气辅成型中气道形状和尺寸对气指缺陷的影响

Effects of gas channel geometry in gas-assisted injection molding on gas fingering defect of part

研究了气体辅助注射成型制品中不同半径的半圆形气道、不同宽高比的矩形气道以及4种截面形状不同,但截面面积相同的气道对聚苯乙烯材质气辅制品的气指缺陷的影响。结果表明:对于半圆形气道,当量半径与板厚比在某一数值范围时,气指的程度最小;当矩形气道宽高比为某一确定值时,气指程度较为严重。对于4个不同截面形状的气道设计,带有肋板的气道设计比不带肋板的气道设计制品气指程度有所减轻。

The effects of the gas channel geometry in the gas-assisted injection molding on the gas fingering defect of the part made of polystyrene were investigated. The semicircular gas channels with different radiuses, the rectangular gas channels with different section width-to-length ratios, and the four gas channels with different cross section shapes but with same section area were studied. In the case of the semicircular channels, a minimum gas fingering defect was observed when the ratio of the section equivalent radius to the part thickness is in a certain range. For the rectangular channels, the gas fingering defect appears the most severe at a certain definite section width-to-length ratio. For the four gas channels with different section shapes, the channel with ribs appears to be better than that without ribs in respect of the gas fingering defect.