Patent ID: 7998575

Claim:
A poly(metaphenylene isophthalamide) polymer fiber, said fiber, before coloration with a dye, shrinks linearly 0.4 percent or less when exposed to 285 degrees Centigrade for 30 minutes; and said fiber, after contact with an aqueous red dye solution for 1 hour at 120 degrees Centigrade, has an “L” value coloration of at least 40 units lower than the “L” value of the fiber before coloration; wherein the fiber is manufactured by a continuous dry spinning process the following steps, in order, comprising: extruding a solution through a shaped orifice into the fiber at a temperature of 110 degrees Centigrade to 140 degrees Centigrade, wherein the solution is extruded into a gaseous medium, wherein the resultant extruded fiber comprises polymer, salt, solvent and water, wherein the gaseous medium evaporates at least 25% of the solvent in the fiber; quenching the fiber in an aqueous quenching solution comprising salt and solvent, wherein the solvent is present in the aqueous quenching solution at a weight percentage, based on total weight of the aqueous quenching solution, in the range of from 2% to 20%, and the salt is present in the aqueous quenching solution at a weight percentage, based on total weight of the aqueous quenching solution, in the range of from 0.5% to 10%, wherein the aqueous quenching solution is at a temperature of 0 degrees to 15 degrees Centigrade; removing the fiber from the quenching solution and contacting the fiber with an aqueous conditioning solution comprising salt and the solvent, wherein the solvent is present in the aqueous conditioning solution at a weight percentage, based on total weight of the aqueous conditioning solution, in the range of from 5% to 40%, and the salt is present in the aqueous conditioning solution at a weight percentage, based on total weight of the aqueous conditioning solution, in the range of from 1% to 10%, wherein the aqueous conditioning solution is at a temperature of 30 degrees Centigrade to 100 degrees Centigrade; and drawing the fiber in an aqueous drawing solution comprising solvent and salt, wherein the solvent is present in the aqueous drawing solution at a weight percentage, based on total weight of the aqueous drawing solution, in the range of from 5% to 40%, and the salt is present in the aqueous drawing solution at a weight percentage, based on total weight of the aqueous drawing solution, in the range of from 1% to 10%.