Investigation of Melting Phenomena in Modular Co-rotating Twin Screw Extrusion
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H. Jung
Abstract
An experimental investigation of the mechanisms of melting of polyolefins in a modular co-rotating twin screw extruder was carried out as a function of (i) barrel temperature including below the melting temperature (ii) screw speed and (iii) feed rate. The modular screws were removed from a twin screw extruder following experiments where pellets of linear low density polyethylene or isotactic polypropylene had been fed and processed under steady state conditions. The modular screws contained thermoplastic carcasses. These were sectioned and removed as well as inspected.
Three melting initiation regimes were identified. These were (i) melting initiated from barrel, (ii) melting initiated from screw, and (iii) melting initiated in the bulk. At high barrel temperatures mechanism (i) is observed, at lower barrel temperatures and slower screw speeds mechanism (ii) is found, and at lower barrel temperatures and higher screw speeds mechanism (iii) is observed. The propagation of the melting process was also investigated. Pellet bed instabilities are usually involved at higher screw speeds. We discuss modeling of these mechanisms.
© 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
