Patent ID: 6627129
Filing Date: 2003-09-30
Classification: D01F,D21F,Y10T

Abstract:
A process for melt phase polymerization of polymer for making filaments for use in making staple fibers for papermaking machine felts, comprising:feeding polymer flake at a temperature of about 120Â° C. to about 180Â° C. into a non vented melt-extruder, the flake comprising: a synthetic melt spinnable polyamide polymer, a formic acid relative viscosity of about 90 to about 120, and a polyamidation catalyst dispersed within the flake; melting the flake in the melt-extruder and extruding molten polymer from an outlet of the melt-extruder to a transfer line wherein the temperature of the molten polymer in the transfer line within about 5 feet (2.4 m) of the outlet of the melt-extruder is about 290Â° C. to about 300Â° C.; conveying the molten polymer through the transfer line to at least a spinneret of at least a spinning machine such that the temperature in the transfer line within 5 feet (2.4 m) of the at least a spinneret is about 292Â° C. to about 305Â° C., with a residence time in the melt-extruder and the transfer line of about 3 to about 15 minutes; and spinning the molten polymer through the at least a spinneret forming a plurality of the filaments having a formic acid relative viscosity of at least about 140.