19-05-2012, 03:37 PM
TEXTILE GLOSSARY FILAMENT
textile_glossary_filament_acetate.pdf (Size: 1.92 MB / Downloads: 50)
ACETATE FIBER:
A manufactured fiber in which the fiber-forming
substance is cellulose acetate (FTC definition). Acetate is
manufactured by treating purified cellulose refined from cotton linters
and/or wood pulp with acetic anhydride in the presence of a catalyst.
The resultant product, cellulose acetate flake, is precipitated, purified,
dried, and dissolved in acetone to prepare the spinning solution. After
filtration, the highly viscous solution is extruded through spinnerets into
a column of warm air in which the acetone is evaporated, leaving solid
continuous filaments of cellulose acetate. The evaporated acetone is
recovered using a solvent recovery system to prepare additional
spinning solution. The cellulose acetate fibers are intermingled and
wound onto a bobbin or shippable metier cheese package, ready for use
without further chemical processing. In the manufacture of staple fiber,
the filaments from numerous spinnerets are combined into tow form,
crimped, cut to the required length, and packaged in bales. Acetate
fibers are environmentally friendly.
ACRYLIC FIBER:
A manufactured fiber in which the fiber-forming substance is any long chain
synthetic polymer composed of at least 85% by weight of acrylonitrile units [-CH2-CH(CN)-]
(FTC definition). Acrylic fibers are produced by two basic methods of spinning (extrusion), dry
and wet. In the dry spinning method, material to be spun is dissolved is a solvent. After
extrusion through the spinneret, the solvent is evaporated, producing continuous filaments which
later may be cut into staple, if desired. In wet spinning, the spinning solution is extruded into a
liquid coagulating bath to form filaments, which are drawn, dried, and processed.
AIR JET SPINNING:
A spinning system in which yarn is
made by wrapping fibers around a core stream of fibers with
compressed air. In this process, the fibers are drafted to
appropriate sliver size, then fed to the air jet chambers
where they are twisted, first in one direction, then in the
reverse direction in a second chamber. They are stabilized
after each twisting operation.