Polyester fibre with high dyeability and pilling

Polyester fibre based on poly(ethylene terephthalate) modified by addition of 3 wt. % sulfoisophthalic acid Na salt dimethyl ester; has high resistance to the pilling effect and elevated dyeability with disperse dyes. Sorption of the dye by the modified fibre at 100 degrees C is several times higher (and in the case of a disperse dye, more than one order of magnitude higher) than sorption of dyes by mass-produced polyester fibre. The fastness of dyeing the modified and mass-produced fibres in different kinds of treatment is almost the same The high sorption capacity of the modified fibre not only allows dyeing it with disperse dyes at normal pressure in a wide range of deep and medium shades, but also reducing the amount of unused dye in the baths and thus decreasing the effect on the environment.