Optimisation method for the quality of combed sliver

The quality of the sliver is a key parameter for assessing the technical level of spinning equipment. As a critical machine in the spinning process, the sliver-quality optimisation system of the cotton comber is crucial for enhancing cotton sliver quality. Based on the process characteristics of cotton combers, this paper proposes a new non-real-time optimisation method for improving the evenness of combed slivers and verifies the feasibility of this method through experiments on combed slivers. Firstly, the paper introduces a new method for optimizing sliver quality. Secondly, online sliver quality data are collected and then processed through smoothing and correlation analysis to determine the periodic variations in sliver quality. Next, according to the principle of sliver evenness and the open-loop control system, a model is established between sliver quality variation and the middle roller speed. The periodic motion law of the middle roller is then determined. Experimental results show that the method, after non-real-time processing of sliver data, reduces the coefficient of variation (CV) of the sliver by 0.5%. Furthermore, a multi-stage speed control for the middle roller is proposed to replace the continuously variable speed control. This reduces the requirements and cost of the control system and still lowers the sliver CV by 0.38%. This proves that the method meets the combed sliver quality optimisation requirements. Finally, the impact of open-loop system delay time on non-real-time processing time during actual operation is analysed to further ensure the optimisation of roller speed regulation. This study provides a practical technical solution and a theoretical basis for online sliver leveling in the combing process.