During the spinning process, when the spinning tension is greater than the strength of the cotton yarn, the yarn will break. This is the essence of yarn breakage. The average value of the two must be that the cotton yarn strength is greater than the spinning tension, otherwise the yarn cannot be spun normally. Spinning tension and cotton yarn strength are fluctuating variables. When the maximum value of spinning tension is greater than the minimum value of cotton yarn strength, the end will break. Therefore, one of the basic ways to reduce yarn breakage is to lower the maximum spinning tension and reduce tension and fluctuations as much as possible.
Factors affecting spinning tension fluctuations
01
The instability of high-speed operation of the spindle belt. When the diameter of the spindle disk 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 operating status of the spindle belt have a great impact on the fluctuation of spinning tension.
02
The instability of high-speed rotation of the spindle. The high-speed rotation of the spindle is the power source for the spinning tension and balloon. Defects such as uneven spindle speed, vibration, and up and down jumps will affect the stability of the spinning tension.
03
Bobbin quality is poor. Spinning winding is achieved by bobbin. If the quality of the bobbin is poor, the bobbin will shake its head, jump up and down, and the bobbin and spindle will not mesh well. The two will rotate synchronously, resulting in uneven bobbin speed, etc., which will affect the stability of the spinning tension. .
04
The influence of steel rings and travelers. The steel ring and traveler are in a high-speed, high-pressure and high-temperature state during spinning. When the spinning frame uses a 42 mm diameter steel ring and the spindle speed is 16 000 r/min ~ 20 000 r/min, the rotation speed of the traveler can be as high as 35.2 m/s ~ 44 m/s, and generates a high temperature of more than 300 ℃ . According to testing and calculations, the contact pressure of 18.2 tex cotton yarn when forming and winding to a large diameter at the bottom of the tube is 243 cN. It is assumed that the instantaneous contact area of the wire ring to the steel ring during the maturation period of the traveler 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 steel ring under special conditions of high speed, high temperature and high pressure, which has a great negative effect on the stability of the spinning tension. The traveler on the steel ring rotates simultaneously with high-speed tilting and swinging in the meridian plane, the horizontal plane, and the transverse plane respectively, causing vibration and frustration. When the tilting swing is excessive, it becomes wedged, causing the spinning tension dilemma and causing end breakage. Therefore, the reasonable selection of steel rings and travelers has a significant impact on the changes in spinning tension.
05
The difference in concentricity between the three points of the spindle, steel ring and yarn guide hook causes the traveler to swing in the space of the steel ring , the probability of tilting and wedging increases, resulting in tension fluctuations.
06
The spinning balloon makes the cotton yarn swing left and right with a certain width on the back and inside of the inner ring of the yarn guide hook, and the swing area If the segments are not horizontal, the balloon will be unstable or a balloon will be formed, which will affect the stability of the spinning tension.
07
The skewed yarn plate can easily cause a spinning balloon and hit the spacer plate, causing the spinning tension to become unstable. Stablize.
08
The wire ring cleaner is worn and has burrs or the distance between the wire ring and the cleaner is too large and the wire cannot be effectively cleaned The flying flowers wrapped around the loop make the spinning tension unstable and tend to increase.
09
Vibrations and beats during the lifting and lowering of the ring plate can also easily cause unstable spinning tension.
10
In the spinning environment, flying flowers are attached to the spinning balloon or the distribution of air conditioning outlets is unreasonable, causing airflow to interfere with spinning. Balloons can also cause spinning tension to fluctuate.
Technical Measures to Stabilize Spinning Tension
01 Spindle System
1) The spindle tip and bottom bearings, the spindle rod and the upper bearing must not be worn;
2) The spindle cannot shake its head when rotating, and it is strictly prohibited to jump up and down;
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3) The spindle foot should not be slightly warm or vibrating;
4) Regularly check and calibrate the eccentric bending of the spindle rod and spindle plate;
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5) The length and tension of the spindle belt are normal. They should not be rotten or twisted. They should not be stained with oil or fiber. They should not rub against the edges of the spindle plate and the roller plate. The joints should not be thick or hard. , do not jump during operation;
6) The surface of the spindle disk and the bearings must not be worn, the bearings should be cleaned regularly, and there should be no hardened oil and dirt, and the rotation should not jump or shake;
7) The bobbin head must not be burred or damaged. The upper eye of the bobbin is tightly meshed with the upper taper of the spindle rod to ensure that the spindle and bobbin rotate synchronously. The lower mouth of the bobbin is in contact with the lower bell of the spindle. There is a slight gap between them;
8) There should be no wire back between the bobbin and the spindle;
9) The bobbin cannot rotate Shake your head, vibrate up and down, and jump.
02 Ring Traveler and Balloon System
1) There should be no rust spots on the steel ring, and there should be no burrs on the upper lip and the traveler track.
2) As the steel ring wears, the service life of the steel ring must be replaced normally. For the normal backgrinding cycle of the traditional steel ring, use a planetary polisher to backgrind the steel ring and use high-quality abrasives. , grinding fluid, pay attention to the backgrinding method to improve the quality of backgrinding.
3) The height of the ring plate should be kept in a straight line regardless of the position from small yarn to large yarn. The ring plate should be horizontal to the left and right, front and back, and the ring should be tight. The ring plate must not be loosened or tilted, and the ring plate must not vibrate or rattle when it is raised or lowered.
4) Select the best type of traveler. The weight of the traveler is based on cotton yarn strength, steel ring condition, spindle speed and traveler line speed, balloon shape, breakage distribution, temperature and humidity Factors such as fluctuations and cotton yarn hairinessReasonable adjustments.
5) The replacement cycle of wire rings should be correctly determined based on the number of broken ends and hairiness, and should be implemented carefully to prevent individual wire rings from missing replacement.
6) Carefully calibrate the spindle level, and carefully align the three centers of the spindle, steel ring, and yarn guide hook. This is just static, and dynamic calibration must be done to lay the foundation. When the spindle is at high speed, the ring plate should be flexibly aligned at the two positions of small yarn and full yarn, and the two centers of the spindle and ring should be recalibrated.
7) The yarn guide hook must not be worn or loose, and the yarn guide plate must not be loose. The yarn guide hook must be kept flush at any position from small yarn to full yarn.
8) There should be no burrs on the gauze plate, and it should not be skewed or loose when installed between the two spindles.
9) The spacing tool of the wire ring cleaner is reasonably designed and accurately manufactured. The cleaner must not be loose or burred, and the spacing must be too small.
10) The spinning balloon must not be skewed. If the inside of the inner hole of the yarn guide hook is not level, the yarn guide hook should be replaced and disabled; spinning The shape of the balloon is stable and cannot vibrate. The balloon should be in the shape of a slight arc when the yarn is full. The balloon must not rub against the bobbin head or touch the yarn separation plate.
11) Regularly inspect the flatness of the ring and the roundness of the inner hole to ensure that the deviation is not greater than 0.05 mm. The actual depth of the inside of the ring’s traveler track must not be less than the design depth.
Stabilizing spinning tension and reducing yarn breakage is a wide-ranging, complex, meticulous and comprehensive system engineering project, which is closely related to the company’s equipment, processes, operations, raw materials and temperature. Basic management work such as humidity and various measures to improve quality are closely related. Only by making overall plans, integrating everything, and persisting in meticulousness and excellence in all technical and management work can we achieve good results. </p
