| Titre : |
Comparative study of ziegler-natta and metallocene based polypropylenes in injection molding : Simulation and experiment |
| Type de document : |
texte imprimé |
| Auteurs : |
Avraam I. Isayev, Auteur ; Y. Churdpunt, Auteur ; X. Guo, Auteur |
| Année de publication : |
2000 |
| Article en page(s) : |
p. 72-82 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Index. décimale : |
668.9 Polymères |
| Résumé : |
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. |
| Note de contenu : |
- THEORETICAL CONSIDERATION : The unified crystallization model - Microstructure and competing mechanism - Injection molding process simulation - Numerical simulation
- EXPERIMENTAL : Materials - Rheological characterization - Injection molding experiments - Sample preparation - Shear-induced crystallization layer and spherulite size distribution - Crystallinity distribution
- RESULTS AND DISCUSSION : Rheological properties - Process simulation and comparison with experiments - pressure traces - Shear-induced crystallization layer - Spherulite size distribution - Crystallinity distribution |
| DOI : |
10.3139/217.1571 |
| En ligne : |
https://drive.google.com/file/d/1Capiy1yrjEbCnidc-HnS3pPsykbDjfOr/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16076 |
in INTERNATIONAL POLYMER PROCESSING > Vol. XV, N° 1 (03/2000) . - p. 72-82
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