Rayon fiber

Fig. 6. The effect of rate of extension on the stress—strain curves of rayon fibers at 65% rh and 20°C. The numbers on the curves give the constant rates of...

Table 2. Properties of Selected Commercial Rayon Fibers...

Several cellulose esters (qv) are prepared commercially. Cellulose xanthate [9032-37-5] is made by reaction of cellulose swollen in 8.5—12% sodium hydroxide solution (alkaU cellulose [9081-58-7J) with carbon disulfide and is soluble in the alkaline solution in which it is made. When such a solution, termed viscose, is introduced into an acid bath, the cellulose xanthate decomposes to regenerate cellulose as rayon fibers or cellophane sheets (see Fibers, REGENERATED CELLULOSICS). 

Cellulose acetate [9004-35-7], prepared by reaction of cellulose with acetic anhydride, acetic acid, and sulfuric acid, is spun into acetate rayon fibers by dissolving it in acetone and spinning the solution into a column of warm air that evaporates the acetone. Cellulose acetate is also shaped into a variety of plastic products, and its solutions are used as coating dopes. Cellulose acetate butyrate [9004-36-8], made from cellulose, acetic anhydride, and butyric anhydride in the presence of sulfuric acid, is a shock-resistant plastic. 

For rayon fiber based eomposites (Seetions 3 and 4) the fiber and powdered resins were mixed in a water slurry in approximately equal parts by mass. The isotropie piteh earbon fiber eomposites (Seetion 5) were manufaetured with less binder, typically a 4 1 mass ratio of fiber to binder being utilized. The slurry was transferred to a molding tank and the water drawn through a porous sereen under vacuum. In previous studies [2] it was established that a head of water must be maintained over the mold screen in order to prevent the formation of large voids, and thus to assure uniform properties. The fabrieation proeess allows the manufaeture of slab or tubular forms. In the latter case, the cylinders were molded over a perforated tubular mandrel covered with a fine mesh or screen. Moreover, it is possible to mold eontoured plates, and tubes, to near net shape via this synthesis route. 

Gold can be used only in very small portions or very thin coatings because of its cost. Most of the applications for wliich it was used in the past have now been accomplished with tantalum at a much lower cost. A gold/ platinum/rhodium alloy is used in the manufacture of rayon-spinning jets in the production of rayon fibers. This alloy presents the combination of strength, corrosion resistance and abrasion resistance necessary to prevent changes in hole dimensions. 

The number of reports about hemicelluloses that have been covered by this review indicates the significantly increased importance of all types of hemicelluloses as plant constituents and isolated polymers during the last decade. Attention has been paid not only to known hemicelluloses but also to the primary structure, physicochemical, physical, and various functional properties of hemicelluloses isolated from hitherto uninvestigated plants. The efforts to exploit a variety of plant as potential sources of hemicelluloses were pointed out particularly for agricultural crops, wood wastes, as well as for by-products of pulp and rayon fiber technologies. Many studies were devoted to characterize seed-storage hemicelluloses from plants that have been traditionally applied in food and medicine of many underdeveloped countries to find substitutes for imported commercial food giuns. 

Azoic dyes Cotton, rayon, Fiber impregnated with Dyeing and printing... 

A) Irradiance to a reactor was limited because the rectangular shape of the reactor contained cuprammonium rayon fiber and was made of glass for two flat sides and stainless steel for the edges. 

In the original process the cellulose nitrate itself was used as the fiber (hence its satirical description as mother-in-law silk ). The regenerating agent is ammonium hydrosulfide. The basic process was first demonstrated by J. W. Swan in London in 1885 but commercialized by Count L. M. H. B. de Chardonnet ( Father of the rayon industry ) in France in 1891 and operated there until 1934. The last working factory, that in Brazil, was burnt down in 1949. The other processes for making rayon fibers by regenerating cellulose ( viscose, cupram-monium) gave superior products. See also Rayon. 

An interesting redox system for grafting, containing cumene hydroperoxide and Fe + ions, has been developed by Simionescu et al. U. They grafted acrylonitrile and isoprene to rayon fibers at low temperatures (20 to A0°C) and long reaction times (up to... 

The peracetic initiator has been successfully applied also for grafting onto rayon fibers and cellophane22. The peracetic initiator has been further developed by Hatakeyama2 who combined the peracetic acid with Fe2+ or Fe + ions to a redox system found to be an effective initiator for grafting to pulps and isolated lignin. The reactions... 

This is the first reported study of the spinning of mesomorphic cellulose solutions, but no fiber properties were given. Quenin et al. (14) used a d -jet, wet spinning system to spin cellulose/MMNO-H20 solutions. Fiber properties equiv dent to the best viscose rayon fiber were obtained. 

Microfibers allow a fabric to be woven that is lightweight and strong. They can be tightly woven so that wind, rain, and cold do not easily penetrate. Rainwear manufacturers use microfibers for this reason. They also have the ability to allow perspiration to pass through them. Thus, so-called microfiber athletic-wear is becoming more commonplace. Microfibers are also very flexible because the small fibers can easily slide back and forth on one another. The first fabric made from microfiber was Ultrasuede in which short polyester microfibers were imbedded into a PU base. Today microfibers are made mainly from polyesters, nylon, acrylic, and rayon fibers. 

Tempra Rayon fiber American Enka Corp. 

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