Finite Element Analysis of Mixing in Partially Filled Twin Blade Internal Mixers
-
V. Nassehi
Abstract
Twin blade internal mixers are the main devices used in rubber processing industry to mix natural and synthetic rubbers with carbon black and other compounding ingredients. To facilitate mixing, these internal mixers are always partially filled. Consequently, the flow regime that becomes established inside the mixer is a multiple random free surface flow with moving external boundaries. The stress field associated with this flow regime is usually very uneven. In addition, the flow stream is continuously divided and rejoined by the action of the counter rotating blades. The combination of these complex effects results in the break down, dispersion and distribution of carbon black agglomerates within the rubber matrix. The efficiency of the entire process mainly depends on the geometry of the mixer blades and the operating conditions. Predictive computer modelling offers a very convenient method for the quantitative analysis of mixing process and can be used to design more efficient internal mixers. However, the successful modelling of a complex process such as rubber mixing requires the development and use of sophisticated mathematical algorithms that can take into account its main characteristics. In this respect, a major difficulty is the imposition of the transient boundary conditions in a continuously varying flow domain. In the present paper we describe a robust method which can very effectively resolve this problem. This method is based on the combination of Lagrangian and Eulerian approaches for the modelling of moving boundary flows. We have used this scheme to simulate flow and mixing in the cross-sectional plane of the blades of a tangential rotor internal mixer.
© 1998, Carl Hanser Verlag, Munich
Articles in the same Issue
- Contents
- Contents
- Editorial
- Third in a Series: Pioneers of Polymer Processing Charles Hancock — The First Thermoplastics Processing Innovator
- Internal Mixers
- Finite Element Analysis of Mixing in Partially Filled Twin Blade Internal Mixers
- Screw Extrusion
- Use of Dye Containing Polymeric Microcapsules for Determining Shear Stresses
- Modeling Flow and Fusion of Mixtures/Blends of Polymer Pellets and a Low Viscosity Phase in a Modular Co-rotating Twin Screw Extruder
- Fiber and Film
- Development of High Quality LLDPE and Optimised Processing for Film Blowing
- Molding
- Impregnating Flow of a Rheokinetic Liquid
- Morphology of Injection Molded Polyacetal during Filling
- Crystal Orientation in Injection Moldings of Talc-filled Polyolefins
- Structure and Properties of Injection Moldings of β-Crystal Nucleator-added PP
- Thermal Effects in the Numerical Simulation of the Thermoforming of Multilayered Polymer Sheets
- Measurement and Prediction of Anisotropy in Injection Moulded PP Products
- Rapid Communication
- Gas Penetrations in Symmetrical Tapping Ribs during Gas-Assisted Injection Molding
Articles in the same Issue
- Contents
- Contents
- Editorial
- Third in a Series: Pioneers of Polymer Processing Charles Hancock — The First Thermoplastics Processing Innovator
- Internal Mixers
- Finite Element Analysis of Mixing in Partially Filled Twin Blade Internal Mixers
- Screw Extrusion
- Use of Dye Containing Polymeric Microcapsules for Determining Shear Stresses
- Modeling Flow and Fusion of Mixtures/Blends of Polymer Pellets and a Low Viscosity Phase in a Modular Co-rotating Twin Screw Extruder
- Fiber and Film
- Development of High Quality LLDPE and Optimised Processing for Film Blowing
- Molding
- Impregnating Flow of a Rheokinetic Liquid
- Morphology of Injection Molded Polyacetal during Filling
- Crystal Orientation in Injection Moldings of Talc-filled Polyolefins
- Structure and Properties of Injection Moldings of β-Crystal Nucleator-added PP
- Thermal Effects in the Numerical Simulation of the Thermoforming of Multilayered Polymer Sheets
- Measurement and Prediction of Anisotropy in Injection Moulded PP Products
- Rapid Communication
- Gas Penetrations in Symmetrical Tapping Ribs during Gas-Assisted Injection Molding
