GB552735A - Improvements in the dyeing of textiles - Google Patents

Abstract

552,735. Dyeing textiles. WATKINS, W. Aug. 16, 1941, No. 10438. Drawings to Specification. [Classes 15 (i) and 15 (ii)] Sulphuretted dyes, dyeing with. In the dyeing of textiles with sulphur dyes, including the sulphide vat dyes known as Hydron blues, the goods leaving the dyebath are subjected, without an intermediate rinsing, to treatment with a fixing reagent, other than air or steam alone, to render the dyestuff insoluble, thus eliminating effluent difficulties due to loss of dyestuff in rinsing, the reagent being one, such as an acid or an acid salt or other suitable metal salt, which will remove the alkalinity of the liquor. A drying step may precede the fixing treatment and, in the continuous treatment of fabrics or warp yarns, the materials leaving the dyebath may be successively steamed, padded, dried, padded in an acid or other fixing bath, rinsed and dried. An oxidizing agent such as sodium bichromate may be added to the fixing bath. In examples, (1) the fabric passes through a boiling aqueous dyebath containing Pyrogene direct blue RL, Liquid Thional black RS, sodium sulphide and sulphonated castor oil and thence, by way of a padding mangle and drying cylinders, through a fixing bath comprising an aqueous solution of acetic acid and sodium bichromate to a second padding mangle and a washing machine, (2) the fabric passes similarly through a boiling aqueous dyebath containing Liquid Thional black RS, sodium sulphide and sulphonated castor oil and a fixing bath comprising an aqueous solution of magnesium sulphate and sodium bichromate.