DYEING OF ALKALI TREATED POLYESTER AND POLYESTER/ VISCOSE BLEND FABRICS AND CHARACTERIZATION OF THEIR PROPERTIES

The alkaline weight reduction of polyester and polyester/viscose blend fabrics and determination of the fabrics dyeing characteristics were evaluated. An alkali treatment of polyester and blend fabrics was carried out in a pilot scale mini jet machine using dilute caustic soda (7 g/L) at 1:20 liquor ratio, in the presence of cetyl trimethyl ammonium bromide, a cationic surfactant (1 g/L), as a reaction accelerator, at 120oC. The weight reduction obtained was 16 % for polyester fabric and 7.5 for the blend (7.5% weight loss at 95 °C). The alkali treated polyester fabric surface was examined using a scanning electron microscope.

The polyester fabric which has been subjected to alkaline hydrolysis was dyed in alkaline (pH 8.5) and acidic medium (pH 4.5), liquor ratio 1:20, using different Dianix, commercial disperse dyes, in a mini jet machine at and 120oC. The results indicated that the alkaline dyed samples exhibited an increase of color strength and slightly better anti-crease property compared to the acid dyed and untreated control fabrics.

Dyeing of polyester/viscose blend fabrics was carried out in a single bath at 120oC, in a mini jet dyeing machine using the conventional Forosol dyeing at pH 4.5. Alkaline weight reduction process improved the fabrics handle properties. Excellent to very good fastness results were observed for the dyed fabrics.