Circularity of thermoplastic ComposIte wound stRuCtUres through innovative materiaL design, peeling-based disAssembly and Re-winding

热塑性复合材料缠绕可以制造出特别适用于运输部门的轻质储罐。然而，对这些由嵌在聚合物基质中的连续纤维制成的有价值的带子进行经典回收而不进行下行循环，是一个重大的技术和经济挑战。为了保持复合材料的价值，使用终点处理应该保持纤维的连续性，以最大限度地提高力学性能，并保持嵌入在基质中的纤维，以简化重复使用。最近的实验结果表明，基于剥离的拆卸能够达到这些目标，并强调了层间性质对回收材料质量的决定性作用。在这些成果的基础上，该项目的目标是通过创新的材料设计、基于剥离的拆卸和使用整体设计重复使用的胶带再加工，实现热塑性复合材料缠绕结构的材料循环性。将研究两种创新的设计策略：(A)以材料为中心的设计，包括在专用的热机械载荷下调整磁带表面，以获得所需的界面性能；(B)以结构为中心的缠绕设计，包括避免相邻层的剥离不利的纤维嵌套；与两种创新的拆卸策略相结合：(I)超声波辅助剥离；(Ii)在低温或高剥离速率下引起层与层界面的脆化。剥离的胶带将在缠绕过程中重复使用。机械性能将在制造、剥离和重复使用胶带材料后确定。将开发一个多物理、多尺度的模拟工具，对不同过程中涉及的机制进行模拟。最后，对所调查的策略的环境足迹进行了比较。

Thermoplastic composite winding enables the manufacturing of lightweight tanks particularly suited for the transportation sector. Nevertheless, a classical recycling without downcycling of these structures made of valuable tapes made of continuous fibers embedded in a polymeric matrix is a major technical and economical challenge. In order to retain the value of the composite, the end-of-usage processing should preserve the continuity of the fibers to maximize the mechanical properties and maintain the fibers embedded in the matrix to simplify reuse. Recent experimental results have demonstrated the ability of peeling-based disassembly to reach these goals and have highlighted the decisive role of the interlaminar properties on the quality of the recovered material. Building on these results, the aim of the project Circular² is to enable material circularity of thermoplastic composite wound structures through innovative material design, peeling-based disassembly and tape reprocessing using a holistic design for reuse approach. Two innovative design strategies will be investigated: (A) material-focused design consisting in tuning the tape surface to induce the desired interface properties under dedicated thermo-mechanical loading; (B) structure-focusedwinding design consisting in avoiding peeling-disadvantageous fiber nesting of adjacent layers; in combination with two innovative disassembly strategies: (I) ultrasonic assistedpeeling; (II) peeling at low temperature or high peeling rate to induce an embrittlement of the layer to layer interface. Peeled tapes will be reused in a winding process. Themechanical performance will be determined after manufacturing, peeling and reuse of the tape material. A multi-physics and multi-scale simulation tool will be developed to model the mechanisms involved during the different processes. Finally, the environmental footprint of the investigated strategies will be compared.