Mathematical modeling of multi-cereal raw material melt flow in the coextrusion process

A mathematical model of the melt flow of a multi-cereal mixture in an extruder channel has been developed to determine the rational parameters of the coextrusion process. The mathematical model includes the equation of motion and the equation of energy conservation and boundary conditions, as well as the rheological law of the melt flow of the mixture under study. As a result of the calculations, the geometric parameters of the screw, the depth and width of the extruder channel, the average flow rate and the temperature of the extrudate along the length of the working chamber were determined. A comparison of the calculated extrudate temperature Tk = 136.2 °C and its experimental value Tk = 135 °C shows high adequacy. The numerical solution of the mathematical model of the flow of a viscous liquid melt of the studied mixture in the considered section through the extruder channel allows us to establish the nature of the change in the speed and pressure of the extrudate melt. The obtained dependencies formed the basis for the calculation and design of the twin-screw extruder design, each screw of which consists of three zones: the first compression zone, which includes three sections: loading, compression and dosing; decompression-extraction zone, which includes two sections: decompression and extraction; and the second compression zone, which includes two sections: homogenization and injection. The use of a twin-screw extruder will expand the technological capabilities of the extruder for the production of extruded products of various polycomponent compositions; ensure the necessary depth of physicochemical transformations of the components of the processed product due to the regulation of heat supply.