啮合同向双螺杆挤出机组合流道的熔体充满长度预测与实验研究

Forecast and Experimental Study of Melt Filled Length of Screw Assembled Field in An Intermeshing Co-rotating Twin Screw Extruder

用Polyflow软件对φ34 mm啮合同向双螺杆挤出机中由螺纹元件和捏合盘元件组成的组合流道进行了模拟,得到了不同螺杆相位角下三维流场的压力分布;分析了设置在组合流道内的观测点压力随相位角变化的规律,对两种流量下组合流道在挤出过程中的熔体充满长度进行了预测,并对分析结果进行了实验验证。结果表明,通过流场模拟的方法可以预测组合流道在挤出过程中的熔体充满长度,其误差为7.5%。而在预测的充满长度区域,实测的观测点压力波动在预测的压力波动范围内。

A simulation of the assembled flow domain composed of screw elements and kneading blocks in an experimental intermeshing co rotating twin screw extruder with 34 millimeter diameter has been carried on. The pressure distribution of three dimensional flow field at different screw phase angle was obtained. Then the variation of pressure of the observing point located in the assembled flow domain against the phase angle was analyzed. The melt filled length of assembled flow domain in the extrusion process was forecasted at two different flow rates. Meanwhile an experiment was made to validate the analysis result. It showed that the melt filled length could be forecasted through the flow field simulation, with an error 7. 5%. And in the forecasted filled length, the measured pressure fluctuation of observing point was got within the forecasted pressure fluctuation.