Disperse Dyes Views
Disperse dyes were originally developed for the dyeing of cellulose acetate, and are water insoluble. The dyes are finely ground in the presence of a dispersing agent and sold as a paste, or spray-dried and sold as a powder. Their main use is to dye polyester but they can also be used to dye nylon, cellulose triacetate, and acrylic fibres. In some cases, a dyeing temperature of 130 °C is required, and a pressurised dyebath is used. The very fine particle size gives a large surface area that aids dissolution to allow uptake by the fibre. The dyeing rate can be significantly influenced by the choice of dispersing agent used during the grinding.
Penetration of the fabric by the dye is more difficult with the hydrophobic synthetic fibres of acetate rayon, PET, and acrylics, so an alternate dyeing technique is needed. These synthetic fabrics are dyed by immersion in an aqueous dispersion of insoluble dyes, whereby the dye transfers into the fibre and forms a solid solution. These disperse dyes were originally developed for acetate rayon...
...colourless compounds by means of alkaline sodium hydrosulfite. Cellulose absorbs these colourless compounds, which are subsequently oxidized to an insoluble pigment. Such dyes are colourfast. Disperse dyes are suspensions of finely divided insoluble, organic pigments used to dye such hydrophobic fibres as polyesters, nylon, and cellulose acetates.
Penetration of the fabric by the dye is more difficult with the hydrophobic synthetic fibres of acetate rayon, PET, and acrylics, so an alternate dyeing technique is needed. These synthetic fabrics are dyed by immersion in an aqueous dispersion of insoluble dyes, whereby the dye transfers into the fibre and forms a solid solution. These disperse dyes were originally developed for acetate rayon...