When the feed extruder sees the material level indicator on the silo indicating that the material level has reached the lowest level, it begins to prepare for shutdown. Do not stop the feeding auger and conditioner at this time. When the host current drops to the no-load current, Stop the feeding auger and conditioner. The raw materials of the feed extruder are evenly fed into the screw extrusion chamber from the feeder. The space volume of the extrusion chamber gradually becomes smaller along the forward direction of the material, and the expansion force on the material gradually increases.
At the same time, the movement of materials in the extrusion cavity is accompanied by strong shearing, rubbing and friction. Sometimes, if necessary, an electric heating chip can be installed outside the puffing chamber to assist heating. As a result of this combined effect, the temperature of the material rises sharply, and the starch in the material is gelatinized. The entire material becomes a molten plastic colloid. At the moment when the material is discharged from the extrusion die hole, the pressure suddenly drops to 0.1Mpa, the water quickly turns into steam and increases the volume, causing the material volume to expand rapidly. The water vapor further evaporates and escapes, causing the material moisture content to decrease. At the same time, the temperature It also dropped quickly.
