Cellulosic-polyester fiber blends, dyeing

Blends of polyester with cotton (qv) or viscose are first dyed with disperse dyes, then with sulfur dyes (see Fibers, polyester Fibers, regenerated CELLULOSics). Disperse and sulfur dyes can also be appHed simultaneously in a pad—dry—thermofix/chemical reduction pad—steam sequence. In this case, the sulfur dyes cannot be used in thein reduced form because of the effect of the sodium sulfide on the disperse dye. Therefore, this method is confined to the solubilized sulfur dyes or sulfur dyes in the dispersed form. 

Sulfur dyes are used mainly for dyeing textile cellulosic materials or blends of cellulosic fibers (qv) with synthetic fibers such as acrylic fibers, polyamides (nylons), and polyesters. They are also used for silk (qv) and paper (qv) in limited quantities for specific applications. Solubilized sulfur dyes are used on certain types of leathers (qv). 

Dye Combinations. In certain cases it is desirable to print fiber blends with combinations of the appropriate dye classes, rather than with pigments. Only polyester-cellulose blends are of commercial importance and the following dye systems have been developed for them. The dyes of the different classes are contained in the same print paste and, therefore, are applied simultaneously in one print operation. They include disperse-reactive combinations, disperse-pigment combinations, and disperse-vat combinations. 

Classification by usage or application is the principal system adopted by the Colour Index [5], Because the most important textile fibers are cotton and polyester, the most important dye types are those used for dyeing these two fibers, including polyester-cotton blends (see Chapter 4). Other textile fibers include nylon, polyacrylonitrile, and cellulose acetate. 

With a few exceptions, sulfur dyes [1] are employed to dye cellulosic fibers. The main applications are the dyeing of corduroy, velveteen, denim articles, twill work clothes, tarpaulins, and backpack fabrics. The dyeing of the cellulosic fiber component of blended fabrics (polyester/cotton blends above all) is increasingly important. 

EGANAL PSA Cone, is used during the dyeing of polyester fibers and its blends with cellulosics and wool under HT dyeing conditions. 

Cottestren C. [BASF AG] Mixed dyes for polyester/cellulose fiber blends. 

Uses Leveling agent, dispersant for dyeing polyester fibers with disperse dyestuffs, fluorescent whitening of polyester fibers with disperse FWAs and dyeing the polyester component of polyester/cellulosic blends by the HT process Features Prevents filtration of dyestuffs does not inc. the AOX content of waste-water pumpable resist, to acids, alkali, salts, hard water Properties YIsh.-brn. Iiq. readily sol. in water dens. 1.0 g/ml (20 C) pH 4,0 (10%)... 

The leuco esters of vat dyes are anthraquinoid or indigoid vat dyes (Section 3.4) that have been made water soluble by reduction and esterification of the hydroxyl groups with sulfuric acid. These dyes are used mainly for dyeing high-quality articles of cellulose fibers in light colors and polyester-cellulose blends to moderate depths of shade [58], [59, p. 568],... 

Blends of polyesterand cellulosic fibers are printed with disperse and reactive dyes only in cases, when pigment printing is unsatisfactory. Dye selection follows basically the rules given for continuous dyeing polyester and cellulose fibers. 

BURCO CARRIER CDP is a carrier for cationic dyes on polyesters such as DACRON 62, 64 or 92. It gives full color yields and excellent leveling on these fibers while reserving other fibers (such as DACRON 54, 56 or cellulosics) in blends. Outstanding color and white (even black and white) effects can be achieved in a one-step dyeing procedure. 

Use Levei 0.5-10% owg (scouring) 0.5-10% owg (one-bath scouring/dyeing of polyester or acrylic fibers and acryllc/cellulosic blends) 0.5-1.0 g/l (wetting for exhaust and continuous systems) 0.5-2.0 g/l (rewettIng)... 

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