Patent ID: 7780889
Filing Date: 2010-08-24
Classification: D01D,D01F

Abstract:
1. A continuous dry spinning process, comprising: extruding a fiber from a solution into a gaseous medium, wherein the solution comprises meta-aramid polymer, solvent, water, and salt; removing at least 25 weight percent of the solvent from the fiber in the gaseous medium; wherein the gaseous medium is maintained at a temperature of at least 250 degrees centigrade; quenching the fiber in an aqueous quenching solution having a first concentration of solvent and salt, wherein the aqueous quenching solution is at a first temperature; contacting the fiber with an aqueous conditioning solution having a second concentration of solvent and salt, the second concentration of solvent being higher than the first concentration, and wherein the aqueous conditioning solution is at a second temperature; and drawing the fiber at least 3 times the initial speed at a tension of 0.25 to 2 grams per denier using a plurality of draw stages, wherein the residence time between each draw stage is at least 1 second; wherein the drawn fiber is a solid fiber.