A Design Tool for Core-Back Timing in Foam Injection Molding
A foam injection molding experiment to infer the bubbles formation in core- back operations was designed. The different stages of bubble nucleation, dissolution and re-nucleation, corresponding to injection, packing and core- back opening, respectively, were analyzed. Based on the observed reduction of the number density of re-nucleated bubbles, an original idea was conceived, grounded on the blowing agent concentration evolution around dissolved bub- bles. A numerical model, assuming Fickian behavior, was derived, validated by comparison with experimental results. The model allowed deriving a pre- dictive tool to design core-back operations in foam injection molding