Preparation of Biomimetic Shells from Biomass Based on Selective Laser Sintering Technology

Shells, a type of food waste, present a notable challenge in achieving high-value applications in the environmental sector owing to their complex compositions, limited recycling applications, and the environmental impact of improper disposal. This study conducts a comparative analysis of the mechanical properties of five types of natural shells: veined red snail, mussel, oyster, scallop, and green willow clam. Shell powders and polylactic acid (PLA) were used as the inorganic and organic components of shells, respectively. The laser sintering mechanism for forming these components was explored, resulting in the fabrication of five biomimetic shells. Results showed that the flexural strength decreased in the order of veined red snail > mussel > scallop > green willow clam > oyster. The flexural strength values of laser-sintered specimens made from five shell powder/PLA composites corresponded closely to those of their respective shells, with values of 8.6, 8.1, 7.6, 6.9, and 6.1 MPa. These values exceeded those of pure PLA specimens. Furthermore, the compressive load capacity of 3D-printed biomimetic veined red snail parts, 3D-printed biomimetic mussel parts, 3D-printed oyster parts, 3D-printed biomimetic scallop parts, and 3D-printed biomimetic green willow clam parts reached 76.69%, 19.10%, 5.57 times, 26.66%, and 70.46%, of the load capacities of the natural shell counterparts, respectively.