新型螺杆挤出机熔体输送理论的研究

Study on the Theory of Melt Conveying for the Novel Screw Extruder

介绍了一种新型嵌套式螺杆挤出机。对熔体输送段进行了深入分析,把内螺杆的运动等效为螺杆轴的反向拖曳和螺棱的正向推力置换两部分作用,建立了对应的物理模型和数学模型,并得到了解析解。重点讨论了沿螺槽方向的流动和横向流动,并与普通单螺杆挤出机作对比,得到了螺杆和机筒同时旋转情况下的体积流率。结果表明, 所建模型的解析解和文献中的实验数据较为吻合,当螺杆和机筒同时旋转时,熔体输送段的体积流率大大增加,横向流动和平行平板模型类似。

A novel nested screw extruder was introduced. The movement of the melt in the melt conveying zone was analyzed in detail. The movement of the inner screw was considered as a negative drag flow of screw core and a positive displacement of flights, based on which a model was formulated and analytic solutions were obtained. The down channel velocity and cross channel velocities were compared with those of a regular single screw extruder. When the screw and barrel rotated in opposite directions, the volumetric flow rate was enhanced and the cross channel velocity is similar to that of a parallel flat flow. The calculated results based on the analytic solutions of the model were consistent with those reported in the literature.