A reactive dye was applied to woven cotton fabric then washed-off
using water and three alkaline agents (ammonium hydroxide,
sodium bicarbonate, sodium hydroxide). The aim of washing-off is
to eliminate of dyes no fixed on fabric to avoid its diss
olution
during washing what reduces fastness to washing.
The duration and temperature of wash-off were fixed, and the
concentrations of alkaline agents used were varied, and the effects
of these variables on the wash fastness of the dyeing were
determined.
There was little difference between the three alkaline agents, in
terms of the level of wash-fastness achieved. The best result was
with sodium bicarbonate and sodium hydroxide
