19-08-2014, 11:19 AM
Sulphur dyes are mainly known for the shades like black, navy, brown, olive and khaki, and these dyes are preferred due to their low cost, simple method of application and overall good fastness properties but suffer from drawback of relatively dull shades. The present work hence was focused on developing brighter shades with topping of same or different colours from different class of dyes and exploring the possibility of further creating various fancy effects with aftertreatments.
Sulphur dyes are mainly known for the shades like black, navy, brown, olive and khaki, and these dyes are preferred due to their low cost, simple method of application and overall good fastness properties but suffer from drawback of relatively dull shades. The present work hence was focused on developing brighter shades with topping of same or different colours from different class of dyes and exploring the possibility of further creating various fancy effects with aftertreatments.
Sulphur dyes possess a great affinity for basic dyes and act as mordant for basic dyes on cellulosics.
As such Basic dyes do not have any affinity for cellulosic goods. Hence cotton goods dyed with sulphur colours were topped with basic dyes so as to get enhanced brilliance of shade and improved washing fastness properties as well. Basically topping is done for opposite charge groups, such as basic dye (cationic) on sulphur dye (anionic) and basic dye (cationic) on direct dye (anionic) however toppingith anionic group on anionic group such as direct dye on sulphur dye us also attempted.
The cotton fabrics were dyed with sulphur dye in three different shades such as 1%, 2%, 3% and were topped as well as simultaneous dyeing with sulphur dyes was carried out with direct dyes in four different shades such as 0.5%, 1.0%, 1.5%, 2.0% o.w.f. Similarly basic dyes were also used on cotton fabric with sulphur dyes in simultaneous as well as topping method in three different shades such 0.5%, 1% and 1.5% o.w.f. The samples were further analyzed for obtained colour with colour matching system and changes were recorded. The dyed samples were evaluated for Wash Rubbing and Light fastness.