Active & Intelligent Packaging Industry Association (AIPIA) member and German research organisation The Fraunhofer Institute has developed a multilayer bio-based packaging film that acts as an oxygen scavenger.
Developed in collaboration with the Technical University in Munich and others, the solution uses a mixture of gallic acid (GA) and atsodium carbone to absorb oxygen.
The film has been developed in a three-step process that involves compounding, flat film extrusion and lamination.
During analysis, the associated researchers tested the film surface colour and oxygen absorption at different relative humidities (RH) and temperatures.
The results were compared with the oxygen absorption of powder, monolayer films, and multilayer films.
It was found that the temperature affected the initial absorption rate of the multilayer films significantly as the corresponding activation energy was 75.4kJ/mol.
The researchers also found that higher RH increases the oxygen absorption rate.
Initially, the films were brownish-red in colour, but they changed to greenish-black during oxygen absorption under humid conditions.
The maximum absorption capacity was observed to be 447mg O2/g GA at 21°C and 100% RH.
The tests found that the introduction of GA into a polymer matrix reduced the rate of oxygen absorption compared to the GA powder as it prevented oxygen and water vapour diffusion.
Researchers said that the new bio-based packaging film can be used in packaging food products that have higher water content.