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Studies of converging flows of viscoelastic polymeric melts. III. Stress and velocity distributions in the entrance region of a tapered slit die
Author(s) -
Han Chang Dae,
Drexler Leonard H.
Publication year - 1973
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1973.070170805
Subject(s) - viscoelasticity , materials science , mechanics , birefringence , vector field , stress (linguistics) , die (integrated circuit) , polystyrene , flow birefringence , optics , composite material , physics , polymer , linguistics , philosophy , nanotechnology
An experimental and theoretical study has been carried out, as a continuation of our previous investigation, to better understand the problems associated with converging flows of viscoelastic polymeric melts. In the present study, measurements were taken of both stresses and velocities in the converging velocity field of polymeric melts flowing into a tapered slit die, stresses by means of the flow birefringence technique and velocities by means of streak photography. The material used was polystyrene. A theoretical analysis was also made of converging flow, using a modified second‐order fluid model which assumes that all three material functions depend on the second invariant of the rate of deformation. Numerical solutions were obtained of the equations of motion, which give predicted velocity profiles in reasonable agreement with the measured velocity profiles. A comparison was also made of the experimentally determined stress distributions with the theoretically predicted ones.