Making Solid Aromatic Polyimide Fibers

Improved wet-spinning process makes aromatic polyamic acid fibers containing no voids, and converts to polyimide fibers also free of voids. Elimination of voids found to improve tensile strength and other tensile properties. Improved polyimide fibers prove useful in protective clothing, sealing materials, filters for harsh chemical and/or thermal environments, and other applications taking advantage of excellent chemical resistance, high thermal stability, and good tensile properties.