Three dimensional visualization of water penetration and melt behavior in water assisted injection molding

Water-assisted injection molding (WAIM) is one of the special injection molding methods beyond traditional methods. The concept was developed from gas-assisted injection molding (GAIM); however, WAIM has some benefits over GAIM such as shorter cycle time and lower medium cost. The current study started from simulations of the flow behavior of various models. Theoretical methods and a numerical solver (Moldex3D R10) were used as the analysis tools. By using its three-dimensional visualization ability, water penetration behavior is easier to understand. Different processing condition effects related to water penetration length were also investigated such as water pressure, water temperature, delay time, and short shot size. The results show good agreements with experimental data. One of the purposes of WAIM is to core out the cavity to save material cost, but parts should still have sufficient strength. This is highly related to the process parameters, material, and part geometry. The current study focuses on processing parameters and core out effects on different models. The results are helpful in understanding flow behavior and potential applications in water-assisted injection molding.