Distributive mixing characteristics of a Dulmage-type screw for a single-screw extruder: Experimental and numerical evaluation

Autor: Koichi Kimura, Yasuya Nakayama, Toshihisa Kajiwara
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Chemical Engineering Journal Advances, Vol 7, Iss , Pp 100137- (2021)
Druh dokumentu: article
ISSN: 2666-8211
DOI: 10.1016/j.ceja.2021.100137
Popis: The mixing characteristics of a Dulmage-type screw, a kind of distributive mixing element, in single-screw extrusion were investigated. To evaluate the mixing ability, a melt-mixing extrusion experiment diluting a masterbatch with its base polymer and a numerical polymer melt flow simulation were performed. The experimental and simulation results revealed that the screw mixing performance oscillates with respect to N/Q, where N and Q are the screw rotation speed and the mass flow rate, respectively. The simulation results demonstrated that the screw mixing progresses by repeating the circumferential mixing in the ring zones and the radial redistribution in the fin zone slots. Based on these mixing kinetics, the number of swirling movements in the fin zone slots that determines the radial redistribution was found to govern the N/Q dependence of the global mixing. This study provides an essential guide for optimizing Dulmage-type screw mixing operations and Dulmage-type screw structure improvements.
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