Characterization of Yarn Irregularity and Variation in Yarn Diameter

Yarn diameter is an important determinant of many fabric parameters and properties e.g. cover factor, porosity, thickness, air permeability etc. There are many methods based on different types of instruments and evaluation techniques used for characterization of yarn mass unevenness and yarn diameter variations. These instruments differ in the principle of measuring and the logic of evaluation of yarn mass irregularity and variation of yarn diameter. It is essential to investigate more deeply which of these methods is more reliable to establish a relationship between the results obtained from different techniques. The present investigation focuses on analysis of the data obtained from Uster and finds it can be approximated to a bimodal distribution in sharp contrast to a normal one. Results are compared with the data obtained from a developed portable instrument QQM3 (Quick Quality Management) based on optical system of measurement for characterization of yarn irregularity. Also the yarns were analyzed using image processing technique. Time series theory has been applied for deeper analysis of diameter characteristics.