When the screw rotates to push the extruded material


Processing method - Inlay or cast a layer of alloy stee […]

Processing method - Inlay or cast a layer of alloy steel material inside the base of ordinary carbon steel or cast steel. It not only meets the material requirements of the barrel, but also saves precious metal materials.
1 Bushing barrel: The barrel is fitted with a replaceable alloy steel bushing. Save precious metal, the bushing can be replaced, increasing the life of the barrel. But its design, manufacturing and assembly are more complicated.
2 Casting barrel: A layer of approximately 2 mm thick alloy is centrifugally cast on the inner wall of the barrel, and then the required inner diameter of the barrel is obtained by grinding. The alloy layer is well bonded to the base of the barrel, and the bonding along the axial length of the barrel is relatively uniform, has no tendency to peel off, does not crack, has excellent sliding performance, and has high wear resistance. long life.

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 bimetal layered barrels. 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.