SALT-FREE DYEING - A NEW METHOD OF DYEING ON LYOCELL/COTTON BLENDED FABRICS WITH REACTIVE DYES

Abstract

Cellulosic/regenerated blended fabrics dyed with reactive dyes require a large amount of salt, which pollutes fresh watercourses. Due to the hydrolysis of the dye, the dyeing effluent consists of a large amount of hydrolysed dye, and it requires a high volume of water to remove the hydrolysed dye in a wash-off process. Lyocell/cotton fabrics were dyed with reactive dyes using conventional methods and pretreating the fabric with polyvinylamine chloride (at five different concentrations). Pretreated samples were dyed without using salt as an electrolyte. The influence of pretreatment on K/S value, wash fastness, rubbing fastness, tensile strength, flexural rigidity and crease recovery were determined. It was found that pretreatment of Lyocell/cotton fabrics with polyvinylamine chloride increases dye uptake and shows good wash fastness and rubbing fastness. There was a slight increase in crease recovery angle and flexural rigidity in the pretreated sample. It was determined that polyvinylamine chloride was found to be effective for pretreatment in salt-free dyeing of Lyocell/cotton fabrics.