Extruder screw design principle and its impact on extrusion effect?

1. Extruder screw design principle
The design principle of the extruder screw mainly revolves around its spiral shape and rotational motion. The screw is usually composed of one or more spiral blades, which rotate in the barrel to push the material from the feed port to the discharge port. During the pushing process, the rotation of the screw and the heating of the barrel work together to gradually soften, melt and evenly mix the material.
Specifically, the design of the screw includes parameters such as its diameter, pitch, and helix angle. The selection of these parameters directly affects the conveying efficiency, heating uniformity and mixing effect of the material. For example, a larger pitch can increase the conveying speed of the material, but may affect the heating uniformity; a smaller pitch is conducive to uniform heating, but may reduce the conveying efficiency.
2. The impact of the extruder screw on the extrusion effect
Material conveying efficiency: Parameters such as the screw's rotation speed, pitch and helix angle directly affect the material conveying efficiency. A well-designed screw can ensure that the material is conveyed quickly and stably in the barrel, thereby improving production efficiency.
Heating uniformity: The rotation of the screw and the heating of the barrel work together to gradually soften and melt the material in the barrel. A properly designed screw can ensure that the material is evenly heated in the barrel, avoiding local overheating or overcooling, thereby improving product quality.
Mixing effect: The spiral shape and rotational motion of the screw help to mix the material. By adjusting the parameters of the screw and the structure of the barrel, the material can be fully mixed in the barrel, thereby improving the uniformity and stability of the product.
Extrusion pressure: The rotation of the screw and the pushing of the material will generate a certain extrusion pressure. A properly designed screw can ensure the stability and controllability of the extrusion pressure, thereby avoiding fluctuations and abnormal phenomena during the extrusion process.
The design principle of the extruder screw and its influence on the extrusion effect are key factors in the performance of the extruder. By reasonably designing the parameters and structure of the screw, the material conveying efficiency, heating uniformity, mixing effect and extrusion pressure can be optimized, thereby improving the production efficiency and product quality of the extruder. At the same time, in practical applications, it is also necessary to select a suitable screw design according to specific production requirements and material characteristics to achieve the best production effect.