English Views: 10 Author: Site Editor Publish Time: 2021-11-24 Origin: Site
In the spinning process, when the spinning tension is greater than the strength of the cotton yarn, it will break, which is the essence of spun yarn breakage. The average of the two must be that the strength of the cotton yarn is greater than the spinning tension, otherwise it will not be able to spin normally. Spinning tension and cotton yarn strength are fluctuating variables. When the maximum spinning tension is greater than the minimum cotton yarn strength, the ends will be broken. Therefore, one of the basic ways to reduce yarn breakage is to lower the maximum spinning tension and reduce tension and fluctuation as much as possible.
1) The instability of the high-speed operation of the spindle. When the spindle diameter is 22 mm and the spindle speed is 20 000 r/min, the linear speed of the spindle belt is as high as 1382.3 m/min. Since the spindle belt drives the spindle through friction, it will directly affect the stability of the spindle speed. Therefore, the quality and running state of the spindle belt have a greater influence on the fluctuation of the spinning tension.
2) The instability of the high-speed rotation of the spindle. The high-speed rotation of the spindle is the power source of the spinning tension and the air ring, and defects such as uneven spindle speed, vibration, and up and down jump will affect the stability of the spinning tension.
3) Poor quality of the bobbin. Spinning winding is achieved by the bobbin. If the quality of the bobbin is poor, the bobbin shakes its head, jumps up and down, and the engagement between the bobbin and the spindle is not good. The synchronous rotation of the two causes the uneven rotation of the bobbin, etc., which will affect the stability of the spinning tension. .
4) The influence of ring and traveler. The ring and traveller are in a high-speed, high-pressure and high-temperature state during spinning. When the spinning frame adopts 42 mm diameter ring and the spindle speed is 16 000 r/min～20 000 r/min, the wire traveler rotation speed can be as high as 35.2 m/s～44 m/s, and the high temperature above 300 ℃ is generated. . According to inspection calculations, the contact pressure of 18.2 tex cotton yarn is 243 cN when the tube bottom is formed and wound into a large diameter. It is assumed that the instantaneous contact area of the traveler to the ring during the traveler maturity period is 0.1 mm, and the contact pressure is 24.3 MPa. It is 1.34 times the maximum limit value of 18.1 MPa specified for the surface pressure of the aircraft engine crankshaft bearing. The traveler rotates on the ring at high speed, high temperature, and high pressure under special conditions, which has a large negative effect on the stability of spinning tension. The traveler is tilted and swung simultaneously on the meridian plane, horizontal plane, and cross-section on the ring, causing vibration and frustration. When the tilting and swinging is excessive, the traveler will be wedged, causing the spinning tension dilemma to cause end breakage. Therefore, the reasonable selection of ring and traveler has a significant effect on the change of spinning tension.
5) The three-point concentricity difference between the spindle, the ring and the guide hook increases the probability of swinging, tilting, and wedging of the traveler in the ring space, resulting in tension fluctuations.
6) The spinning balloon makes the cotton yarn oscillate in a certain width around the inner circle of the yarn guide hook. If the swing section is not level, the balloon will be unstable or form a balloon, which will affect the stability of spinning tension.
7) The yarn separator is skewed, which can easily cause spinning balloons and hit the yarn separator, making the spinning tension unstable.
8) The traveler cleaner is worn with burrs or the distance from the traveler to the cleaner is too large, which cannot effectively remove the fly entangled on the traveler, which makes the spinning tension unstable and tends to increase.
9) Vibration and pauses during the lifting of the ring plate can also cause unstable spinning tension.
10) In the spinning environment, the flying flowers are attached to the spinning balloon or the air outlets of the air conditioner are unreasonably distributed. The airflow interference with the spinning balloon will also cause the spinning tension to fluctuate.
Spindle Subsystem
1) The spindle tip and spindle bottom bearing, spindle rod and upper bearing must not be worn out;
2) Do not shake the head when the spindle is rotating, and it is strictly forbidden to jump up and down;
3) The spindle feet should not be lukewarm or vibrate;
4) Regularly check the eccentric bending of the calibration spindle and spindle;
5) The length and tension of the spindle belt are normal, no rotten edges, twisted, no oil stains, fiber accumulation, no friction with the side of the spindle or roller, the joints should not be thick or hard, and the running should not be jumpy;
6) The surface of the spindle reel and the bearing should not be worn, the bearing should be cleaned regularly, there should be no hardened grease, and the rotation should not be bounced or shaken;
7) The bobbin head must not have burrs or damage. The upper eye of the bobbin and the upper taper of the spindle are tightly meshed to ensure the synchronous rotation of the spindle and the bobbin. There is a slight gap between the lower mouth of the bobbin and the lower bell column of the spindle;
8) There should be no wire waste between the bobbin and the spindle;
9) Do not shake the head, vibrate up and down, or skip the tube when rotating the bobbin.
Ring traveler and balloon system
1) There should be no rust spots on the ring, and no burrs on the upper mouth and traveler runway.
2) With the wear of the ring, the ring life cycle should be changed normally. For the normal regrind cycle of the traditional ring, the planetary polishing machine is used to regrind the ring and the high-quality abrasives and liquids are used. Pay attention to the regrind method to improve the quality of regrind. .
3) The height of the ring plate should be kept in a straight line regardless of the position of the small yarn to the large yarn. The ring plate should be horizontal, left and right, front and back. The ring is fastened to the ring plate and cannot be loosened or inclined. Do not shake or pause when lifting.
4) Select the preferred type of traveler. The weight of the traveler is reasonably adjusted according to factors such as cotton yarn strength, ring status, spindle speed, traveler wire speed, balloon shape, end break distribution, temperature and humidity fluctuations, and cotton yarn hairiness.
5) The traveler exchange cycle is correctly formulated according to the number of broken ends and hairiness, and is implemented carefully to prevent individual travellers from missing replacement.
6) Carefully calibrate the level of the spindle, and carefully align the three centers of the spindle, the ring and the guide hook. This is only static, and dynamic verification must be done to lay the foundation. For this position, the two centers of the spindle and the ring must be calibrated lively, and the yarn guide hook that re-adjusts the position of the spindle must be re-calibrated.
7) The yarn guide hook must not be worn or loosened, the yarn guide plate must not be loosened, and the yarn guide hook should be kept even at any position from the small yarn to the full yarn.
8) The yarn spacer must not have burrs, and it must not be skewed or loose when installed in the middle of the two spindles.
9) The distance tool of the traveler cleaner is reasonably designed and manufactured accurately. The cleaner must not be loose or burly, and the distance is too small to grasp.
10) The spinning balloon must not be skewed. If the inner side of the inner hole of the yarn guide hook is not level, the yarn guide hook should be replaced and disabled; the spinning balloon shape is stable and cannot be vibrated. There is a small arc shape; the air ring cannot rub the bobbin head or touch the gauze plate.
11) Regularly inspect the flatness of the upper surface of the ring, and the deviation of the inner hole roundness is not more than 0.05 mm, and the actual depth of the inner side of the traveler runway of the ring shall not be less than the design depth. Stabilizing spinning tension and reducing spun yarn breakage is a wide-ranging, complex, meticulous and comprehensive system project, which is related to various basic management tasks such as equipment, technology, operation, raw materials, temperature and humidity, and various aspects of improving quality. The measures are closely related. It is necessary to make overall plans, to be thorough, and to insist on being meticulous and to do a good job in various technical and management tasks in order to receive good results.
