PROCESS FOR EXTRUDING A MODIFIED HIGH MOLECULAR WEIGHT POLY(ETHYLENE TEREPHTHALATE) RESIN

摘要

ABSTRACTPoly(ethylene terephthalate) resin andblends of poly(ethylene terephthalate) resin withother polymers are extruded while being coupled withan organic diisocyanate under conditions where carbondioxide gas is vented smoothly, as it is formed. Theextruder has a number of zones designed to performspecific functions. The temperature in the kneadingzone and in the venting zone must be maintained atabout 280-320°C to bring about rapid reaction and topermit efficient gas evolution and removal withoutthermally degrading the polymeric material. Theextruded article is free of trapped gas bubbles andother imperfections. This process is particularlysuitable for making PET billets, which then arestretched to form strapping useful in packagingapplications.