Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/30568
Título: | Predicting extrusion instabilities of commercial polyethylene from non-linear rheology measurements |
Autor(es): | Cyriac, Febin Covas, J. A. Hilliou, L. Vittorias, Iakovos |
Palavras-chave: | Polyethylene Instabilities Fourier-Transformrheology (FT-rheology) LAOS Non-linear rheology |
Data: | 2014 |
Editora: | Springer |
Revista: | Rheologica Acta |
Resumo(s): | Processing at the highest possible throughput rates is essential from an economical point of view. However, various flow instabilities and extrudate distortions like sharkskin, stick slip, and gross melt fracture (GMF) may limit the production rate of high-quality products. Predicting the process conditions leading to the occurrence of rheological instabilities is the key for improving product quality, process control, and optimization. Large-amplitude oscillatory shear (LAOS) and FT-rheology were used to quantify the non-linear rheological behavior and instabilities of a series of wellcharacterized commercial polyethylene (PE). From the latter, we derive the critical non-linearity parameter, F0,c, which corresponds to the normalized intensity of the third harmonic at the critical strain amplitude, γ0,C (defined by the appearance of the second harmonic), normalized by γ0,C. The F0,c is correlated with the high molecular mass fraction of the polymers and with the Deborah numbers. Linear rheological parameters and molecular structures were related to F0,c. An experimental correlation between F0,c of commercial PE melts and pressure fluctuations associated with flow instabilities (sharkskin) was established both for capillary rheometry and extrusion. |
Tipo: | Artigo |
Descrição: | Published online : 23 September 2014 |
URI: | https://hdl.handle.net/1822/30568 |
DOI: | 10.1007/s00397-014-0798-7 |
ISSN: | 0035-4511 1435-1528 |
Versão da editora: | http://link.springer.com/article/10.1007/s00397-014-0798-7 |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | IPC - Artigos em revistas científicas internacionais com arbitragem |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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rheol acta Febin Iakovos PE (2014).pdf Acesso restrito! | author personal copy | 1,83 MB | Adobe PDF | Ver/Abrir |