Abstract
The use and installation requirements of the yarn guide rod in the feeding mechanism of the spinning equipment are analyzed. The impact of process height on yarn quality, and through special comparative experiments, data are used to demonstrate the impact of the position of the spun yarn guide rod on yarn quality. Through comparative analysis of test data, it is pointed out that the position of the spun yarn guide rod directly affects the stability and consistency of the spun yarn quality data, and indirectly affects the winding production efficiency and yarn recovery rate.
Keywords: spinning yarn guide rod, yarn quality, winding efficiency
The spinning process is an important process in ring spinning , not only because the spinning process is the core process of output, but also a key process for the stability and consistency of yarn quality. The spinning process that affects the quality of the yarn is mainly divided into equipment status, special equipment, process setup, temperature and humidity control, personnel management, roving quality, etc. In terms of process quality control in the spinning process, there are many papers and test cases on the drafting process, winding process, and special equipment. However, few focus on analyzing and testing the impact of the feeding mechanism on the yarn quality, especially the impact of the yarn guide rod on the yarn quality. Case studies on the impact of yarn quality.
Recently, a customer pointed out that the long and thin cutting defects in the winding process are unstable, and in the bobbin data tested in the laboratory, the detailed data vary greatly. In response to this problem, we guided the company to carry out technical research, and focused on the test and comparison of the yarn guide rod in the spinning process. By optimizing the yarn guide rod design and process height, we collected laboratory bobbin test data and winding defect cutting data. dropped significantly and tended to be stable.
Winding online data analysis
Aiming at the unstable problem of cutting defects in winding details, through The electro-clearance quality data was analyzed (see Figure 1) and it was found that long detailed defects among the cutting defects accounted for a large proportion. However, from the tested roving evenness index and unevenness curve, the corresponding details could not be seen, so it was judged The problem mainly lies in the spinning process.
Figure 1 Electrical cleaning and cutting defect data before rectification
For this reason, the spinning process was mainly inspected. The company’s spinning equipment is the FA502 spinning frame, and the roving creel has been changed from the tray type to the current ceiling-type creel. However, there are many problems during the transformation process. About 70% of the spinning machines have a single row of yarn guide rods, and the roving is vertically fed into the bell mouth, resulting in unstable unwinding of the roving and unexpected drafting details, resulting in an increase in yarn defects in the long details of the bobbin (see Figure 2); even if It is a machine equipped with double rows of yarn guide rods. The height setting of the yarn guide rods is also unreasonable. The roving is prone to end breakage when unwinding or the friction on the yarn guide rods increases after unwinding, causing detail problems in the roving, resulting in Bobbin length details increased.
Figure 2 Single row of spun yarn guide rods
Improvement of spun yarn guide rods
For this reason, we conducted special tests and changed the single row of spun yarn guide rods to double rows of yarn guide rods , and adjust the height of the yarn guide rod to 1/3 of the lower part of the roving (see Figure 3).
Figure 3 Spinning yarn double row yarn guide rod status
After the adjustment, we tracked and analyzed the winding defect data per million meters and the graded yarn defect data per million meters, and found that the detailed defect data and graded yarn defect data had improved significantly (see Figure 4).
Figure 4 Corrected electro-cleaning defect data
Test Comparative analysis of data
3.1 Comparison of laboratory data
The bobbins before and after adjustment were tested for evenness and graded yarn defects, and various quality indicators were significantly improved (see Figure 5, Table 1, Table 2).
Figure 5 Bobbin evenness test results before and after adjustment
Table 1 Bobbin evenness test indicators before and after adjustment
Table 2 Bobbin before and after adjustment Graded yarn defect test indicators
Conclusion
After the company adjusted all the yarn guide rods of the FA502 spinning machine, it tracked and analyzed the quality indicators, winding efficiency, yarn recovery rate and other data of the bobbin and package yarn for 2 consecutive months, and the reduction rate of detailed graded yarn defects of 100,000 meters long. Reaching 24%, neps and thick yarn defects per 100,000 meters are reduced by 14.6%, the number of cut defects per million meters in winding is reduced by 20%, winding production efficiency is increased by 1.8%, and winding yarn waste rate is reduced by 0.1%. The bobbin evenness, details, thick places, and neps have all been reduced to varying degrees, and the problem of long details that has troubled the company for a long time has been completely solved. </p
