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Wet granulation of cohesive powders : Rheology, growth mechanisms and granule strength

Chitu, Toma Mihai. Wet granulation of cohesive powders : Rheology, growth mechanisms and granule strength. PhD, Institut National Polytechnique de Toulouse, 2009

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Official URL: http://ethesis.inp-toulouse.fr/archive/00001025/


This study is dedicated to the understanding of the wet granulation process in high shear mixers. A systematic study has been carried out that allows the investigation of the influence of operating conditions, technology and physico-chemical properties of the starting materials. This investigation is achieved by morphological, rheological and mechanical characterization methods. By linking recorded torque curves during the granulation process to granule growth kinetics, microscope characterizations and to the end-granule properties granulation outcome prediction becomes possible. The characterization of the mechanical properties has been done at two scales: at the granule bed scale the bulk wet mass consistency has been determined on a mixer torque rheometer, at the granule scale single dry granule direct compression tests were carried out. This approach gives complementary information allowing better description of the torque curves directly related to the wet mass properties and the competition between static and viscous forces conditioning the dry end granule quality. The factors investigated in this study are: the effect of fill ratio, impeller speed, chopper presence and design, mixer design, binder physico-chemical properties and formulation properties for binary water-soluble / water insoluble powder mixtures.

Item Type:PhD Thesis
Uncontrolled Keywords:
Institution:Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Laboratory name:
Research Director:
Oulahna, Driss and Hemati, Mehrdji
Deposited On:21 Nov 2012 13:05

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