Dyestuff fabrics

Chemical substances are materials which can be produced or used in chemical processes. Chemical processes include such reactions as combustion. Since the rise of the modem chemical industry in the nineteenth century, numerous chemical substances have been developed and created including acids, bases, fertilizers, ceramics, catalysts, dyestuffs, fabrics, explosives, paints, plastics, petrochemicals, pharmaceuticals, agricultural chemicals, specialty chemicals, automotive materials, and home and commercial electronics components. 

Standard polyester fibers contain no reactive dye sites. PET fibers are typically dyed by diffusiag dispersed dyestuffs iato the amorphous regions ia the fibers. Copolyesters from a variety of copolymeri2able glycol or diacid comonomers open the fiber stmcture to achieve deep dyeabiHty (7,28—30). This approach is useful when the attendant effects on the copolyester thermal or physical properties are not of concern (31,32). The addition of anionic sites to polyester usiag sodium dimethyl 5-sulfoisophthalate [3965-55-7] has been practiced to make fibers receptive to cationic dyes (33). Yams and fabrics made from mixtures of disperse and cationicaHy dyeable PET show a visual range from subde heather tones to striking contrasts (see Dyes, application and evaluation). 

Fluorescent Dyestuffs. Very few dyes are of use in making daylight-fluorescent products. Of the dyes discovered up to 1920, only the brilliant ted and salmon dyes of the rhodamine and rosamine classes ate used in fluorescent materials in the 1990s. The first of these, Rhodamine B, was discovered in 1877. Fluorescence excited by both uv and visible light components in daylight was formally recognized as a notable property of certain dyed fabrics by the 1920s (1). 

Color Color Association of the United States 24 East 39th Street New York, NY 10016 Color standards for fabrics, paints, wallpaper, plastics, floor coverings, automotive and aeronautical materials, china, chemicals, dyestuffs, cosmetics, etc. 

Textile finishing includes various efforts to improve the properties of textile fabrics, whether for apparel, home, or other end uses. In particular, these processes are directed toward modifying either the fiber characteristics themselves or the gross textile end properties. Such modifications may be chemical or mechanical in nature. One modification that is not covered in this article relates to the dyeing of textiles and the dyestuffs employed for fibers however, areas that involve chemical finishing designed to modify the normal dye receptivity and the growing use of enzyme treatments are included. 

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. 

Thermal Fixation Properties of Disperse Dyes on Polyester—Gotton. This method assesses the fixation properties of disperse dyes as a function of the time, temperature, dyestuff concentration, or presence and amount of auxiUary agents. The polyester—cotton fabric is padded and dried, the cotton dissolved in sulfuric acid and washed out of the blend, and the amount of dye on the polyester component assessed by either reflectance or measuring the optical density of a solution of dye obtained by extracting the dye with boiling chloroben2ene solvent. 

Hydrogen cyanide From metal plating, blast furnaces, dyestuff works Metal fabricating, primary metals, textiles Capable of affecting nerve cells... 

Phosgenes Thermal decomposition of chlorinated hydrocarbons, degreasing, manufacture of dyestuffs, pharmaceuticals, organic chemi- Metal fabrication, heavy chemicals Damage capable of leading to pulmonary edema, often delayed... 

Plastics are high-molecular-weight organic compounds of natural or mostly artificial origin. In fabrication, plastics are added with fillers, plasticizers, dyestuffs and other additives, wliich are necessary to lower the price of the material, and give it the desired properties of strength, elasticity, color, point of softening, thermal conductivity, etc. 

Aniline and other aromatic amines are valuable industrial raw materials. They form an important starting point from which many of our dyestuffs, medicinals, and other valuable products are prepared. For example, you have used the indicator, methyl orange, in your laboratory experiments. Methyl orange is an example of an anQine-derived dye, although it is used more as an acid-base indicator than for dyeing fabrics. The structure of methyl orange is as follows ... 

NaN02 is used for diazotizing in dyestuff manuf, in org synthesis, rubber accelerators, prepn of nitric oxide, pharmaceuticals, photographic reag, curing meats, dyeing and printing textile fabrics, etc... 

The other source of modem dmgs was the European dyestuff industry of the nineteenth and early twentieth centuries. The goal of this industry was to make useful dyes, principally for fabrics. In the course of handling novel molecules, scientists occasionally make unexpected observations (serendipity) that suggest novel utilities. For example, the commonly used sweetener aspartame was discovered by accident when a scientist licked a finger containing a bit of this substance. It turned out to be surprisingly sweet. 

In the tests with dilute acetic add or dilute ammonia, the extraction should be repeated on the same piece of fabric with the view of completing the extraction and also because it sometimes happens that, in the first boiling with dilute ammonia, certam add dyestuffs dye white cotton, whilst during the second boiling such coloration assumed by the cotton in the first treatment disappears. When boiling with white cotton is prescribed, a... 

Reduction and reoxidation tests. Reduction with hydrosulphite B X is effected by boiling the fabric in this reagent for about two minutes. Azines, thiazines, oxazines, etc., and most of the azo-dyestuffs are completely reduced in about half a minute, but insoluble azo-dyestuffs require more prolonged boiling for their complete reduction. 

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