Screw Heating and Cooling

In some cases, screw cooling is used to improve the pressure-generating capability of the screw. The screw is cooled all the way into the metering section. The colder screw surface freezes the polymer close to the screw or, at least, significantly increases the viscosity of the polymer melt close to the screw surface. This reduces the effective channel depth of the extruder screw and can result in improved pressure-generating capacity if the screw was cut too deep to begin with. Therefore, if 

Machine Design, Eluid Power Reference Issue (1982) 

Singleton, paper presented at Filtration Society Conference, London, Sept. (1973) 

Filtration of Polymer Melts, VDI PuhUcation, Duesseldorf, Germany (1981) 

Kramer, Motors and Drives for Extrusion Appiications, SPE ANTEC, 268-272 (1999) 

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