굴 패각 분말로 제작된 주꾸미 인공산란시설물의 물성특성

Material Properties Evaluation of Artificial Shelter pots for Webfoot Octopus (Amphioctopus fangsiao) Reinforced with Oyster Shell Powder

In plastic manufacturing, inorganic fillers such as calcium carbonate (CaCO3) are commonly used to reduce cost and enhance performance. Oyster shells, primarily composed of CaCO3 and produced in Korea at approximately 30,000 tons annually, offer a sustainable alternative to limestone. This study investigates the use of oyster shell powder as a filler in biodegradable plastic composites for artificial webfoot octopus shelter pots. Composites containing 30–60 wt% shell powder were prepared via melt blending and injection molding and subsequently characterized for their thermal and mechanical properties. The addition of shell powder improved thermal stability and reinforced mechanical strength, with optimal performance observed at 30 wt% loading. At this composition, compressive strength reached 12.35 kN/mm2—far exceeding that of natural a Rapana venosa shells (1.81 kN/mm2)—while density (1.45 kg/L) and heat deflection temperature (90.8 °C) met the standards set by the Ministry of Oceans and Fisheries. Higher filler contents (≥40 wt%) reduced flowability and caused surface d fects, thereby lowering overall strength. These results demonstrate that oyster shell powder is an effective and sustainable filler for biodegradable aquaculture structures, supporting both enhanced material performance and the marine waste within a circular economy framework.