Effect of caustic pretreatment at varying tension level on dyeing behaviour of jute, flax and ramie

Abstract

The effect of caustic soda pretreatments at slack and at different levels of tension on the dyeing behaviour of jute, flax and ramie yarns has been studied using direct, reactive (cold and highly exhaustive brands) and basic dyes. It is observed that the higher the hemicellulose content of the lignocellulosic fibre, the higher is the weight loss on caustic soda treatment. Weight loss increases for all the fibres with increase in caustic soda concentration or decrease in tension level during treatment. Decrease in basic dye uptake and increase in direct and reactive dye uptake are observed with the increase in caustic soda concentration

during pretreatment for all the fibres. With increase in tension level during treatment, the dye uptake decreases to some extent, irrespective of the fibre type or caustic soda concentration.