Polyester-Cellulose Blends

The most important fiber blends consist of polyester and cellulose fibers or wool. Of the worldwide consumption of PES fibers, ca. 45 % is used in blends with cellulose fibers. In polyester-cellulose blends the cellulose component is usually cotton or viscose staple fibers The preferred mixing ratio is PES CEL 67 33 and, for textiles worn close to the skin, 50 50 to 20 80. 

In dyeing PES-CEL mixtures, disperse dyes are used for the PES component. The CEL portion can be dyed with practically all classes of dyes suited to cellulose (see Sections 4.2-4.8). The selection of suitable dyes depends not only on the equipment available, the desired shade, and the batch size, but also on economic factors, with the required fastness taken into account. Thus, reactive dyes (see Section 4.2) are used preferentially for all types of clothing textiles, but vat dyes (see Section 4.4) are employed where extreme demands are made on washfastness or weatherproofness. 

Dyeing with premixed disperse and vat dyes is especially easy. The mixed dyes can be applied in a single bath by the exhaustion or continuous process. The dyes are formulated in such a way that the same shade is obtained on both fibers, which facilitates shade matching [85, pp. 62-63, 221-246], They are normally intended for 80 20 to 50 50 PES-CEL blends. 

For matching off the two fibers, the components often must be inspected separately. To this effect, the cellulose in PES-CEL blends can be dissolved out by treatment with sulfuric acid (72%, 45 min at room temperature or 5 min at 70°C) or orthophosphoric acid (85%, 3-5 min at 80-90 °C), which is facilitated by ultrasonic treatment. 

Dyeing Processes. Since safe and efficient continuous dyeing methods are well known, and large yardages are often dyed in the same color, PES-CEL mixtures are frequently dyed in continuous processes [142], Nevertheless, batch dyeing is 

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Disperse liquid brands of sulphur, vat or disperse dyes, including mixed formulations of disperse and vat dyes in matching hues for the dyeing of polyester/cellulosic blends, have been commercially available for many years. The proportion of reactive dyes marketed as aqueous solutions is expected to increase markedly [10] because of ... 

Considerable research effort has been devoted to developing a new generation of disperse dyes designed to optimise fastness to washing and minimise cross-staining of the cellulosic component of polyester/cellulosic blends [97,98]. Diester-containing monoazo disperse dye structures (4.91) that yield a dicarboxylic acid on hydrolysis and certain thienylazo blues... 

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. 

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],... 

Multi-purpose non-foaming dyeing assistant for jet dyeing of polyester/cotton blends. Also, used in other dyeing procedures of polyester/cellulosic blends when foaming is a potential problem. REMOL NFE is also very well suited for afterscouring. 

FIXAPRET PEC is a 45% aqueous solution of selected reactant compounds of the N-methylol and O-methylol range. The product was specially developed for the resin finishing of polyester/ cellulosic blends. 

FIXAPRET PEC imparts a very elegant, flowing handle, particularly to polyester/cellulose blends. 

POMOCO SR 92 is a very versatile product, used on polyester and polyester/cellulosic blends as a dyebath detergent, a dye-bath lubricant, and as a finishing agent. 

MYKON EJ softener is very effective when used with permanent press resin finishes. It improves sewability and tear strength of cotton, rayon, and polyester/cellulosic blends without effecting chlorine resistance, lightfastness or scorch resistance of the finished fabric. MYKON EJ emulsion also softens the treated fabric. 

DylevCDL. [Apolto] Direct dye leveler and stabili fa dyeing oi cellulosic and polyester/cellulosic blends. 

Flame retardantfinishes for polyester/cellulosic blends. Effectively flame retarding polyester/cotton blends is not simple and the problems associated with it have been discussed elsewhere.Within the technical textile sector, however, the uses of these... 

Tesoro, G.C., Rivlin, J., Moore, D.R., 1972. Flame-retardant fiitishing of polyester-cellulose blends. Ind. Eng. Chem. Prod. Res. Dev. 11, 164—169. 

Scanning electron microscopic image of the polyester-cellulose blend (a) initial blend, (b) after biodegradation of cellulose fibres. 

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%)... 

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