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Residence time distribution in twin‐screw extruders
Author(s) -
Todd David B.
Publication year - 1975
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760150607
Subject(s) - materials science , residence time distribution , distribution (mathematics) , residence time (fluid dynamics) , residence , mechanics , composite material , demographic economics , mathematics , engineering , geotechnical engineering , mathematical analysis , physics , flow (mathematics) , economics
Twin screw extruders are finding increased usage in reacting and devolatilizing applications. Using self‐wiping profiles, the twin screws fulfill the requirement that there be no “dead” or “unmixed” zones. Agitator design must be chosen with care so that a reasonable balance can be obtained between forwarding rate, surface‐generation rate, vapor passageway, power, and axial mixing. Techniques have been developed for measuring residence time distributions and characterizing axial flow behavior. The method also permits direct determination of the holdup in starved barrel applications. Data on residence time distribution are presented for 4‐in. diameter twin screw equipment with a variety of rotor configurations.