ERI: Fused Filament Fabrication of Thermoplastic-Composite Molds Embedded with Heating Wires for Energy-Efficient Production of Thermoset Composites

作为金属零件的替代品，高性能聚合物复合材料在许多轻质和增强结构应用中具有吸引力。然而，与复合材料制造相关的成本，更具体地说，模具制造和模具加热的广泛成本确实限制了它们的大规模生产。传统的高压灭菌加热模具需要模具组装和相对较长的交货期，这增加了制造成本，并对广泛采用构成了巨大的挑战。该工程研究启动奖(ERI)支持基础研究，以了解热塑性复合材料烘箱外模具的添加制造(AM)，以制造热固性复合材料。这项研究工作将开发和集成一种低成本的工具，该工具能够在非极性溶剂存在的情况下，在熔丝制造(FFF)制造的部件中沉积加热丝，以制造复合模具。如果成功，这种创新将消除作为复合材料制造技术基础的昂贵和能源密集型高压灭菌炉的必要性，并提高美国复合材料模具在全球市场的竞争力。该ERI项目还将吸引不同的学生群体，包括代表人数不足的少数族裔，参与新的制造技术，并提供实践经验，以发展科学、分析思维和领导技能。此外，该团队将与休斯敦墨西哥湾沿岸地区的学区合作开展外联活动，以促进K-12学生在STEM相关领域的职业生涯。本研究的总体目标是建立和了解由短碳纤维增强聚碳酸酯制成的电阻加热丝嵌入烘箱外复合材料模具的AM系统。为了在3D打印过程中嵌入加热丝，该项目将利用固态核磁共振和傅里叶变换红外光谱研究非极性溶剂导致热塑性膨胀的基本原理。这项研究将为双挤出FFF打印机的开发奠定基础，该打印机与电阻加热丝沉积系统集成在一起，为研究加热丝与热塑性塑料之间的相互作用生产复合模具。丝材加热对所制模具温度分布的影响将通过红外热像仪进行表征，并与所制复合材料模具的力学评估相关联。此外，还将对热丝埋模与传统高压罐模具制作的热固性复合材料部件进行定量比较。这项研究的结果有望为节能复合材料制造的嵌入式加热复合材料模具的基于材料挤压的AM产生新的知识。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。

High-performance polymer composites are attractive for many lightweight and reinforced-structure applications as an alternative to metallic parts. However, the associated cost with composite manufacturing, more specifically, the extensive cost of mold-making and mold heating do limit their large-scale production. The traditional autoclave heating of a mold requires tooling assembly and a relatively long lead time, which add up the manufacturing cost and pose significant challenges to widespread adoption. This Engineering Research Initiation (ERI) award supports fundamental research to understand additive manufacturing (AM) of thermoplastic-composite out-of-oven molds to make thermoset composites. The research effort will develop and integrate a lower-cost tool that enables the deposition of heating wires within parts made by fused filament fabrication (FFF), in the presence of a nonpolar solvent, to fabricate composite molds. If successful, such an innovation will eliminate the necessity of costly and energy-intensive autoclave ovens, serving as technological groundwork of composite manufacturing and enhance the U.S. composite tooling competitiveness in the global market. This ERI project will also engage a diverse group of students, including underrepresented minorities, in new manufacturing technologies and provide hands-on experiences to develop scientific, analytical thinking, and leadership skills. In addition, the team will partner with school districts in the gulf coast area of Houston for outreach activities that promote K-12 students to pursue a career in STEM-related fields.The overall goal of this research is to establish and understand a system for AM of resistance heating wire embedded out-of-oven composite molds made of short carbon-fiber reinforced polycarbonate. For embedding heating wires during 3D printing, the project will investigate the fundamentals of thermoplastic swelling due to nonpolar solvents by solid-state nuclear magnetic resonance and Fourier transform infrared spectroscopy. The study will build the basis for the development of a dual-extrusion FFF printer integrated with a resistance heating wire deposition system to produce composite molds for the investigation into the interaction between heating wires and thermoplastics. The effect of wire heating on the temperature profile of the fabricated mold will be characterized by infrared thermography and correlated with the mechanical evaluation of fabricated composite molds. In addition, thermoset composite components made by the heating-wire embedded molds and conventional autoclave molds will be quantitatively compared. The findings of this research are expected to generate new knowledge on material-extrusion based AM of embedded heating composite molds for energy-efficient composite manufacture.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.