Three Models of the 3D Filling Simulation for Injection Molding: A Brief Review

This article reviews the state-of-the-art research and development in the 3D filling simulation of injection molding, most notably the different models. The article organizes prior studies into three sequential categories, namely, mid-plane models, surface models, and solid models. In the mid-plane models, the arbitrary planar mid-plane is used to represent the three-dimensional geometry of the part. Their model and formulation are presented based on the Hele-Shaw approximation. The article further discusses the main disadvantage of the mid-plane models, which introduces the surface models. The surface models represent a three-dimensional part with a boundary or skin mesh on the outside surfaces of a solid geometric model. This kind of model still adopts the Hele-Shaw approximation, but can avoid the re-modeling of the mid-plane. Subsequently, the situations that cannot be accurately predicted using the Hele-Shaw approximation are discussed, in which a full 3D simulation has become a promising solution. The leading 3D simulation approaches are summarized, including the finite element method, the finite volume method, the control-volume-based finite-element-method, and the boundary element method. The tracking algorithms of the melt fronts are also described.