注塑模充模过程动态分析

Dynamic Simulation of Injection Molding Filling Process

注塑成型是利用型腔模制造理想制品主要的成型加工方式 ,塑料熔体的流动行为将直接影响着最终塑件的质量 ,塑料熔体在三维薄壁型腔内的流动属于带有运动边界的粘性不可压缩流体的流动 ,本文针对塑料注塑成型特点 ,经过量纲分析和引入合理而必要的假设 ,得到了适合于充模分析的数学模型。控制方程的求解主要包括三个阶段 :压力场、温度场和流动前沿位置的确定。数值求解采用有限元法求解压力场、有限差分法求解温度场、并利用控制体积法跟踪熔体前沿 。

Injection Molding is one of the most widely used processes on manufacturing plastics and composite products. One of the most significant factors that influences part quality in injection molding process is the polymer flow pattern. The mold filling of polymer melt in three dimensional thin parts is a viscous, incompressible flow with moving boundaries. After discussed some assumptions, such as material properties and cavity geometry of injection molding, a simplified set of equations for analysis of the filling is presented in this paper. Solution of the equations is done in three main stages: calculation of the pressure field, calculation of the temperature field and finally advancement of the flow front. Finite element methods are used for the pressure calculation while temperature calculation use finite difference methods. Advancement of flow front uses a control volume approach and dynamic simulation of the mold filling process is achieved.