Sustainable three-dimensional printing of waste paper-based functional materials and constructs

Three-dimensional (3D) printing is a prominent technology across various industrial sectors, and its increasing popularity urgently calls for sustainable 3D printing materials. However, the availability of such materials remains under exploit. Here, we present a low-cost strategy to harnesses waste papers as a feedstock to develop sustainable 3D printing inks. This approach offers a remarkable printability and circular utilisation of biodegradable paper wastes to produce 3D printed constructs, with desired mechanical properties and shape stability for high temperature applications. Our constructs can be efficiently recycled into inks for reprinting, and our method can be applied to various types of waste papers. By employing multi-material printing, our approach can be extended to produce multi-coloured constructs, security information printings, and mechanically appealing designs. This strategy offers an innovative and sustainable solution that addresses the need for repurposing paper wastes, which would otherwise end up in landfills, while concurrently reducing the reliance on virgin plastics for 3D printing.