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What is a bimetallic screw barrel?

Update:13 Sep 2018
Summary:

When the screw rotates to push the extruded material fo […]

When the screw rotates to push the extruded material forward, the heat is transferred from the outside of the barrel to the raw material, and the volume of the screw thread groove is gradually reduced, so that the raw material is squeezed, flipped and sheared in the forward movement. After a variety of forces, it is uniformly kneaded and plasticized into a molten state to complete the plasticizing work on the plastic. The application of the structural form of the screw barrel of the injection molding machine is divided into: integral, segmented, bushing, casting, and bimetallic screw barrel. Integral barrel: In the case of injection molding machines and extruders, the most suitable ones are monolithic barrels, especially small and medium-sized models, which basically adopt this type of structure. The barrel is generally used for 38CrMoALA. Moreover, the temperature control is accurate and easy, and the machining accuracy is relatively easy to ensure. Segmented barrel: Mainly used in larger format extruders and exhaust type extruders. Since the total length of the barrel is divided into several sections, the machining of each barrel is convenient, and the temperature control of heating and cooling is relatively large. The rubber screw barrel sorting barrel is generally designed as a one-piece type, and the multi-section combined barrel is rarely used now. In the solid matter delivery theory, it has been discussed how to increase the solid transport capacity problem, mainly from the rational selection of the structural parameters of the screw to analyze the structural parameters, but the improvement of solid transport capacity is not significant, the efficiency is only 20% -40%.