The CO2 permeability problem

Paul Boughton

Carbon Dioxide (CO2) is both a greenhouse gas and essential to life (photosynthesis). It is used to make drinks as well as in a huge range of industrial and commercial processes such as welding, oil production, electronics, paper making, steel manufacture, water treatment and even in the theatre.

The problem is that it is also very good at getting into places you do not want it to be, and out of places you do. Not through leakage - but through because it permeates through the actual materials that are used to enclose it.

Using the right materials for an application is critical and some common plastics, for example, allow over a hundred times more CO2 to escape than others.

Now Versaperm has launched a new version of its CO2 permeability meter which can accurately measure this property for a wide range of materials, coatings, components, bottles, enclosures and even finished products. This measurement is becoming increasingly important due to the never-ending search for new materials and performance characteristics.

The meter can measure to an accuracy in the parts per million (PPM) range and is around 100 times faster than conventional gravimetric techniques. The Versaperm instrument can optionally be configured to measure the permeability of a wide range of gases, including hydrogen, helium, hydrocarbons, oxygen, nitrogen and water vapour.

Versaperm's new MK VI meter is highly automated and its multiple chambers can cope with several samples at one time - and still produce a permeability measurement in as little as 30 minutes for some materials and gasses . It needs very little re-calibration and requires, at most, minimal training.