Textile fibers cellulose acetate

Year Cigarette-filter tow Textile fibers Cellulose acetate plastics Total... 

The global supply of cellulose acetate fibers is controlled by a few companies. These companies produce both tow and textile fibers. Celanese Acetate holds 29% of the world supply. Voridian, a division of the Eastman Chemical Co., follows with a 24% share. The remaining 32% of supply is manufactured by Rhodia, Daicel, Mitsubishi Rayon, and Acordis. There has been a recent trend of these companies closing down their smaller flake-production units and getting their product from larger and more efficient locations (104). 

Most of the acetic acid is produced in the United States, Germany, Great Britain, Japan, France, Canada, and Mexico. Total annual production in these countries is close to four million tons. Uses include the manufacture of vinyl acetate [108-05-4] and acetic anhydride [108-24-7]. Vinyl acetate is used to make latex emulsion resins for paints, adhesives, paper coatings, and textile finishing agents. Acetic anhydride is used in making cellulose acetate fibers, cigarette filter tow, and ceUulosic plastics. 

The predominant cellulose ester fiber is cellulose acetate, a partially acetylated cellulose, also called acetate or secondary acetate. It is widely used in textiles because of its attractive economics, bright color, styling versatiUty, and other favorable aesthetic properties. However, its largest commercial appHcation is as the fibrous material in cigarette filters, where its smoke removal properties and contribution to taste make it the standard for the cigarette industry. Cellulose triacetate fiber, also known as primary cellulose acetate, is an almost completely acetylated cellulose. Although it has fiber properties that are different, and in many ways better than cellulose acetate, it is of lower commercial significance primarily because of environmental considerations in fiber preparation. 

Fibrillated Fibers. Instead of extmding cellulose acetate into a continuous fiber, discrete, pulp-like agglomerates of fine, individual fibrils, called fibrets or fibrids, can be produced by rapid precipitation with an attenuating coagulation fluid. The individual fibers have diameters of 0.5 to 5.0 ]lni and lengths of 20 to 200 )Jm (Fig. 10). The surface area of the fibrillated fibers are about 20 m /g, about 60—80 times that of standard textile fibers. These materials are very hydrophilic an 85% moisture content has the appearance of a dry soHd (72). One appHcation is in a paper stmcture where their fine fiber size and branched stmcture allows mechanical entrapment of small particles. The fibers can also be loaded with particles to enhance some desired performance such as enhanced opacity for papers. When filled with metal particles it was suggested they be used as a radar screen in aerial warfare (73). 

Cellulose acetate, the second oldest synthetic fiber, is an important factor in the textile and tobacco industries 731,000 metric tons were produced worldwide in 1991 (Fig. 11) (74). Acetate belongs to the group of less expensive fibers triacetate is slightly more expensive. An annual listing of worldwide fiber producers, locations, and fiber types is pubHshed by the Fiber Economics Bureau, Inc. (74). 

Fig. 11. World production of cellulose acetate and triacetate fibers I, cigarette tow B, textile (74).

Originally, the word rayon was appHed to any ceUulose-based man-made fiber, and therefore included the cellulose acetate fibers. However, the definition of rayon was clarified in 1951 and includes textiles fibers and filaments composed of regenerated cellulose and excludes acetate. In Europe the fibers are now generally known as viscose the term viscose rayon is used whenever confusion between the fiber and the cellulose xanthate solution (also called viscose) is possible. 

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. 

From 1980 to 1988, aimual cellulose acetate flake production in the United States showed a slight decrease in production from 392,000 t to 323,000 t with an aimual decline of —0.4 to —0.1% (Table 6). World demand for cellulose acetate flake has also fallen. A modest recovery has occurred in recent years as a result of the increased demand for cigarette-filter tow world consumption of cigarette-filter tow has risen about 2.5% per year since 1980 (Tables 7 and 8). In contrast, world demand for textile fibers and cellulose ester plastics decline 4.6% and 4.2% per year, respectively (Fig. 9). 

