同向双螺杆不同螺纹元件混炼效果的数值研究

摘要

The flow of polypropylene （PP） in channel of screw element of a co-rotating twin-screw extruder was simulated using Polyflow software. Three dimensional isothermal flow fields of PP in the channel of a regular and a slotted screw element were calculated. The logarithm stretching, segregation scale, and resident time of particles in the channel of regular and slotted screw elements were analyzed. The mixing performances in the two kinds of screw elements were compared through particle tracking analysis （PTA）. Because of the leakage flow, the slotted screw element had lower conveying capacity, lesser dispersive mixing performance, but longer resident time and better distribution mixing performance than the regular screw element.%采用Polyflow软件数值模拟了啮合同向双螺杆挤出机流道内聚丙烯（PP）熔体的流动，数值计算了常规螺纹元件和开槽螺纹元件流道内PP熔体的三维等温流场，采用粒子示踪分析法（PTA）分析了不同螺纹元件流道内粒子的拉伸度自然对数、分离尺度和停留时间，比较了常规螺纹元件和开槽螺纹元件的混炼效果。结果表明，与常规螺纹元件相比，由于熔体在沟槽内产生漏流，开槽螺纹元件的建压输送能力较低，分散混合性能较弱；开槽螺纹元件流道内因粒子的停留时间较长，其分布混合性能优于常规螺纹元件。