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Re: he diffusion through PET
Posted by Diffusion in Polymers on June 15, 2004 at 20:37:00:
In Reply to: he diffusion through PET posted by claudio raggi on June 11, 2004 at 17:26:57:
The figures for polyethylene terphthalate PET and Helium are:
- Temperature: 25 degrees Celsius
- System Pressure: 1 bar (1 x E5 Pa)
- Helium Pressure: 1 bar (1 x 1E5 Pa)
PSystem = PHelium = 1 bar
Solubility Helium in PET: 0.001 (m3 stp He / m3 PET)
Diffusion coefficient Helium in PET: 5 E-11 m2/s
Permeability in volume:
= D (diffusion coefficient) x S (solubility)= 5 E-14 [-] m2/s.
Density of Helium at 25 degrees Celsius, 1 E5 Pa, ideal gas law: 40 gram / m3
Permeability in mass
= D x S x rho = 2 E-12 gram / m x s
: here`s my question:
: I`m looking for the value of diffusion and permeability for Helium through PET.
: thank you for your help