Stability of a Blown Film Extrusion Process
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K.-S. Yoon
Abstract
The stability of a blown film extrusion process has been investigated using a simple isothermal Newtonian model. Although the Newtonian model may be an oversimplification for polymer melts, it serves as a reasonable first approximation for linear polymers (e.g., linear low density polyethylene) in extensional flow situations. The results obtained by the method of linear stability analysis indicate that the blown film process becomes unstable if the blow-up ratio (BUR) or the film thickness reduction is larger than a certain critical value. In addition, existence of an optimum freeze-line-height is predicted at which the region of stable operation is largest in terms of the BUR and the film thickness reduction. These predicted trends are in qualitative agreement with experimental observations for linear polymers such as LLDPE.
© 1999, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Editorial
- Fifth of a Series: Pioneer of Polymer Processing John Wesley Hyatt (1837–1920)
- Internal Mixer
- Modeling the Distributive Mixing in an Internal Batch Mixer
- Biomedical Engineering
- Processing of Biodegradable Polymer Composites as A Drug Delivery System in Vitro
- Fibers and Films
- Tensile Force Measurements in the PA 6 High Speed Fiber Spinning and their Utility
- Crosslinking Modification of UHMWPE Fibers by Ultra-violet Irradiation
- Effect of Wall Slip on Rheotens Mastercurves for Linear PE Melts
- Stability of a Blown Film Extrusion Process
- Molding
- Blank Design and Fiber Orientation Distribution During Compression Molding of GMT
- Injection Moulding of a Commercial β-Nucleated Polypropylene
- Weld Line Strength in PC/ABS Injection Moldings
- Computer Controlled Rotational Molding of a Hollow Femur for 3-D Photoelastic Analysis
- Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer
- Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer
- Generalized Predictive Observer-Controller For Injection Moulding
- Fiber Orientation in 3-D Injection Molded Features
Artikel in diesem Heft
- Editorial
- Fifth of a Series: Pioneer of Polymer Processing John Wesley Hyatt (1837–1920)
- Internal Mixer
- Modeling the Distributive Mixing in an Internal Batch Mixer
- Biomedical Engineering
- Processing of Biodegradable Polymer Composites as A Drug Delivery System in Vitro
- Fibers and Films
- Tensile Force Measurements in the PA 6 High Speed Fiber Spinning and their Utility
- Crosslinking Modification of UHMWPE Fibers by Ultra-violet Irradiation
- Effect of Wall Slip on Rheotens Mastercurves for Linear PE Melts
- Stability of a Blown Film Extrusion Process
- Molding
- Blank Design and Fiber Orientation Distribution During Compression Molding of GMT
- Injection Moulding of a Commercial β-Nucleated Polypropylene
- Weld Line Strength in PC/ABS Injection Moldings
- Computer Controlled Rotational Molding of a Hollow Femur for 3-D Photoelastic Analysis
- Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer
- Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer
- Generalized Predictive Observer-Controller For Injection Moulding
- Fiber Orientation in 3-D Injection Molded Features
