What is the plastic injection screw? What are the characteristics of the screw? 
The application of plastic products is closely related to our lives. Injection molding and extrusion molding are currently the most economical and energy-saving processing methods. Among them, the most important key component of plastic plasticizing screw has its own physical characteristics for different plastics, which makes the design of plastic plasticizing screw different. For the design of plastic plasticizing screw, the rule of thumb has been used in the past. The cost is high and the problem is not necessarily solved. Therefore, some details in the design of plastic plasticizing screw are worthy of our discussion and analysis.
Introduction of plastic plasticizing screw
The solid plastic raw material enters the screw channel from the feed hopper. Due to the high-speed rotation of the screw, it produces a shearing effect with the barrel. The plastic raw material is mixed and transported along the screw channel to make the solid The plastic raw material is heated by the electric heating plate outside the melt cylinder and the shear heat generated by the screw, so that the inside of the melt cylinder is heated and melted into a melt state.
The plasticizing screw can be divided into four zones according to its function:

1. Solid conveying zone
This section is connected with the feed hopper, and the plastic solid particles are tightly compressed to form a solid bed, which is subjected to the shearing effect of the melt cylinder. In addition to gradually increasing the temperature of the plastic, the plastic is transported forward.
2. Delay of melting
This section is from the end of the solid conveying area to the area before the formation of the melt pool. Its main feature is that a thin film layer composed of melt is formed on the surface of the solid bed and the melt cylinder. The melt in the film layer is subjected to the melt cylinder. The drag force accumulates in the front screw groove, and the pressure formed at the end of this area is large enough to deform the solid bed, and the accumulation in the front screw groove gradually forms a melting pool.
3. Melting zone
This zone is the end of the melting delay zone until the plastic is completely melted. This zone can be divided into two parts for discussion, one is plastication, and the plasticization mainly comes from the shear effect of the melt barrel, and the other It is melt conveying, which conveys the melt to the melting tank.
4. Melt conveying zone
When all the plastic is completely melted, it starts to enter this section and ends at the end of the plasticizing screw, maintaining a uniform temperature of the melt and stabilizing the flow of the molten plastic.