17. ขขขขขขขข (power law equation Ostwald–de–Waeleขขขขขขขข (power law equation Ostwald–de–Waele
n = ขขขขขขขขขขข ขขขข power law index (0 < n
18. ขขขขขขขขขขขขขขขขขขขขขขขขขขขขข
power law index ขขข zero shear viscosity
ขขขขขขขขขขขขขขขขขข ขขขข
ขขขขขขขขขขขขขขข Log (shear stress)
ขขข Log (shear rate) ขขขขขขขข
ขขขขขขขขขขขขขขขขขขขขขขขขขขขขข
ขขขขขข n ขขขขขขขขขขขขขขขข y ขข
ขขขขขขขขขข K
43. Melt Fracture
ร As the shear rate and shear stress
are associated with a flowing polymer
melt, there is a stage reached where
the structure of the extrudate breaks
down. This rupture is well known as
“melt fracture or elastic turbulence”.
ร The nature of the extrudate varies
depending on the polymer and can be
totally irregular, spiral or consists of