Sy. Na et Dh. Kim, 3-DIMENSIONAL MODELING OF NON-NEWTONIAN FLUID-FLOW IN A COAT-HANGER DIE, The Korean journal of chemical engineering, 12(2), 1995, pp. 236-243
The three-dimensional model of isothermal flow of power-law fluid in a
coat-hanger die has been developed using finite element method. The s
hape of coat-hanger die used in the present model was determined accor
ding to the previous analytical design equation which is based on one-
dimensional now model in the manifold and the slot. Because uniform fl
ow rate across the die outlet is most important to achieve uniform thi
ckness of extruded polymer sheet or film, flow rate distribution is ma
inly examined to determine the valid process condition for the design
equation as the design parameters are changed. The effects of fluid pr
operty in terms of power-law index and process parameters not consider
ed in one-dimensional design equation such as die inlet size and the p
resence of land were analyzed. Results show that the manifold angle is
the most influencing design parameter on flow rate distribution. When
the material of different power-lau index from design value is proces
sed, the change of power-law index affects the uniformity of now rate
appreciably.