Posted by diffusion-polymers.com on January 24, 2005 at 10:16:57:

In Reply to: Migration of Olive Oil through PE posted by Steve Thompson on January 21, 2005 at 19:09:58:

Dear Steve Thompson,

We got the following figures for Olive Oil migration/diffusion/permeation in Low Density Polyethylene. Mind that Antioxidants, like Irganox, Pigments and Anti statics and other effects may influence the migration of Olive Oil through Low Density Polyethylene. Please send an inquiry to obtain an official complete answer with references when required (according to EU regulations). Diffusion-polymers.com does not accept liability for any possible consequences of actions taken by the inquirer based on the message(s) in this forum.

Olive Oil - LDPE ->
Max volume fraction: 0.02 and
Olive Oil Density: 920 kg/m3 at 25 degrees Celsius and 1 Atmosphere,
Diffusion Coefficient: 1 E-13 m2/s.

Taking the free volume of the Low Density Poly Ethylene at this temperature into account, it can be stated that the LDPE does not swell during the migration of Olive Oil, and that we have Fickian diffusion:

Time lag (time for the first molecule to diffuse/migrate/permeate through the wall of 0.1 mm thickness after t=0): 4 hours and 20 minutes.

Stationary Flux (stationary mass transfer per square meter of LDPE reached after around 12 hours after t=0): 1.6 gram Olive Oil / m2 x day.

Regards,

: Dear Forum,

: Could you give me an indication/calculation of the
: migration rate of Olive Oil in a sheet of 0.1 mm of
: low density poly ethylene (amorphous fraction 50 volume percent)? Thanks!

: Regards,
: S. Thompson