Statistical analysis of yarn to metal frictional coefficient of cotton spun yarn using Taguchi design of experiment

Yarn's surface to metal friction is an important consideration in the subsequent process of knitting and weaving as it influences mainly the ends down rate, fly generation, process efficiency, wear and tear of machine parts, and production rate of the process. These frictional properties are measured in terms of the coefficient of friction of yarn. The effect of cotton type, yarn twist, yarn linear density, process type, and finishing treatment was studied on the surface to the metal friction coefficient of cotton spun yarn using Taguchi experimental design. The experiments were conducted with Pakistani and Indian cotton using combed and carded ring spinning processes. Using Taguchi design of experiment, a total of 36 samples of cotton ring-spun yarns were produced. The coefficient of friction between the yarn's surface and metal's surface is measured in compliance with ASTM D3108. The outcome of the Taguchi model to predict the coefficient of friction of yarns with a predefined combination of constituting parameters was further confirmed with nine yarn samples. The frictional characteristics of yarns are found to be influenced by all factors. In addition to the application of wax, the longer fiber length, lower trash count, lower short fiber index, and the optimum level of twist are found advantageous to reduce the yarn coefficient of friction.