Effect of frequency conversion in the yarn spinning process

2017-01-20

Effect of variable frequency speed regulation on spinning broken ends

More Endbreaking, in excluding air conditioning, machinery, operation and cleaning work, bad bad, bad after roving bobbin, the variable frequency speed after the Endbreaking rate can be reduced by about 30%. Regardless of the machine, or with the adjacent machine than the broken ends are reduced. Compared with the data, the number of broken yarn is not obvious, the reason is that the speed of the small yarn segment is shorter, and the area of the peak of the yarn tension is not large.

Effect of frequency on Yarn Hairiness

According to the literature reports, Guangdong Zhanjiang cotton mill in spinning process, spinning spindle speed in small yarn from 11900 R / min increased to 13950 R / min, the spindle speed is increased by 17.22%, hairiness value H from 4.10 mm to 4.53 mm, an increase of 10.50%; in the spindle speed increased by 14.4%, H increased 17.28% large hairiness value; the spindle speed is increased by 10%, hairiness value of H increased 17.1%. I plant is measured in the same conditions, the same spindle roving hairiness number with increasing spindle speed proportional, and the conclusions are.

The spinning machine adopts frequency control, spinning hairiness test results are shown in table 2. Set a small yarn, yarn speed down 10%, yarn growth rate of 5%. Table 2 shows the frequency conversion device, the yarn hairiness is reduced, the yarn hairiness was reduced by 38.12%.

In addition, in the grouping test, test third, four, eight in the group when no frequency, large, medium and small yarn for steel collar or bead hairiness than other groups obviously factors for sudden increase, the number of normal hairiness 3 times to 4 times, and the domestic steel collar widespread surface the processing quality of discrete big problems, so the large range of hairiness. However, the frequency governor after the three group machine small yarn hairiness decreased synchronously, that after reducing speed can significantly reduce yarn tension, reduce spindle difference.

Variable speed and yarn twist

Changes of spinning yarn twist in a doffing process for: (1) the winding diameter is the same, the yarn twist with the gas ring height increases, the yarn twist small yarn full yarn for parts; (2) in the ring plate a dynamic range, small diameter of winding the yarn twist is large diameter winding, and ring plate decreased slightly more when the yarn twist ratio rises.

Fundamentally speaking, the ring spinning winding characteristics, the existence of different circumstances, twist unevenness is the objective existence, of course, the twist difference will not be much difference. But the real factors affecting twist irregularity are the main differences between the rolling wheel, slippery roller, spindle and spindle belt wheel, spindle and bobbin bobbin supporting poor itself quality problems causes the running jump tube etc..

Variable frequency speed change control is spindle speed, and the front roller is synchronous, change of twist is synchronous, but can not correct uneven twist due to slippery difference. In addition, in the above mentioned ring plate up and down conversion moment spinning tension, not only easy to cause breakage, and the spinning section due to the tension fluctuation of negative twist transmission. In order to solve this one contradiction, adding a buffer device adjusting ring plate down conversion, the tension tester, can effectively inhibit the tension peak, peak frequency after spinning tension and tension peak frequency when compared to decreased by about 60%.

Of course, improve the twist should be considered, such as spinning process optimization, application of new spinning equipment such as high performance rubber tape, the use of new technologies such as single spindle motor drive, but the frequency both in theory or in practice are not see deterioration of twist irregularity.

Good attention should be paid to the frequency converter

Although the inverter in textile equipment widely used, but in the spinning machine application time is not long, the main reasons are: (1) spinning workshop requirements 24h continuous production, must be able to run for a long time without failure; (2) inverter to adapt to high temperature and high humidity, more environmental differences (fly short air conditioning condition of each plant); (3) the price factor.

Through the production practice, the frequency converter in the use should pay attention to the following points:

(1) the preparation of the power inverter and allow engine power spinning machine to have 20% room. I plant the spinning motor power is 15kW, use the VT230S-018H type inverter. Otherwise, due to the difference between the machine transmission resistance and the process of pressure adjustment and other factors caused by excessive load overload inverter.

(2) inverter itself has a radiator duct and a fan for cooling, but in use, such as direct spinning workshop will cause the air soon blocked does not work properly, even stop overheating. A better solution should be added to a simple filter apparatus, tender timing cleaning, very simple and reliable.

(3) spinning workshop in high temperature and high humidity season temperature is usually around 30 to 35 DEG C. The inverter permissible ambient temperature is 40 DEG C, which can meet the requirements of spinning temperature.

(4) the inverter can be adjusted according to the parameters of the alarm system, with a capacity of 150%, 1 min, can not be found before the parking problem, and pre processing, the inverter plays a reliable protection.

(5) the spindle speed is up to 15000 R / min, starting with the traditional converter of variable speed motor starting. Such as the start time is too long or the collar plate position is improper, can cause the broken end after driving obviously increased, and even can not drive. Through the optimization of the parameters of the inverter module, it can achieve the minimum dead end effect.

6 concluding remarks

(1) variable frequency speed regulation can reduce the breakage on the basis of increasing the output, or in the case of keeping the existing output