Non-isothermal injection molding with resin cure and preform deformability

Abstract

In this paper, a non-isothermal model to simulate some injection molding processes used to fabricate composite materials is deduced. The model allows the solid constituent in both the dry and the wet region to deform during infiltration. The dry porous material is assumed to behave elastically, while the mixture of resin and preform is assumed to behave as a standard linear solid. The model also takes into account the fact that the liquid undergoes an exothermic cross-linking reaction during infiltration and eventually gels stopping the infiltration process. Focusing then on one-dimensional problems it is shown that the integration of the mechanical problem in the uninfiltrated region can be reduced to the integration of an ordinary differential equation defining either the space-independent volume ratio or the location of the infiltration front, depending on whether the flow is driven by a given infiltration velocity or by a given inlet pressure. The remaining system of partial differential equations in the two interfaced and time-dependent domains is then posed with the proper interface and boundary conditions. After writing the problem in a Lagrangian formulation fixed on the solid constituent, domain decomposition techniques are used for the simulation.