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

这个PFI：空气技术翻译项目专注于翻译一项技术，即延伸式混合元件(EMES)，该技术通过提高单螺杆和双螺杆挤出机的混合和复合能力来改善聚合物挤出。这项技术的应用跨越了现有的塑料配方，并提供了生产需要更复杂混合的新聚合物的能力。EMES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，从而产生性能更好、功能更强、重量更轻的新产品。该项目将为双螺杆挤出机和单螺杆挤出机优化EMES原型。它们的独特之处在于，由于在静止的双曲收缩通道中以伸展为主的流动，它们提供了大大改善的色散混合。初步结果表明，与标准捏合块结构的挤出机相比，纳米复合材料和不相容聚合物共混物的混合情况有了显著改善。这个项目解决了一个关键的技术差距(S)，因为它从研究发现转化为商业应用。啮合式同向旋转双螺杆挤出机(co-TSE)是填充聚合物体系和母粒混合、聚合物熔体均质、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。共混物中的混合作用通常是通过一组捏合块来传递的，这些捏合块对材料和一些但较少的拉伸施加强烈的剪切。由于与伸展流动相比，剪切流动对于弥散混合在能量上是低效的，因此有很大的优化空间。同样，单螺杆挤出机是世界上最广泛使用的挤出机类型，因为即使它们通常是糟糕的混合设备，它们也允许较大的产量。同样，人们非常希望开发具有更好的混合能力的单螺杆挤出机，同时保持其良好的泵特性。在双螺杆挤出机的情况下，EME概念将通过定义允许的最小和最大几何构型进行优化，例如收缩比和长度，从而改善混合，而不会在压降和机器磨损方面造成不必要的损失。这将使人们更好地了解EMES的设计规则，并将其扩展到工业规模的机器。在这个项目的第二阶段，我们建议将EME的概念扩展到SSE，从而显著提高它们的混合能力，同时保持它们优异的熔体泵特性。这种在聚合物共混物和复合材料中实现更精细和可控的结构和形态的能力，以及将SSE转变为高效混合物的能力，同时保持其出色的泵特性，将对实践具有变革性。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。除了准备技术文档外，学生还将参与与潜在客户的电话交谈/会议、会前和会后汇报，从而使他/她第一手熟悉以行业为导向的可交付成果研究、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CWRU工程管理硕士的课程，从而进一步提高他/她发展这些能力的能力。

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.