半结晶聚合物薄壁微制品微注塑成型流动特性、制品形态结构演化及其与力学性能的关系

The morphological and structure of the plastic parts has an important influence on the properties and performance of the parts. At present,the evolution mechanism of the morphology and structure of the micro-injection molded parts is not clear. The morphology and structure of the parts are formed under the special thermal history and mechanical history in the molding process. For the thin micro injection molded parts of semi-crystalline polymer,the thermal history and shearing history of the melt in the micro-cavities were proposed as a bridge in this subject, and the research works started from the flow characteristics and molding mechanism in micro-injection molding process. Velocity field of the melt in micro-cavities can be measured using the visualization measurement techniques,temperature field and pressure field can be measured by the temperature and pressure sensors. The thermal history and shearing history of the melt in the cavities can be obtained accordingly. The formation mechanism of shearing history and thermal history of the melt in different scale cavities under different processes would be investigated, and the morphology and structure and mechanical properties of the corresponding micro parts would be characterized. A comprehensive analysis of the influence of thermal history and shearing history of the melt in the cavities under various processing conditions on the morphology and structure of the parts would be conducted. Mechanism of morphology and structure evolution of the micro-injection molded parts will be obtained;The mechanical properties of the micro injection molded parts and the influnce of the morphology and structure of the parts on mechanical properties will be analyzed. The relationship of the micro-injection molding process - - the shearing history and thermal history - - the morphology and structure of the parts - - mechanical properties of the parts will be established. The research of this subject has important scientific significance to perfecting and establishment of flow and heat transfer theories, morphology evolution theories of micro injection molding, and the relative basic mechanics theories under micro scale.

塑料制品的形态结构对制品的性能有重要的影响，目前微注塑制品的形态结构演化机理尚不明确。制品形态结构是在成型过程中的热历史和力历史作用下形成的。针对半结晶聚合物薄壁微注塑制品,本课题提出以熔体的热历史和剪切历史为桥梁，从微注塑充填过程的流动特性及成型机理入手，采用可视化量测技术测量熔体在微型腔中的速度场、温度场和压力场，分析获得熔体经历的热历史和剪切历史；研究不同工艺下熔体在不同尺度型腔中的剪切历史和热历史的形成机制，并对相应制品的形态结构和力学性能进行表征；全面分析各种情况下熔体经历的热历史和剪切历史及对制品形态结构的影响,获得微注塑制品形态结构演化机理；分析微制品的形态结构对力学性能的影响，建立微注塑成型工艺- - 熔体剪切历史和热历史- - 制品形态结构- - 制品力学性能之间的关系。课题的研究对完善和建立微注塑成型流动传热理论、结晶形态演化理论及相关微尺度力学基础理论具有重要的科学意义。

塑料制品的形态结构对制品的性能有重要的影响，制品形态结构是在成型过程中的热历史和力历史作用下形成的。本项目针对半结晶聚合物薄壁微注塑制品, 建立了微注塑成型中熔体流场测量的可视化实验平台和方法，研究分析了微注塑成型中聚合物流动和传热的规律，以熔体的热历史和剪切历史为桥梁，从微注塑充填过程的流动特性及成型机理入手，采用数值模拟与可视化量测技术结合，分析获得不同工艺下熔体在不同尺度型腔中经历的热历史和剪切历史；对相应制品的形态结构和力学性能进行了表征，系统分析了不同热历史和剪切历史下制品的形态结构和对应的力学性能，分析获得微注塑制品形态结构演化机理；分析微制品的形态结构对力学性能的影响，获得了微注塑成型工艺、尺度——熔体剪切历史和热历史——制品形态结构——制品力学性能之间的关系。课题的研究对完善和建立微注塑成型流动传热理论、结晶形态演化理论及相关微尺度力学基础理论具有重要的科学意义。同时对调控工艺参数以控制制品形态结构、提高微注塑制品性能质量提供理论基础和具有重要的指导意义。.本项目研究成果已发表学术论文12篇，其中在国内外重要学术期刊发表论文8篇，均被SCI或EI收录，国际会议论文2篇，国内会议论文2篇。另有3篇期刊论文目前在审、2篇论文正在整理有待发表。申请专利7项，其中发明专利3项，实用新型专利4项，已授权3项；培养研究生13名。.本项目按计划顺利完成了项目的目标。