Stretching flows for thin film production: Part 1. Bubble blowing in the solid phase 

 -  Journal of Non-Newtonian Fluid Mechanics, 4(1-2), p.57-72, 1978 .
<br/><br/> A mathematical model is presented for the cold film blowing process leading to biaxial extension and orientation of crystalline polymer films. A simple but suitable rheological model (Funt [ 121)is chosen for a particular type of polypropylene for which some experimental data are available, and is extended to cover non-isothermal flows. New boundary conditions are developed for earlier derived (Pearson and Petrie [ 21)mechanical equations for the film blowing process. Numerical procedures for solution and results obtained are discussed.