Cotton color

Mughal, M.J., Naeem, M., Aleem, A., Saeed, R., Ahmed, K., 2008. Effect of a cationising agent on the conventional reactive dyeing of cotton. Color. Technol. 124, 62-65. 

Prabu, H.G., Sundrarajan, M., 2002. Effect of the bio-salt trisodium citrate in the dyeing of cotton. Color. Technol. 118,131-134. 

Catechol (o-dihydroxybenzene) was first discovered by Hugo Reinsch in 1839, by distilling catechin, a tannin-like cotton colorant. Since it was produced by destructive distillation, it was originally called pyrocatechol. 

Replacement of one of fluorine atoms in 2,4-difluoro-6-(4-arylazophenyl)-amino-l,2,4-triazines 150 with methoxy or amino group is used for the synthesis of fluorotriazine dyes 151 and 152, which are effective for cotton coloring (Scheme 63) [39,40],... 

Xu et al. [12] used fuzzy logic for color grading of cotton fibers to reduce the HVI-classer disagreement in cotton color grading. The authors used Rd and +b as the input variables and five major classes of cotton color as the output variables. They selected five... 

ANN has made its presence felt in all related aspeets in textile from the fiber cultivation to garment manufacturing. Pattern recognition is one of the areas where ANN has played a significant role. Attempts have been made to identify fibers as well as trash using neural networks and NIR spectrophotometry. Even the animal fibers, merino and mohair have been recognized and classified by She et al. [2]. Cotton colors are also classified based on chromatic differences by the use of neural network. Classification of trash, such as leaf, bark and seed coat, the content of each of these trash particles is important in the sense to deeide the cleaning process. 

Since the early 1980s, the viscose-based staple fibers have, like the cuprammonium and viscose filament yams in the 1970s, ceased to be commodities. They have been repositioned from the low cost textile fibers that were used in a myriad of appUcations regardless of suitabUity, to premium priced fashion fibers dehvering comfort, texture, and attractive colors in ways hard to achieve with other synthetics. They are stiU widely used in blends with polyester and cotton to add value, where in the 1980s they would have been added to reduce costs. 

Various methods of home-dyeing cotton and wool materials using natural dyes made from hulls of butternut, hickory nut, pecan, eastern black walnut, and Knglish walnut have been described (149). As far back as during the Civil War, butternut hulls have been used to furnish the yellow dye for uniforms of the Confederate troops. More recent attempts have been made to manufacture yellow and brown dyes from filbert shells on a commercial scale. The hulls are treated with copper sulfate and concentrated nitric acid to produce a yellow color, with ferrous sulfate to produce oHve-green, or with ammonia to produce mby-red (150) (see Dyes AND DYE INTERMEDIATES Dyes, natural). 

Phloroglucinol is Hsted in the Colourindex as Cl Developer 19. It is particularly valuable in the dyeing of acetate fiber but also has been used as a coupler for azoic colors in viscose, Odon, cotton (qv), rayon, or nylon fibers, or in union fabrics containing these fibers (157). For example, cellulose acetate fabric is treated with an aromatic amine such as (9-dianisidine or a disperse dye such as A-hydroxyphenylazo-2-naphthylamine and the amine diazotizes on the fiber the fabric is then rinsed, freed of excess nitrite, and the azo color is developed in a phloroglucinol bath at pH 5—7. Depending on the diazo precursor used, intense blue to jet-black shades can be obtained with excellent light-, bleach-, and mbfastness. 

The greatest industrial consumption of monobasic aluminum acetate has been as a solution in the preparation of red color lakes for the dyeing of cotton. Formation of a water-resistant coating on fabrics, paper, leather, or other materials is also an important appHcation. In this process, for example, cloth is dipped into a solution of water-soluble soap, then into the aluminum salt solution, forming an insoluble, water-resistant aluminum soap coating on the fiber surfaces (10). 

Other Inks. The alkan olamine titanates, such as TYZOR TE, when mixed with a coloring agent used to print fibrous materials such as cotton, wool, or silk, promote adhesion of the dye molecule to the fiber, thus minimizing bleeding of the printed design (511). 

Other Cellulosics. Rayon is bleached similarly to cotton but under milder conditions since the fibers are more easily damaged and since there is less colored material to bleach. Cellulose acetate and triacetate are not usually bleached. They can be bleached like rayon, except a slightly lower pH is used to prevent hydrolysis. The above fibers are most commonly bleached with hydrogen peroxide. Linen, dax, and jute requite more bleaching and mil der conditions than cotton, so multiple steps are usually used. Commonly an acidic or neutral hypochlorite solution is followed by alkaline hypochlorite, peroxide, chlorite, or permanganate, or a chlorite step is done between two peroxide steps. A one-step process with sodium chlorite and hydrogen peroxide is also used. 

In the name Procion Red H-E 7B, Procion is the Zeneca trade name for its range of reactive dyes for cotton. Red denotes the main color of the dye. H-E denotes the dye to be hot dyeing and an exhaust dye (high fixation), and 7B denotes it to be a very bluish red dye, ie, a magenta. 

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