Study on the Damaging of Dyed Cotton Fibers with Direct Dye in Spinning Processes and its Effect on the Properties of Cotton Mélange Yarn

The influence of dyeing and spinning on the characteristics of cotton fibers and its impact on the properties of cotton mélange yarn has been investigated. Grey cotton fibers with mean fiber length and fineness of 29 mm and 4.2 micronair were pre-treated and dyed. Three ring yarns were spun from 100 % grey cotton (R.R.Y), 50-50 % blend of dyed and grey cotton (M.R.Y) and 100 % dyed cotton fibers (D.R.Y). The extent of fiber damage was assessed by measuring the length and the mechanical characteristics of cotton fibers after passing the lap machine and the draw frame II. Consequently, properties of R.R.Y, M.R.Y and D.R.Y yarn samples were examined. According to the results, the tenacity and elongation at the break of grey and dyed cotton fiber were very close together. Differences between fibers length by weight and number, nep, short fiber content of grey and dyed cotton fiber were meaningful. There is not a meaningful difference between the elongations of three yarn samples. Tenacity of the R.R.Y yarn sample was the highest and coefficient of mass variation (Cv %), imperfections and hairiness of this yarn sample was the lowest in comparison with those parameters for M.R.Y and D.R.Y yarn samples respectively.