A study on the relationship between irregularity and hairiness of spun yarns

In this study, Photoshop software was used to do image analysis on the photos of spun yarns. The result showed that yarn could be divided into two parts: the surface hairs and the stem. Based on this finding, a mathematical model of yarn unevenness was built to analyze the relationship between yarn unevenness and surface hairiness. The relationships among the coefficients of mass variance of the yarn, the stem and the surface hairs, expressed as CV t , CV s and CV h , respectively, were investigated in detail. Results indicate that the CV s of an uneven yarn always coincides with the irregularity of the yarn hairiness. More specifically, the CV t of a yarn cannot be better than those of both yarn hairiness and stem (CV h and CV s ), even if one of them is excessive. It is rare for CV t to be higher than CV s after removal of yarn hairs. In particular, it is irrational for the CV t value to be higher than both CV s and CV h , which prompts a rethinking of the exact distribution of yarn hairs on the yarn body.