Sustainable manufacturing of composite materials

自20世纪60年代引入以来，先进的碳纤维复合材料已被用于开发特定应用的结构，与其金属前辈相比，其重量减少了30%。对航空航天工业的潜在好处是显而易见的，因为减少20%的飞机质量可以节省大量的燃料成本，并减少二氧化碳排放量，其规模相当于从流通中减少一千辆汽车。复合材料也改变了飞机的制造方式。大型结构元件通过自动纤维铺放机逐层组装，然后在大型加压高压釜中固化。对零件进行最终无损检测，确保它们没有缺陷，并为装配过程的下一步做好准备。虽然在过去的二十年里取得了许多进展，但复合材料结构的制造工艺还远远不够完善。如今，约66%的原材料在材料沉积阶段因预浸料切割或超过保质期的预浸料卷而浪费。在部件的最终修整期间产生更多固化的复合材料废料。此外，如果在最终部件中检测到过多的制造缺陷，则部件的拒收会显著增加总体制造报废率。复合材料制造废物和产品在其使用寿命结束时大多被填埋，这对环境有害。这项工作的目标是开发新的工艺，材料系统和设计工具，以降低制造成本，改善复合材料制造对环境的影响。我们建议使用过程建模工具，以减少设计阶段的风险，以及经常产生大量废料的试错量。我们将开发一种自动化的材料检测方法，以减少可能导致最终零件缺陷的材料工艺变化。我们将实施新的加热模具概念，其中来自工具的热量直接传递到零件，以实现额外的节能。最后，我们将把预浸料废料从切边机切下的废料或过期的卷材转化为增值产品。这项工作的结果将使加拿大中小企业对其生产线进行成本效益高的改造，以适应新的环境条例，并扩大其市场份额。

Since their introduction in the 1960’s, advanced carbon fibre composites have been used to develop application-specific structures featuring as much as a 30% reduction in weight compared to their metallic predecessors. The potential benefit to the aerospace industry is clear, as a reduction of 20% of an aircraft mass yields significant fuel cost savings and reduces CO2 emissions on a scale equivalent to removing a thousand cars from circulation. Composites have also changed how aircrafts are built. Large structural elements are assembled layer by layer with automated fibre placement machines and then cured in large pressurized autoclaves. Final nondestructive inspection of the parts ensure that they are free of defects and ready for the next step of the assembly process. While many progresses have been made in the last twenty years, the manufacturing process of composite structures is far from perfect. Today, about 66% of the raw material is wasted during the material deposition phase from prepreg cutting or prepreg rolls that have exceeded their shelf life. More cured composite waste is generated during the final trimming of the part. Furthermore, if excessive manufacturing defects are detected in the final component, rejection of the part can significantly increase the overall manufacturing scrap rate. Composite manufacturing waste and products at the end of their useful life are mostly landfilled, which is detrimental for the environment. The objective of this work is to develop new processes, material systems and design tools in order to reduce manufacturing costs and improve the environmental impact of composite materials manufacturing. We propose the use of process modelling tools to reduce risks during the design phase and the amount of trial-and-error that often generates very high volumes of scraps. We will develop an automated material inspection method in order to reduce material process variability that can cause defects in the final part. We will implement new heated tooling concepts in which the heat from the tool is transferred directly to the part to realize additional energy savings. Finally, we will transform prepreg wastes from ply-cutter offcuts or expired rolls into a value added product. The results of this work will provide Canadian SMEs with cost-effective modifications to their production lines in order to cope with new environmental regulations and to augment their market share.