Production of polycaproamide filaments of uniform water content

Claim 1

IN A PROCESS FOR PRODUCTION OF FILAMENTS FROM WATERWASHED E-CAPROLACTAM HOMOPOLYMER BY MELT SPINNING, THE IMPROVEMENT WHICH COMPRISES, BEFORE MELT SPINNING THE SAME, BRINGING THE AVERAGE WATER CONTENT OF SOLID WATERWASHED PARTICLES OF SAID POLYMER, OF ITS ULTIMATE WEIGHT, BASED ON WEIGHT OF THE POLYMER OF ITS ULTIMATE LEVEL REACHED IN THE CONDITIONING BELOW RECITED, SAID WATER CONTENT LEVEL BEING IN THE RANGE FROM ABOUT 0.035% TO ABOUT 0.115%; THEN CONDITIONING THE RESULTING POLYMER PARTICLES FOR SPINNING BY CONTACTING THE PARTICLES WITH AN INERT GAS HAVING A SUBSTANTIALLY CONSTANT TEMPERATURE IN IN THE RANGE BETWEEN ABOUT 30* C. AND ABOUT 120* C. AND THE RANGE BETWEEN ABOUT 30* C. AND ABOUT 120* C. AND HAVING A SUBSTANTIALLY CONSTANT WATER VAPOR PARTIAL PRESSURE IN THE RANGE BETWEEN ABOUT 0.001 AND ABOUT 10 MM. OF MERCURY SAID CONTACT BEING MAINTAINED SUBSTANTIALLY CONTENT OF THE POLYMER RESULTING FROM SAID CONDITIONING BEING IN THE RANGE FROM AOUT 0.035% TO ABOUT 0.115% BY WEIGHT OF THE POLYMER AND BEING AT A VALUE W$0.01 WHERE W IS DETERMINED BY THE FOLLOWING EQUATIONS IN UNITS OF WEIGHT PERCENT BASED ON POLYMER: (1) LOG10Z=1495/T-0.261, WHERE T IS THE TEMPERATURE TO BE MAINTAINED IN THE MELT FOR SPINNING, IN DEGREES ABSOLUTE; (2) V=-285.209+2164.33Y+11.7188/Y, WHERE V IS THE RELATIVE VISCOSITY OF THE POLYMER; (3) Z=C(0.555W)/(Y-A)Y, WHERE Z IS DEFINED BY EQUATION 1 ABOVE: Y IS DEFINED BY EQUATION 2 ABOVE IN UNITS OF GRAM EQUIVALENTS OF COOH END GROUPS PER KILOGRAM OF POLYMER; C IS THE CONCENTRATION OF (-CONH-) GROUPS IN THE POLYMER IN GRAM-EQUIVALENTS PER KILOGRAM; AND A IS THE CONCENTRATION OF ANY MONOCARBOXYLIC ACID INCORPORATED IN THE POLYMER, IN GRAM-EQUIVALENT PER KILOGRAM; THEREBY BRINGING UNIFORMITY OF WATER CONTENT OF THE SOLID POLYMER WITHIN A STANDARD DEVIATION NOT ABOVE ABOUT 0.003% OF WATER BY WEIGHT BASED ON WEIGHT OF THE POLYMER WITHIN RESULTING POLYMER HAVING RELATIVE FORMING ACID VISCOSITY IN THE RANGE FROM ABOUT 40 TO ABOUT 80 WITH STANDARD DEVIATION NOT ABOVE ABOUT 0.6 RELATIVE FORMIC ACID VISCOSITY UNITS, AS MEASURED AT 10% CONCENTRATION IN AQUEOUS 90% FORMIC ACID SOLUTION AT 25* C.