茂金属聚乙烯交联反应挤出流动模型分析

Flow models analysis of crosslinking reactive extrusion of metallocene polyethylene in twin-screw extruder

在研究茂金属聚乙烯在双螺杆挤出机中进行的复合交联反应挤出过程流动模型时,在三参数关联流动模型中引入了第4个参数,获得了更好的停留时间分布曲线拟合效果。但是,其物理意义难以确定。为此,根据双螺杆挤出机的结构特点提出了RDBFC模型,获得了较好的拟合效果,物理意义更加合理。

A Gaussian equation with four eigenvalues was proposed and applied to the crosslinking reactive extrusions of mPE and LDPE in a twin-screw extruder to elucidate the rules of their macroscopical mixing based on another Gaussian equation with three eigenvalues. It was found that the regression results of the Gaussian equation with four eigenvalues to the residence time distribution （RTD） curves of the crosslinking reactive extrusions of mPE and LDPE were more precise than that of the Gaussian equation with three eigenvalues, but these two kinds of Gaussian equations did not have definite physical meanings. For these reasons, we proposed a double main-flows plus single backflow cell model （revised DBFC model, named as RDBFC） according to the structural characteristics of the twin-screw extruder, which can describe the RTD curves of the crosslinking reactive extrusions of mPE and LDPE more satisfactorily because its eigenvalues all have definite physical meanings.