A NUMERICAL ANALYSIS ON THE BEHAVIORS OF POLYMER FILM AND RESIN IN AN IN-MOLD DECORATION PROCESS

摘要

In various manufacturing industries, an in-mold decoration (IMD) process for plastic objects is widely utilized because a film forming and an injection molding process run simultaneously. In the present study, the deformation of polymer film and resin in the IMD process were numerically investigated to evaluate the quality of the plastic object formed by the IMD process, which consists of vacuum suction and injection molding. To obtain the initial shape of the polymer film during the injection molding process, the deformation of the polymer film in the vacuum suction process was pre-formed using the operating conditions needed to attach the film to a cavity. Since the properties and deformation of polymer film are greatly affected by the behavior of polymer resin being injected into a cavity, numerical simulations for the injection molding and film forming were performed with one-way coupling method. The results showed that the resin being injected could lead to the tearing of the polymer film in local regions near the corners. In order to verify the proposed numerical methodology, the numerical results of the deformation patters printed on the initial polymer film were compared with the experimental data.