**5. Main methods of disperse dyeing**

Disperse dyes are the most important class of dye used in dyeing polyester fibres and provide a wide range of hues with good build-up and fastness properties adequate for most purposes. The rate of dyeing may be raised to the level of commercial acceptability, either by raising the working temperature to the region of 130C, or by dyeing at the boil in the presence of an accelerating agent or 'carrier' (Waters, 1950). Disperse dyes can also be transferred to polyester fibres under dry conditions by impregnating the goods with a suitable dispersion, drying and then baking at temperatures in the range 190-220C (Ingamells, 1993).
