Home Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding
Article
Licensed
Unlicensed Requires Authentication

Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding

Simulation and Experiment
  • A. I. Isayev , Y. Churdpunt and X. Guo
Published/Copyright: June 6, 2013
Become an author with De Gruyter Brill

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.


* Mail address: Prof. Dr. A. I. Isayev, Institute of Polymer Engineering, University of Akron, Akron, Ohio 44325-0301, USA

Received: 1999-6-14
Accepted: 1999-10-12
Published Online: 2013-06-06
Published in Print: 2000-03-01

© 2000, Carl Hanser Verlag, Munich

Downloaded on 22.11.2025 from https://www.degruyterbrill.com/document/doi/10.3139/217.1571/html
Scroll to top button