Ordinary single screw extruders are also known as three-stage screw extruders. When the material moves forward along the screw, it undergoes changes in temperature, pressure, viscosity, etc. According to the changing characteristics of the material, single screw barrel the screw can be divided into three segments in the effective length, that is, the feeding section (solid conveying section), the melting section (compression section), and For the homogenization section (metering section), the effective length of the three sections is determined according to the screw diameter, the pitch, and the groove depth.
Conventional full-thread three-stage screw can be divided into equidistant deepening screw, constant depth variable pitch screw and variable depth variable pitch screw according to the change of thread lift and groove depth. However, due to processing problems, the widely used ordinary screw is etc. The screw is deeper.
The first commercial co-rotating twin-screw extruder was born in 1939. The widely used modular twin-screw extruders were first introduced in 1953 by the ZSK series produced by Werner & Pfleiderer. The co-rotating twin-screw extruder consists of the main parts of the extrusion system, the feeding system, the transmission system, the heating and cooling system and the control system.
By combining various threaded components, all co-rotating twin-screw extruders have the functions of feeding, melting, mixing, venting, building pressure and conveying to achieve material conveying, plasticizing, shearing, venting, building pressure and extrusion. Wait for various processes. The structure and function of the co-rotating twin-screw extruder are similar to those of a single-screw extruder, but there are significant differences in the working principle.