Twin screw extruder features
The feeding is easy and the extrusion amount is high; the residence time of the material in the twin-screw extruder is short; the exhaust performance is good; the dispersion, homogenization, mixing and plasticizing effect of the material are good; the self-cleaning effect is good; the unit input power output is high The volumetric efficiency is high. PVC plastic plastic profiles are mostly produced by tapered reverse twin-screw extruders.
The tapered reverse twin-screw extruder has the following advantages over the parallel reverse twin-screw extruder: the strength of the screw is high; the front end of the screw is small, the axial force is half of the parallel twin screw, and the service life of the distribution drive gear is parallel. Four times the twin screw; the diameter of the extrusion section is smaller than the diameter of the parallel twin screw; the feed section increases the screw diameter. The counter-rotating twin-screw extruder is suitable for processing hard quinol chloride blends. In twin-screw extruders, the wear of the screw and barrel is much more severe than that of a single-screw extruder. To this end, foreign countries have used metal barrels of high-strength alloy coatings that are resistant to wear and corrosion, and steel rods are used to make screws. After the blasting rod is nitrided, hard chrome or nickel plating is needed at the bottom and the periphery of the screw groove to facilitate material flow and corrosion resistance.
The ribbed top back can be surfacing or wear-resistant alloy or nitriding treatment. It is also one of the effective measures for constant temperature. When the heat carrier is applied, the structure of the flow channel should ensure that the screw temperature is uniform, which is beneficial to eliminate the fluctuation of the material temperature and stabilize the product quality. Excessive screw speed will accelerate the screw. And the wear of the barrel. The twin-screw extruder is suitable for the forming of rigid PVC plastic profiles, and it can efficiently produce high-quality products under the condition of large head resistance. The heating of the extruder is realized by external electric heating. The thermocouple is used to measure and control the temperature. The plastic moves in the screw groove, is deuterated by the external heating and the frictional heat of the plastic rotation, and is extruded into a desired shape through the filter plate or the filter screen and the machine head.