Single Screw Extrusion Theory
The effective length of the single screw is generally divided into three sections which are defined to the diameter, screw pitch and screw depth.
The last thread of feeder is called transportation section where the materials are required to be preheated and squeezed at pressure instead of plasticization. It is proved that the materials are actually the solid plugs rather than the loose bodies which are reported by the previous theory. As the result, the function the single screw extruder is to convey the materials.
When it comes to the second section, that is compression section, the volume of the spiral groove is gradually become smaller and smaller and the temperature reaches to the degree of the plastics. After that it has been compressed to the original statement according to the compression ratio--- 3:1. It may changes sometimes.
The third section is called measurement section, where the temperature keeps the plastics degree or a little higher, just as precise and quantitative as the metering pump conveying to melt materials in order to provide to the top.
The last thread of feeder is called transportation section where the materials are required to be preheated and squeezed at pressure instead of plasticization. It is proved that the materials are actually the solid plugs rather than the loose bodies which are reported by the previous theory. As the result, the function the single screw extruder is to convey the materials.
When it comes to the second section, that is compression section, the volume of the spiral groove is gradually become smaller and smaller and the temperature reaches to the degree of the plastics. After that it has been compressed to the original statement according to the compression ratio--- 3:1. It may changes sometimes.
The third section is called measurement section, where the temperature keeps the plastics degree or a little higher, just as precise and quantitative as the metering pump conveying to melt materials in order to provide to the top.
