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 defects
(1) Thick joints When the lap is too long or too short or the wrapping is too tight or too loose, thick and thin wefts are formed.
(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) The slivers behind the roving frame were hung with wool and batches were dropped. The lathe on duty did not find out 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 was formed due to poor work or careless cleaning work.
3. Uneven even yarn defects
Irregular evenness Uniform yarn defects are divided into regular unevenness and irregular unevenness. 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) and The strip bundler is damaged, the opening is too small and not smooth, the width of the strip guide frame 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 entangled, the transmission gears are poorly meshed, and the gears are non-standard parts.
(4) The gap between the swing pin jaws of the roving frame is greatly different, the positioning screws are slipping or loose, and the lower rubber ring is deflected or damaged, etc.
(5) The roving pressurization fails, there is pile pattern in the bundler or the sliver is not in the central zone bundler.
(6) The roving sliver guide frame is not functioning properly and rotates and stops, causing unexpected elongation of the sliver.
Solutions
For those who often suffer from combed cotton varieties Through observation and analysis of these three types of defects, 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 the work of sorting and catching defects, enhance work enthusiasm, Responsibility.
(2) Put an end to barbaric operations such as “fanning, blowing, slapping, and hitting” 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, and repair them promptly if any white flowers are found to be sucked in.
(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 Taiwan, 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) Carry out sugar elimination on raw cotton with 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; the springs in the sliver barrels should be appropriately soft and hard, and unqualified springs should be replaced 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 to put on the car, such as FA31l typeThe distance between the rollers in the middle and rear areas of the draw frame is appropriately enlarged, and the vehicle speed is appropriately slowed down while ensuring supply.
(4) Ensure that the paralleling and coarsening transmission gear rack is in good operating condition, do a good job in maintaining the rubber rollers, rollers, and gears of the paralleling and roughening machine, and check the integrity of the equipment from time to time. Check the status and deal with problems in time if found.
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
