Gas assisted injection molding (GAIM)

as an innovative molding technique

has received extensive attention in recent years.GAIM can effectively decrease sink marks and volumetric shrinkage of the part

while GAIM is inherently more complex than conventional injection molding.At the same time

it involves many additional process parameters

such as gas delay time

gas pressure and gas injection time.In this study gas channels supplant ribs were used to achieve stable and smooth surface quality.In order to find optimum process parameters of GAIM

the experimental design of the Taguchi method was used to determine the GAIM conditions

and the cases were simulated by using the integrated commercial software packages.All molding conditions and affecting factors were discussed regarding the depth of sink marks of the shell of a machine.The results showed that the gas channels supplant ribs can effectively reduce raw material consumption

eliminate sink marks

diminish differential shrinkage and residual stress

improve finish surface

and enhance stability of part dimension.