Surfactants and Their Activity in Dyeing Baths

Abstract

Textile finishing as a series of processes and operations aimed at attaining optimal usability of the textile material treated, would not be possible without surface active agents. Surfactants can be absorbed on a solid surface and reduce the angle of contact between the liquid and solid matter. Even low concentrations of surfactants soluted in water considerably reduce surface tension in relation to the air of border surface in contact with other surfactants. They accelerate the processes and ensure uniform effects of the treatment applied. Surfactants are used in dyeing baths for the purpose of levelling out, acting as retarders or the agents to solubilise the dyestuffs. Their function as dispersing agents is also prominent, especially when dyeing with disperse and reducing dyes, in which case the process of dyeing would be utterly impossible without them. Sometimes dispersing agents are also used in dyeing with other groups of dyes, mostly when dyeing in darker hues. Under some conditions they can be employed for fixing dyestuffs onto the fibre, enhancing considerably colour fastness.