Abstract

The surface dynamic and static coefficient of friction of yarns is one of the most important means of characterizing the surface structure of yarns and can provide an important basis for yarn performance evaluation and quality monitoring. The lack of highly stable, high precision and low-cost instruments for measuring the dynamic coefficient of friction of yarns is a major constraint to yarn performance evaluation and performance improvement. The entanglement method calculates the coefficient of friction between yarns by measuring the input and output tensions on both sides of the yarn at its own kink point, which is easy to use and highly accurate. Based on this, a yarn dynamic friction coefficient measurement system was developed based on the kink principle and the measurement error was evaluated using 28tex cotton yarn and 420 D polyester yarn in turn. After five repeatability tests using 28tex cotton yarn, 36tex aramid and 420 D polyester, the coefficient of friction between the three yarns themselves fluctuated by less than 0.01 and the instrument showed good stability and repeatability. In six comparative tests with the CTT constant tension transfer system from Lawson, USA, the inter-group CV of the coefficient of friction between the yarns themselves was only 3.66% after six tests. A final comparison of the data from the entanglement and the Rhodes method tests shows that the coefficients of friction obtained show the same trend. The yarn running speed and pre-tension are adjustable and the system has a timed test function, which allows the input and output tensions of the yarn and the dynamic coefficient of friction between the yarn and the yarn to be measured and displayed in real time. This improves the measurement accuracy, reduces the price of the product and helps to evaluate the surface properties of yarns and improve product quality.

摘要

纱线表面动静摩擦系数是表征纱线表面结构的重要手段之一，可为纱线性能评价和质量监测提供重要依据。缺乏用于测量纱线动态摩擦系数的高稳定性、高精度和低成本的仪器是制约纱线性能评估和性能改进的主要因素。缠结法是通过测量纱线自身扭结点两侧的输入和输出张力来计算纱线间的摩擦系数，使用方便，精度高。基于此，基于扭结原理开发了纱线动摩擦系数测量系统，依次使用28tex棉纱和420D涤纶纱对测量误差进行评估。使用28tex棉纱、36tex芳纶和420D涤纶进行5次重复性测试，三种纱线本身的摩擦系数波动小于0.01，仪器表现出良好的稳定性和重复性。在与美国 Lawson 的 CTT 恒张力传递系统的六次对比测试中，在六次测试后，纱线本身之间的摩擦系数的组间 CV 仅为 3.66%。纠缠和罗德方法测试数据的最终比较表明，获得的摩擦系数显示出相同的趋势。纱线运行速度和预张力可调，系统具有定时测试功能，可以实时测量和显示纱线的输入和输出张力以及纱线与纱线之间的动态摩擦系数。这提高了测量精度，降低了产品价格，有助于评估纱线的表面性能，提高产品质量。