Jft. Pittman et al., MECHANICAL EFFECTS IN EXTRUSION - SLIT DIES - EXPERIMENTAL AND NUMERICAL DETERMINATION OF THE DIE BODY DEFLECTION, International polymer processing, 10(2), 1995, pp. 137-147
Simulations of the elastic deflection of a 1.2 m slit die under load d
uring the extrusion process have been performed, using the commercial
finite element package MARC. The melt pressure distribution needed to
assign the loads to the MARC package was previously obtained by a Hele
-Shaw based finite element program, and was thus not coupled with the
deflection analysis. Existing analytical calculation methods for defle
ction are also examined. Experiments using production scale machinery
have been conducted to record the die deformations under different mel
t pressures and compared with the computed data. Analytic deflection p
redictions are shown to be inadequate. The numerical results are fair,
but it is clear that coupling of flow and deflection analyses is esse
ntial.