Influence of Non-Newtonian Behaviour on the Processing Characteristics of Wall-slipping Materials
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Abstract
So far it has been assumed that when describing the flow process in single-screw extruder, the melt will be wall-adhering. Using certain process conditions, however, some materials such as PVCs, high-molecular PEs, elastomers, polymer suspensions, ceramic materials and food products become wall-slipping [1 to 4].
During simulation of the flow process using the Finite Element Method (FEM), the boundary condition of “wall-adhering” was substituted for “wall-slipping”. The numeric results refer to one-dimensional, non-Newtonian, isothermal flow processes and have been evaluated accordingly.
Since the wall-slipping properties are dependent on critical shear stress, the influence of non-Newtonian behaviour on wall shear stress is illustrated by investigating the barrel and screw root surface. Conclusions with regard to wall-slipping properties may be drawn from the resulting upper and lower limits.
The effect of wall slippage on pressure/throughput behaviour is examined along with the various velocity profiles, resulting from different compression ratios, dimensionless critical shear stress, material-related constants and screw configuration.
© 2003, Carl Hanser Verlag, Munich
Articles in the same Issue
- Editorial
- Fourteenth in a Series: Heinz List and his Family of Continuous Mixing Machines
- Screw Extrusion
- Influence of Non-Newtonian Behaviour on the Processing Characteristics of Wall-slipping Materials
- Neural Network Approach to Density Control of Rigid PVC Foam in Extrusion Process
- Investigation of Melting Phenomena in Modular Co-rotating Twin Screw Extrusion
- Mixing and Compounding
- Montmorillonite Co-intercalated with Octadecylamine and Stearic Acid by Low Temperature Melting and its Influence on PP Nanocomposites
- Analysis and Optimization of Kenics Static Mixers
- Electret-thermal Analysis of Polymer Blends
- Effects of Zinc Fatty Acids on Improved Polymer Processing for Critical Extrusions
- Flexible Sheet Molding Compound (SMC) Using Aliphatic Polyester as Cross Linker
- Co-Extrusion
- Investigation of the Interfacial Instabilities in the Coextrusion Flow of PE and PS
- Film
- Radiant Heating of Plastics: Application to Film Blowing Processes
- Injection Molding
- Measurement and Prediction of Temperature Distribution in an Injection Molding Cavity
- A Study of Processing Conditions on the Properties of Diffraction Optical Elements by Injection/Compression Molding Process
- Flow Behavior of Sandwich Injection Molding in Sequential and Simultaneous Injection
- Rotational Molding
- Rotational Moulding and Powder Processing of Natural Fibre Reinforced Thermoplastics
Articles in the same Issue
- Editorial
- Fourteenth in a Series: Heinz List and his Family of Continuous Mixing Machines
- Screw Extrusion
- Influence of Non-Newtonian Behaviour on the Processing Characteristics of Wall-slipping Materials
- Neural Network Approach to Density Control of Rigid PVC Foam in Extrusion Process
- Investigation of Melting Phenomena in Modular Co-rotating Twin Screw Extrusion
- Mixing and Compounding
- Montmorillonite Co-intercalated with Octadecylamine and Stearic Acid by Low Temperature Melting and its Influence on PP Nanocomposites
- Analysis and Optimization of Kenics Static Mixers
- Electret-thermal Analysis of Polymer Blends
- Effects of Zinc Fatty Acids on Improved Polymer Processing for Critical Extrusions
- Flexible Sheet Molding Compound (SMC) Using Aliphatic Polyester as Cross Linker
- Co-Extrusion
- Investigation of the Interfacial Instabilities in the Coextrusion Flow of PE and PS
- Film
- Radiant Heating of Plastics: Application to Film Blowing Processes
- Injection Molding
- Measurement and Prediction of Temperature Distribution in an Injection Molding Cavity
- A Study of Processing Conditions on the Properties of Diffraction Optical Elements by Injection/Compression Molding Process
- Flow Behavior of Sandwich Injection Molding in Sequential and Simultaneous Injection
- Rotational Molding
- Rotational Moulding and Powder Processing of Natural Fibre Reinforced Thermoplastics
