Hostname: page-component-848d4c4894-75dct Total loading time: 0 Render date: 2024-06-10T16:22:58.569Z Has data issue: false hasContentIssue false

A simple model of the melt fracture instability

Published online by Cambridge University Press:  26 September 2008

J. M. Greenberg
Affiliation:
Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, MD 21228, USA
Y. Demay
Affiliation:
Institut Non-Linéaire de Nice U.M.R.-C.N.R.S. no. 129, Sophia Antipolis, 1361 Route des Lucioles, 06560 Valbonne, France

Abstract

In this note we develop and analyse a system of equations describing a molten linear polymer being extruded in a capillary rheometer which is operating under the controlled condition that the mean velocity at the capillary inlet is maintained at a constant value. Slipping of the melt at the pipe wall is permitted and an evolution equation for the boundary slip parameter is postulated. The combined system governing the mean cross-sectional velocity and slip parameter is shown to exhibit relaxation oscillations similar to those observed in actual rheometers.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Agassant, J. F., Avenas, P., Sergent, P. & Carreau, P. J. 1991 Polymer Processing: Principles and Modeling. Hanser Verlag, Munich.Google Scholar
[2]Hatzikiriakos, H. A. & Dealy, J. M. 1992 J. Rheol. 4 (36), 703741.CrossRefGoogle Scholar
[3]Hatzikiriakos, H. A. & Dealy, J. M. 1992 J. Rheol. 5 (36), 845884.CrossRefGoogle Scholar
[4]El Kissi, N. 1989 Thèse de Doctorat. INPG, Grenoble, France.Google Scholar
[5]Durand, V., Vergnes, B., Agassant, J. F. & Koopmans, R. J. 1992 Influence of the molecular weight on the oscillating flow of HDPE melts. In Theoretical and Applied Rheology (Moldenaers, P. & Keuning, R., eds.). Elsevier, Amsterdam, p. 416.CrossRefGoogle Scholar
[6]Beaufils, P., Vergnes, B. & Agassant, J. F. 1989 Int. Polym. Proc. 4 (78).CrossRefGoogle Scholar