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，与金属材料相比，其重量减轻了30%。这对航空航天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，减少的二氧化碳排放量相当于从流通中减少了1000辆汽车。复合材料也改变了飞机的制造方式。大型结构元件由自动纤维放置机逐层组装，然后在大型高压灭菌器中固化。对零件进行最后的无损检查，确保它们没有缺陷，并为下一步的装配过程做好准备。虽然在过去的二十年中取得了许多进展，但复合材料结构的制造工艺还远远不够完善。今天，大约66%的原材料在预浸料切割或预浸料卷超过保质期的材料沉积阶段被浪费。在零件的最后修整过程中产生了更多固化的复合废料。此外，如果在最终部件中检测到过多的制造缺陷，则该部件的废品率会显著增加。复合材料制造废弃物和产品在其使用寿命结束时大多被填埋，这对环境是有害的。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来降低设计阶段的风险和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，以实现额外的能源节约。最后，我们将把预浸料废料从切纸机边角料或过期卷料转化为增值产品。这项工作的结果将为加拿大中小企业提供具有成本效益的生产线改造办法，以便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.