The close relationship between screw barrel and plastic

‌ There is a close relationship between the screw and the barrel and the plastic, they play a vital role in the processing of plastics. ‌
The screw is the core component of injection molding machines and extruders, and its main functions include conveying, compacting, melting, stirring and pressurizing plastics.
The heat generated by friction is absorbed and used to raise the plastic temperature and melt the plastic. The structure of the screw directly affects the degree of these effects, according to the different plasticizing quality, the screw design has a separation type screw, a barrier type screw or a flow type screw.

The barrel also plays an important role in the plasticizing process of plastics, providing the power for the advance and mixing of plastics, which comes from the relative rotation of the screw and the barrel. According to the different shapes of the plastic in the screw groove, the screw is generally divided into a solid conveying section (feeding section), a melting section (compression section), and a homogenizing section (metering section).

The material, processing technology, hardness and wear resistance of the screw and barrel are directly related to the service life and product quality of the equipment. The screw and barrel of the regular plastic recycling granulator are made of alloy steel, which are manufactured by multi-stage processes such as tempering, finishing, nitriding, inlaid with wear-resistant alloy, quenching and polishing to increase durability.

In addition, the clearance between the screw and the barrel is also an important design parameter, which directly affects the output and processing performance of the extruder. Too small clearance will increase the wear of the screw and the barrel, while too large clearance will lead to an increase in leakage flow and a decrease in production. Therefore, in the design of the extruder, it is necessary to consider the gap between the screw and the barrel from various factors, and select the appropriate gap value to ensure the best performance of the extruder.

In summary, the close relationship between the screw and the barrel and the plastic is reflected in the fact that they work together to achieve the plasticization, transportation and molding of plastics, while their material, structure and clearance design directly affect the performance of plastic processing equipment and product quality .