【摘要】 为了提高双螺杆挤出机的混炼剪切效果,搭建带有捏合盘元件的双螺杆和带有反螺纹元件的双螺杆的组合螺杆模型,导入Gambit进行网格划分,使用Polyflow对等温条件下线型低密度聚乙烯与苯乙烯–丁二烯–苯乙烯共聚物共混熔体在不同组合螺杆中进行瞬态任务的仿真,利用粒子示踪法分析并得出不同螺杆中粒子的分散混合与分布混合规律,将结果与常规螺杆进行对比分析。从而得出结论:组合螺杆的混合效果比常规螺杆更好,其中具有反螺纹元件的螺杆在挤出过程中比常规螺杆提高约78%的剪切应力;其轴向的反流情况增加了粒子的停留时间,适用于反应挤出实验;且径向粒子混合效果优异,粒子间混合后的分离尺度是常规螺杆的一半,说明其混合均匀程度能够达到常规螺杆的2倍。更多还原

【Abstract】 To improve the mixing shear effect of twin-screw extruder,a combined screw model with pinching disc element and twin-screw with anti-thread element was built,introduced into the Gambit for mesh division,and the mixture of linear low density polyethylene and styrene-butadiene-styrene copolymer was simulated in different combination screw under isothermal conditions.The particle tracer method was used to analyze and obtain the dispersion and distribution of particles in different screw.It is concluded that the mixing effect of the combined screw is better than that of the conventional screw,in which the screw with the anti-thread element increases the shear stress by about 78% compared with the conventional screw during extrusion.The axial reflux increases the particle residence time and is suitable for the reaction extrusion experiment.更多还原