Cellophane production

Carbon disulfide has been u imtjur chemical I m main years, Two-thirds of ils use was in viscose ruyon und cellophane production. Most of the real was used to produce carbon tetrachloride. Neither of these outlets appear to provide much future growth for carbon disulfide. The major manufacturing route is to react methane and sulfur vapor at OOtTC over u catalyst... 

Cellulosics. Rayon and other cellulose products such as cellophane and cellulose ethers (qv) consume 1.9% of U.S. caustic soda demand. Because of competitive products, however, this market has been decreasing since 1965 and forecasted average annual growth through 1992 is less than 0.4% (6) (see Cotton). 

Cast films provide a high clarity, heat sealable film and are primarily used as an overwrap for boxes and other packaging. These films have a lower density than cellophane and provide a longer product shelf life. Properties of polypropylene films are given in Table 12. 

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. 

The principal chemical iadustry based on wood is pulp and paper. In 1995, 114.5 x 10 metric tons of wood were converted iato - 60 x 10 metric tons of fiber products ranging from newsptint to pure cellulose ia the United States (1,76). Pure cellulose is the raw material for a number of products, eg, rayon, cellulose acetate film base, cellulose nitrate explosives, cellophane, celluloid, carboxymethylceUulose, and chemically modified ceUulosic material. 

Many other polymers compete with cellophane such as polyethylene which is extruded as a tough film or in greater thickness as a nonbreakable bottles. Vinyl products used in films are polystyrene, polyesters, and nylon. A chemical derivative from nature rubber, chlorinated rubber, gives films of extraordinary stretch ability. 

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). 

Zell-gewebe, n. cellular tissue, -gift, n. intracellular toxin, -glas, n. a product similar to cellophane, cellxfiose glass. T. . -hant, /. a product similar to cellophane (T.. ) Biol.) cell membrane, -hom, n. celluloid or a similar product. 

Cellophane is an old and respected packaging material which has been improved over the years. The two general types are coated with nitrocellulose (N/C) and polyvinylidene chloride (PVDC), respectively. Nitrocellulose-coated cellophane is moisture proof and useful for packaging dry products. It does not exclude oxygen or moisture completely, but for noncritical products it is entirely satisfactory. Baked goods are often packaged in this breathing type film. It is often used for cookies, candies, and rolls because its lack of taste and odor makes it very compatible with these products. 

The structure—N/C-coated cellophane/polyethylene/aluminum foil/ adhesive/50ga polyester/adhesive/polyethylene—had a shelf life of over 6-9 months with no moisture, flavor, or color loss. This barrier system contained the product successfully (see Table IV). 

Cellulose may be solubilised by treatment with sodium hydroxide and carbon disulfide. It can be regenerated by acidification of the solution. This is the basis of the production of regenerated cellulose fibre, so-called viscose rayon , which is a major textile fibre. The technique is also used for the production of continuous cellulose-derived film, so-called cellophane (from cellulose and diaphane , the latter being French for transparent). 

There are a number of methods that have been proposed to help prevent the loss of circulation fluid [1214]. Some of these methods use fibrous, flaky, or granular material to plug the pores as the particulate material settles out of the slurry. Examples are oat hulls [855], rice products [294,295], waste olive pulp [519], nut cork [654,1532], pulp residue waste [750], petroleum coke [1840], and shredded cellophane [296]. 

Highly bleached and purified kraft process wood pulp suitable for conversion into products such as rayon, viscose, acetate, and cellophane... 

Hestrin, Avineri-Shapiro and Aschner9 report that levan formation by means of B. subtilis is greater if cultural products other than levan are continually removed by dilution or dialysis. The organism was inoculated into a phosphate-buffered solution contained in a cellophane bag suspended in a large volume of sucrose peptone solution. 

Cellulose is sometimes used in its original or native form as fibers for textile and paper, but is often modified through dissolving and reprecipitation or through chemical reaction. The xanthate viscose process, which is used for the production of rayon and cellophane, is the most widely used regeneration process. The cellulose obtained by the removal of lignin from wood pulp is converted to alkali cellulose. The addition of carbon disulfide to the latter produces cellulose xanthate. 

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