Mechanistic investigations on the action of levelling agents in reactive wool dyeing

Although levelling agents for reactive dyes have been on the market for more than twenty years, there still remains some uncertainty as to their mode of action. Therefore an investigation has been carried out, using Albegal B as a typical levelling agent and reactive dyes from the Lanasol range. There are three mechanisms proposed to describe how auxiliaries such as Albegal B can act to overcome tip/root unlevelness when dyeing wool fibres: a dye complex mechanism, a surface mechanism and a fibre mechanism. These are discussed in the light of the experimental results.