PFI:AIR - TT: Extensional Mixing Elements for Improved Dispersive Mixing in Extrusion Operations

PFI:AIR - TT：用于改善挤出操作中分散混合的延伸混合元件

• 批准号: 1640680
• 负责人: Joao Maia
• 金额: $ 19.95万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1640680&HistoricalAwards=false
• 关键词: PFI; AIR; TT; Extensional; Mixing

This PFI: AIR Technology Translation project focuses on translating a technology, extensional mixing elements (EMEs), that improves polymer extrusion by improving the blending and compounding ability of both single- and twin-screw extruders. The application of this technology spans existing plastic compounding as well as providing the ability to produce new polymers that require more complex mixing. The application of EMEs will improve the extrusion process and will allow new classes of polymers to be designed and brought to market leading to new, better performing, functional, lightweight products. The project will result in prototype EMEs optimized for both twin- and single-screw extruders. These are unique in that they provide much improved dispersive mixing due to the extension-dominated flow through stationary hyperbolically contracting channels. Preliminary results have shown significant improvement in the mixing of nanocomposites and immiscible polymer blends by comparison with standard kneading block-configured extruders. This project addresses a critical technology gap(s) as it translates from research discovery toward commercial application. Intermeshing co-rotating twin-screw extruders (co-TSE) are the equipment of choice for compounding of filled polymer systems and masterbatches, polymer melt homogenization, modification and blending mainly because of their good distributive and dispersive mixing capabilities. The mixing action in co-TSEs is usually imparted via sets of kneading blocks, which impart intensive shear on the material and some, but less, extension. Since shear flows are energetically inefficient for dispersive mixing by comparison with extensional flows, there is much room for optimization. Similarly, single-screw extruders are the most widespread type of extruder worldwide because even though they are typically poor mixing devices, they also allow for large throughputs. Again, it is highly desired to develop single-screw extruders with improved compounding ability, while maintaining their good pump characteristics. In the case of twin-screw extruders, the EME concept will be optimized by defining the minimum and maximum geometrical configurations admissible, e.g., contraction ration and length, which lead to improved mixing without an undue penalty in pressure drop and machine wear and tear. This will allow a better understanding of the design rules of the EMEs and perform upscaling to industrial-sized machines. In the second phase of this project, we propose to expand the EME concept to SSEs and thus improve significantly their mixing ability, while maintaining their excellent melt pump characteristics. This ability to achieve much finer and controlled structures and morphologies in polymer blends and composites TSEs and the transformation of SSEs into efficient compounders while maintaining their excellent pump characteristics will be transformational for the practice.The project will involve one graduate student who will develop first-hand knowledge of how to interact with top-level manufacturing companies. Besides preparing the technical documents, the student will participate in phone conversations/meetings with the potential customers, pre-meetings and post meeting debriefs, thus imparting him/her with first-hand familiarity with industry-directed research with deliverables, product development, project management and the ability to navigate high pressure situations. In addition, the student will have a tailored plan of studies, which will include courses from the CWRU Masters in Engineering Management, thus furthering his/her ability to develop these competencies.

该PFI：AIR技术翻译项目的重点是翻译一项技术，即延伸混合元件（EME），该技术通过提高单螺杆和双螺杆挤出机的共混和配混能力来改善聚合物挤出。该技术的应用涵盖了现有的塑料复合，并提供了生产需要更复杂混合的新聚合物的能力。EME的应用将改进挤出工艺，并将允许设计新的聚合物类别并将其推向市场，从而产生新的、性能更好的、功能性的、轻质的产品。 该项目将导致原型EME优化双螺杆和单螺杆挤出机。这些是独特的，因为它们提供了大大改善的分散混合，由于扩展主导的流动通过静止的双曲收缩通道。初步结果表明，与标准捏合块配置的挤出机相比，纳米复合材料和不混溶的聚合物共混物的混合有显着改善。 该项目解决了从研究发现到商业应用的关键技术差距。啮合同向旋转双螺杆挤出机（co-TSE）是填充聚合物体系和色母粒配混、聚合物熔体均化、改性和共混的首选设备，主要是因为其良好的分布和分散混合能力。co-TSE中的混合作用通常通过捏合块组赋予，捏合块组赋予材料强烈的剪切和一些但较少的延伸。由于剪切流与拉伸流相比，分散混合的能量效率低，因此有很大的优化空间。类似地，单螺杆挤出机是全世界最广泛使用的挤出机类型，因为即使它们通常是较差的混合装置，它们也允许大的吞吐量。同样，高度期望开发具有改进的配混能力同时保持其良好的泵特性的单螺杆挤出机。在双螺杆挤出机的情况下，EME概念将通过定义可允许的最小和最大几何构型来优化，例如，收缩比和长度，这导致改进的混合，而不会在压降和机器磨损方面造成不适当的损失。这将有助于更好地理解EME的设计规则，并将其升级到工业规模的机器。在该项目的第二阶段，我们建议将EME概念扩展到SSE，从而显着提高其混合能力，同时保持其出色的熔体泵特性。这种在聚合物共混物和复合材料TSE中实现更精细和受控的结构和形态的能力，以及将SSE转化为高效的混合物，同时保持其优异的泵特性，将是实践的转型。该项目将涉及一名研究生，他将发展如何与顶级制造公司互动的第一手知识。除了准备技术文件外，学生还将参加与潜在客户的电话交谈/会议，会前和会后汇报，从而使他/她熟悉行业导向的研究成果，产品开发，项目管理和驾驭高压情况的能力。此外，学生将有一个量身定制的学习计划，其中将包括从CWRU工程管理硕士课程，从而进一步提高他/她的能力，发展这些能力。