Developing faded denim using surface-modified disperse dye dyeable cotton yarn

Abstract

In this study, faded denim fabrics have been developed using an unconventional route. The surface of cotton yarn is
modified using an unsaturated polyester-based resin, thus making this yarn disperse dye dyeable. FTIR spectroscopy has
been used to confirm the presence of resin on the surface of the yarn. A twill (3 up 1 down) weave fabric is produced using a
combination of surface-modified and gray cotton yarns. After curing at 180oC, the fabric has been dyed in CDR using lowenergy
disperse dyes in the presence of vanillin as a carrier. Statistical analysis (ANOVA) has been carried out to establish a
relationship between the concentration of vanillin and the colour strength. The surface-modified disperse dyed yarn in the
fabric is found to have a ring dyeing effect, as only the surface of the yarn is dyed. The developed fabric is washed using
two different methods (mild and harsh) to get different fading effects. The unwashed and washed samples are analyzed for
tensile strength, tear strength and bending length properties. The tensile strength of unwashed samples is found to be
between 585 - 648 N and 516 - 588 N for warp-wise and weft-wise directions respectively and after various washing
conditions, it decreases to 395 - 594 N and 395 - 550 N for warp-wise and weft-wise directions respectively. In the case of
tear strength, the warp-wise and weft-wise values of unwashed samples lie at 33.5 - 38 N and 30 - 33 respectively and after
various washing conditions, these values are 19.5 - 22 and 17.5 - 21 N respectively. The bending length of the unwashed
fabric samples are 1.9 - 3.0 mm and 1.8 - 2.9 mm for warp-wise and weft-wise respectively and after washing, the bending
length decreases to 1.5 - 2.7 and 1.3 - 2.5 mm for warp-wise and weft-wise respectively.