微孔发泡注塑成型工艺对表面气泡破裂的影响

Effect of Microcellular Foaming Injection Molding Process on Surface Bubble Breakup

通过正交实验设计分析了工艺参数对微孔发泡注塑成型过程中熔体黏度、壁面剪切应力的影响。结果表明,熔体黏度随着注塑速率和超临界流体含量的增大而降低,壁面剪切应力随着注塑速率和超临界流体(SCF)含量的增大而减小。结合气泡破裂模型得到:壁面处气泡临界破裂尺寸随着注塑速率和SCF含量的增大而减小,而熔体温度对熔体黏度、壁面剪切应力及气泡破裂形变的影响不大。

To obtain the effect of process parameters on melt viscosity and bulk shear stress in microcellular foaming injection molding by orthogonal experimental design. The research results show that the melt viscosity reduces with the increase in the injection rate and the percentage of supercutical fluid （SCF）. The wall shear stress increases with the increase in the injection rate and the SCF percentage. Combined with the bubble breakup model, it is showed that the critical bubble breakup size decreases along with the increase of the injection rate and the SCF percentage. At the same time, the effect of melt temperature on the surface bubble breakup behaviors is less significant.