3D study of cooling system effect on the heat transfer during polymer injection molding

The aim of the cooling system of a plastic injection mold is to provide thermal regulation in the injection molding process. When the hot plastic melt enters the mold cavity, it cools down and solidifies by dissipating heat through the cooling system. To study the effect of the cooling system design on the solidification and heat transfer of polymer by injection molding, a full three-dimensional time-dependent injection molding numerical analysis is carried out. The configuration studied consists of the mold with cuboids-shape cavity having two different thicknesses. The cooling of the polymer material is carried out by cooling water flowing through horizontal six cooling channels. A numerical model by finite volume is used for the solution of the physical model. A validation of the numerical model is presented. The effect of the cooling channels position and their cross-section shape on the cooling process is carried out. The results indicate that, for the same cross-sectional area and coolant flow rate of the cooling channels, the cooling channels having the form rectangular perform the minimum time required to completely solidify the plastic product. They also indicate that when the cooling channels approach to the product surface, the cooling efficiency increases. (C) 2009 Elsevier Masson SAS. All rights reserved.