Rheological parameters identification using in-situ experimental data of a flat die extrusion

Nadhir Lebaal (1) , Stéphan Puissant , Fabrice Schmidt (1)

1 CROMeP - Centre de Recherche Outillages, Matériaux et Procédés

Viscosity is an important characteristic of flow property and process ability for polymeric materials. A flat die was developed and brought into service at Maillfer[8], to make rheological characterizations. Measurements were made with two different slit heights, at different extrusion speeds, for one type of material (LDPE). In this paper, the optimization by response surface method, with the moving least squares approximate (MLS) [5-6], is used to identify the rheological parameters of thermoplastic melt. The objective is to minimize the difference between the measurement pressure obtained in flat die and the numerical pressure calculated by one dimensional finite difference programme by sections [1]. Global relative error between these both pressure is the objective function. This objective function is minimised by varying the rheological parameters. For this minimization two methods are used i.e. local response surface and global response surface. The rheological parameters obtained by these methods allow calculating the viscosity, validated by comparing an experimental viscosity measured on a capillary rheometer.

Mots clés: MLS; Numerical Simulation; Identification of rheologicals parameters; Extrusion

Domaines: Sciences de l'ingénieur [physics]

Nadhir Lebaal, Stéphan Puissant, Fabrice Schmidt. Rheological parameters identification using in-situ experimental data of a flat die extrusion. AMPT'2005 -8th International Conference on Advances in Materials and Processing Technologies, May 2005, Gliwice-WIsla, Poland. 4 p. ⟨hal-01788421⟩