The manufacturer of single screw extruder tells you from polymer physics that there are three physical states of polymer, namely glass state, high elastic state and viscous flow state. Under certain conditions, these three physical states will undergo interconversion. After the solid plastic is fed into the barrel from the hopper, it advances toward the nose with the rotation of the screw. In this process, the physical state of the plastic is constantly changing. The manufacturer of single screw extruder tells you that according to the change process of the three physical states of the plastic in the extruder and the working requirements of each part of the screw, the screw of the extruder is usually divided into a feeding section (solid conveying zone) and a compression section (melting zone). Zone) and homogenization zone (melt conveying zone). The manufacturer of single screw extruder tells you that for a screw with a conventional gradual screw, the extrusion process of the plastic in the extruder can be described by the basic functions of each section of the screw and the physical state change process of the plastic in the extruder.

1. Feeding section
The manufacturer of single screw extruder tells you that the plastic enters the barrel of the extruder from the hopper, and moves forward due to the friction between the inner wall of the barrel and the surface of the screw under the action of the rotation of the screw. In this section, the function of the screw is mainly to compact the plastic and provide the power for forward transportation. The material still exists in a solid state. Although due to the strong frictional heat, the manufacturer of the single screw extruder tells you that it will be in contact with the inner wall of the barrel when it is close to the end. The plastic in contact has approached or reached the viscous flow temperature, the surface of the solid particles began to stick, but the melting has not yet begun. This area is called the hysteresis area, which refers to the viscous flow state from the end of the solid conveying area to the initial melting.
2. Homogenization section
The single screw extruder manufacturer tells you that the material from the melting section to the per capita homogenization section is a viscous fluid that has been completely melted. Under the resistance of the die of the machine head, part of the backflow of the viscous fluid that is conveyed forward is further mixed and plasticized, and part of it is extruded from the die of the machine head in a quantitative and constant pressure.
From the working principle of the single screw extruder above, it is not difficult to see that the plastic is plasticized in the extruder and squeezed forward. The main power comes from the solid conveying in the feeding section. The uniformity of plasticization is largely due to homogenization. The backflow caused by the structure of the segment and the resistance of the die of the machine head. The single screw extruder manufacturer tells you that there are many new structures in improving the screw mixing structure, but they are often suitable for polymers with good thermal stability, but not suitable for the production of PVC resins. This will not be introduced one by one.