EXTRUSION DESIGN WITH THE CARREAU MODEL

摘要

This paper gives a solution for the steady, fully developed two-dimensional flow in a shallow channel, typical of screw extruders, and specific data for the Carreau and the Ostwald-deWaele model fluids with PMMA as an example. It is concluded that the Carreau model should be given preference over the Ostwald-deWaele model, the latter being the standard in engineering practice. The Ostwald-deWaele model fails to represent viscosities deviating from the power-law region, leading in certain situations to significant errors. The inclusion of the Carreau model does not necessarily introduce added complexity into the analysis.