The purpose of this study is to demonstrate the potential of three-dimensional printing technology for the remanufacturing of end-of-life (EoL) composites. This technology will enable the rapid fabrication of environmentally sustainable structures with complex shapes and good mechanical properties. These three-dimensional printed objects will have several application fields, such as street furniture and urban renewal, thus promoting a circular economy model.,For this purpose, a low-cost liquid deposition modeling technology was used to extrude photo-curable and thermally curable composite inks, composed of an acrylate-based resin loaded with different amounts of mechanically recycled glass fiber reinforced composites (GFRCs). Rheological properties of the extruded inks and their printability window and the conversion of cured composites after an ultraviolet light (UV) assisted extrusion were investigated. In addition, tensile properties of composites remanufactured by this UV-assisted technology were studied.,A printability window was found for the three-dimensional printable GFRCs inks. The formulation of the composite printable inks was optimized to obtain high quality printed objects with a high content of recycled GFRCs. Tensile tests also showed promising mechanical properties for printed GFRCs obtained with this approach.,The novelty of this paper consists in the remanufacturing of GFRCs by the three-dimensional printing technology to promote the implementation of a circular economy. This study shows the feasibility of this approach, using mechanically recycled EoL GFRCs, composed of a thermoset polymer matrix, which cannot be melted as in case of thermoplastic-based composites. Objects with complex shapes were three-dimensional printed and presented here as a proof-of-concept.

中文翻译：

---

通过紫外线辅助 3D 打印再制造报废玻璃纤维增​​强复合材料

本研究的目的是展示 3D 打印技术在报废 (EoL) 复合材料再制造方面的潜力。该技术将能够快速制造具有复杂形状和良好机械性能的环境可持续结构。这些三维打印的物体将有多个应用领域，例如街道家具和城市更新，从而促进循环经济模型。为此，使用低成本的液相沉积造型技术挤出光固化和热固化复合油墨，由丙烯酸酯基树脂组成，其中含有不同数量的机械回收玻璃纤维增​​强复合材料 (GFRC)。研究了挤出油墨的流变特性及其可印刷性窗口，以及紫外光 (UV) 辅助挤出后固化复合材料的转化率。此外，还研究了通过这种 UV 辅助技术再制造的复合材料的拉伸性能。发现了 3D 可印刷 GFRCs 油墨的可印刷性窗口。对复合可印刷油墨的配方进行了优化，以获得具有高含量回收 GFRC 的高质量印刷品。拉伸试验也显示出用这种方法获得的印刷 GFRC 具有良好的机械性能。本文的新颖之处在于通过三维印刷技术再制造 GFRC，以促进循环经济的实施。这项研究表明了这种方法的可行性，使用机械回收的 EoL GFRC，由热固性聚合物基质组成，不能像热塑性复合材料那样熔化。具有复杂形状的物体被 3D 打印并在此处作为概念验证呈现。