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Viscose rayon, manufacture

There are ten viscose rayon manufacturing plants in the U.S., all of which are believed to use zinc sulfate in their spinning bath. This process greatly enhances the economics of removing this source of zinc pollution, allowing neutralization of the acid stream and recovery of the zinc while generating a good profit for industrial yarns and at a moderate cost for textile yams. [Pg.21]

Carbon disulfide (CS2) is one of the most significant sulfur compounds because of its widespread use and toxicity. This compound has two sulfur atoms, each separately bonded to a carbon atom. This compound is a volatile, colorless liquid (mp, -111°C bp, 46°C). Unlike most organosulfur compounds, it is virtually free of odor. Although its uses are declining, it has numerous applications in chemical synthesis, as a solvent to break down cellulose in viscose rayon manufacture, and in the manufacture of cellophane. It has also been used as an insecticide and fumigant. [Pg.366]

The widely different and varied design of present-day viscose rayon plants makes it impractical to describe all of the facilities for making rayon. However, because the chemistry of the process is common to all viscose fiber production, a brief outline of the principal methods will help to consolidate the understanding of how rayon is made. The basic steps of viscose rayon manufacture are outlined schematically in Figure 10.62. Basically, there are two types of process technology, batch and continuous. Pulp is supplied normally in bales of a predetermined weight and sheet size or in rolls. [Pg.733]

FIGURE 10.62 Conventional batch process for viscose rayon manufacture (schematic). (Courtesy of John Wiley Sons, New York.)... [Pg.734]

A later development was a fluidized bed process for removing carbon disulfide vapors from air leaving a viscose (rayon) manufacturing plant. The process was developed by Courtaulds, Ltd., and installed at its viscose plant in Hoizwell, Wales. [Pg.1110]

Its early commercial success owed much to the flammabUity disadvantages of the Chardoimet process, but competition from the viscose process led to its decline for aU but the finest filament products. The process is stiU used, most notably by Asahi in Japan where sales of artificial sHk and medical disposable fabrics provide a worthwhile income. However, its relatively high cost, associated with the cotton fiber starting point, prevented it from reaching the large scale of manufacture achieved by the viscose rayon process. [Pg.344]

C. R. Woodings and A. 1. Bartholomew, "The Manufacture, Piopeities and Uses of Inflated Viscose Rayon Fibres," 23rdMan-Made Fibres Congress, Dombim, Austria, 1984. [Pg.355]

CeUulose is subsequendy regenerated from the viscose solution in sulfuric acid and carbon disulfide is Hberated. These are the basic steps in manufacturing viscose rayon. The production of regenerated ceUulose is estimated to account for mote than 75% of the total carbon disulfide consumption woddwide... [Pg.27]

There was significant interest in developing commercial processes based on phenolic resins in the 1890-1910 era. By this time, cellulose nitrate, vulcanized rubber, and viscose rayon had all found places in commerce [24]. Smith patented processes for manufacture of commercially useful molded articles from phenolic in 1899-1900 [2,25-28]. His products were made with phenol, paraldehyde (2,4,6-trimethyl-1,3,5-trioxane) or parafonnaldehyde, and additives in the presence of HCl at elevated temperatures. [Pg.870]

World production in 1991 was about 1 million tonnes the principal industrial uses being in the manufacture of viscose rayon (35-50%), cellophane films (15%) (see below), and CCI4 (15 30%) depending on country. Indeed the CCI4 application dropped to zero in USA in 1991 because of environmental concerns (p. 304). [Pg.317]

Other uses of HCI are legion and range from the purification of fine silica for the ceramics industry, and the refining of oils, fats and waxes, to the manufacture of chloroprene mbbers, PVC plastics, industrial solvents and organic intermediates, the production of viscose rayon yam and staple fibre, and the wet processing of textiles (where hydrochloric acid is used as a sour to neutralize residual alkali and remove metallic and other impurities). [Pg.812]

Over 22.7 million kg (50 million lb) of zinc sulfate are used annually in the U.S. for the manufacture of approximately 454 million kg (one billion lb) of viscose rayon. Zinc is used as a regeneration retardant in the acid spinning bath. Because it is not consumed in any of the viscose reactions, these 22.7 million kg (50 million lb) of zinc represent process losses, through dragout by the filaments to the subsequent wash streams, filter backwashing, splashes, leaks, and the washing of equipment.14... [Pg.20]

Salts of the series of xanthic acids of the general formula ROCSSH. Certain xanthates such as ZIX are ultra accelerators for mbber. Cellulose xanthate is the intermediate product in the manufacture of viscose. See Viscose Rayon. Xanthogen Sulphide... [Pg.72]

One of the earlier methods was to treat cellulose with sodium hydroxide and carbon disulfide to obtain xanthate esters which could be dispersed in water and cast into sheets or spun into fibers. Subsequent treatment with acid decomposed the xanthates and gave regenerated cellulose, either in fiber or film form. The fibers were called viscose rayon and the films were named cellophane. Cellophane is still used as a wrapping film and some of it is still manufactured by the xanthate process. By treatment with nitric acid, cellulose was converted to a trinitric acid ester, which could be cast into units which were satisfactory for making gun cotton for a smokeless powder for either artillery shells or shotgun ammunition. It was quite insoluble but it could be converted to a jelly-like mass, which could be shaped into a desired form for ammunition use. Under milder conditions, a lower nitrate... [Pg.54]

