Evaluation of Injection Moldied Products by Dimensional Changes Taking Local Variations into Consideration

Abstract

Optimization of injection molding was studied both with actual machinery and by simulation, focusing on dimensional transferability, in an attempt to verify the principle that optimal molding occurs when every part shrinks equally relative to the mold. Data obtained in an optimization study conducted by simulation,paired with experimental data obtained in a past transferability study, were reanalyzed on a localized basis. As a result, it was confirmed that the effects of control factors differ significantly from one place to another in the mold. Control factors taking these local variations into consideration were selected, and the gain resulting from the optimization by simulation showed some degree of reproducibility, but large local interaction effects with the control factors were found, demonstrating the limits of optimization of injection molding.