Plasticizing mechanism of injection screw

‌ Injection screw is an important part of the injection molding machine, its main functions include conveying, compacting, melting, stirring and pressurizing plastics. This process is achieved through the rotation of the screw in the barrel, the plastic in the process of progress continues to absorb the heat of the external heat source, at the same time due to the shear action of the screw to produce shear heat, the plastic gradually melt. The rotation and propulsion of the screw not only make the plastic move forward, but also generate heat through friction, further increasing the temperature of the plastic until it reaches a molten state. The molten plastic is injected into the mold cavity under the push of the screw to complete the plasticization process.

Specifically, the plasticization mechanism of injection molding screws can be divided into the following steps:

‌ feed section ‌ : The plastic enters the barrel through the hopper, and the screw rotation brings it in and pushes it forward along the screw.
‌ melting stage ‌ : In the melting stage, the plastic is gradually melted under the double action of thermal energy and shear stress. The rotation and propulsion of the screw make the plastic subject to strong shearing in the barrel, and the temperature rises until it reaches a molten state.
‌ homogenizing section ‌ : In the homogenizing section, the molten plastic is further mixed evenly through the stirring action of the screw to ensure the quality and performance of the plastic.
In addition, the design and parameters of the injection screw (such as the speed of the screw, the temperature of the barrel, etc.) have an important impact on the plasticizing effect. By optimizing these parameters, plasticizing efficiency and product quality can be further improved. ‌ ‌