Permeation Cell OTR-PSt3 / -PSt6 / -PSt9

A well-characterized 100 μm PET film (Hostaphan®RB 100) was used for measurements with the Permeation Cell and a PSt6 sensor The permeability of this film is well known and was determined to range from 12.26 to 14.10 cm³ (STP) / (m² d bar) in more than 100 reference measurements. First, both chambers of the measurement cell were flushed with nitrogen to determine the leakage of the device (zero value). Then the lower chamber was filled with oxygen and measurements were taken over several days. The increase of oxygen partial pressure recorded with the optical sensor showed a quasi/linear slope up to 40 hPa. The oxygen permeation determined in the measurement cell was 12.78 cm³ (STP) / (m² d bar), which is in good accordance with the previously determined permeability for the reference film.
(Müller K., et al.: New Permeation Measurement Device Using Chemical Optical Sensor Spots, 25th IAPRI Symposium on Packaging, 2011, Berlin)

The required oxygen barrier properties for food packaging can vary in a wide range. Some respiring fresh fruits or vegetables need ultra low barrier packaging. These highly permeable materials cannot be measured using the established gas carrier method. With the optical permeation measurement system, on the other hand, even perforated films and paper compounds can be investigated. The highest measured permeability with this system was 2 x 10⁷ cm³ (STP) / (m² d bar) for a 30 μm PET film filled with CaCO₃.

High barrier materials are needed in technical applications, like e.g. for vacuum insulation panels or photovoltaic modules, and can show permeation rates below 5 x 10^-3 cm³ (STP) / (m₂ d bar). A film composed of several metallized PET layers with a PE sealing layer had been measured in the Permeation Cell with integrated PSt9 sensor. The determined zero value was 0.0176 cm³ (STP) / (m² d bar). So this measurement system can be used to determine oxygen permeation in high barrier materials.