Factors affecting yarn and thread spinning tension fluctuation
In spinning process, when the yarn and thread spinning tension is greater than the strength of cotton yarn thread, it will break the end, which is the essence of spinning broken end.
The average value of the two must be that cotton yarn thread strength is greater than spinning tension, otherwise it can not spin normally.
Because spinning tension and cotton yarn thread strength are fluctuating variables, when the maximum of spinning tension is greater than the minimum of cotton yarn thread strength, it will cause broken ends.
Therefore, the basic way to reduce yarn breakage is to reduce the maximum spinning tension and tension fluctuation as much as possible, on the other hand, to raise the minimum strength of cotton yarn thread and reduce the strength fluctuation of cotton yarn.
Factors affecting yarn and thread spinning tension fluctuation
1) Instability of high-speed operation of ingot belt. When the diameter of ingot disc is 22 m m and the speed of ingot is 20 kr/min, the linear speed of ingot belt can reach 1 382.3 m/min. Because the spindle belt drives the spindle by friction, it will directly affect the stability of the spindle speed. Therefore, the quality and running state of spindle belt have great influence on the fluctuation of yarn and thread spinning tension.
2) Instability of spindle rotation at high speed. Spindle high-speed rotation is the power source of yarn and thread spinning tension and balloon, spindle speed uneven, vibration, up and down jump and other defects will affect the stability of yarn and thread spinning tension.
3) Poor tube quality. Yarn and thread spinning winding is realized by barrel. If the barrel quality is poor, the yarn tension stability will be affected by the unsynchronized rotation of barrel shaking head, up and down jumping, and the unsynchronized rotation of barrel and spindle.
4) The influence of rings and travellers. Rings and travellers are in the state of high speed, high pressure and high temperature in yarn and thread spinning. When a 42 m m diameter ring is used in the spinning frame and the spindle speed is 16 kr/min~20 kr/min, the travelling speed of the traveller can reach 35.2 m/s~44 m/s, and the high temperature above 300.
According to the test calculation, the contact pressure of 18.2 tex cotton yarn thread is 243 cN when the tube bottom is formed and wound to a large diameter.
It is assumed that the contact area of the instantaneous ring to the ring is 0.1 mm2 and the contact pressure is 24.3 MPa during the ripening period of the ring, which is 1.34 times of the maximum limit value of 18.1 MPa stipulated by the surface pressure of the crankshaft bearing of the aircraft engine.
The traveller rotates at high speed, high temperature and high pressure on the ring, which has a negative effect on the stability of yarn and thread spinning tension.
The traveller rotates at high speed in meridian plane, horizontal plane and transverse section respectively.
Vibration and setback occur, and wedge occurs when the inclined swing is excessive, resulting in the sudden increase of yarn and thread spinning tension and broken ends.
Therefore, the reasonable selection of rings and travellers has a significant influence on the yarn and thread spinning tension.
5) The difference of concentricity between spindle, ring and guide hook increases the probability of wobble, inclination and wedge of traveller in three-dimensional space of ring and produces tension fluctuation.
6) The yarn and thread spinning balloon makes the cotton yarn oscillate about a certain width in the back and inside of the inner ring of the guide hook.
If the swing section is not horizontal, the balloon will be unstable or a skewed balloon will affect the spinning tension stability.
7) The yarn thread separator skewed easily results in spinning balloon and impact the separator, which makes the spinning tension unstable.
8) The wear of traveller cleaner is burr or the distance between traveler and cleaner is too large to remove the flying flowers wrapped on traveler effectively, which makes the yarn and thread spinning tension unstable and tends to increase.
9) Vibration and beating of ring plate during lifting and lowering can also cause unstable yarn and thread spinning tension.
10) In the yarn and thread spinning environment, the distribution of flying flowers attached to the spinning balloon or air conditioning outlet is unreasonable, and the disturbance of air flow to the spinning balloon will also cause the spinning tension fluctuation.
11) Poor or or absence of yarn and thread spinning blowing and suction nozzles may cause air flow to interfere with the yarn and thread spinning balloon and also cause fluctuation of spinning tension.
