01 Basis for process optimization
Spinning yarn unevenness mainly consists of three parts: random unevenness, additional unevenness in the feeding roving process, and additional unevenness in the spinning process. composition. The first part depends on the quality of the raw cotton, and the second part depends on the quality of the roving. Therefore, in order to reduce the unevenness in the spinning process, it is necessary to reduce the additional unevenness in the spinning process. The additional unevenness in the spinning process is mainly caused by the drafting part.
The function of the drafting in the rear area of spun yarn is to bear part of the total drafting and at the same time prepare for the drafting in the front area. Since the fed roving has twist, if the rear area is a simple roller drafting Stretching and improper process configuration will directly affect yarn quality and normal drafting.
02 Double pressure rod technology in the rear area of spun yarn
In the rear drafting area, in order to To effectively control fibers, the holding distance should be smaller. The traditional process uses the method of tightening the roller spacing to reduce the holding distance. The reduction of the roller spacing will inevitably lead to heavy pressure and will shorten the life of the process equipment.
In order not to affect the service life of the spinning process equipment, it is proposed to use double pressure rods in the rear area to strengthen the control of the fibers. Using this technology is beneficial to controlling the drafting area The movement of the inner fibers can prevent the whiskers from slipping under the roller jaws, thereby improving the uniformity of the output whiskers.
03 Confirmatory test of rear area pressure rod
3.1 Comparative test of CF94S with and without rear dual pressure rods (see Table 1)
It can be seen from the above test data that after using the double pressure rods in the rear area, the The yarn dryness CV%, thick details and neps are significantly improved.
3.2 Comparative test of CF80S with and without rear dual pressure rods (see Table 2)
3.3 Comparative test of CF50S with and without rear area double pressure rods (see Table 3). From the above test data, it can be seen that after using the rear area double pressure rods, the yarn evenness CV%, details and neps are obvious. improve.
04 Conclusion
As can be seen from the above test data, using After double pressure rods are installed in the rear area, the yarn dryness CV%, -40 details and +35 thick places are significantly improved.
4.1 Through a series of tests, it was proved that the double pressure rod in the rear area has a significant effect on improving the quality of yarn, so it has been promoted and used. It is beneficial to improve yarn quality without increasing costs.
4.2 After loading on a large area, some varieties have more broken heads, which increases the workload of operation. After inspection on the vehicle, it was found that it was caused by the failure of some sliver fibers to be drafted. Therefore, greater efforts must be made to study the configuration of the roving twist and the drafting multiple of the fine yarn in the rear area when using the double pressure rods in the rear area.
4.3 The series of tests on the double pressure rods in the rear area were conducted on V-type drafting spinning frames. Further tests are needed to determine whether they can be used on other drafting spinning frames. get conclusion. </p
