Modeling Solids Conveying in Polymer Extruders
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J. A. Yamamuro
, D. Penumadu and A. Campbell
Abstract
Modeling solids conveyance in a polymer extruder is difficult because it is a highly complex process. The solids are subjected to pressure and temperature gradients from the hopper through a heated section, where it is melted into a liquid over a finite distance. The polymer material possesses shear strength, which causes an anisotropic stress distribution to exist between the down channel pressure and the normal stresses on the flights, barrel and core. A new formulation incorporating anisotropic stress states into an isotropic model is presented. Assumptions regarding the direction of the driving force applied by the screw have been examined in addition to coupling its direction with the orientation of the barrel friction force. These assumptions allow the new model to provide increased nonlinearity and flexibility to accurately predict extruder output over wide variations with discharge pressure. A new parameter, the skew angle, is introduced in the proposed model. Predictions of extruder output for varying discharge pressures and barrel temperatures show excellent agreement with experimental data.
© 1998, Carl Hanser Verlag, Munich
Articles in the same Issue
- Contents
- Contents
- Editorial
- J. A. Biesenberger, G. Astarita, D. C. Bogue
- Screw Extrusion/Mixing
- Modeling Solids Conveying in Polymer Extruders
- Comparison between LDPE Conventional and Autothermal Extrusion Characteristics
- Transesterification of Ethylene Acetate Copolymer in a Twin Screw Extruder
- Stabilising the Structure of HDPE by the Use of Highly-dispersed Mixture of Fe/FeO
- Pumping Characteristics of an Intermeshing Co-rotating Twin Screw Extruder
- Flow Behaviour of Blends of Poly(ethylene-Co-Acrylic Acid) and Epoxidised Natural Rubber
- Die Extrusion
- Rheological Behaviour of HDPE/PA 11 Blends
- Melt Flow Properties of LDPE/HDPE Blends in Capillary Extrusion
- Fibers and Film
- Rheological Behaviour of LLDPE/LDPE Blends under Elongational Deformation
- Processing/Structure Relationships of Mica-Filled PE-Films with Low Oxygen Permeability
- On the Charge State of Melt-Blown Polymer Materials
- Temperature Measuring in Plastics Processing with Infrared Radiation Thermometers
- Comparative Study of Structure Development in Melt Spinning Polyolefin Fibers
- Moulding
- Sintering Rheology of Semi-Crystalline Polymers
- Molding
- Melt Flow Instabilities of Filled HDPE
- Experimental Validation of Shrinkage Predictions for Injection Molded Products
Articles in the same Issue
- Contents
- Contents
- Editorial
- J. A. Biesenberger, G. Astarita, D. C. Bogue
- Screw Extrusion/Mixing
- Modeling Solids Conveying in Polymer Extruders
- Comparison between LDPE Conventional and Autothermal Extrusion Characteristics
- Transesterification of Ethylene Acetate Copolymer in a Twin Screw Extruder
- Stabilising the Structure of HDPE by the Use of Highly-dispersed Mixture of Fe/FeO
- Pumping Characteristics of an Intermeshing Co-rotating Twin Screw Extruder
- Flow Behaviour of Blends of Poly(ethylene-Co-Acrylic Acid) and Epoxidised Natural Rubber
- Die Extrusion
- Rheological Behaviour of HDPE/PA 11 Blends
- Melt Flow Properties of LDPE/HDPE Blends in Capillary Extrusion
- Fibers and Film
- Rheological Behaviour of LLDPE/LDPE Blends under Elongational Deformation
- Processing/Structure Relationships of Mica-Filled PE-Films with Low Oxygen Permeability
- On the Charge State of Melt-Blown Polymer Materials
- Temperature Measuring in Plastics Processing with Infrared Radiation Thermometers
- Comparative Study of Structure Development in Melt Spinning Polyolefin Fibers
- Moulding
- Sintering Rheology of Semi-Crystalline Polymers
- Molding
- Melt Flow Instabilities of Filled HDPE
- Experimental Validation of Shrinkage Predictions for Injection Molded Products