Recycling catfish bone for additive manufacturing of silicone composite structures

As a notable commercial aquaculture species, channel catfish ( Ictalurus punctatus) in US faces challenges including the global market competition and enhanced feed costs. Since fish bone waste is a major source of calcium and hydroxyapatite, re-utilization gives birth to several advanced products in the development of animal feed, fertilizers, and nutrition supplements. Recent research findings introduce fish bone powder (FBP) reinforcement in Fused Deposition Modeling (FDM) of plastic composites. However, FBP so far has not been widely utilized for Direct Ink Writing (DIW) 3D printing of silicone composite. In this paper, catfish bone waste has been recycled and processed with a thermal procedure. FBP reinforced silicone composite structures have been developed and manufactured using low-viscosity DIW 3D printing. Morphological and chemical structures of FBPs were analyzed and compared before and after calcination. The rheological and mechanical characterization have indicated the potential of calcinated FBP in advancing the silicone composites. With 0%–50% weight percentages of FBP, composite samples can be designed to get any specified mechanical response (0.5–1.4 MPa in 50% tension strain and 150–550 N in 30% compression strain). The shape holding, overhang, and dimensional accuracy of FBP reinforced silicone composites in single (DIW) and dual (FDM + DIW) 3D printing processes have been demonstrated and summarized. With appropriate adjustments, this FBP-based 3D printing technology can be applied to byproduct recycling of all the US food-fish species, poultry, and livestock.