Introduction to the structural characteristics of the barrels and screws
1、 The material selection for the barrel screw is 38CrMoAlA, and the structural characteristics of several types of barrel screws are introduced as follows: Differences in conventional, low filler, and high filler structures (1) Geometric shapes and pairing relationships of screw edges and grooves Low CaCO3 content: larger between screw flights High CaCO3 content: The gap between the screw flights should be small, with the aim of improving shear force and increasing plasticization (2) The role of each regional segment. The screw is generally divided into: feeding section, compression section, blocking section, mixing section, exhaust section, and metering section. Feed section: Generally, the screw flights gap in the conveying section is large, resulting in fast conveying. Conversely, it is small. It is also related to the formula and CaCO3 components. Compression, blocking, and mixing: The main impact is on the plasticization ability. If there is no blocking before compression, plasticization can be increased. If there is a blocking, it is not suitable for high calcium. Mixing and compression are set together, usually only suitable for low calcium. Exhaust section: The plasticizing ability of the material can be observed from the vacuum port, which includes granular, powder, and strip shapes. Measurement section: If the screw flights clearance is large, the extrusion is fast, otherwise it is small. Introduction to the structural characteristics of low and high packing: The feeding section, compression, and mixing of the low packing screw are connected together. During machining, the last section of the feeding section has a