Caractérisation et lois rhéologiques d’élastomères chargés à basse température pour la simulation du procédé d’extrusion

Abstract : The present work deals with the characterization of the rheological behaviour of two rubbers filled with carbon black in a range of temperature encountered in extrusion (90°C to 40°C) and the modelling of the single screw extrusion process. The rheological characterization of the two rubbers shows behaviour totally different. The synthetic SBR rubber and SBR compounds filled with carbon black (with different amounts, from 16 to 33 wt%) showed a flow curve that can be divided in two stable parts (branch I and branch II) separated by a plateau. The occurrence of wall slip, low in branch I and important in branch II has been highlighted. The second rubber of the study, natural rubber, showed a different behaviour with a strain hardening due to the occurrence of a strain induced crystallization. The flow curve can be thus divided in two different parts: the first part without strain hardening and the second part with this phenomenon. The existence of a characteristic crystallization time, reduced by the shear rate, has been evidenced. By analysing data respectively on branch I for SBR and without strain hardening for NR, viscosity curves for all tested materials have been defined. General viscosity law have been proposed: for the SBR compound filled with carbon black valid in the range of temperature from 40°C to 90°C and for NR in the range of temperature from 50°C to 90°C. The rheological law defined for the SBR compound filled 33%wt with carbon black has been implemented in two different models: 1 D and 3D. Numerical results have been compared to experimental results obtained after experimentations on instrumented single screw extruder. The 1D approach was not sufficient to take into account all phenomena occurring during extrusion process. Then a 3D approach has been developed in order to take into account some effects as side effects and temperature gradients. The presence of the slip phenomenon in the modeling has been proved.
Complete list of metadatas

Cited literature [91 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-01201983
Contributor : Abes Star <>
Submitted on : Friday, September 18, 2015 - 2:28:05 PM
Last modification on : Monday, November 12, 2018 - 10:57:03 AM
Long-term archiving on : Tuesday, December 29, 2015 - 8:42:12 AM

File

2014ENMP0085.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01201983, version 1

Citation

Alice Crié. Caractérisation et lois rhéologiques d’élastomères chargés à basse température pour la simulation du procédé d’extrusion. Mécanique des matériaux [physics.class-ph]. Ecole Nationale Supérieure des Mines de Paris, 2014. Français. ⟨NNT : 2014ENMP0085⟩. ⟨tel-01201983⟩

Share

Metrics

Record views

751

Files downloads

9743