Influence of Stretching and Cooling Conditions in Cast Film Extrusion of PP Films
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P. Duffo
Abstract
In cast film extrusion, the polymer melt is extruded through a slit die, slightly stretched in air and then cooled on a chill-roll. An important part of the present work was to study the effect of the roll temperature on the polymer crystallization in the thickness of extruded films. A thermomechanical model of the whole process taking into account the polymer crystallization was used to determine the mean stretching stress in air, local temperature, local cooling rate and local crystallization development. The morphologies in the thickness of the films were observed by optical microscopy on microtomed slices and the crystalline structures were investigated by wide-angle X-ray diffraction and DSC measurements. From DSC melting curves of thin sections it is possible to know the local crystallization temperature and to check the thermomechanical model. The model is validated and explains the influence of the roll temperature on the formation of structures and morphologies. Nevertheless neither the existence of three different zones in the thickness nor the high p phase concentration are predicted by the model, which needs new developments.
© 1990, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Contents
- Contents
- Original Contributions
- Innovative Extrusion Systems for Advanced Fiber and Film Extrusion
- Influence of Melting Zone and Melt Homogeneity on Extrusion and Injection Molding Processes
- Further Considerations of Simulation of Flow in Pin Barrel Extruders and in Screw Extruders with Sliced Flights
- Deformation Fields and Residence Time Distributions in Polymer Melt Flows
- Flow History – Morphology Development in Crystallizable Polymer Melts
- Rheological Studies on Solutions of Poly-p-phenylene Terephthalamide in H2SO4
- Instability Phenomena in Film Casting Process
- Influence of Stretching and Cooling Conditions in Cast Film Extrusion of PP Films
- Melt Strength Behavior of PE and its Relation to Bubble Stability in Film Blowing**
- Dynamics of Double Bubble Tabular Film Process for Producing Biaxially oriented Nylon 6 Film
- A Finite Difference Study of Roll Design in Calendering Processing
Artikel in diesem Heft
- Contents
- Contents
- Original Contributions
- Innovative Extrusion Systems for Advanced Fiber and Film Extrusion
- Influence of Melting Zone and Melt Homogeneity on Extrusion and Injection Molding Processes
- Further Considerations of Simulation of Flow in Pin Barrel Extruders and in Screw Extruders with Sliced Flights
- Deformation Fields and Residence Time Distributions in Polymer Melt Flows
- Flow History – Morphology Development in Crystallizable Polymer Melts
- Rheological Studies on Solutions of Poly-p-phenylene Terephthalamide in H2SO4
- Instability Phenomena in Film Casting Process
- Influence of Stretching and Cooling Conditions in Cast Film Extrusion of PP Films
- Melt Strength Behavior of PE and its Relation to Bubble Stability in Film Blowing**
- Dynamics of Double Bubble Tabular Film Process for Producing Biaxially oriented Nylon 6 Film
- A Finite Difference Study of Roll Design in Calendering Processing
