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Communication dans un congrès

Phenomenological model of maize starches expansion by extrusion

Abstract : During extrusion of starchy products, the molten material is forced through a die so that the sudden abrupt pressure drop causes part of the water to vaporize giving an expanded, cellular structure. The objective of this work was to elaborate a phenomenological model of expansion and couple it with Ludovic® mechanistic model of twin screw extrusion process. From experimental results that cover a wide range of thermomechanical conditions, a concept map of influence relationships between input and output variables was built. It took into account the phenomena of bubbles nucleation, growth, coalescence, shrinkage and setting, in a viscoelastic medium. The input variables were the moisture content MC , melt temperature T, specific mechanical energy SME , shear viscosity η at the die exit, computed by Ludovic®, and the melt storage moduli E’(at T > T g ). The outputs of the model were the macrostructure (volumetric expansion index VEI, anisotropy) and cellular structure (fineness F) of solid foams. Then a general model was established: VEI = α (η/η 0) n in which α and n depend on T, MC , SME and E’ and the link between anisotropy and fineness was established.
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Communication dans un congrès
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Contributeur : Magalie Prudon <>
Soumis le : lundi 12 décembre 2016 - 15:24:30
Dernière modification le : jeudi 24 septembre 2020 - 17:22:56



Magdalena Kristiawan, Guy Della Valle, Kamal Kansou, Amadou Ndiaye, Bruno Vergnes. Phenomenological model of maize starches expansion by extrusion. ESAFORM 2016, Ecole Centrale de Nantes (ECN). Nantes, FRA. University of Zaragoza - Universidad de Zaragoza (Zaragoza), ESP., Apr 2016, Nantes, France. pp.180002, ⟨10.1063/1.4963605⟩. ⟨hal-01414766⟩



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