Abstract: An apparatus for mercerizing textiles and fabrics of cotton or cotton blends; the textile material, before and during impregnation with lye, is guided between a drum mantle and a synchronous liquid-permeable pressure band; removal of the lye is effected through the textile material while the latter is looped around the drum. The shrinkage of edges, especially of fabrics, is to be avoided both with certainty and also in a lasting manner. Also to be achieved is a complete impregnation of the textile material, as well as a removal and recovery of the strong lye without a dilution thereof by weak lye or water used for removal of lye.