Die Swell Extrusion Barus Ratio Calculator
Polymer processing & die tooling design: Calculate the extrudate swell ratio ($B = D_e / D_0$) from wall shear stress ($\tau_w$), first normal stress difference ($N_1$), and die aspect ratio ($L/D$).
Die Geometry & Operating Stress
Longer dies relax entrance elastic memory
First Normal Stress Difference N₁
Recoverable shear strain measurement
Die Swell Ratio & Extrudate Dimensions
Swell Ratio B (D_e / D₀):
--
diametric expansion
Final Extrudate Diam D_e:
--
millimeters (mm)
Normal Stress N₁:
--
kPa
Area Expansion:
--
B² ratio
Melt Fracture Risk:
--
critical stress check
Tanner Elastic Recovery Partition
Newtonian Inelastic Hydrodynamic Baseline:
1.10 (B_newton)
Elastic Normal Stress Swell Component:
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