DYEING PROPERTIES OF COTTON FIBERS TREATED WITH LIQUID-AMMONIA

Both scoured and sodium hydroxide mercerised cotton fibres have been t reated with liquid ammonia at -33.4 degrees C using commercial operati ng equipment and then the ammonia removed at 130 degrees C in a hot dr um. The moisture regain and water absorbency of the fibres treated wit h liquid ammonia were increased compared with values on untreated fibr es, whereas both these parameters on mercerised cotton fibres were dec reased by subsequent liquid ammonia treatment. The fibres were dyed wi th Cl Direct Red 2 and Cl Direct Blue 1. Liquid ammonia treatment of t he scoured cotton fibres increased the rate of dyeing, equilibrium dye adsorption, standard affinity, heat of dyeing and change of entropy, while the dyeing properties of mercerised cotton were adversely affect ed by subsequent liquid ammonia treatment.