Problem 1: In a manufacturer process, multilayer packaging material with three layers in series is produced in the medium of air on one side and inert gas on the other side. The total critical permeability of the O2 has been decided to 2.5 barrer for the product in which the details of the layers were given in Table below as: Layer Materials Thickness (um) 1 A 2.25 2 B 1.5 3 OTR (mL m min) 8 14 18 What should be the thickness of the Material C' to achieve that critical value of the total permeability? (10-10) (ml STP) cm Barrer = (cm2)(s)(cm Hg)