel guide frame is in good operating condition, and the maintenance work of the rubber rollers, rollers, and gears of the roughening machine should be done well. The equipment should be checked in good condition from time to time, and problems should be dealt with in a timely manner.
Through the above measures, the number of yarn defects per 100,000 m gradually showed a decreasing trend, which shows that certain results have been achieved. When dealing with specific situations, it is necessary to conduct detailed and scientific analysis, implement the responsibility system at all levels, do basic work well, focus on small things, put the word “strict” first, fully mobilize employees, rely on employees, focus on prevention, prescribe the right medicine, and check at all levels. </p
