Multi-rib comb shaped parts have a complex structure with multiple ribs and hollow cavities

and traditional injection molding is difficult to achieve good molding results. Therefore

gas-assisted injection molding is usually used as the manufacturing process. However

gas assisted forming under complex structures will produce gas finger defects

seriously restricting the quality of part forming. Taking the calf support of a multi-rib comb shaped part as the research object

aiming at the gas finger defect of the part

based on the analysis of the structural design of the product and the molding technology

the formation mechanism of gas finger defect was analyzed theoretically. Based on Moldflow software

the finite element model of calf support was established to analyze the formation mechanism of gas finger. Based on the principle of thinning wall thickness

the wall thickness of the main body and the wall thickness of ribs were improved

and the scheme of reducing glue in the crater was proposed. The results show that with the thickness of the main body and the wall thickness of ribs decrease

the gas fingering is improved. The use of volcanic crater glue reduction scheme can avoid large-scale thinning while eliminating gas fingering defects. The test mold has verified that local thinning can accelerate the cooling of parts

form an effective freezing layer

and thus eliminate gas fingering defects.