Investigation of steady-state gas diffusion through angled metallised polymer films for applications in fibre reinforced pressure vessels as barrier membranes

Pressure vessels used for the storage of hydrogen gas, particularly carbon-fibre reinforced pressure vessels (CPVs), must demonstrate sufficient leak tightness. Currently, this is achieved by costly metallic liners which come at a weight disadvantage compared to CPVs. Therefore, novel concepts for designing CPVs with low permeation characteristics are of high interest for various industrial applications. In this paper, a new concept is proposed based on overlapping intersections of metallised polymer films. Manufacturing trials are carried out on a laboratory scale to demonstrate the feasibility of a new barrier membrane design that can also be integrated into the winding process of CPVs. An efficient analytical model, as well as finite element simulations, are compared against experimental findings for the permeation of Helium. The findings indicate significant promise for implementing the barrier concept in CPVs, with tests and models demonstrating an over 1000 - fold decrease in the permeability of the barrier membrane compared to pure polymer, even when utilizing unoptimized tape materials. Reductions by a factor of over 10 000 are possible with material optimisation.