Experimental and analytical study on filling of nano structures in micro injection molding

Nano technology is attracting more attention and has increasing applications in the recent years. Among the products with nano technology, many of them are made of polymer plastics. Micro injection molding is one of the critical processes for polymer plastics. In micro injection molding, the ability for the polymer melt to flow into the micro/nano structures is a crucial factor for successful molding. The flow behavior of polymer in nano structures needs to be explored further to facilitate the molding process. In this study, we investigated the effects of the processing parameters on the filling of nano structures analytically and experimentally. Firstly, mold inserts with nano channels were constructed by LIGA-Like process. Secondly, an analytical model was developed to model the filling of polymer melt in the nano channels. Molding experiments were performed to verify the analytical filling model. With this verified model, a theoretical penetration distance can be obtained, and the suitable processing parameters can be estimated for different product geometries. (C) 2010 Elsevier Ltd. All rights reserved.