GOALI: Development of Advanced Molding Technology for Polymer Micro-/Nano-Fabrication

目标：开发聚合物微纳制造先进成型技术

• 批准号: 0084919
• 负责人: Ly James Lee
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0084919&HistoricalAwards=false
• 关键词: GOALI; Development; Advanced; Molding; Technology

This Grant Opportunities for Academic Liaison with Industry (GOALI) research project is to investigate thermoplastic polymer-based molding technologies, i.e. high speed/ high pressure (thin wall) injection molding, and micro-embossing, because of their great potential for low cost mass production. In high speed/high pressure (thin wall) injection molding, the polymer melt may flow under a pressure twice as much as in conventional injection molding, and the shear rate can be more than 10 times higher. Current commercial simulation codes which are typically used to evaluate moldability and cycle time do not accurately predict mold filling at these extremely high pressures and shear rates. An experimental data base of the high shear rate and high pressure rheology of polycarbonate will be created and used as input in a commercial software called C-MOLD. The effect of high shear stresses on mold wear and 'molded-in' stresses will also be investigated in detail. C-MOLD will be used to simulate the molding of micro-scale features. The simulation software is capable of predicting flow patterns, pressures and shear stresses on the mold surface. In micro-embossing, the plan is to carry out detailed thermorheological study around the glass transition temperature of selected polymers. The molding cycle will be designed according to the rheological behavior of polymers, instead of arbitrarily chosen molding temperatures. The thermorheology results will also be used in FEM simulation to calculate the stress distribution in the mold and in the molded polymer product. Predicted shear stresses on the micron scale mold features will be correlated with the experimentally observed level of mold wear and 'molded in' stresses. The simulations and experimental results (pressures, temperatures, shear stresses, fill time, and cooling time) will also be used to design a process window as a function of feature size/aspect ratio, mold material, and processing conditions. The goal is to develop an efficient mass production method with cycle time similar to or less than that in conventional injection molding and embossing.

这个学术联络与工业（GOALI）研究项目的资助机会是研究基于热塑性聚合物的成型技术，即高速/高压（薄壁）注塑和微压花，因为它们具有低成本大规模生产的巨大潜力。在高速/高压（薄壁）注射成型中，聚合物熔体的流动压力可能是常规注射成型的两倍，剪切速率可能高出10倍以上。目前通常用于评估可塑性和周期时间的商业模拟代码不能准确预测在这些极高的压力和剪切速率下的模具填充。将创建一个关于聚碳酸酯高剪切速率和高压流变性的实验数据库，并将其作为C-MOLD商业软件的输入。高剪切应力对模具磨损和“模内”应力的影响也将进行详细的研究。C-MOLD将用于模拟微尺度特征的成型。该仿真软件能够预测模具表面的流动模式、压力和剪应力。在微压印中，计划是围绕选定聚合物的玻璃化转变温度进行详细的热流变研究。成型周期将根据聚合物的流变行为来设计，而不是任意选择成型温度。热流变学结果也将用于有限元模拟，以计算模具和成型聚合物产品中的应力分布。微米尺度模具特征上的预测剪切应力将与实验观察到的模具磨损水平和“模内”应力相关。模拟和实验结果（压力、温度、剪切应力、填充时间和冷却时间）也将用于设计工艺窗口，作为特征尺寸/长宽比、模具材料和加工条件的函数。目标是开发一种有效的批量生产方法，其周期时间与传统注塑和压花相似或更短。