快速热循环注塑聚合物热粘弹流动和分子构象多尺度多物理场耦合分析

项目名称： 快速热循环注塑聚合物热粘弹流动和分子构象多尺度多物理场耦合分析

项目编号： No.51503078

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 刘继涛

作者单位： 济南大学

项目金额： 20万元

中文摘要： 聚合物过早冷凝、熔体充模和转印能力差是光学制品、微型零件以及超长薄壁件注塑成型面临的主要难题，快速热循环注塑是解决上述问题的有效途径。然而，变模温环境下熔体复杂流动成型的变形机理尚不明确，其工艺过程尚缺乏可靠的理论指导。本项目拟针对快速热循环注塑聚合物热粘弹流动过程开展多尺度模拟和实验研究：基于分子理论建立联系熔体宏观粘弹效应与分子拓扑结构演变的动力学模型；构建能够同时描述熔体宏观流场和大分子链构象变化的聚合物热粘弹流动多尺度模型；实现耦合模具传热的熔体热粘弹流动过程多尺度、多物理场耦合问题的数值模拟；通过多尺度模拟和实验研究，获得模具温度场、熔体流场、温度场、应力应变场以及聚合物大分子链构象状态的变化规律，阐明变模温环境下聚合物热粘弹两相流动过程的成型机理。本项目密切结合快速热循环注塑技术存在的主要科学问题，项目的顺利实施将为其模具设计、塑件设计和工艺参数优化控制奠定理论和技术基础。

中文关键词： 快速热循环注塑；热粘弹流动；分子构象；多物理场耦合；多尺度模拟

英文摘要： Premature condensation, poor filling and replication ability of polymer melts are the main bottlenecks for the production of optical parts, miniature products and ultra-long thin-wall parts in injection molding process. Rapid heat cycle molding technology is an effective way to solve the aforementioned problems. However, the deformation mechanism of polymer melt complex flow under variothermal molding environment is still unclear, and its forming process lack of reliable theoretical guidance. The current project aims to numerically research on the multi-scale behavior of melt thermal viscoelastic flow in rapid heat cycle molding process. A new constitutive model which can connect melt viscoelastic behavior in macroscale and topology changes of polymer molecular chains in mesoscale will be developed by using the molecular dynamics method. The multi-scale model for melt macro filling filed and molecular conformation variation in mecsoscale will be established for melt thermal viscoelastic flow. And the multi-scale multi-field model along with its numerical implementation will be established for the simulation of the thermal viscoelastic two-phase flow process coupled with mold heat transfer. According to the numerical simulation and experiment, the variations of the mold temperature, together with the flow field, temperature field, stress-strain field and molecular conformation for polymer melt will be revealed. As a result, the processing mechanism for melt thermal viscoelastic two-phase filling flow under variothermal molding environment will be elucidated. The current project contacts tightly with the main scientific problems faced by the rapid heat cycle molding technique. Therefore, the smooth implementation of the proposed project can provide theoretical guidance and technical support for the mold design, part design and optimization of process parameters in rapid heat cycle molding process.

英文关键词： Rapid heat cycle molding;Thermal viscoelastic flow;Molecular conformation;Coupled multi-Field ;Multi-scale simulation