PET切片干燥过程中的固相缩聚

本文通过测定干燥后PET切片的特性粘度及所纺成纤维的强伸度,研究了直接酯化法生产的PET切片在连续式充填干燥器中干燥过程中所发生的固相缩聚。研究结果表明干燥温度和干燥时间对固化反应的速度和程度都有很大影响,固相缩聚后的干切片粘度和分子量有所提高,并将导致熔体温度和POY强度提高。干燥温度和时间的波动会导致干切片特性粘度的不均,并进一步导致纤维的不匀率提高。

THE SOLID PHASE POLYCONDENSATION OF PET CHIPS IN THE DRYING PROCESS

The solid phase polycondensation of direct esterfication method PET chips occured during the drying process in the continuous filling column dryer has been investigated by determinations of intrinsic viscosity of chips after drying and the stress-strain relation of spun fiber, the result show that drying temperature and time both have a great influence upon the speed and degree of solid phase polycondensation, after reaction the viscosity and molecular weight of chips are increased and so are the temperature of melt and tenacity of POY, any fluctuation of drying time and temperature will cause the uneven ness of chip's intrinsic viscosity and finally the unevenness of the fiber.