微注塑成型中熔体充模流动的影响因素研究

针对微注塑成形中因熔体的质量小、所含的热量少及流动通道截面尺寸微小等特点所带来的不同于宏观注塑成形中的熔体流动问题及影响因素,进行了理论分析及相关试验研究。结果表明,微注塑成形中,模具温度是影响微尺度下熔体流动的重要工艺因素,且随通道截面尺寸的减小而逐渐增大;而壁面滑移对微小熔体流动行为的影响,也随通道尺寸的减小而增大。此外,模具排气、通道表面粗糙度等因素的对微注塑成形的影响也不可忽视,而表面张力等因素的影响可被忽略。

Study on the influence factors on the filling flow for polymeric melt in micro injection molding

For the characteristics of micro injection molding, such as a few of the quantity, the thermal heating and the section dimension of channels, the sequentially emerging melt flowing behaviors and the influence factors differed from those in the conventional injection molding are theoretically analyzed and the related experimental researches are carried out. The investigation results indict that in micro injection molding the mold temperature is the important factor influencing on the melt flowing in microscale, and the influence degree is increased with the decrease of the section dimension of channels as well as the effect of the wall slip on the flowing behaviors of the micro melt. In addition, the effects of the factors such as the vent of micromold, the surface roughness of channel etc., on the micro injection molding cannot be neglected. On the contrary, the other factors such as the surface tension,the inertia force, etc, may be ignored.