For designing injection molds the use of injection molding simulation-software is state of the art, but the mold deformation due to melt pressure is not analysed. Mold deformation may result in dimensional problems or even in breaking of mold components. Although Finite-Element-Methods are capable of simulating such tasks, they are hardly used in industry due to the complexity and time effort.
In the presented work a calculation method was developed to estimate the maximum deflection of mold plates and cylindrical cores due to melt pressure based on a few simple input data like plate or core dimensions. projected area of the acting pressure and the pressure level. First, some reference geometries were tested experimentally in a simple bending test. These experiments were also simulated using a commercial FEM-software. The simulation results were in good agreement with the experiments. Based on this verification of the simulation-software the dimensions of these simple geometries were varied systematically in many steps and analysed (more than 1000 different cases). The results were used as data basis for the calculation tool, where arbitrary pressure levels and dimensions within a defined range can be entered and the maximum deformation is calculated by interpolating between the simulated results. With this method the average error of the new calculation tool compared to the simulation results was below 4 %. Thus a tool was created that allows the mold designer to estimate critical mold deformations with a few mouse-clicks with satisfying accuracy.
