Cellulose acetate rayon manufacture

Fig. 10.56, is the same in principle but is used in the larger diameter towers to reduce the length of travel of the liquid film on the baffle. Baffle spacing in these towers is ordinarily 4 to 6 in. The towers are versatile, capable of handling a wide variety of liquids and flow rates, and have had application in the extraction of acetic acid from pyroligneous liquors and from solutions used in cellulose acetate rayon manufacture, in the extraction of caffeine in the food industries, and for general chemical recovery in the synthetic organic chemicals industries. 

Uses. Solvent in the manufacture of dyes, plastics, and cellulose acetate rayon anesthetic agent... 

Direct Oxidation. Direct oxidation of petroleum hydrocarbons has been practiced on a small scale since 1926 methanol, formaldehyde, and acetaldehyde are produced. A much larger project (29) began operating in 1945. The main product of the latter operation is acetic acid, used for the manufacture of cellulose acetate rayon. The oxidation process consists of mixing air with a butane-propane mixture and passing the compressed mixture over a catalyst in a tubular reaction furnace. The product mixture includes acetaldehyde, formaldehyde, acetone, propyl and butyl alcohols, methyl ethyl ketone, and propylene oxide and glycols. The acetaldehyde is oxidized to acetic acid in a separate plant. Thus the products of this operation are the same as those (or their derivatives) produced by olefin hydration and other aliphatic syntheses. 

Uses Methylamine is a colorless, fishlike-smelling gas at room temperature. It is used in a variety of industries such as manufacture of dyestuffs, treatment of cellulose, acetate rayon, fuel additive, rocket propellant, and leathertanning processes. 

Uses Dimethylamine is a colorless, inflammable gas at room temperature. It is used in the manufacture of several products such as detergent soaps, in leather tanning, in pharmaceutical manufacture, and for cellulose acetate rayon treatment. 

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). 

The most important commercial aliphatic anhydride is acetic anhydride (R=CH3). About 1 million tons are manufactured annually, mainly to react with alcohols to form acetates. The two most common uses are in making cellulose acetate (rayon) and aspirin (acetylsalicylic acid). 

Plastics and Other Synthetic Products. Sulfur is used in the production of a wide range of synthetics, including cellulose acetate, cellophane, rayon, viscose products, fibers, and textiles. These uses may account for 2% of sulfur demand in developed countries. Sulfur intermediates for these manufacturing processes are equally divided between carbon disulfide and sulfuric acid. 

Nature uses cellulose primarily as a structural material to impart strength and rigidity to plants. Leaves, grasses, and cotton, for instance, are primarily cellulose. Cellulose also serves as raw material for the manufacture of cellulose acetate, known commercially as acetate rayon, and cellulose nitrate, known as guncotton. Guncotton is the major ingredient in smokeless powder, the explosive propellant used in artillery shells and in ammunition for firearms. 

Uses Manufacture of acetate rayon, acetic anhydride, acetone, acetyl compounds, cellulose acetates, chloroacetic acid, ethyl alcohol, ketene, methyl ethyl ketone, vinyl acetate, plastics and rubbers in tanning laundry sour acidulate and preservative in foods printing calico and dyeing silk solvent for gums, resins, volatile oils and other substances manufacture of nylon and fiber, vitamins, antibiotics and hormones production of insecticides, dyes, photographic chemicals, stain removers latex coagulant textile printing. 

Like the triacetate, secondary cellulose acetate (CA) is used in solution processes to produce fibers and films. CA fibers were originally called "rayon." the name that was already in use for regenerated cellulose fibers. In 1951. however, the regulatory authorities formally acknowledged the chemical distinction between CA and cellulose, and the term rayon was reserved for libers of regenerated cellulose. CA fibers are officially called acetate. and they are used in a wide variety of fabrics. They also are used for cigarette filters. However, the majority of CA produced is used for manufacture of plastics. 

PULP (Wood) PRODUCTION AND PROCESSING. Pulps can be defined as fibrous products derived from cellulosic fiber-contaiumg materials and used in the production of hardboard, fiberboard, paperboard, paper, and molded-pulp products. With suitable chemical modification, pulps can be used in Hie manufacture of rayon, cellulose acetate, and other familiar products. Pulps can be produced from any material containing cellulosic fiber but in North America and several other regions of the world, wood is the predominant source of pulp. This description is confined to the production and processing of wood pulp,... 

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 ... 

THE TERM PULP is used to describe theraw material for the production of paper and allied products such as paper-board, fiberboard, and dissolving pulp for the subsequent manufacture of rayon, cellulose acetate, and other cellulose products. More specifically, pulp is wood or other biomass material that has undergone some degree of chemical or mechanical action to free the fibers either individually or as fiber bundles from an enbodying matrix. Paper,... 

For the purpose of conversion to textile fibers, dispersions or solutions of cellulose or its derivatives are achieved by various means, in order to make possible the extrusion of the fiber-forming material through the small orifices of the spinning jets. Wood pulps prepared for these and similar uses (such as the manufacture of cellophane) are known as dissolving pulps. The manufacture of dissolving pulps is a highly developed art, with processes protected by patents or, more effectively, within company files. The purification of sulfite pulps to a degree suitable for manufacture of textile rayon (90 to 94% alpha-cellulose), tire cord (94 to 9.5% alpha-cellulose), and cellulose acetate (9.5 to 90% alpha-cellulose) requires some kind of... 

In contrast to the polymeric products derived from fossil fuels, the production of synthetic polymers from biomass—the rayons and cellulose acetates—is quite small despite the fact that cellulose is one of the world s most abundant raw materials. The rayons are any of a variety of regenerated celluloses manufactured via intermediates such as alkali salts and cellulose xanthates. The process... 

TextUe filaments of cellulose acetate are classified as rayon, that term having been adopted for all manufactured textile fiber or yarn produced... 

Acetic acid is used in the manufacture of various acetates, acetyl compounds, cellulose acetate, acetate rayons, plastics, and rubber. It is also used in tanning, as laundry sour, in printing calico, and in dyeing silk. It is an acidulant and preservative in food. It is a solvent for gums, resins, volatile oils, and many other substances. Acetic acid is widely used in commercial organic synthesis. 

Establishments primarily engaged in manufacturing cellulosic fibers (including cellulose acetate and regenerated cellulose such as rayon by the viscose or cuprammonium process) in the form of monofilament, yarn, staple, or tow suitable for further manufacturing on spindles, looms, knitting machines, or other textile processing equipment. 

Acetic acid occurs in vinegar. It is produced in the destructive distillation of wood. It finds extensive application in the chemical industry. It is used in the manufacture of cellulose acetate, acetate rayon, and various acetate and acetyl compounds as a solvent for gums, oils, and resins as a food preservative in printing and dyeing and in organic synthesis. 

Synthetic fibres, manufactured fibres can be divided into those derived from natural polymers (such as regenerated protein fibres rayon, cellulose acetates, or alginates) and those derived from synthetic polymers including nylons, polyesters, acrylics, and polyolefins. 

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