Viscosity model for Microcellular injection molding
The dissolution of gas into the polymer melt will impact on the viscosity model used for Microcellular injection molding.
The viscosity model for microcellular injection molding is given by the following equation: 
where:
is the viscosity of the polymer-gas system
r is the viscosity of the resin (without gas)
is the volume fraction of the nucleated gas bubble
is the initial gas concentration- and
, 
and 
are data-fitted coefficients