Methods of continuously manufacturing polymide fibers

摘要

Methods for making high quality polyimide fibers suitable for continuous industrial production are described. Polyimide fibers are continuously prepared from a polyamic acid solution through sequentially spinning the polyamic acid solution by either a wet or a dry-wet process, coagulating, drying or drying after washing, thermally treating and stretching the resulting polyamic acid fibers to obtain polyimide fibers, and winding polyimide fibers as prepared into rolls.

主权项

1. A method comprising:
reacting a diamine and a dianhydride in a solvent to obtain a polyamic acid solution; filtering the polyamic acid solution; defoaming the filtered polyamic acid solution under vacuum; spinning the defoamed polyamic acid solution to obtain polyamic acid fibers; coagulating polyamic acid fibers in a solvent; drying polyamic acid fibers; treating and stretching the dried polyamic acid fibers in a tubular heating furnace for a period time from about 5 minutes to about 25 minutes at a plurality of temperatures such that polyimide fibers are continuously prepared from the polyamic acid solution, the tubular heating furnace having three furnace segments, the plurality of temperatures comprising a temperature from about 80° C. to about 280° C. in a first furnace segment of the three furnace segments, a temperature from about 200° C. to about 450° C. in a second furnace segment of the three furnace segments, and a temperature from about 400° C. to about 550° C. in a third furnace segment of the three furnace segments; and winding polyimide fibers to obtain rolls of polyimide fibers.