Numerical Study on Heat Retardation of In-Mold Decoration Film in Injection Molding Processes

• Main Authors: Yi-Han Li, 李奕翰
• Other Authors: Shiu-Wu Chau
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/tcsz4e

碩士 === 國立臺灣科技大學 === 機械工程系 === 99 === This study proposes a numerical model to simulate the filling phase of injection molding process for in-mold decoration production, where the filling simulations with various processing conditions are also performed to investigate their effects on the retardation temperature drop due to the installation of film. The flow field of melt and air in the cavity is described by the continuity, momentum, and energy equations, while the melt front is tracked by the front transport equation. The temperature field of the mold is obtained by solving the energy equation in the solid domain. The govern equations are discretized by a finite volume approach and the volume-of-fluid method is employed to calculate the location of melt front. The non-Newtonian rheological behavior of polymer is modelled by the modified Cross-WLF model in this study. The proposed numerical model is proved to give both qualitative and quantitative agreement with corresponding experiments. The predicted results reveal that the retardation temperature drop decreases with the increase of the initial temperature of film, the thermal conductivity of film and the film thickness. For PC and PET films, the former tends to give a higher retardation temperature drop than that of the latter one.