Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding
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A. I. Isayev
, Y. Churdpunt and X. Guo
Abstract
Injection molding of the isotactic polypropylenes polymerized using metallocene and Ziegler-Natta catalysts and having the same molecular weights was performed. Rheological properties and shear-induced crystallization kinetics were measured and their comparative analysis is made. These data are fitted to the equations necessary for simulation of the injection molding process. Numerous injection molding runs were carried out and pressure measurements during molding were performed. The gapwise distribution of crystallinity, spherulite size and thickness of flow-induced crystallized layer in moldings were measured. The effect of various processing conditions on these values was determined. The measured values were compared with the results obtained from the simulation of injection molding process using unified theory of crystallization proposed earlier. Comparative analysis is made between flow conditions and crystallization behavior of these polymers and their effect on the pressure development and structural characteristics of the moldings.
© 2000, Carl Hanser Verlag, Munich
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- Computer Aided Optimisation of Profile Extrusion Dies
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- Molding
- Compressive Squeeze Flow of Generalized Newtonian Fluids with Apparent Wall Slip
- Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding
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Articles in the same Issue
- Editorial
- Sixth of a Series: Pioneer of Man-Made Fibers and Solution Spinning Louis-Marie-Hilaire Bernigaud, Comte de Chardonnet
- Screw Extrusion
- A Network Analysis of a Screw Mixing Zone
- Experimental and Numerical Study of Rhomboidal Mixing Sections
- Reactive Extrusion
- Bulk Polymerization of ∊-Caprolactone in Twin Screw Extruder
- Die Extrusion
- Computer Aided Optimisation of Profile Extrusion Dies
- Fibers and Films
- An Investigation of Venturi and Coanda Effects in Blown Film Cooling
- Blends
- Solidification Behaviour of PA6/iPP Blends at High Cooling Rates
- Polymer Blends with Fibrillar Phase Morphology Prepared by Self-Reinforcing Technique
- Molding
- Compressive Squeeze Flow of Generalized Newtonian Fluids with Apparent Wall Slip
- Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding
- The Pressure-Volume-Temperature Behavior Polyethylene Melts
- Evaluation of the Thermal Behaviour of Injection Moulds
- Polymer Solidification under Pressure and High Cooling Rates