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Film insert molding (FIM) has been modeled numerically to predict residual stress and viscoelastic deformation of the part. Nonisothermal three dimensional flow analysis for filling, packing, and cooling stages was carried out by using a commercial software. It was assumed that the inserted film was solid throughout the entire molding procedure although remelting could occur at the interface with the substrate. The flow analysis results, e.g., temperature, stress, and density distribution in the substrate domain, were transported to a finite element stress analysis program for viscoelastic stress analysis. Deflection of the FIM part was obtained as soon as the part was ejected from the mold by assuming isotropic elastic material. The residual stress distribution in the FIM part was acquired by removing the constraints along the boundary of the molded part. Viscoelastic deformation of the FIM part was predicted by performing viscoelastic stress analysis in order to understand long term behavior of the FIM part when exposed to room temperature. Durability of automotive and electronic parts produced by the film injection molding can be predicted by the procedure adopted in this study. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

A new local film heating system (LFHS) can precisely control the local mold wall temperature in the nanoinjection molding process.

We have demonstrated a robust platform that can not only sustainably fabricate a lab-on-a-chip (LOC) device using microinjection molding but also elucidate the filling process of microstructures based on the multiscale analysis. In addition, a novel dimensionless number, i.e., the filling number μ(f) which can provide an insight into the underlying filling mechanism for micropillars, has been proposed based on the understanding of the characteristics of polymeric flow and cavity dimension. This study suggests a solid experimental and numerical tool for the production of microfluidic devices with the use of a micromolding technique, which is expected to help materialize the commercialization of the LOC devices in a more sustainable manner.

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