Regenerated cellulose fibers

Viscose rayon is but one variety of rayon, a more general term for derivatized or reconstituted cellulose. Other rayons include fiber prepared from collodion, cellulose acetate, and cellulose fiber regenerated from a cellulose-copper ammonium solution cuprammonium rayon) (Kauffman 1993). 

The first carbonization of cellulose-based fibers dates back to Thomas Edison, who carbonized a natural cellulose filament for use as an incandescent lamp filament. In the mid-1950s, the Carbon Wool Corporation introduced the first commercial carbonized rayon fibers (79). PAN- and pitch-based carbon fibers have replaced rayon-based fibers in most high performance applications however, they continue to find use as ablative materials in missile nosecones and heat shielding (16). Additionally, the combination of low cost, ease of handling, and high natural porosity makes rayon an attractive precursor for activated carbon fibers (see CELLULOSE Fibers, Regenerated). 

Newer technology, based on the use of N-methylmorpholine-N-oxide as a cellulose solvent (40), has been developed with the aim of reducing hazardous by-products and producing a more environmentally friendly process. The viscose technology, however, still dominates (see Cellulose Fibers, Regenerated). 

Almost all the fibers used in nonwovens are synthetic. The split is approximately as follows Polypropylene 63% polyester 23% viscose rayon 7% acrylic 2% polyamide 2% other 3% (see Propylene Polymers (PP) Olefin Fibers Polyesters, Fibers Cellulose Fibers, Regenerated Acrylic Fibers Polyamides, Fibers). 

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