In an ever more competitive global market which represents
close to $700 billion, the textile industry is seeking new sources of innovation,
one of which is biotechnology. In 1996, the global enzyme market for textiles amounted to
just $178 million. However, textile and Apparel companies are now spending more
time and money on environmentally relevant issues. Regulatory pressure is
expected to intensify for both textiles and leather as less polluting
technologies become available and it becomes possible to generate less waste.
Enzymes have been used in textile processing since the early
part of the last century to remove starch-based sizing, but only in the past
decade has serious attention been given to using enzymes for a wide range of textile applications.
Enzymes are expected to have an even greater impact on effluent quality as more
fiber preparation, pre-treatment and value-added finishing processes convert to
biotreatment. In addition, enzymes are very effective catalysts even under mild
conditions and do not require the high energy input often associated with
Producing new fibers through biotechnology
Biotechnology makes it possible to produce cotton with
improved fiber features. Agricetus has produced a genetically engineered cotton
which contains a bacterial gene that produces a polyester-like substance that
is reported to have the texture of cotton but to be much warmer. Zeneca uses
microbes to produce a naturally occurring polyhydroxybutyrate (PHB) by
bacterial fermentation. Monsanto is now investigating genetically engineered
plants to be used to produce PHB. Weyerhaeuser has already commercialized
bacterially derived cellulose which is finer, more uniform, and more resilient.
Sony has developed stereo speaker cones and diaphragms from bacterial
DuPont has developed a microbe-based fermentation process
for the manufacture of 1, 3-propanediol, a key ingredient in pclytrimethylene
terephthalate, a polyester that is superior to the widely used polyethylene
terephthalate (PET), but which was previously too expensive to make in large
Cellulases are also gaining widespread use in the production
of the relatively new fiber, Iyocell, the generic name for solvent-spun
cellulosic fibers. Lyocell is spun from wood pulp in a closed amine oxide
solvent system. The solution is then filtered and extruded to form the
filament. Compared to other man made fibers (such as rayon), Iyocell has
greater strength and a more environmentally favorable manufacturing process.
However, the fiber tends to fibrillate during processing. This fibrillation is
unique to Iyocell and can be controlled by cellulase treatment to achieve a
soft, luxurious fabric and laundering fastness. In one case, Iyocell was
treated with Primafast(r) SGL cellulase from Genencor International, which is
an engineered cellulase composition designed specifically to achieve the
Cellulose-based fabrics such as cotton and linen, but also
synthetic cellulosics such as rayon, can form unsightly little "bobbles"
on the surface. Courtaulds Chemicals has recently developed a new cellulosic
fabric from Iyocell fiber, called Tencel, which has better strength and
handling properties but is subject to this defect. Coats Viyella Clothing
Stevensons, a UK company, in conjunction with Courtaulds, has shown that enzyme
treatment prevents this problem. "Once this process has been carried out,
the fabric is stable for the rest of its life", says Dr. John Scotney of
Coats Viyella Clothing Stevensons.
Biostoning of denim
Jeans, manufactured from denim, are one of the world's most
popular clothing items. The "stonewash look" has been traditionally
achieved by locally removing the indigo dye using a process in which pumice stone
is added to the washing drum to abrade the garment. Enzymes can be used to
facilitate removal of the indigo from the yarn surface. In practice, three
washing methods can be used:
- stone washing with pumice only;
- stone-free washing with enzymes only ("biostoning");
- washing with a combination of pumice and enzymes.