EFFECT OF EXTRUDER DIE NOZZLE SIZE ON CORNSTARCH EXPANSION

Abstract

The article studied the effect of extruder die nozzle configuration on starch expansion index. Conventional cornstarch was extruded through nozzles with different L/D ratios. An EK-40 laboratory extruder was used as an extruder. The coefficient of expansion of the extruded starch during the study increased from 4.5 to 13, with a ratio of length to diameter of the nozzle L/D of the extruder from 2.5 to 3.4. Further, with an increase in the ratio of length to diameter of the nozzle L/D of the extruder from 3.4 to 10.3, the expansion coefficient gradually decreased to 8.5. The backpressure in the extruder barrel was directly proportional to the length to diameter ratio of the nozzle L/D, with the optimum expansion at about 7,1 MPa.