Theoretical and experimental study of the molten polymer flow in the calender bank

Abstract

The flow of molten polymers in the calender bank has been computed using a finite‐element method with stream function and vorticity. Two nonsymmetrical‐recirculating regions have been obtained fully in agreement with the experimental observations on poly(vinyl chloride) melt banks. The pressure distribution along the flow axis is very close to the one obtained using the classical‐lubrication approximation.

Theoretical analysis of the exiting thickness of sheets in the calendering of FENE-P fluid

“…All above mentioned studies were based on lubrication approximation theory (LAT). A numerical study of two-dimensional flow in calendering process was carried out by Mitsoulis et al [15] and Agassant and Espy [16]. These attempts confirmed the existence of large vortices in the fluid bank before the rolls as observed by…”

Numerical simulation of calendering viscoplastic fluids

“…Lifting this assumption leads to a twodimensional analysis (2D), as was done by Mitsoulis et al [11] and Agassant and Espy [12]. These two works have shown very interesting results with intricate patterns dominated by large vortices in the fluid bank before the rolls, found both experimentally [12] E-mail address: mitsouli@metal.ntua.gr. and computationally [11,12].…”

“…These two works have shown very interesting results with intricate patterns dominated by large vortices in the fluid bank before the rolls, found both experimentally [12] E-mail address: mitsouli@metal.ntua.gr. and computationally [11,12]. Another important work offered new insights about the detachment of the sheet and its acquired free surface for Newtonian, pseudoplastic (power-law) and viscoelastic fluids [13].…”

Calendering of coextruded polymer structures

“…Early models are based on the so called lubrication approximation [1,2,3,4,5] using Newtonian or viscoplastic shear thinning behaviour. First, assuming that there is no flow parallel to the roll axis, two-dimensional monolayer finite element models have been developed [6,7]. Then, with a three-dimensional monolayer finite element model, Luther has accounted for the widening of the polymer sheet through the calender bank [8].…”

“…Then, with a three-dimensional monolayer finite element model, Luther has accounted for the widening of the polymer sheet through the calender bank [8]. In two-dimensional isothermal monolayer conditions, Agassant [6] has considered the vortices, shown figure 4, which may occur in an important calender bank. The results obtained for the pressure field are similar to those get with a model based on a symmetrical qualitative analysis.…”