Dyeing Dyers

Figure 1 shows the shades of these color lakes obtained from dyeings produced with the principal yellow natural dyes dyer s rocket (C.I. Natural Yellow 2), quercitron (C.I. Natural Yellow 10), unripe buckthorn berries (C.I. Natural Yellow 13), fustic (C.I. Natural Yellow 11), curcuma (C.I. Natural Yellow 3), and kamala (C.I. Natural Yellow 25). These lakes, which differ markedly in their shades from the others, are marked with a cross. They are the tin lakes of quercitron and curcuma, the curcuma iron lake, and the copper lakes of dyers rocket, unripe buckthorn berries, and fustic. A report on these methods has been published (15). The natural yellow dyes are shown in Figure 1 as examples of the lakes produced. 

English name Weld, Yellow dye, Dyer s rocket... 

Stilbene dyes ate classed as a subgroup of azo dyes having excellent colorfastness and typical direct dye wash fastness on cotton and ate arranged iato six categories by the Society of Dyers and Colourists (2), as described ia the foUowiag. 

C. L. Bind, The Theoy and Practice of Wool Dyeing Society of Dyers and Coloudsts, Bradford, U.K., 1972. 

A carrier is selected by the dyer according to various criteria. The type of equipment and conditions under which it is to be used have already been mentioned. Other considerations include color yield, dye migration, and product and emulsion stabiUty. 

E. Clayton, Identification of Dyes on Textile Fibres, 2nd ed.. Society of Dyers and Colorists, Bradford, UK, 1963. 

There is Httle correlation between classifications according to chemical type and appHcation properties. AppHcation classifications are of most practical usefulness to the dyer, and therefore the chemical constitutions of dyes are described here only briefly. Further detailed information on dye types (10) and their chemical manufacture (11) can be found elsewhere, and ia many other Eniyclopedia articles to which references are made. 

Control of Dyeing Equipment. Over the years, the dyer and machinery manufacturer have appHed any mechanical or electrical equipment that would enable them, day after day, to produce repeatable dyeings of top quaHty. First, thermometers were installed in dye lines these soon evolved into thermocouples with remote recording. Other improvements were soon developed, such as automatic four-way valves with variable-interval controls, flow controls, pressure recorders, hydrauHc and air pressure sets on roUers, pH controls, etc. 

There are many completely automated computer-controUed exhaust dyehouses. Some firms have a no-add procedure in the dyehouse by which the dyer loads the fabric or yam, weighs the dye, punches a button, and lets the computer take over the entire process. This procedure ensures a constant dyeing cycle and the only variables are the dye index of the fiber or the quaHty of the dyestuff. 

C. Preston, ed.. The Dyeing of Cellulosics Fibres, Dyers Company PubHcations Tmst, London, 1986. 

Turkey, for centuries, has been known for the beauty of its handwoven mgs dyed with natural dyes. Nowadays Turkish peasants prefer to dye machine-made mgs with synthetic dyes since these are more readily available and easier to apply. However, there is a growing demand by collectors and connoisseurs connoisseurs for handmade mgs dyed with natural dyes, especially alizarin, and they command premium prices (22). Also, there is a small demand for natural alizarin by artists and home dyers who claim that natural alizarin produces subde shades not obtainable with synthetic alizarin. Just as synthetic alizarin forced natural alizarin out of the market, synthetic alizarin has been replaced by azoic dyes since they are easier to apply. 

Chemical classification is based on chromogen. For example, nitro dyes have the chromophore -NOj. The Color Index (C.I.), published by the Society of Dyers... 

FSrberei, /, dyeing dye house, dye works. Fkrbereiche, /. dyer s oak, quercitron, farbereichemisch, a. pertaining to the chemistry of dyeing. 

Farber-erde, /. Armenian bole, -flechte, /. archil, dyer s moss, -flotte, /. dye liquor, dye bath, -ginster, m. dyer s broom (Ge-niata tinctoria). -holz, n. dyer s wood, dye-wood. 

Streich-flache,/. striking surface (for matches), rubber, -holz, -holzchen, n. friction match, -instrument, n. stringed instrument, -kappe, /. (Expl.) friction cap. -kasten, m. (Dyeing) color tub. -kraut, n. dyer s rocket, -lack, m. brushing lacquer, -masse, /. friction composition (for matches), -mischung, /. coating mixture, -muster, m. (Paper) stained-paper pattern, -ofen, m. reverberatory furnace. -papier, n. coated paper, -stein, m. touchstone hone, -torf, m. pressed peat, molded peat. -zUndholzchen, n. friction match. 

Saito, K. and Miyakawa, K., A new procedure for the production of carthamin dye from dyer s saffron flowers, Lebensm. Wiss. Technol, 27, 384, 1994. 

A. H. M. Renfrew, Reactive dyes for Textile Fibres the Chemistry of Activated n-bonds as Reactive Groups and Miscellaneous Topics, Society of Dyers and Colourists, Bradford, 1999. 

The natural dyes industry was also a large, sophisticated, and worldwide employer. Master dyers made a wide range of reasonably fast colors and handed down secret dye recipes to their apprentices. Europe s two staple dyes were madder red from the Mediterranean and indigo blue from India. Other natural dyes included violet from lichens dark red from the forget-me-not family brown from African aloe plants and black from tumorlike... 

Hofmann himself made a fabulously brilliant violet that replaced Perkin s mauve, even though the professor s dye was not as fast as his student s. Dyers thought no one would want fleeting tints, but, no matter, the experts were wrong. Women craved raucous and dramatic hues they... 

Lillie, R. D. (1979), The red dyes used by ancient dyers Their probable identity, /. Soc. Dyers Colourists 57-61. 

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