Study on numerical simulation of cavity filling in gas-assisted injection molding

Based on the generalized Hele-Shaw flow model, the mathematic model of cavity filling in gas-assisted injection molding(GAIM), boundary condition of gas penetration, key technology of CAD/CAE modeling, and the system programming method are set up by providing reasonably accurate assumptions. The numerical simulation on gas penetration, pressure field distribution, displacement process of melt-gas boundary in different times and skin melt forming on the cavity wall is carried out for GAIM parts. Research results show that increasing gas injection pressure or decreasing melt temperature and non-Newtonian index makes the thickness ratio increase. These results are close to experimental values by other investigators and consistent with actual GAIM process.