Demand for cellulose acetate flake in the United States is projected to decline slightly from 1988 to 1993. Cigarette-filter tow for export is the only market projected to grow. Cellulose acetate for textile fibers is expected to decline, as will flake demand for plastics, with the growth of photographic films somewhat offsetting declining markets in other plastics end uses. 

Cellulose ester flake production for nonfiber appHcations represents a small part of the total U.S. output. Cigarette-filter tow and cellulose acetate textile fibers consume more than 80% of flake production (104). 

The cellulose esters with the largest commercial consumption are cellulose acetate, including cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose acetate is used in textile fibers, plastics, film, sheeting, and lacquers. The cellulose acetate used for photographic film base is almost exclusively triacetate some triacetate is also used for textile fibers because of its crystalline and heat-setting characteristics. The critical properties of cellulose acetate as related to appHcation are given in Table 10. 

A rather impressive Hst of materials and products are made from renewable resources. For example, per capita consumption of wood is twice that of all metals combined. The ceUulosic fibers, rayon and cellulose acetate, are among the oldest and stiU relatively popular textile fibers and plastics. Soy and other oilseeds, including the cereals, are refined into important commodities such as starch, protein, oil, and their derivatives. The naval stores, turpentine, pine oil, and resin, are stiU important although their sources are changing from the traditional gum and pine stumps to tall oil recovered from pulping. 

Other textile fibers include nylon, polyacrylonitrile, and ceUulose acetate (see Fibers, acrylic Fibers, cellulose esters Fibers, polyamide). 

The textiles printing industry has an appreciable interest in P.Y.17 and applies it in the form of pigment preparations. Where its fastness properties satisfy the specifications and where the use requirements are not too demanding, the pigment is also utilized for spin dyeing purposes. Manufacturer recommendations include media such as polyacrylonitrile and cellulose acetate fibers, on which 1/3 SD pigment prints exhibit a lightfastness which is equal to step 5 on the Blue Scale. 

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. 

Table 9.2 summarizes the uses of acetic acid. Vinyl acetate is another top 50 chemical. Acetic anhydride is used to make cellulose acetate and at times has been in the top 50 chemicals itself. Cellulose acetate is a polymer used mainly as a fiber in clothing and cigarette filters. Ethyl acetate is a common organic solvent. Acetic acid is used as a solvent in the manufacture of terephthalic acid (TA) and dimethyl terephthalate (DMT), which are monomers for the synthesis of poly(ethylene terephthalate), the polyester of the textile industry. A minor household use of acetic acid is as a 3-5% aqueous solution, which is called vinegar. 

Cellulose acetate and triacetate may be used as plastics or spun into fibers for textiles. They are made by the reaction of cellulose with acetic anhydride. 

Cellulose acetate fibers are defined by the Textile Fiber Products Identification Act as manufactured fibers in which the fiber-forming substance is cellulose acetate in which not less than 92% of the hydroxyl groups are acetylated. Cellulose triacetate is employed to make many tricot fabrics and sportswear. Cellulose triacetate textile is shrink- and wrinkle-resistant and easily washed. 

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 ... 

Classification by usage or application is the principal system adopted by the Colour Index [5], Because the most important textile fibers are cotton and polyester, the most important dye types are those used for dyeing these two fibers, including polyester-cotton blends (see Chapter 4). Other textile fibers include nylon, polyacrylonitrile, and cellulose acetate. 

Modification of cotton textiles by chemical plating of their surfaces with cobalt (II) or nickel (II) salts produced metallized fibers and fabrics with high electrical conductivity and the capability to transport and dissipate thermal energy (109). The heat capacity of cellulose acetate fibers was increased by treatment with epoxy compounds (110). 

Cellulose is the most abundant naturally oeeurring polysaccharide formed out of glucose-based repeat imits, connected by 1,4-beta-glucosidic linkages. Cellulose and its derivatives are widely used as tough versatile materials. Cellulose nitrate, cellulose acetate (CA) and cellulose xanthate (rayon) can be easily molded or drawn into fibers for textile applications, for designing composite materials (safety glass), as thermoplastics etc [80]. 

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... 

---