The Online Monitoring Of Drafting Force And Process Research In The Break Draft Zone Of Cotton Spinning Frame

Based on analyzed the existing measuring device and method of drafting force on drafting system, This project present and design a method and device, which can online monitoring the drafting force effectively in the break draft zone of cotton spinning frame. Using mechanics analysis method, the mathematical model between the drafting force and the sensor payload in drafting process was deduced. Making use of the online monitoring device of drafting force by Independent design in break draft zone of spinning frame, when different process parameter such as break drafting ratio, ratch, roving twist multiplier and roving weight , the variety regular of drafting force was tested, and the relation between the variety regular of drafting force and the yarn quality index such as unevenness, thickness and thinness was studied.Research result showed: when the drafting ratio was smaller, the drafting force increased gradually with the drafting ratio increased, and the drafting force reached maximum at 1.7-1.8, after that it decreased gradually with the break drafting ratio increased continually. When the break drafting ratio was smaller, the roving twist multiplier was almost no influence on drafting force, but after the break drafting ratio increasing, the drafting force increase gradually with the roving twist multiplier. Drafting force was gradually increasing trend with the roving weight, and that was gradually decreasing trend with the ratch. Through the comparative analysis, when the roving twist multiplier was 100, the roving weight was 4.0g/10m, the ratch was 53mm and the break drafting ratio was between 1.2-1.6 respectively, the value of drafting force increased gradually, but the CV% of drafting force was low level. Correspondingly, the CV% of yarn, thinness, thickness, neps etc. were improved. However, the correlation was not significant between the CV% of drafting force and the tenacity and hairiness index of yarn. To sum up, when the breaking drafting ratio was less than 1.7, the larger the drafting force, the more smaller and stable the fluctuation of drafting force, and the better the yarn quality such as CV% of yarn, thinness, thickness and neps and so on.