Patent ID: 6605694
Filing Date: 2003-08-12
Classification: D01F,D21F,Y10T

Abstract:
A process for solid phase polymerizing polymer flake having a polyamidation catalyst dispersed within the flake and a formic acid relative viscosity of about 40 to about 60 utilizing substantially oxygen free inert gas, comprising:feeding the flake into a solid phase polymerization vessel; separating and removing dust and/or polymer fines from the gas; drying at least a portion of the gas with a serially connected dual desiccant bed regenerative drying system such that the gas entering the vessel has a dew point of no more than about 20Â° C.; heating the gas to a temperature of about 120Â° C. to about 200Â° C.; circulating the filtered, dried, heated gas through interstices between the flake in the vessel for about 4 to about 24 hours; and removing the flake having a formic acid relative viscosity of at least about 90.