Flame Retardant Fibers
- Flame retardance is achieved by
the adhesion of the correct flame- retardant chemical to viscose.
Examples of additives are alkyl, aryl and halogenated alkyl or aryl
phosphates, phosphazenes, phosphonates and polyphosphonates. Flame
retardant rayons have the additives distributed uniformly through the
interior of the fiber and this property is advantageous over flame
retardant cotton fibers where the flame retardant concentrates at the
surface of the fiber.
Super-Absorbent Rayons
- This is being produced in order
to obtain higher water retention capacity (although regular rayon
retains as much as 100 % of its weight). These fibers are used in
surgical nonwovens. These fibers are obtained by including water-
holding polymers (such as sodium polyacrylate or sodium carboxy methyl
cellulose) in the viscose prior to spinning, to get a water retention
capacity in the range of 150 to 200 % of its weight.
Micro-Denier Fibers
- Rayon fibers with deniers below 1.0
are now being developed and introduced into the market. These can be
used to substantially improve fabric strength and absorbent properties.
Cross-Section Modification of Viscose Rayon
Modification in cross-sectional shape of viscose rayon can
be used to dramatically change the fibers' aesthetic and technical
properties. One such product is Viloft, a flat cross sectional fiber
sold in Europe, which gives a unique soft handle, pleasing drape and
handle. Another modified cross section fiber called Fibre ML(multi
limbed) has a very well defined trilobal shape. Fabrics made of these
fibers have considerably enhanced absorbency, bulk, cover and wet
rigidity all of which are suitable for usage as nonwovens .