Coupled part and mold temperature simulation for injection molding based on solid geometry

This paper presents a coupled method that determines the interface temperatures by filling and cooling analyses simultaneously to simulate the mold and part temperature distributions for injection molding. The mold temperature is assumed to be changing and is calculated with melt together at the filling stage instead of keeping constants as is usually done in conventional methods. The mold temperature is first determined with a 3-D finite element method by specifying the heat-flow rate at the interface between mold and part. Then the finite difference approach is employed to solve the melt thermal problem to get melt temperature distributions inside the cavity and the heat-flow rate at the interface. The under-relax scheme is used to correct the boundary condition and to resolve both mold and melt thermal problems until the solutions are convergent. This method can simulate transient and multicycle problems with more complex process conditions. The simulated results agree with experimental data.