A new conformal cooling lattice design procedure for injection molding applications based on expert algorithms

Abstract

The paper presents the geometric design of a new lattice element of conformal type integrated into the cooling system of an injection mold. The geometric variables of this element are parameterized and are included in the design of the mold cooling system so that it can be valid for any type of geometry of plastic parts. Similarly, a physical model is presented to analyze the energetic behavior of the cooling lattice. Through the application of expert-type optimization algorithms to the presented physical model, the geometrical variables of the cooling lattice are dimensioned as well as the technological variables that govern the cooling phase of the plastic part. This methodology has been applied to four plastic parts with different geometrical characteristics. The results obtained have been compared with numerical simulations carried out by means of CFD-type software for plastic parts analysis, concluding that the new cooling lattices are adapted to the design criteria of an optimal cooling system. The new cooling lattices improve, in turn, the efficiency of thermal exchange in the cooling phase for plastic parts with large concavities, fine details, internal turrets, and housings. A simplified model focused on the energy analysis of a single cooling cell has been defined, which allows us to evaluate the thermal exchange between the cooling lattice and the plastic part, avoiding the computational complexity in the generation of the discrete mesh of the mold inserts. Similarly, in order to guarantee the structural safety of the cooling grids, a numerical mechanical analysis of the structural behavior of the injection mold insert under the most unfavorable contour conditions during the injection process has been carried out. The new conformal system presented in the paper does not require expert designers for its dimensioning, considering it as an adequate tool for reducing the overall design time of the mold while allowing the manufacturing process to be more efficient, reducing cycle time, and increasing the quality of the parts produced.