Papers by Franck Pigeonneau
Chemical Engineering Science
In this short communication, the residence time distribution of molten polymer in a liquefier of ... more In this short communication, the residence time distribution of molten polymer in a liquefier of a material extrusion process is numerically investigated. The Laplace transform is used to easily fit the residence time distribution. As a result, the liquefier can be decomposed into a plug flow and a continuous stirred tank reactor in series. The local mean residence time is also studied numerically to provide information about the flow structure.
Additive manufacturing, Nov 1, 2022
The material extrusion process is investigated by focusing on the geometry of a single strand ext... more The material extrusion process is investigated by focusing on the geometry of a single strand extruded through a printing nozzle and deposited on a substrate of a 3D printer. An experimental protocol is set to determine the width W , and the height H, of a strand. The geometry depends mainly on the nozzle diameter D, the gap between the substrate and the tip of the nozzle g, the extrusion velocity U and the printing velocity V. The relevant parameter to determine W/D and H/g is reduced to one dimensionless parameter equal to (D/g)(U/V). A computational multiphase flow is described using a level set approach and a finite element method. The heat transfer is also taken into account in the set of governing equations. The polymer is considered as a generalised Newtonian fluid. An accurate description of the interface between the polymer and the surrounding air is developed based on an anisotropic remeshing procedure. Two different situations are numerically solved for which: (i) a first case with a g/D ratio less than one and (ii) a second case with a g/D ratio larger than one. In the first situation, the spreading below the nozzle is more or less radial around the vertical axis of the extruder which is not the case in the second situation. The numerical shape geometry is in good agreement with experimental observations. The thermal cooling underlines that the relevant parameters are the perimeter and the area of the strand cross-section and the Péclet number based on the printing velocity. The numerical predictions of W/D and H/g agree with experimental results.
HAL (Le Centre pour la Communication Scientifique Directe), 2004
International audienc
Additive Manufacturing
The material extrusion process is investigated by focusing on the geometry of a single strand ext... more The material extrusion process is investigated by focusing on the geometry of a single strand extruded through a printing nozzle and deposited on a substrate of a 3D printer. An experimental protocol is set to determine the width W , and the height H, of a strand. The geometry depends mainly on the nozzle diameter D, the gap between the substrate and the tip of the nozzle g, the extrusion velocity U and the printing velocity V. The relevant parameter to determine W/D and H/g is reduced to one dimensionless parameter equal to (D/g)(U/V). A computational multiphase flow is described using a level set approach and a finite element method. The heat transfer is also taken into account in the set of governing equations. The polymer is considered as a generalised Newtonian fluid. An accurate description of the interface between the polymer and the surrounding air is developed based on an anisotropic remeshing procedure. Two different situations are numerically solved for which: (i) a first case with a g/D ratio less than one and (ii) a second case with a g/D ratio larger than one. In the first situation, the spreading below the nozzle is more or less radial around the vertical axis of the extruder which is not the case in the second situation. The numerical shape geometry is in good agreement with experimental observations. The thermal cooling underlines that the relevant parameters are the perimeter and the area of the strand cross-section and the Péclet number based on the printing velocity. The numerical predictions of W/D and H/g agree with experimental results.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 19, 2020
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2018
International audienc
Physical Review E, Aug 27, 2013
Physical review fluids, Jul 28, 2016
HAL (Le Centre pour la Communication Scientifique Directe), Nov 16, 2020
Multiphase Science and Technology, 2004
HAL (Le Centre pour la Communication Scientifique Directe), Aug 29, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Jul 3, 2022
Social Science Research Network, 2023
Additive manufacturing, Mar 1, 2023
HAL (Le Centre pour la Communication Scientifique Directe), May 13, 2019
HAL (Le Centre pour la Communication Scientifique Directe), May 21, 2019
Optical Materials Express, Jun 17, 2022
Since its first creation, glass has always fascinated with its optical properties, its ability to... more Since its first creation, glass has always fascinated with its optical properties, its ability to let light through without being invisible. One of the most spectacular achievements of optical glass is the optical fiber for which considerable work has been done to make it as transparent as possible. However, for twenty years, contrary to this quest for transparency, nanoparticles have been inserted into optical fibres. First designed to develop new lasers and amplifiers, the lowest possible particle-induced light scattering then sought has for the last four years, on the contrary, been exacerbated in order to develop new sensors.
Additive manufacturing, Mar 1, 2020
The heating of a polymer in a liquefier of a material extrusion 3D printer is numerically studied... more The heating of a polymer in a liquefier of a material extrusion 3D printer is numerically studied. The problem is investigated by solving the mass, momentum, and energy conservation equations. The polymer is taken as a generalized Newtonian fluid with a dynamical viscosity function of shear rate and temperature. The system of equations is solved using a finite element method. The boundary conditions are adapted by comparison with the previous work of Peng et al. [5] showing that the thermal contact between the polymer and the liquefier is very well established. The limiting printing conditions are studied by determining the length over which the polymer temperature is below the glass transition temperature. This provides a simple relation for the inlet velocity as a function of the working parameters and the polymer properties.
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Papers by Franck Pigeonneau