Crystallization Studies of LLDPE during Tubular Blown Film Processing
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M. D. Bullwinkel
Abstract
The final physical properties of semi-crystalline blown films are highly dependent on the crystalline morphology and orientation of polymer chains within the film. Simultaneous on-line SALS (Small Angle Light Scattering) and IR (Infrared) temperature measurements were successfully used to study crystallization during tubular blown film extrusion of LLDPE. SALS patterns were recorded at various vertical positions along the bubble. For LLDPE, an undeformed spherelulitic structure is formed if the stress level during processing is not too high. The change in average scattered intensity with axial position can be described using multiple step Avrami kinetic processes in parallel. The first step accounts for crystal growth and corresponds to the well-known temperature plateau. The later processes start with the impingement of the growing spherulites and may reflect secondary crystallization and orientation processes. Because the magnitude of the average intensity is responsive to changes in process conditions, the on-line SALS system is potentially a useful tool for monitoring process-property interactions.
© 2001, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Editorial
- 10.3139/217.0101
- Invited Paper
- Polymer Processing Technology in the 21st Century from the Viewpoint of the Japanese Plastics Industry
- Screw Extrusion Blend
- Polymer Blends in Co-Rotating Twin-Screw Extruders
- Reactive Extrusion
- Polymerization of ∊-Caprolactone in a Twin Screw Extruder
- Fiber and Film
- Crystallization Studies of LLDPE during Tubular Blown Film Processing
- Numerical Study of Internal Bubble Cooling (IBC) in Film Blowing
- Modeling Heat Transfer with Crystallization in Rods and Filaments
- Molding
- Relevance of Crystallisation Kinetics in the Simulation of the Injection Molding Process
- Causes of Cracks in Petaloid Bottom of Carbonated PET Bottle
Artikel in diesem Heft
- Editorial
- 10.3139/217.0101
- Invited Paper
- Polymer Processing Technology in the 21st Century from the Viewpoint of the Japanese Plastics Industry
- Screw Extrusion Blend
- Polymer Blends in Co-Rotating Twin-Screw Extruders
- Reactive Extrusion
- Polymerization of ∊-Caprolactone in a Twin Screw Extruder
- Fiber and Film
- Crystallization Studies of LLDPE during Tubular Blown Film Processing
- Numerical Study of Internal Bubble Cooling (IBC) in Film Blowing
- Modeling Heat Transfer with Crystallization in Rods and Filaments
- Molding
- Relevance of Crystallisation Kinetics in the Simulation of the Injection Molding Process
- Causes of Cracks in Petaloid Bottom of Carbonated PET Bottle
