A. Lawal et al., A NEW APPROACH TO SIMULATION OF DIE FLOW WHICH INCORPORATES THE EXTRUDER AND ROTATING SCREW TIPS IN THE ANALYSIS, International polymer processing, 12(2), 1997, pp. 123-129
The traditional method of mathematical modeling of the die flows treat
s the die as a stand alone tool which is independent of the extrusion
conditions which feed the polymer melt into the die. Here, we demonstr
ate that especially under the conditions where a breaker plate is not
used the flow and the deformation which occur in the die are dependent
on the prevailing velocity and the stress conditions of the fluid at
the extruder which feeds the die. A finite element method based techni
que is used to solve the conservation equations using a mesh which cov
ers both; the die and the rotating conical screw tips of the extruder.
The presented methodologies provide a more realistic representation o
f the thermo-mechanical history experienced by the polymer melt or str
uctured fluids including emulsions or suspensions in the die and thus
provide better tools for die design and process optimization. The resu
lts also suggest that significant improvements in die design and hence
die performance could ensue by using the geometry of the screw tips,
the distance between the screw tips and the die and the rotational scr
ew speed as additional parameters for design and optimization.