Indirect estimation of the skewness of yarn pieces mass distribution based on the its unevenness parameters

The quadratic (CV) and the linear (U) measures of irregularity are based on the standard deviation and the mean deviation. The CV/U ratio is 1,25 for Gaussian distribution, but the distribution of the weights of cut pieces of cotton yarns is slightly skewed. Skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive or negative. The CV/U ratio for cotton yarns can be determined according to the USTER® TESTER data. The relation between the skewness value and the CV/U ratio for carded ring-spun cotton yarns was investigated. It’s necessary for subsequent determination of the relation between tenacity and skewness. The mathematical model for calculating the skewness value based on the unevenness parameters was developed. The relative error between the results of calculations does not exceed 5 %.