Gas permeability of packaging often underestimated
By Maaike Rijk
The functional value of packaging is increasing rapidly. The demand for barrier characteristics suited to the product and the required quality is increasing equally. "Unfortunately, gas permeability as a barrier is often underestimated", according to Dimitri Adons of the Packaging Centre
How do you know if a packaging meets the required quality standard and the correct barrier? “To measure is to know”, say Dimitri Adons and Dr Roos Peeters of the Packaging Centre, part of Xios in Belgium and joined with Hasselt University from 1 October 2013. As a knowledge institute, they carry out an independent service for companies from various sectors.
The product is the determining factor
Dimitri Adons: “The research into barrier characteristics is important for determining the quality retention of the packaged goods. The product determines the requirements of the material in order to safeguard optimal quality. One material characteristic we focus on at the Packaging Centre is gas permeability. This is a characteristic which is often underestimated. Breathing products, such as fruit and vegetables, require a packaging material with a high gas permeability for oxygen. Other products require a limited or minimal permeability for specific gasses in order to realise quality retention.”
Dimitri Adons responds as follows when we ask for examples: “Think of the protection of cheese against incoming oxygen, to avoid the growth of aerobic bacteria. Or the prevention of rust forming on metallic car parts due to the presence of water vapour.” But what about bulk packaging, which many of our clients work with? “Bulk packaging has to offer the required barriers in order to safeguard the quality of pharmaceutical or chemical products, during the entire life cycle”, Mr Adons adds to the statement of his colleague Dr Roos Peeters. “After all, the packaged product must be usable for its intended purpose. In addition to this, the safety of humans and the environment must in no case be endangered by the effects of gas permeability.”
The correct gas permeability = the correct packaging?
Does a product or the correct gas permeability determine the appropriate choice of packaging? “No”, says Roos Peeters. “Other characteristics must also be taken into consideration such as tensile strength, transparency and tear strength. It is important that research into permeability of oxygen, carbon dioxide, water vapour and other gasses is done in a standardised manner. This is set out in international standards such as ASTM, ISO and DIN. On the other hand, attention must be paid to differences in testing methods.”
“The gas barrier can be tested according to the equal pressure principal, but also with the vacuum method with pressure difference. Furthermore, the measuring sensors can differ. Other important parameters when testing gas permeability include the choice of the test gas, the test temperature, the required relative humidity and the orientation of material and packaging during the test. Correct control and monitoring of these parameters is essential. Especially knowing that humidity-sensitive materials may lose their original positive characteristics in gas permeability at higher levels of humidity. Or, as is generally stated, that the gas permeability increases by 5 to 7% when the temperature increases by one degree Celsius.”
Ing. Dimitri Adons
Dr. Roos Peeters
(As of 1 October 2013 part of Hasselt University (BE))
When packaging, handling and transporting your goods, you may run unnecessary risks. CurTec packaging can help you prevent many of these risks. All CurTec’s plastic packaging is water and water vapour proof. This already means they are protected against many outside influences. Upon request, extra barriers can be provided, so the quality of your product is optimally protected.
Do you have a packaging challenge? There is almost always a solution. We are very happy to give advice in the area of barrier improvement.Back to news