Method and apparatus for applying vat dye, in particular indigo dye sustained-oxidation.

摘要

A process for applying indigo dyestuff on a textile substrate is described, wherein the substrate is saturated with liquid steeping liquor containing indigo dyestuff and the saturated substrate is directly passed through a first low-oxygen wet dwelling section and only thereafter is dewatered. To maximize the dyestuff yield or diffusion into the individual fibers of the substrate, a second enclosed low-oxygen wet dwelling section is defined by an essentially sealed housing which is connected to the first wet dwelling section. The substrate is initially heated in the second wet dwelling section and the substrate travels through the remainder of the second wet dwelling section for a sufficient time to permit diffusion of the dyestuff into the fibers of the still moist substrate.