Experimental study of ring-spinning.

摘要

Ring spinning, is a process for converting staple fibers to yarn. It is a major source of the world's yarn supply despite the fact that its core technology is over a century old. The superior quality of ring spun yarn overcomes disadvantages of the process, including higher labor costs and lower productivity. Consequently, current research has focused its attention on studying the process in more depth to boost both processing speeds and yarn quality simultaneously. A brief description of the current status of research and development in ring spinning is mentioned.; The developments of ring-spinning technology have led to high spindle speeds. These high spindle speeds cause frequent outbursts of short-term, high-tension peaks. In order to study these rare tension peaks, tension measurements must be carried out continuously at high sampling rates. In the present work, an online multi-channel measuring system was developed to overcome the inadequacies of current measuring systems. It simultaneously measures yarn tension, ring-rail height, balloon profiles and traveler speed at high sampling rates over the entire build of the bobbin. The high frequency sensors, data acquisition system and large storage capacity of the computer, enabled the study of both long and short-term variations in yarn tension. The study revealed the possibility of using inexpensive non-contact type sensors as a real-time monitoring device.; The measuring system was used to empirically validate the yarn tension and balloon profiles predicted by the theoretical model. Results showed that at short balloon heights and heavier traveler masses, the experimental data correlated well with the theory. At larger balloon heights and lower traveler masses, the predicted tension values were higher than that observed. Although with this measuring system, a quantitative comparison of yarn balloon shapes could not be made, a qualitative comparison showed actual balloon collapses in regions predicted by the model.; Time series models were used to predict yarn tension variation during ring spinning. The study was done in both the time and frequency domain. In the time domain, the errors or random fluctuations in the spinning tension, which formerly could not be explained by the traditional method of statistical analysis, can now be fitted to time series models. Spectral analysis or analysis in the frequency domain, proved to be a useful tool in detecting sinusoidal components in yarn tension.