Numerical simulation on in-mold micro assembly molding process based on viscoelastic thermal fluid structure coupling

doi:10.11949/j.issn.0438-1157.20160767

Abstract

Abstract:

In-mold micro assembly molding technology should be expected to be high efficiency low cost industrialized manufacturing technology of polymer micro-mechanical systems, but how to predict accurately and control precisely thermal-fluid-structure coupling deformation still is its industrialized technical bottlenecks of in-mold micro assembly molding technology. The theoretical prediction model of viscoelastic thermal-fluid-structure coupling deformation in molding process was established based on the boundary constraints of secondary viscoelastic melt filling flow. Research shows that viscoelastic thermal-fluid-structure coupling deformation is controlled by the coupling pressure, viscoelastic supporting normal stress, viscous friction drag shear stress on the micro assembly interface and anti-deformation stiffness, and will reduce with increasing of melt injection speed. The PMMA anti-deformation stiffness in near-surface local region exceeded 393 K will be drastically reduced, which is the key control factor of thermal-fluid-structure coupling deformation reducing with melt injection speed increasing.

Key words: viscoelasticity, in-mold micro assembly molding, thermal-fluid-structure coupling, numerical simulation, polymers, fabrication

摘要：

模内微装配成型技术有望成为高效低成本产业化聚合物微小机械系统制造技术，而如何准确预测和精确控制热流固耦合变形仍是其工业化的技术瓶颈。为此研究建立了考虑二次黏弹性熔体充填流动边界约束作用的模内微装配成型黏弹性热流固耦合变形的理论预测模型，研究表明热流固耦合变形受控于微装配面所承受的热流固耦合压力、黏弹性支撑正应力、黏性摩擦拖曳剪切应力和微型轴的抗变形刚度，且随成型熔体注射速度提高而减小，而微型轴近表面局部跨越393 K区域的PMMA刚度急剧下降是导致微型轴热流固耦合变形随熔体注射速度增加而减小的主控因素。

关键词: 黏弹性, 模内微装配成型, 热流固耦合, 数值模拟, 聚合物, 加工制造

CLC Number:

TQ320.66

ZHOU Guofa, YANG Peimin, LUO Zhi, JIANG Xiannian. Numerical simulation on in-mold micro assembly molding process based on viscoelastic thermal fluid structure coupling[J]. CIESC Journal, 2017, 68(3): 1129-1137.

周国发, 阳培民, 罗智, 江先念. 基于黏弹性热流固耦合作用的模内微装配成型过程数值模拟[J]. 化工学报, 2017, 68(3): 1129-1137.

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