A Study of the Injection Molding : 2nd Report, Analysis of the Partial Thermal Shrinkage in the Rib Structures

Abstract

An analytical method for evaluating the sink mark in rib structures is proposed. In the analysis model, when the shape of the cross section does not change in the longitudinal direction, 2-dimensional time-transient thermal analysis by FDM is used. At the same time, by assuming the fiber elements, and by treating the model as a thermal-elast-plastic strain problem, the growth of the sink mark in the die is theoretically evaluated. In consideration of the P-V-T characteristics of the resin, the analytical results are correlate well with the experimental data.