Generally speaking, the screw barrel of an injection molding machine can be divided into a feeding section, a compression section, and a homogenizing section (also called a metering section). (Note: The ratio of the three sections of different screws is different, the depth of the screw groove is different, and the transition form of the screw bottom diameter is different.)
Description of the feeding section: The depth of the spiral groove in this section is fixed, and its function is to be responsible for preheating and plastic solids conveying and pushing. It must be ensured that the plastic begins to melt at the end of the feed section.
Compression section description: This section is a tapered screw sulcus tooth depth. Its functions are melting, mixing, shear compression and pressurization of plastic raw materials. The plastic will completely dissolve in this section, and the volume will shrink. The design of the compression ratio is important.
Description of the homogenization section: This section is a fixed depth of the screw groove. Its main functions are mixing, melt transfer, and metering. It must also provide sufficient pressure to maintain the uniform temperature of the melt and stabilize the flow of the molten plastic.
Screw is an important part of injection molding machine. Its role is to transport, compact, melt, stir and apply pressure to the plastic. All this is done by the rotation of the screw in the barrel. When the screw rotates, plastic will cause friction and mutual movement between the inner wall of the barrel, the bottom surface of the screw groove of the screw, the advance surface of the screw edge, and plastic and plastic. The forward movement of plastic is the result of this combination of movements, and the heat generated by friction is also absorbed to increase the temperature of the plastic and melt the plastic. The design structure of the screw will directly affect the extent of these effects.