Influence of Eri silk fibre on the physical characteristics and dyeing properties of Eri silk/cotton blended yarn

Different blending ratios of Eri silk and cotton fibres were prepared. The optimum bleaching condition chosen for the blends containing 0–25% silk content was the oxidative bleaching method, whereas the blends at 50–100% should be bleached using the two‐stage bleaching method (oxidative bleaching followed by reductive bleaching). These conditions did affect the force–displacement characteristics of the fibres with no yield point. X‐Ray diffraction results showed that the percentage of crystallinity of the cotton yarn tended to increase after bleaching, whereas the percentage of crystallinity of the Eri yarn decreased marginally. Dyeing properties of the blended yarns were investigated using warm‐dyeing reactive dyes. Percentage exhaustion and the colour yield of the blends tended to decrease with the increasing silk content. Shade variation was observed on the yarns at different blend ratios. This was expected to be caused by the different physical nature of Eri silk and cotton fibres. Consequently, the dye uptake and visual shade of each dye on the two fibres were different.