Biomedical Engineering Reference
In-Depth Information
Japan, and other developed countries is gradually reduced. Some enterprises for
regenerated fiber gradually are being transferred to developing countries, mainly in
Asia.
Regenerated cellulose fibers mainly include viscose fibers, acetate fibers, and
cuprammonium fibers.
(1) Viscose fiber
The production process for viscose fiber generally is as follows: First, make the
plant cellulose to form the cellulose xanthate, and the cellulose xanthate is dissolved
in dilute sodium hydroxide to make viscose, which is extruded into a coagulation
bath from a spinneret hole, then is solidified and decomposed to form regenerated
cellulose fiber. Viscose fiber is the most productive regenerated cellulose fiber,
but because of heavy pollution and other problems, there is gradual reduction
of the traditional process of viscose fiber production in developed countries. The
production capacity growth worldwide for viscose fiber is mainly centralized in
China; the output of viscose fiber accounts for about half of the total output of the
global regenerated cellulose fiber.
Now, the varieties of viscose fiber include modal, high-strength fibers, and
conventional fibers. Despite environmental pollution, the viscose fiber will continue
to be produced for a long time and trend toward the high-quality modern viscose
fiber, which has improved performance.
(2) Acetate fiber
First, in the production process for acetate fiber, cellulose is formed into cellulose
acetate, and then the cellulose acetate is saponified into acetate fiber. The production
of acetate filament is mainly centralized in Europe, the United States, Japan, and
other developed countries. The United States was the first country to product acetate
fiber; it also has the largest productivity. But, in recent years because of the decline
of the domestic market and the aging of production equipment, acetate fiber used in
textiles in the United States gradually has decreased. The same situation also applies
to Western Europe. The worldwide production of acetate filament is estimated to
remain at 20 million tons for the next few years.
(3) Cuprammonium rayon
In the production process for cuprammonium rayon, first the pulps are dissolved in
cupric tetramminohydroxide solution to prepare a viscous solution that is extruded
into a coagulation bath and then regenerated to cellulose fibers. Cuprammonium
rayon is a type of cellulose fiber with low productivity; it is mainly produced in
Japan, but production has declined in recent years. The productivity of cuprammo-
nium rayon is not expected to have much fluctuation in the next few years.
9.1.2.2
New Technologies for Regenerated Cellulose Fiber
Viscose fiber occupies an important position in textile raw materials and occupies
about a 90 % market share of regenerated cellulose fiber because of the mature
technology and low cost, but with the strengthening of environmental awareness on
