Process for producing polyester resin powder, process for producing polyester preform and apparatus for heat-treatment of polyester resin powder

摘要

The present invention relates to a process for producing polyester resin powder by heat-treatment thereof comprising holding the polyester resin powder in plural vessels and subjecting the polyester resin powder to contact with a heated gas, which process comprises repeating the steps of: (a) supplying a certain amount of polyester resin powder to said treatment vessels, (b) carrying out heat-treatment of said polyester resin powder by supplying the heated gas to said treatment vessels for a certain period of time and (C) discharging the treated polyester resin powder from said treatment vessels; and which process carries out said steps (a), (b) and (c) successively with a different operational phase for each treatment vessel. By this process, it is possible to attain effective heat-treatment of resin powder and more homogeneous quality of products.