Yarn Quality Indexing Using a Mechanical Stylus

Abstract

Fabric hand, an important characteristic to the textile industry, is influenced by such fiber parameters as flexural rigidity and friction and by yarn parameters such as count, twist, CV%, hairiness, stiffness, and softness. This study deals primarily with predicting the softness of knitted T-shirts from yarn quality parameters. The work consists of a short literature review on the existing yam parameters as well as fabric hand evaluation and prediction techniques. The latest developments in measuring the roughness of textile material surfaces are, also covered. Using the surface profile as tested by the mechanical stylus surface analyzer (MSSA), developed at North Carolina State Uni versity, a novel yarn surface analysis parameter called the "surface response average" (SRA) is developed, along with a model for the fiber/stylus tip interaction. Ten T-shirts produced from ten different yarn samples are ranked based on their softness by a panel of judges. The yams used to make these T-shirts are tested by Uster III and MSSA, and standard roughness parameters are calculated. The results show no significant corre lation between standard roughness parameters and fabric softness. The correlation be tween hand and SRA is about -0.6, which suggests that a higher SRA corresponds to a softer fabric.