Uses Manufacture of viscose rayon, cellophane, flotation agents, ammonium salts, carbon tetrachloride, carbanilide, paints, enamels, paint removers, varnishes, tallow, textiles, rocket fuel, soil disinfectants, electronic vacuum tubes, herbicides grain fumigants solvent for fats, resins, phosphorus, sulfur, bromine, iodine, and rubber petroleum and coal tar refining solvent and eluant for organics adsorbed on charcoal for air analysis. [Pg.257]

Approximately 73% of all North American sodium sulfate is obtained directly from natural salt sources in Searles Lake, California and in Texas, Mexico, and Canada. Miscellaneous methods of manufacture account for smaller percentages. This includes 5% as a by-product in the production of viscose rayon, where sulfuric acid and sodium hydroxide are used to degrade the cellulose. Sodium dichromate manufacture gives another 6% of sodium sulfate as a by-product. [Pg.228]

Commercial uses grew rapidly from about 1929 to 1970. when the principal applications included manufacturing viscose rayon fibers. [Pg.291]

The natural fibers obtained from cotton, wood, flax, hemp, and jute all are cellulose fibers and serve as raw materials for the textile and paper industries. In addition to its use as a natural fiber and in those industries that depend on wood as a construction material, cellulose is used to make cellulose acetate (for making rayon acetate yarn, photographic film, and cellulose acetate butyrate plastics), nitric acid esters (gun cotton and celluloid7), and cellulose xanthate (for making viscose rayon fibers). The process by which viscose rayon is manufactured involves converting wood pulp or cotton Iinters into cellulose xanthate by reaction with carbon disulfide and sodium hydroxide ... [Pg.933]

The first man-made fibers of commercial importance were the cellu-losics. With respect to regenerated cellulose fibers, viscose rayon predominates. Between 1900 and 1967, world production of viscose rayon rose from 1000 tons to 2,700,000 tons (3). Cellulose derivative fibers did not go into commercial production until the 1920s. At that time cellulose acetate was manufactured. Cellulose triacetate fiber was brought into commercial production in the United States in 1954 (4). [Pg.213]

Fig. 12.6. Steeping of cellulose in the manufacture of viscose rayon. (Courtesy Avtex Fibers, Inc.)... Fig. 12.6. Steeping of cellulose in the manufacture of viscose rayon. (Courtesy Avtex Fibers, Inc.)...
Rayon. Viscose rayon, like cotton, is comprised of cellulose. In the manufacturing process, wood pulp is treated with alkali and carbon disulfide to form cellulose xanthate. Subsequently, the reaction mass is forced through a spinneret and precipitated in an acid coagulation bath as it is formed into a continuous filament. The fiber has a round striated cross-section. Rayon staple is made by breaking the continuous strands into staple-length fibers. Viscose rayon is conventionally produced in diameters varying from 9 to 43 microns. [Pg.504]

LAURYL PYRIDINIUM CHLORIDE is a cationic surface active agent which is used as a dispersing and wetting agent to keep spinnerettes clean in the manufacture of viscose rayon. In the textile industry it is used as a stripping agent for vat and other dyes. [Pg.231]

Carbon di.sulphide, CSg, is a volatile liquid (b.p. 46°), highly refractive, insoluble in water but soluble in ethyl alcohol and ether. It is made by the action of sulphur vapour on electrically heated coke. Its main uses are as a solvent and in the manufacture of CCI4 (p. 290), thiocarbanilide and viscose rayon ... [Pg.297]

The process of cellulose regeneration in the form of lyocell fibers is significantly simpler than that of the viscose rayon process. It is illustrated in O Fig. 16. A solution containing 14% cellulose, 10% water, and 76% NMMO plus stabilizers is extruded at a temperature slightly above 100 °C into an aqueous NMMO-bath from which cellulose is precipitated [74,75]. The extrusion has been described as a melt-spinning process that has recently made it possible to manufacture cellulosic self-bonded meltblown nonwovens as well [76]. [Pg.1495]


See other pages where Viscose rayon, manufacture is mentioned: [Pg.446]    [Pg.226]    [Pg.23]    [Pg.144]    [Pg.190]    [Pg.689]    [Pg.750]    [Pg.446]    [Pg.226]    [Pg.23]    [Pg.144]    [Pg.190]    [Pg.689]    [Pg.750]    [Pg.26]    [Pg.32]    [Pg.118]    [Pg.306]    [Pg.81]    [Pg.248]    [Pg.218]    [Pg.433]    [Pg.441]    [Pg.443]    [Pg.494]    [Pg.495]    [Pg.1191]    [Pg.407]    [Pg.177]    [Pg.311]    [Pg.429]    [Pg.37]   
See also in sourсe #XX -- [ Pg.1472 ]

See also in sourсe #XX -- [ Pg.1472 ]

See also in sourсe #XX -- [ Pg.1472 ]




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