SBIR Phase II: Increasing Maker Manufacturing through 3D Printing with Reclaimed Plastic & Direct Drive Pellet Extrusion

熔丝制造（FFF）为快速成型、大规模定制和低成本制造提供了巨大的好处。这为进一步开发该技术创造了一个未开发的机会，以支持价格敏感和新兴市场的小批量工业制造。采购当地可用的原材料，并将其直接作为颗粒或刨花送入打印机，而不是挤压长丝，对于制造商和最终用户来说，在降低成本和提高原型制作能力方面都是非常有利的。当3D打印大型工业对象（定义为18英寸立方）时，这种创新的好处被放大了。首先，大规模产品的生产意味着更大的时间和材料成本投入（颗粒成本约为长丝成本的1/10）。颗粒挤出的重要性的第二个原因是它解决了打印速度更快的需要。最后，对挤出热成型塑料的依赖限制了可用的打印库和混合材料以设计新配方的能力。凭借在大规模3D FFF打印领域的专业知识，re:3D提出发展在第一阶段开发的原型颗粒3D打印机，通过将直接驱动颗粒挤出技术与针对再生塑料优化的研磨机、干燥机和进料系统相结合，能够满足所有这些需求。re:3D打算利用对聚对苯二甲酸乙二醇酯（PET）和聚丙烯（PP）的材料要求进行的第一阶段研究，进一步优化颗粒打印机，使其能够接受回收的片状和非均匀颗粒。聚对苯二甲酸乙二醇酯（PET）和聚丙烯（PP）是全球最可用的两种再生塑料。这项工作将包括开发持续干燥输入材料的能力，以及易于清洁和在材料之间切换的能力。还将开发一种新的机制，用于将更大体积的颗粒和/或薄片送入平台，并配备必要的控制装置。一旦完成，该公司将通过IC2在德克萨斯州以及波多黎各进行试点，波多黎各是一个拥有复杂供应链的岛屿领土，与波多黎各科学研究信托基金确定的废物流/合作伙伴一起。第二阶段开发的新硬件集成解决方案将被整合到第一阶段的原型平台中，该原型平台利用了密歇根理工大学（MTU）在第一阶段进行的验证和材料测试工作，为FFF 3D打印机修改直接驱动回收机器人的工作，以及开源固件和软件研究。为了确保卓越，原型将使用MTU的设备进行广泛的测试，回收PP和PET打印，用于铸造，模具生产和承载应用。一旦商业可扩展性的原型设计在MTU得到验证并进行现场测试，所有的进展都将公开记录并共享，以便尽快将解决方案套件扩展到多个平台。该硬件将在项目完成后作为集成3D打印解决方案和独立硬件进行商业销售，因为它具有超越笛卡尔3D打印系统的应用潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Fused Filament Fabrication (FFF) offers tremendous benefit for rapid prototyping, mass customization, and low cost fabrication. This creates an untapped opportunity to develop the technology further to support low volume industrial manufacturing for price sensitive and emerging markets. The ability to source locally available raw material and feed it directly as pellets or shavings into a printer rather than extruded filament is extremely advantageous for both manufacturer and end user in regards to reducing cost and increasing capabilities in prototyping. The benefits of this innovation is amplified when 3D printing large-scale industrial objects (defined as 18 inches cubed). First, the production of large-scale products represent a larger investment of time and material costs (pellets are ~ 1/10th the cost of filament). A second reason for the importance of pellet extrusion is it addresses the need to print faster. Finally, a dependence on extruded thermoform plastics limits the available library for printing and the ability to mix materials to engineer new formulations. With domain expertise in large-scale 3D FFF printing, re:3D proposes to evolve a prototype pellet 3D printer developed under Phase I to be able to address all of these needs by coupling direct drive pellet extrusion technology with a grinder, dryer and feeding system optimized for reclaimed plastics. re:3D intends to leverage Phase I research conducted on material requirements for polyethylene terephthalate (PET) and polypropylene (PP), two of the most available reclaimed plastics worldwide, to further optimize the pellet printer to be able to accept reclaimed flake as well as non uniform pellets. This effort will include developing the ability to consistently dry the input materials and to easily clean and switch between materials. A novel mechanism for feeding larger volumes of pellets and/or flake into the platform will also be developed with the requisite controls. Once complete, the company will pilot the solution in Texas through IC2 as well as in Puerto Rico, an island territory with a complicated supply chain, in conjunction with waste streams/partners identified by the Puerto Rico Science & Research Trust. The new hardware integration solutions developed in Phase 2 will be incorporated into the Phase I prototype platform which leveraged Michigan Technological University's (MTU) prior work conducting validation and materials testing in Phase I, prior work modifying direct drive recyclebots for FFF 3D printers, and open source firmware and software research. To ensure excellence, prototypes will be extensively tested using MTU's facilities with reclaimed PP and PET in prints to be used for casting, mold production and load bearing applications. Once the prototype design for commercial scalability has been validated at MTU and field-tested, all progress will be openly documented and shared in an effort to scale the solution suite to multiple platforms as quickly as possible. The hardware will be sold commercially after completing the project as both an integrated 3D printing solution and also as independent hardware due to the potential to be applied beyond Cartesian 3D printing systems.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.