Process Description
Polymerization of feed material takes place in reactor vessels
with pure water. The resulting polymer is purified dried and
stored in preparation for dissolving in a concentrated solution
of nitric acid. The "dope" liquid formed is then cooled, filtered,
and de-aerated in preparation for spinning.
The dissolved Polymer
is extruded through Spinnerettes in a strong solution of nitric
acid. Spinnerettes are stainless steel unit with many thousands
of small holes. As the Polymer emerges from the holes it coagulates
to form fiber filaments. The solution of nitric acid mixes with
a water solution which is pumped continuously around the spinning
baths in which the spinning process takes place. Once the filaments
are formed they are carried on to be washed clean of the remaining
nitric acid. The fiber is then stretched to improve its strength
and to transform it to a more "wool" like product. Two separate
drying and oiling processes are carried out to improve the anti-static
properties and the process ability of the fiber. The fiber is
then set by steam heating to an exact temperature for a controlled
time period. This standardizes the dimensional stability and
the dye ability of the fiber so that color is guaranteed during
downstream dying.
The tow, which is a "rope" like fiber, is
packed into bales. Stable fiber is soft crimped and then cut
to selected lengths before baling. |
