Dynamic Performance of Single-Screws of Different Configurations
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A. C.-Y. Wong
Abstract
A 45 mm diameter single-screw “transparent” extruder was employed for an investigation on the dynamic performance of screws of different configurations. The extruder had eight glass windows installed along the entire metal barrel which enabled visual observation to be easily made. It was demonstrated, with this extruder, that pressure profile appeared to be an important factor for screw performance such as throughput rate, residence time, mixing characteristics, break-up of solid-bed, etc. The full-flight screw had the lowest pressure profile among all the screws tested, and its performance was found to be generally inferior to that of the mixing screws. The Darnell and Mol solid plug flow theory was shown to be applicable only to the mixing screws for the solid flow behaviour in the entire solid conveying section. The secondary flight of the barrier screw was found to effectively suppress solid bed break-up, but only at low screw speed. A screw with a Maddock mixing device was found to have the highest throughput rate. Other findings were believed to be of practical significance in the screw design.
© 1999, Carl Hanser Verlag, Munich
Articles in the same Issue
- Regular Contributed Articles
- Polymer Processing Problems from Non-Rheological Causes1
- Utilization of Rheology Control to Develop Wood-Grain Patterned PVC/Wood Flour Composites
- Screw Drive Power of Single Screw Plasticating Units With Smooth Barrels
- Design of Dispersive Mixing Devices
- Dynamic Performance of Single-Screws of Different Configurations
- A Comparative Study of Residence Time Distributions in a Kneader, Continuous Mixer, and Modular Intermeshing Co-Rotating and Counter-Rotating Twin Screw Extruders
- Influence of a ‘Rotating Tip’ on the Properties of Tubing Made Using a Cross-Head Tubing Die
- Modelling of Capillary Rheometer Data and Extrapolation of the Viscosity Function into the Linear Viscoelastic Region
- Relationship Between Structure and Spinning Processing of As-Spun PP Fibres
- Rheological and Theoretical Estimation of the Spinnability of Polyolefines
- Drawing of β-Crystal Nucleator-Added PP
- Wave Behavior in the Coating Process of Multilayer Polymeric Materials
- Process Optimization of Thermoforming PP/CaCO3 Composites
- A Stiffness Criterion For Cooling Time Estimation
Articles in the same Issue
- Regular Contributed Articles
- Polymer Processing Problems from Non-Rheological Causes1
- Utilization of Rheology Control to Develop Wood-Grain Patterned PVC/Wood Flour Composites
- Screw Drive Power of Single Screw Plasticating Units With Smooth Barrels
- Design of Dispersive Mixing Devices
- Dynamic Performance of Single-Screws of Different Configurations
- A Comparative Study of Residence Time Distributions in a Kneader, Continuous Mixer, and Modular Intermeshing Co-Rotating and Counter-Rotating Twin Screw Extruders
- Influence of a ‘Rotating Tip’ on the Properties of Tubing Made Using a Cross-Head Tubing Die
- Modelling of Capillary Rheometer Data and Extrapolation of the Viscosity Function into the Linear Viscoelastic Region
- Relationship Between Structure and Spinning Processing of As-Spun PP Fibres
- Rheological and Theoretical Estimation of the Spinnability of Polyolefines
- Drawing of β-Crystal Nucleator-Added PP
- Wave Behavior in the Coating Process of Multilayer Polymeric Materials
- Process Optimization of Thermoforming PP/CaCO3 Composites
- A Stiffness Criterion For Cooling Time Estimation
