I need to get some rough calculations done on the permeability of HFC-134a across various polymers (polyamide, polyethylene terephthalate, polyethyelene naphtathalate, polyether etherketone, etc.) at different pressures and different wall thicknesses of 0.25mm - 0.75mm. Ideally I would like an Excel spreadsheet created -or the diffusion multilayer simulation programme described on the website (CheFEM software) - that I could plug in different values. I am trying to determine if I can make a small injected molded part containing HFC-134a (Chemical Name 1,1,1,2-tetrafluoroethane, Molecular Formula CH2FCF3) under pressure. The part would be a tiny doughnut shaped container with the gas at 80psi - 100psi. I need to
determine what mass of gas and how much pressure I would lose over a two year period.

Additionally, I would look for suggestions and calculations on how to improve the permeability of the polymer with coatings and/or unique blends.

Thanks in advance.

Keep up the good work,
Trevor McCaw