Abstract: Based on the generalized Hele-Shaw, the mathematic model of cavity filling in gas-assisted injection molding(GAIM), boundary condition of gas penetration, key technology of CAD/CAE model, and the system programming method are set up by providing reasonably accurate assumptions. This numerical simulation on gas penetration, pressure field, displacement process of melt-gas boundary in different time, and skin melt forming on the cavity wall is developed 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.

Key words: Gas penetration, Gas-assisted injection, Molding, Numerical simulation