酯化物密度计在聚酯生产中的应用

Application of Esterification Densitometer in PET Polyester Production

聚酯生产主要是以精对苯二甲酸和乙二醇为原料,在催化剂和辅料的作用下,经过配浆、酯化、预缩聚、终缩聚等过程的一种聚合反应,其中酯化作为一个十分重要的反应过程,直接决定了聚酯熔体指标的优劣和纺丝的稳定性。但是在实际生产中,影响酯化反应的因素非常多,任何一个变量都可能引起酸值、酯化率的变化。目前的监测手段是对酯化物进行取样、化验分析,但是这种方法无法对连续聚酯生产进行实时监控。基于这种情况,引进了酯化物密度计,通过研究找到了其变化数值与酸值、酯化率之间的对应关系,实现对酯化反应程度的实时监控。

Polyester production is a kind of polymerization reaction using refined terephthalic acid and ethylene glycol as raw materials,under the action of catalysts and auxiliary materials,through the processes of the slurry,esterification,pre-polycondensation and final polycondensation,in which esterification as a very important reaction process,directly determines the quality of polyester melt index and the stability of spinning.However,in the actual production,there are many factors affecting the esterification reaction,and any variable may cause changes in the acid value and esterification rate.The current monitoring methods are sampling the esterification and laboratory analysis,but this method cannot be monitored in real time for continuous polyester production.Based on this situation,the esterification densitometer was introduced,and the corresponding relationship between its change value,acid value and esterification rate was found through research,so as to realize real-time monitoring of esterification reaction degree.