Extrudate Swell of High Density Polyethylenes in Slit (Flat) Dies
| Autor: | Vinod Kumar Konaganti, Mahmoud Ansari, Evan Mitsoulis, Ehsan Behzadfar, Savvas G. Hatzikiriakos |
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| Rok vydání: | 2016 |
| Předmět: |
business.product_category
Materials science Polymers and Plastics General Chemical Engineering 02 engineering and technology Die swell Radiation 01 natural sciences Industrial and Manufacturing Engineering law.invention Rheology law 0103 physical sciences Micrometer Materials Chemistry Composite material chemistry.chemical_classification 010304 chemical physics Polymer 021001 nanoscience & nanotechnology Swell Shear rate chemistry Die (manufacturing) 0210 nano-technology business |
| Zdroj: | International Polymer Processing. 31:262-272 |
| ISSN: | 2195-8602 0930-777X |
| DOI: | 10.3139/217.3215 |
| Popis: | Extrudate swell of industrial-grade high-molecular mass high-density polyethylenes (HDPEs) in flat/slit dies is studied using both experiments and simulations. The experimental set-up consists of an optical micrometer to measure the extrudate dimensions and a pair of radiation heaters to control the extrudate temperature outside the die attached to the capillary rheometer. The simulation of extrudate swell phenomenon is carried out by using a well-known integral K-BKZ model. The effects of several rheological characteristics, die characteristics, and processing conditions on swell measurements are studied systematically, and the corresponding two-dimensional, steady-state numerical predictions are presented in this paper. This study includes the effects of polymer molecular characteristics, apparent shear rate, die geometrical characteristics (length to die gap (L/H) and width to die gap (W/H)), and distance from the die exit. It is found that the integral K-BKZ model predicts well both the width and thickness extrudate swells. Extrudate swell measurements demonstrate that the thickness swell is predominant in comparison with width swell. |
| Databáze: | OpenAIRE |
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