Differences in the polymer architecture directly impact processability and flow behavior, such as flow rate, die swell, melt stability, recoverable shear
and internal stresses in blow molding, injection molding, sheet forming, cable jacket extrusion, among other production processes (refs.
Other elastic parameters such as recoverable shear strain ([[gamma].
the values of the recoverable shear strain [[gamma].
Melt elasticity can also be determined by the recoverable shear
strain  according to Eq.
Gullet and Seriai (2) stated that the swelling phenomenon is mainly due to the recoverable elongational strain induced by the converging flow at the die entrance, as well as by recoverable shear
strain originating within the die.
44) on blown polyethylene (PE) films has found that the total haze percent exhibited a complex parabolic relationship with the logarithm of the recoverable shear
the apparent wall shear rate, the shear stress at the wall, or the recoverable shear
The recoverable shear compliance versus blend composition for the stabilized blends is shown in Fig.
Recall from Eq 2 that the recoverable shear compliance depends upon both the zero shear viscosity and G'/[[omega].
infinity]] is the recoverable shear
strain at the die wall.
Although it is understood that elastic behavior involves no dissipation of energy and no time-dependence, the term has been considered to be synonymous or has been related to viscoelastic functions such as normal stress differences and storage modulus; also, to extensional viscosity, recoverable shear
strain, entrance-exit pressure drop (Bagley correction) (2-4), and parameters of practical importance in polymer processing such as extrudate swell and melt strength (5, 6).
For long dies Tanner (23, 27), showed that the swell is a function of the recoverable shear