Yarns, rayon

Processing Quality, 19.7 mg/m Yarn — Rayon Wash Line ... 

Geometric effects coupled with diffusion and nucleation usually control the rates of all solids deposition phenomena. Such effects can be put to good use in the production of special products such as cellulose yarn (rayon), by the precipitation of cellulose in filament form as it emerges as sodium cellulose xanthate liquid from the spinnerets into a bath containing sulphuric acid, which extracts the sodium as sodium sulphate, and the carbon disulphide. In a similar manner, the fabrication of aromatic polyimide fibres is performed by dissolving the polymer in concentrated sulphuric acid and forcing the solution through spinnerets into water. 

Uses Mfg. of viscose rayon fibers (prod, of rayon filament yarn, rayon tire yarn, rayon... 

Standard Test Methods for Tire Yarns, Cords, and Woven Fabrics. ASTM standard D885M-94 includes test methods for characterizing tire cord twist, break strength, elongation at break, modulus, tenacity, work-to-break, toughness, stiffness, growth, and dip pickup for industrial filament yams made from organic base fibers, cords twisted from such yams, and fabrics woven from these cords that are produced specifically for use in the manufacture of pneumatic tires. These test methods apply to nylon, polyester, rayon, and aramid yams, tire cords, and woven fabrics. 

Stapel, m. staple warehouse pile, heap, stack, -farbe, /. staple color, -faser, /. staple fiber (rayon yarn), -gemfise, n. staple vegetables. 

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. 

In cellulose II with a chain modulus of 88 GPa the likely shear planes are the 110 and 020 lattice planes, both with a spacing of dc=0.41 nm [26]. The periodic spacing of the force centres in the shear direction along the chain axis is the distance between the interchain hydrogen bonds p=c/2=0.51 nm (c chain axis). There are four monomers in the unit cell with a volume Vcen=68-10-30 m3. The activation energy for creep of rayon yarns has been determined by Halsey et al. [37]. They found at a relative humidity (RH) of 57% that Wa=86.6 kj mole-1, at an RH of 4% Wa =97.5 kj mole 1 and at an RH of <0.5% Wa= 102.5 kj mole-1. Extrapolation to an RH of 65% gives Wa=86 kj mole-1 (the molar volume of cellulose taken by Halsey in his model for creep is equal to the volume of the unit cell instead of one fourth thereof). 

Type of rayon Dry yarn strength g. per denier Elongation, percent Accessibility, percent... 

P.R.170 is not always heat stable enough to allow application in polyolefins. In HDPE systems formulated at 1/3 SD, the pigment tolerates exposure to 220 to 240°C for one minute. Its tinctorial strength, on the other hand, is excellent. P.R.170 is also occasionally used in polypropylene and polyacrylonitrile spin dyeing in the latter medium, it satisfies the specifications of the clothing and home textiles industries. Besides, P.R.170 lends color to viscose rayon and viscose cellulose it is used for the mass coloration of semisynthetic fibers made of cellulose last but not least, it colors yarns, fibers, and films made of secondary acetate. 

This cotton was carded at 13.6 kg/hr and processed into 1A.8 mg/m yarn of 37.2 twist factor at 10000 rpm spindle speed. Ends down per thousand spindle hours was AO as compared to 56 for the same cotton washed on the rayon line. Yarn appearance characteristics were also slightly better for the wool scoured cotton. 

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 ... 

Rayon was first made by denitration of cellulose fibers (Chardonnet process). The cellulose was first reacted with a mixt of nitric and sulfuric acids to form NC, The prod was then dissolved in a mixt of eth and ethanol and spun into yarn by a "dry spinning process. In some instances the yarn was denitrated by alkaline hydrosulfites, neutralized and then w washed and dried (Ref 9). See also under "Cellulose Nitration, Denitration in Vol 2, C118-R to C119-R... 

Substrate and its Preparation. The substrate used for grafting purpose were jute fiber (defatted and bleached) and KPM rayon yarn. Jute fiber under investigation was of Corchorus Capsularis variety. It was arbitrarily divided into three portions. The middle portion was chosen for the purpose of study. 

Grafting Procedure and Calculation of Percent Grafting. Graft copolymerisation treatment of KPM rayon yarn and jute fiber were carried out in a well stoppered, Erlenmeyar flask. Fifty millimeter CAS solution of known concentration was kept at a desired temperature. One millimeter MMA was added following immediately by 1.0 gm of KPM rayon yarn, after which the contents were stirred intermittently. After the end of the reaction, the flask were removed from the thermostat and methanol was immediately added. 

Figure 1. Plot of percent decrease of tenacity vs. percent grafting. Key , rayon yarn O, defatted jute C, bleached jute.

Figure 3. Changes of stiffness of MMA grafted fiber. Key , rayon yarn , defatted jute O, bleached jute.

The continuous process for spinning and purifying textile-grade rayon yarn merits particular mention from the standpoint of industrial chemistry, as it is rather an axiom that a continuous process is to be preferred over a batch or discontinuous operation. This method employs advancing rolls or godets that make it possible for the yam to dwell for a sufficient length of time on each pair, thus allowing the several chemical operations to take place in a relatively small area. Their... 

Spun Yarn. After rayon became established in the textile industry, where it could be used as a silklike fiber, and its selling price was greatly... 

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