使用有限元方法数值计算双螺杆平行4孔模具内高黏度聚合物熔体的等温流场,分析模具压差对熔体流场的影响.研究结果表明,随着模具压差的增加,物料的平均速度、平均剪切速率增加,平均黏度降低,产量增大；在模具入口段,物料平均速度和平均剪切速率减小,平均黏度增大；在模具过渡段和平直段,熔体平均速度和平均剪切速率增大,平均黏度减小；模具内熔体各物理量梯度小,在模具过渡段,压力没有急剧增大；模具平行各孔道中熔体物理量分布基本相同,可以说明该模具能够均匀挤出制品,该平行4孔模具的设计合理.实际生产验证双螺杆挤出平行4孔模具可挤出成型多个质量合格制品.%Isothermal flow fields of a kind of high-viscosity polymer melting in a new parallel 4-hole twin-screw die were simulated by using the finite element method. The effects of pressure on polymer flow fields were analyzed. The numerical results show that average velocity along with average shear rate of melting and yield increases as the differential pressure increases, but average viscosity decreases. Average velocity and shear rate of melting decrea-ses , and average viscosity increases in the entrance of the die. Average velocity and shear rate of melting increases, and average viscosity decreases in the transition and straight section. The gradient of physical quantities of melting is small in the die. There is no sharp increase of pressure in transition. Flow fields of melted material in every pore are basically the same. This shows that the products were uniformly extruded in the die. The design of a parallel 4-hole die is good. It is proven that quality products are extruded by a polymer parallel 4-hole extrusion die of a twin-screw extruder in factory production.
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