Integrated process simulation of thermoforming and injection moulding

In cooperation with the Institute for Machine Tools and Production Technology at the TU Braunschweig, a model for the numerical prediction of the boundary layer strength is being developed using the example of a coupled thermoforming-injection moulding process. As an essential requirement for the simulation with the finite element method (FEM), all necessary temperature-dependent material parameters are first determined and material models are parameterised. These are validated using the individual processes for thermoforming and injection moulding of fibre-reinforced plastics. In addition, extended knowledge about the local temperature and shear stress distribution during thermoforming as well as about the mould filling and local temperature distribution during the injection moulding process will be obtained. Thus, fundamental statements can be made about the material behaviour during the manufacturing processes and subsequently process variables can be predicted. This is followed by experimental characterisation and modelling of the compound to calculate the composite strength. This is of decisive importance for the component quality. The composite properties are significantly influenced by the process. The most important parameters are the temperatures of both materials and the pressure in the boundary layer. Finally, a holistic simulation model for the integrated process simulation of thermoforming and injection moulding will be developed and validated. This provides an SME-friendly method for calculating and visualising the composite strength. In contrast to the simulation of the individual processes, the fluid-structure interaction between the injection moulding compound and the organic sheet is also taken into account, so that a deformation of the sheet is considered. This also includes the "push back" of the matrix material that has flown into the punch cavities.