Extruder and Melt Pump Enhance Melt Mixing Ability and Output
Generally, using the existing conventional single screw extruder in series with the melt pump, conservatively estimates, the output will also increase by 10% - 15%. According to rough estimation method, the output can be increased by 5%-7% for every 7 MPa reduction in the head pressure. Another reason for the increase of SP unit output is also the main reason, that is, because the screw used in SP unit no longer needs to provide metering and high pressure, the screw structure design principle can be significantly different from the conventional screw. Its basic ideas and main characteristics are as follows: to improve the melt plasticizing ability of screw as much as possible; to reduce the melt conveying section to 1/2-1/3 of the conventional measuring section; to lengthen the melt section, such as increasing the length of the separated screw section, increasing the length or number of shear and mixing components; to adopt a smaller compression ratio or to increase the groove depth of the melt conveying section; Section groove depth is deeper than conventional screw and so on. The screw with the above characteristics is called "SP screw" or "non-metering section screw". The production of SP screw is increased mainly because of its enhanced melting and plasticizing ability. Only when SP screw is used in series with melt pump can it show higher benefit.