Dyeing Blends

New water-insol. naphthalic acid imide dyestuffs - used to dye blends of polyamide or urethane- and polyester or tri acetate fibres having good light and washing fastness C91-110.342 RICH DE GB LI) ... 

Dyes based on these compounds possess, in addition to good lightfastness, excellent wetfastness and are usually neutral-dyeing on wool. This, although of no importance for dyeing pure wool, plays an important role in dyeing blended spun yam and blended fabrics of wool and cotton or wool and viscose staple. The neutral-dyeing acid dye can be used in combination with direct dyes (union wool recipes). Examples are C.I. Acid Yellow 56, 24825 [6548-24-9] (17), and C.I. Acid Red 154, 24800 [6507-79-5] (18 R = CH3). 

Reactive dyes are well suited to dye blends of cellulose and PA fibers. Clear shades with very good fastness are obtained. Like with vat dyes, the depth of shade of reactive dyes depends relatively strongly on the type of PA and structural differences. Dyeing is carried out in a three-step process with appropriately selected products. First, the reactive dyes in a weakly acidic liquor are allowed to absorb on the PA component. Salt is then added to improve the yield on the cellulose component. Finally, the liquor is made alkaline for reaction with the cellulose fiber. Dyes (e.g., with MTC anchor) that dye PA from a neutral liquor in the presence of salt are applied in a two-step process, as in the case of cellulose. In the reversal of this dyeing process, the cellulose component is dyed first at alkaline pH, followed by neutralization with acid, and the PA component is then covered at elevated temperature. 

Reactive dyes will not color polyester, and thus the conventional process for dyeing blends consists of four distinct and separate procedures dyeing of the polyester with disperse dyes, reduction/clearing of the polyester, impregnation of the cotton component with reactive dyes, and fixation of the reactive dye. 

Dye blends—One of the reactive dyes, a scarlet, was a b1 end, composed of an orange component and a red component. The orange and red components exhausted at different percentages, thus blocking analysis and dye blend adds. The dye manufacturer provided Georgia Tech on a confidential basis with a detailed analysis of the dye blend, allowing reuse analysis and adds of the individual components. 

Dyeing, cross n. A method of dyeing blend or combination fabrics to two or more shades by the use of dyes with different affinities for the different fibers. 

Semi-permanent dyes are usually applied to natural, unbleached hair after shampooing. The formulations use mixtures of dyes, blended to the desired shade. It is common to use several dyes of similar colour but with different molecular sizes to provide even coloration. Larger dye molecules tend to be retained by the more damaged tip of the hair, but do not penetrate so readily into the roots, while smaller molecules penetrate the entire hair fibre but wash out of the more porous tip. 

Figure 32 Electrically tunable energy transfer from a single semiconductor nanorod to a dye molecule. High-resolution (a) and overview (b) transmission electron micrographs showing the structure of the CdSe/CdS nanocrystals used, (c) For a specific set of a single nanocrystal and a single dye molecule no energy transfer occurs because of the lack of spectral overlap between nanocrystal emission and dye absorption, (d) After application of an electric field, the nanocrystal s PL is red shifted, resulting in the resonance of the nanocrystal and dye transitions. This leads to energy transfer to the dye and subsequent emission, (e) Absorption (dashed lines) and PL (solid lines) spectra of nanocrystals (blue lines) and dye (red lines). Absorption spectra were measured in chloroform solution at room temperature, whereas emission spectra in polystyrene/dye blends at 50 K. Note the considerable spectral overlap of nanocrystal emission with dye absorption. The inset shows the solution absorption and PL of the nanocrystal excitonic feature. (Reprinted by permission from Macmillan Publishers Ltd from Ref. 72.)...

Dehydd 100 Rhodaqual RP-50 Rhodaquat RP-80 dispersant, disinfectants Eccowel W-50 Eccowel W-88 dispersant, disperse dye blends Matexi DA N... 

Wool-acrylic blends Wool combing Wool-cotton blends Wool dyes Woolen systems... 

Electrically Conducting Fibers. FlectricaHy conducting fibers are useful in blends with fibers of other types to achieve antistatic properties in apparel fabrics and carpets. The process developed by Nippon Sanmo Dyeing Co., for example, is reportedly used by Asahi in Casbmilon 2.2 dtex (2 den) staple fibers. Courtaulds claims a flame-resistant electrically conductive fiber produced by reaction with guanadine and treatment with copper sulfide (97). 

Dyes, application and evaluation). Foi dyeing fibei blends such as viscose—polyamide, polyamide—Spandex, oi polyestei—cotton, only compatible FWAs may be used that do not inteifeie with one another oi have any detrimental effect on fastness properties. 

Polymer Applications. The reaction of sahcylaldehyde with poly(vinyl alcohol) to form an acetal has been used to provide dye receptor sites on poly(vinyl alcohol) fibers (89) and to improve the light stabihty of blend fibers from vinyl chloride resin and poly(vinyl alcohol) (90) (see Fibers, POLY(VINYL alcohol)). ... 

Color Mixing. The various types of dye powders used to make dye stains are blended to achieve the desired color. Most finishers purchase wood stains premixed to specified colors. In the wood-finishing industry, various shades of brown are the most common. These colors are usually blended from primary colors. Color-matching skills can be acquired only by practice, but the basic theory of color matching is relatively simple and easily understood. The basic theory of color matching can be demonstrated by using the color circle shown in Figure 1 (see Color). 

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

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. 

The sulfur dyes are widely used in piece dyeing of traditionally woven cotton goods such as drill and corduroy fabrics (see Textiles). The ceUulosic portion of polyester—cotton and polyester—viscose blends is dyed with sulfur dyes. Their fastness matches that of the disperse dyes on the polyester portion, especiaUy when it is taken into account that these fabrics are generaUy given a resin finish. 

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