Screw classifiers screw according to its scope of application can be divided into general screw and special screw, general screw is also known as conventional screw, can process most of the low, medium viscosity of high thermoplastics, crystalline and amorphous civil plastics and engineering plastics, is the most basic form of screw, corresponding to the special screw, for processing with ordinary screw difficult to process plastics; According to the screw structure and its geometric shape characteristics, the rotary shaft two-color injection molding machine manufacturers can be divided into conventional screw and new screw, it is the basic form of the screw, it is the basic form of the screw, for processing plastics difficult to process with ordinary screw.

According to the screw structure and its geometric shape characteristics, it can be divided into conventional screw and new screw, it is the basic form of screw, it is the basic form of screw, used for processing ordinary screw, wave screw, no metering section screw and so on. The effective length of the thread of the traditional screw is usually divided into the feeding section (conveying section), the compression section (plasticizing section), the metering section (homogenizing section), and according to the different properties of the plastic, it can be divided into gradual, mutant and universal types.

① Gradual screw: the compression section is long, the plasticizing energy conversion is slow, and it is mostly used for plastics with poor thermal stability such as PVC. ② Mutant screw: the compression section is shorter, the plasticizing energy conversion is more intense, and it is mostly used for crystalline plastics such as polyolefin and PA. ③ Ordinary screw: universal screw with strong applicability, can adapt to various plastic processing, avoid frequent replacement of screw, which is conducive to improving production efficiency. The length of the ordinary spiral section of the automatic disc injection molding machine is as follows: screw type feeding section (L1) Compression section (L2) homogenization section (L3) Gradual type 25~30%15~20% Mutant type 25~30%15~5%20~25% general type 45~50%30