Recyclability of Earth-Fiber Materials for 3D Printing (2024-08)¶

Advanced fabrication using additive manufacturing is predominantly focused on cementitious and petroleum-based materials, which have a high carbon footprint and low recyclability potential. As a result, development processes, which are heavily experimental for digital fabrication technologies, result in large quantities of spoil and waste. Novel bio- and geo-genic materials that are readily available, minimally processed, and non-toxic, may provide a critical solution to low-carbon, fully recyclable 3D printing futures. These materials may prove critical not only in the construction industry but also in educational mock-ups and research design and development. This paper presents the first comprehensive assessment of the viability of fully recyclable earth-fiber composites for 3D printing, developed at scale for pedagogical purposes in design. Using a micro-to-macro material design approach, the developed earth-fiber-bio composites were assessed for their structural behavior and recyclability potential. Once fully dried, the designed artifacts were rehydrated and utilized as a paste to create recycled 3D-printed specimens. A comparison of compressive strength and printability was performed for newly prepared and recycled earth-fiber materials. The selected composite, made with hemp fibers, clay soils, and biopolymer additives, was then used in a week-long hackathon with a 3D Potter Scara Elite large-scale printer to produce real-scale designs while instrumentalizing the circularity potential of the materials. As a final demonstration, the fabricated designs were showcased in an exhibition on the university campus grounds, after which they were reprocessed and reused for further fabrication.