Fabrics rayon

Despite the anhydride stmcture, it is remarkably stable, surviving addition to the highly alkaline viscose, the acidic coagulating bath, and also resisting multiple laundering of the rayon fabric. The unusual stability may be attributed to the sulfur atoms, which enhance hydrophobicity, and to the stericaHy hindering neopentyl groups that retard hydrolysis. 

The solution (pad bath) contains one or more of the amino resias described above, a catalyst, and other additives such as a softener, a stiffening agent, or a water repeUant. The catalyst may be an ammonium or metal salt, eg, magnesium chloride or ziac nitrate. Synthetic fabrics, such as nylon or polyester, are treated with amino resias to obtaia a stiff finish. Cotton (qv) or rayon fabrics or blends with synthetic fibers are treated with amino resias to obtain shrinkage control and a durable-press finish. 

The RFK mechanism can be used with loomstate nylon and rayon fabrics, but polyesters will require a pre-treatment to achieve good adhesion. Hexamethylene tetramine should be avoided as the methylene donor when polyester fabrics are being used, as aminolysis of the ester linkages in the polyester can occur, which would cause significant degradation of fabric and adhesion to take place under severe service conditions. Hexamethylolmelamine ethyl ether should be used as the methylene donor in this case. 

The carcass ply/plies coat compound functions are basically the same as the steel breaker compound. Normally in the steel belted PCT the ply is textile cord of polyester or rayon fabrics which are soft and flexible. The truck radial steel tire normally uses a steel cord ply. Earthmover tires are of two basic constructions, ie, radial using steel and bias using textiles (see Tire cords). 

The cuprammonia process, the viscose process, and the acetate process have been employed for the production of rayon. Cuprammonia and viscose rayons have similar chemical and physical properties. Both are easily dyed and lose their strength when wet because of a disruption of hydrogen bonding this wet strength is improved through chemical treatment of the rayon fabrics. Acetate rayon is readily softened in the ironing process and loses its luster in boiling water. 

The oxidation of the film follows first-order kinetics with rates close to those found for decreases in tear strength and depolymerization of cotton and rayon fabrics. The reaction mechanisms appear not to be affected by temperature. The infrared spectra of the film and of the water extract of the aged film are essentially the same as those found for naturally aged linen. 

Grafting of Rayon Fabrics in Cold Plasma Conditions... 

In order to limit extensive side reactions (advanced destruction of the support-polymer, modification of grafting monomers structure) which usually accompany grafting reactions in electrical discharge conditions, we have elaborated the solid-solid grafting procedure in cold plasma. Thus, the rayon fabric was grafted with halogen and phosphorus containing polymers in... 

There are, of course, other methods for treating fibers and rayon fabrics with organo-phosphorus compounds (9-13) in order to improve their flame-retardant properties. However, the modified fibers present the changed physical and mechanical properties due to large additives utilised and often these additives are eliminated after repeated washings. 

In this paper, the surface grafting of rayon fabrics with nitrogen and phosphorus containing polymers in cold plasma is studied. The analytical data (IR spectroscopy, TGA, electron microscopy, elemental analysis, etc.) indicate the formation of grafted copolymers. The grafted rayon fabrics present improved flame-retardant properties, the best behavior was proved by those grafted with polyurea of phosphinic acid. 

The rayon fabrics (3 x 21 cm) extracted with solvents in order to remove the textile ingredients were impregnated for an hour with grafting solutions of different concentrations (10-25%), then were dried at room temperature. 

The extracted rayon fabrics were analysed by spectral, physical and chemical methods in order to prove that the grafting reactions took place and what kind of new properties the fabrics have obtained. 

Grafting experimental conditions and phosphorus and nitrogen contents of the plasma grafted rayon fabrics ... 

The elemental analysis also shows low nitrogen and phosphorus contents of these fractions, due probably to bound or enclosed polymer fragments into the structure of the rayon fabrics and to the fact that the grafting agents are sufficiently resistant at the hydrolysis. 

Figure 3. IR spectra of the soluble fraction III. Key 1, standard rayon 2, P-1 grafted rayon fabric 3, P-2 grafted rayon fabric 4, P-3 grafted rayon fabric 5, P-4...

For the burning test, pieces of the grafted rayon fabrics were burned on a semicircle tester according to DIN 54 331. 

It can be remarked that the rayon fabrics grafted with P-1, P-2 and P-3 have more reduced extinguishing angles and burning times than those of standard rayon. The macroscopical aspects of the grafted rayon fabrics are not changed. 

Flammability teats by standard laboratory procedure carried out on the grafted rayon fabrics. 

F-2 grafted rayon fabric P-3 grafted rayon fabric P-4 grafted rayon fabric... 

Figure 5. The aspect of the grafted rayon fabrics after the flammability test. Key left to right, P-1 grafted compact rayon fabric P-2 grafted compact rayon fabric P-3 grafted rayon fabric P-4 grafted rayon fabric P-1 grafted lower compact rayon fabric P-2 grafted lower compact rayon fabric P-3 grafted lower compact rayon fabric P-4 lower compact grafted fabric.

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