Sustainable approach to the revalorization of crab shell waste in polymeric filament extrusion for 3D printing applications

This study concentrates on the potential recycling and cleaner conversion of marine industry wastes such as crab shell wastes as particles in the development of novel polylactic acid (PLA) biocomposite filaments for 3D printing applications. The filaments were extruded with varying extrusion process parameters such as extruder speed (20, 30, 40, and 50 mm/s), extrusion temperature (170, 175, 180, and 185°C), environmental conditions (no, air, and water medium), and crab shell particle concentration (0, 1, 5, 7, and 10%). The quality of the extruded biopolymeric composite filaments is accessed in terms of filament tensile strength and average diameter. The results concluded that the optimized conditions for achieving better tensile strength and average filament diameter will be an extrusion speed of 40 mm/s, extrusion temperature of 180°C, environmental condition of water medium, and crab shell particle concentration of 7%. The extrudability and wind ability results show that the PLA/crab shell (7%) composite has passed the quality checks which makes it suitable for large-scale production. For the proof of concept of converting the filament to product development, the extruded filaments like neat PLA and PLA/crab shell (7%) composite filaments are used for the 3D printing process via the fused filament fabrication (FFF) method. The various mechanical properties such as tensile, flexural, compression, impact strength, and contact angle measurement were made on the novel 3D-printed composites. The results proclaimed that the addition of crab shell particles of 7% has shown the maximum tensile and flexural strength of 38.09 MPa and 28.43 MPa respectively than the neat 3D-printed PLA polymer composite. And also, the 3D-printed PLA/crab shell (7%) composite shows a decrease in the contact angle of 29°. This indicates that the developed novel composite material is more suitable for the development of biopolymeric components. It is recommended that the use of 3D printing with recyclable biomaterials is more suitable for the development of bio-scaffold and bone graft material preparation in a cleaner and sustainable way.