Measurement and modelling of wall friction in the ram extrusion of stiff microcrystalline cellulose-based pastes
| Autor: | M.P.F. Sutcliffe, H.C. Ayton, P. Müller, J. Schäfer, S.L. Rough, D.I. Wilson |
|---|---|
| Přispěvatelé: | Wilson, DI [0000-0003-3950-9165], Apollo - University of Cambridge Repository |
| Rok vydání: | 2020 |
| Předmět: |
business.product_category
Materials science General Chemical Engineering Paste 02 engineering and technology Slip (materials science) Modelling Physics::Fluid Dynamics chemistry.chemical_compound 020401 chemical engineering Rheology 0204 chemical engineering Composite material Wall slip Extrusion Conical surface 021001 nanoscience & nanotechnology Microcrystalline cellulose chemistry Solid mechanics Die (manufacturing) Computer Science::Programming Languages 0210 nano-technology business Body orifice |
| DOI: | 10.17863/cam.57003 |
| Popis: | Simulation of paste extrusion requires knowledge of the material–wall interactions and bulk deformation behaviour. A systematic approach to decoupling these is presented for a stiff paste, comprising microcrystalline cellulose/calcium carbonate/water, employing three different experimental configurations to separate paste-wall friction from bulk rheology. The bulk yielding behaviour was identified from ram extrusion testing with orifice dies, while wall friction was characterised using the twin-die extrusion apparatus reported by Bryan et al. [ 1 ]. Further extrusion tests with square and conical entry dies featuring various die land lengths provided data for comparison with simulations. The wall friction exhibited non-linear Navier slip with negligible pressure dependency: this relationship was included within a solid mechanics-based simulation of ram extrusion with ABAQUS. The estimate of the plastic yield stress from orifice die testing was refined using simulations of flow through square-entry dies and predicted the extrusion pressure for conical-entry dies with reasonable accuracy. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|