사출구 구조와 탄산가스 주입이 옥수수 압출성형물의 물리적 특성에 미치는 영향

The objective of this study was to determine the effect of die geometry and carbon dioxide injection on the physical properties of extruded corn flour. The extrusion variables were melt temperatures of 95 and 110°C; carbon dioxide gas flow rates of 0, 100 and 200 mL/min. In die dimension, the length was 2 or 5 mm and the tapered angle of die hole was 57 or 95°. The specific mechanical energy (SME) input was the lowest at 110°C melt temperature, 200 mL/min carbon dioxide gas flow rate and 3.36×10^-10 m³ die constant. The sectional expansion of corn flour extrudate was higher at 57° than that at 95° tapered angle. Also, the sectional expansion was increased with increasing carbon dioxide injection flow rate from 0 mL/min to 200 mL/min. The specific length was increased with increasing carbon dioxide injection rate. The density, breaking strength and apparent elastic modulus were lower in the low die constant. Extruded corn flour at 95° tapered angle had more pores than one at 57° tapered angle.