Hoechst Celanese Corporation

John L Wesley

M Ishaq Haider

Stuart M French

Robert M Mininni

Henry H George, Jr

Preceramic fibers are produced by dissolving a solid organosilicon preceramic polymer in a solvent to form a spinning solution containing at least seventy percent polymer solids, dry spinning and extracting solvent in the presence of a non-oxidizing gas at a temperature and pressure sufficient to vaporize solvent from the fiber, and at least one curing agent being added to the non-oxidizing gas or spinning solution, or both, to induce on-line curing of the fiber or to aid in subsequent curing of the fiber or both. The preceramic fibers are thereafter pyrolyzed to ceramic form.

Process for dry spinning thermally sensitive organosilicon preceramic

Improved melt spinning of friable, thermally sensitive organosilicon preceramic polymers is obtained by using externally-metered feed means for continuous feeding of the polymer to an extruder. Starve feeding by metering the feed at a rate less than that required to fill the feed screw flights prevents pulverizing and compaction of the friable polymer, leading to cross-linking of trapped polymer and solid plugging, which would cause the extruder to bind and cease to function. Metered feed can be obtained by either monitoring of screw loading or discharge pressure and adjustment of hopper feed rate or control based upon measured values of extruder speed or metering pump speed.

Growing community of inventors

Wayne, NJ, United States of America

John L Wesley