1. Injection screw diameter ratio and compression ratio is relatively small;
2. The screw of the screw is homogenized;
3. The feeding section of the injection screw is longer and the homogenization section is shorter;
4. Injection screw head structure, with a special form.
5. Injection screw work, the plasticizing capacity and melt temperature will change with the axial displacement of the screw.
Injection molding machine screw according to its adaptability to the plastic, can be divided into general screw and special screw, general screw, also known as conventional screw, can handle most of the low, medium viscosity of the thermoplastic, crystalline and non-crystalline civilian plastic and Engineering plastics, is the most basic form of the screw, and its corresponding special screw, is used to process with ordinary screw difficult to process the plastic; according to the screw structure and its geometric characteristics, can be divided into conventional screw and new screw, conventional screw Also known as the three-stage screw, is the basic form of the screw, the new screw form there are many kinds, such as separate screw, shunt screw, wavy screw, no measuring section screw.
Conventional screw The effective length of the screw is usually divided into feeding section (conveying section), compression section (plasticizing section), measuring section (equalization section), according to the different nature of plastic, can be divided into gradient type, mutant type and universal screw.
Gradient screw: Compression section is longer, plastic energy conversion when the ease, and more for the thermal stability of PVC and other poor plastic.
Mutant screw: Compression section is shorter, plastic energy conversion is more intense, and more for polyolefin, PA and other crystalline plastic.
Universal screw: adaptability of the general-purpose screw, can adapt to a variety of plastic processing, to avoid frequent replacement screw, is conducive to improving production efficiency.