Permeability measurements and non-isothermal mold filling simulation in liquid composite molding

Polymer reactive molding covers many manufacturing processes in which reactive resins are injected into a closed mold cavity to produce polymer or composite products. During processing, the flow pattern, the temperature field, and the conversion distribution can be very complicated because of resin reaction. This research includes the material characterization and the molding simulation. LCM mold filling processes are often analyzed based on theoretical models developed for flow through porous media. The most widely used model is Darcy's law in which the flow property of the fiber reinforcement is permeability and the flow property of the fluid is viscosity. After measuring the flow properties, molding processes can be simulated and analyzed.;This study presents two independent methods to measure both the in-plane permeability and the trans-plane permeability such that the results from these two methods can be compared with each other. The measured data can be used as the input parameter for the mold filling simulation. Permeability measurement itself is a mold filling process. The problems in measuring the permeability, such as race tracking, fiber mat consolidation, and stacking sequence effect, may also occur in the actual mold filling process. Therefore, experience gained from the permeability measurement may help us in the flow analysis.;Many computer codes for the simulation of polymer processing are based on the control volume finite element method (CVFEM) because it is more user friendly and more robust than the conventional finite element methods. However, using lower order interpolation functions in CVFEM may create significant numerical errors. This is especially true for convection-diffusion problems with a changeable source term. In this study, an Eulerian-Lagrangian approach is proposed where an Eulerian coordinate system is used to solve the velocity field, while the chemical species balance and the energy balance are based on a Lagrangian coordinate system. In order to obtain more accurate velocity profiles, especially for complicated geometry, another innovative method is applied to the Eulerian-Lagrangian approach. They are used to simulate the non-isothermal resin transfer molding (RTM) process. The simulation results from this approach and the CVFEM method are compared.