摘要
微尺度通道中的高聚物熔体流动行为与宏观熔体流动有许多不同。基于对微注塑成型中的熔体充模流动特性的理论分析,建立了微小通道中熔体流动的表面张力模型,并以不同的表面张力系数和不同接触角,对矩形微通道中的熔体流动速度分布进行了数值模拟。结果表明,接触角小于90°时,熔体在通道壁面附近具有最大速度;接触角大于90°时,熔体在壁面处具有最大速度。无表面张力时,熔体填充流动所需时间明显长于有表面张力时的填充时间,即表面张力对微小通道中的熔体流动具有促进作用。
The behavior of polymer melt in micro scale is different from that in macroscopic scale in many aspects.Based on the theoretical analysis of flow characteristics in filling flow of micro injection molding,the melt flow model of surface tension in micro channels was developed.The distribution of melt flowing velocity in rectangular cross-section micro-channel was simulated with different surface tension coefficients and various contact angles.The results indicate that the melt flow maximum speed occurs near the wall of micro channel when the contact angle is less than 90° while when the contact angle is more than 90° the melt flow maximum speed remains in the wall.The melt filling time required without surface tension is significantly larger than that with surface tension,that is to say that surface tension can promote the melt filling flow in micro channels.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2009年第12期153-157,共5页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(50275020)
"十一五"国家科技支撑计划重点项目(2005BAF04B13)
关键词
微注塑成型
熔体流动
表面张力
数值模拟
micro injection molding
melt flow
surface tension
numerical simulation
