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.
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