对共挤复合吹膜工艺所采用的螺旋芯棒式模头内部熔体流动进行二维数值模拟,简化分析模型并得到挤出过程中熔体流动的流速及压力变化的相对趋势。模拟结果表明:熔体进入模头螺旋部分后具有一定的环向速度,随着螺旋槽深度变浅,流动的方向逐渐由螺旋环向变为挤出方向的轴向,且流速变得均匀;熔体在螺旋槽旋转处静压力较大,接近挤出方向后压力逐渐变小,口模出口处熔体流动速度仍大于流入模头的入口速度。 The two-dimensional numerical simulation of the melt flow in the spiral mandrel die used in the co-extrusion composite blown film process was made to simplify the analysis model and obtain the relative trend of the melt flow velocity and pressure during the extrusion process. The simulation results show that the melt has a certain circumferential velocity after entering the helical part of the die. As the depth of the helical groove becomes shallower, the direction of the flow gradually changes from the helix to the axial direction of the extrusion direction, and the flow velocity becomes uniform. Melt in the spiral groove rotation static pressure, close to the extrusion direction pressure becomes smaller, the exit of the die melt flow rate is still greater than the inlet into the die speed.