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壁面滑移在聚合物熔体注塑成型过程对熔体充模流动行为具有显著的影响.本文基于对超声辅助微注塑加工机理的研究,分析了超声振动对微尺度型腔中熔体壁面滑移的作用方式.结合聚合物熔体壁面滑移方程和超声对熔体壁面滑移的影响机理,阐明了不同情况下的壁面滑移理论模型.采用毛细管流变仪研究了超声振动作用下的聚合物熔体的壁面滑移行为,通过分析壁面滑移的临界剪切应力变化,明确了超声振动作用下的熔体壁面滑移行为对微尺度型腔充模情况的影响.研究结果表明,超声辅助微注塑过程中,超声作用下的微尺度型腔中熔体壁面滑移的临界剪切应力降低或变为零,壁面滑移速度随剪切应力增加而增加,不同剪切速率时超声作用下的熔体黏度均明显降低,进而提升了熔体对微尺度型腔的充模能力并改善了微塑件的成型质量.
The wall slip has a significant influence on the melt flow behavior during melt injection molding process.Based on the study of ultrasonic assisted micro-injection molding process, the effects of ultrasonic vibration on melt wall slip in micro-scale cavity .According to the influence mechanism of polymer melt wall slip equation and ultrasonic wave on the melt wall slippage, the theoretical model of wall slippage under different conditions is clarified.Using capillary rheometer to study the effect of ultrasonic vibration The effect of ultrasonic vibration on the surface sliding behavior of the melt is analyzed by analyzing the critical shear stress changes of the wall slippage, In the auxiliary micro-injection process, the critical shear stress of the melt wall sliding in the micro-scale cavity under ultrasonic action decreases or becomes zero, the wall slip velocity increases with the increase of the shear stress, and the ultrasonic action at different shear rates Under the melt viscosity were significantly reduced, thereby increasing the melt on the micro-scale cavity filling ability and improve the quality of micro-plastic molding.