PROCESS FOR PRODUCING POLYESTER ARTICLES HAVING LOW ACETALDEHYDE CONTENT

摘要

Disclosed is a process for removing acetaldehyde from polyester which comprises the steps of a) transporting molten polyester to a vented, continuous screw conveyor having a polymer compression zone, b) rotating the screw of said conveyor so as to compress and convey through the extruder the molten polymer for a time of less than 15 minutes and at a temperature of less than 300 DEG C., c) simultaneously with step b), flowing a purge agent into and out of said extruder to thereby remove volatile impurities and avoid appreciable build-up of acetaldehyde, and d) conveying the devolatized polymer melt to a mold wherein an article of manufacture is formed.