Structured Filaments for High Performance 3D Printed Plastic Objects

这笔赠款将支持研究，这些研究将为3D打印的一种常见方法提供与原料设计有关的新的基本知识，为改进塑料部件提供指导，使其能够从快速成型转化为制造。加法制造从数字计算机模型生成几乎任何形状的近净形状物体，对于开发对国家生产力至关重要的新制造方法至关重要。添加制造通常被称为3D打印，它为个人消费者提供了大规模定制的革命性可能性，因此Fit在人体工程学上是完美的。然而，几乎所有塑料部件的添加剂制造工艺都会导致部件的固有缺陷，使其劣于传统制造的塑料。这笔赠款支持基础研究，通过对一种称为熔丝制造的3D打印的原料进行可扩展的改变，为提高添加剂制造的塑料部件的性能提供必要的知识。新材料将与现有打印机兼容，包括向公众提供的消费类打印机，但将在获得与所需尺寸更匹配的部件和更好的韧性方面实现重大改进。随着医疗保健的应用，塑料部件的添加剂制造正在增长，以帮助医生规划手术，并为航空航天部件定制颅面修复植入物，以减轻非关键部件的重量。通过提高塑料零件的性能，这项研究将为美国经济和社会带来好处，扩大可添加制造的塑料零件的潜在应用。这项研究涉及制造、材料科学和机械工程等多个学科，将为参与研究的学生提供独特的教育体验。此外，生产的材料将与许多商业3D打印机兼容，包括一些K-12学校的3D打印机，因此，与这些学校的接触将为学生提供一个机会，通过实践方法学习添加剂制造和材料设计。结构长丝的设计是为了克服与挤出聚合物添加剂制造相关的机械性能和尺寸精度之间的内在权衡。通常情况下，由于聚合物链的相互扩散受到温度的限制，印刷过程中存在较差的夹层强度，而提高印刷温度会导致印刷件的流动和变形。这项研究试图克服这一权衡与核-壳结构的原料长丝，其中核提供机械增强，以抑制流动，而壳在较低的温度固化，以提供层间强度。然而，对于添加剂制造中的核壳材料，与材料选择和印刷处理相关的基本要求知之甚少。本研究通过系统的实验研究，填补了核壳聚合物的固化温度、力学性能与相容性之间关系的知识空白。研究团队将建立工艺参数、聚合物的固有材料特性、印刷部件的尺寸精度和机械特性之间的关系，以深入了解基于挤出的塑料对象添加剂制造的局限性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This grant will support research that will contribute new fundamental knowledge related to the design of the feedstock for one common method of 3D printing to provide guidance for improved plastic parts to enable the translation from rapid prototyping to manufacture. Additive manufacturing generates near net shape object of virtually any shape from a digital computer model and is critical to the development of new manufacturing approach essential for the national productivity. Additive manufacturing is commonly called 3D printing and offers revolutionary possibilities in terms of massive customization for the individual consumer, so the fit is ergonomically perfect. However, almost all additive manufacturing processes for plastic parts lead to inherent weaknesses in the parts that make them inferior to traditionally manufactured plastics. This grant supports fundamental research to provide needed knowledge for the development of improved performance of additive manufactured plastic parts through scalable changes in the feedstock for one type of 3D printing called fused filament fabrication. The new materials will be compatible with existing printers, including consumer printers that are available to the general public, but will enable significant improvements in obtaining parts that better match the desired dimensions and with improved toughness. Additive manufacture of plastic parts is growing with applications from healthcare to assist doctors with planning surgery and custom implants for craniofacial restoration to aerospace parts to decrease the weight of non-critical components. Through improving the performance of plastic parts, this research will benefit the U.S. economy and society by extending the potential applications for additively manufactured plastic parts. This research involves several disciplines including manufacturing, materials science, and mechanical engineering, which will provide a unique educational experience for the students involved in this research. Additionally, the materials produced will be compatible with many commercial 3D printers, including those found in some K-12 schools, so outreach to these schools will provide the students with an opportunity to learn about additive manufacturing and design of materials with a hands-on approach. The design of structured filaments is hypothesized to overcome the intrinsic trade-off between mechanical properties and dimensional accuracy associated with extrusion-based polymer additive manufacturing. Generally, there is poor interlayer strength during the print as the interdiffusion of polymer chains is limited by the temperature and increasing the printing temperature leads to flow and deformation of the printed part. This research seeks to overcome this trade-off with a core-shell structure to the feedstock filament, where the core provides mechanical reinforcement to inhibit flow, while the shell solidifies at lower temperature to provide interlayer strength. However, the fundamental requirements associated with the materials selection and the print processing are poorly understood for the core-shell materials in additive manufacturing. This research will fill the knowledge gap on the relationships between solidification temperature, mechanical properties and miscibility of the core and shell polymers through systematic experimental investigation. The research team will establish relationships between process parameters, intrinsic material properties of the polymers, the dimensional accuracy of the printed part, and mechanical properties to provide insights into the limitations of extrusion-based additive manufacturing for plastic objects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.