what is the working principle of food extruder?

The working principle of food extruder：

The working principle of the extruder is actually relatively simple. As we mentioned in the overview of the extruder, the extruder uses mechanical energy to convert thermal energy to provide kinetic energy, usually using the extrusion propulsion of the extruder's non-equidistant non-standard screw system. The gas in the material is discharged and quickly filled with the material, and the material is backflowed by the shear force, which increases the pressure in the machine chamber. It becomes a gel state with flowing properties. When the material is extruded to the outlet, the pressure instantly changes from high pressure to normal pressure, and from high temperature to normal temperature instantaneously, resulting in the rapid evaporation of water from the tissue structure. The friction between the materials fully mixes, extrudes, heats, glues, and gelatinizes to produce tissue changes. The original structure is destroyed, and numerous microporous structures are formed inside. Then, through the cutting device, the puffed food is formed after cutting and cooling.