Crystallinity adjustment for pet solid-state polymerization process

Abstract

An apparatus for producing solid crystallized polymer particles. The apparatus includes a precrystallizer followed by a static vessel. The crystallinity of the polyester is increased in the static vessel compared to the crystallinity of the polyester from the precrystallizer or the single crystallizer. Inert gas is fed to the static vessel to remove oligomers and fines from the chip and assist with chip mobility. It can optionally include a single crystallizer. The static vessel can replace one or both of the crystallizers in a conventional polyester process. A method for making polyester particles is also described.

Dependencies are inferred from the claim text.