【摘要】 双螺杆挤出机凭借其优异的混合能力、加工适应性和自洁性能，已成为高分子材料共混改性、反应挤出及复合材料制备的核心装备。针对传统双螺杆因几何对称性导致的混合性能不足的问题，本文提出一种新型折流板双螺杆。为研究该构型对流动特性的影响，使用有限元软件Polyflow对传统双螺杆与四种不同折流板高度的双螺杆进行数值模拟，对比分析其速度场、剪切速率、混合指数、粒子运动轨迹及停留时间。结果表明，折流板的引入显著增强了双螺杆流道内流场的非对称扰动、剪切作用及拉伸流动，促进了物料在相邻和相对螺槽间的一分二、二合一的反复分离和汇集，从而有效提高了物料的的混合性能。其中较低折流板高度更有利于剪切且强拉伸区域增大，但BTS15.5构型凭借较长的停留时间，在输送效率与混合效果之间表现出较优平衡。更多还原

【Abstract】 Twin-screw extruders serve as the core equipment for polymer blending modification, reactive extrusion, and composite preparation, owing to their superior mixing capability, processing adaptability, and self-cleaning properties.However, conventional twin screws often suffer from an insufficient mixing performance due to their inherent geometric symmetry.To study the influence of this configuration on the flow characteristics, the finite element software Polyflow was used to conduct numerical simulations for the traditional twin-screw and four different height configurations of the twin-screw.The velocity field, shear rate, mixing index, particle movement trajectory and residence time were compared and analyzed.The results reveal that the baffle introduction significantly enhances the asymmetric disturbance, shear effect and stretching flow in the twin-screw flow channel, promoting the repeated separation and recombination of the material between adjacent and opposite screw grooves, thereby effectively improving the mixing performance of the material.In particular, relatively lower baffle heights are associated with stronger shear action and a larger strongly extensional region, whereas the BTS15.5 configuration, due to its longer residence time, achieves a more favorable compromise between conveying efficiency and overall mixing performance.更多还原