New nanosheet coatings can replace non-recyclable metallized films in food packaging


A team of researchers at the University of Oxford in th […]

A team of researchers at the University of Oxford in the UK has developed a new food packaging nanosheet coating that can replace the metallized film currently in use. In their paper published in Nature Communications, the team described their processes and hoped that their products would make food packaging for the entire category more recyclable.
The shiny silver coating that is commonly used to keep fresh packaged foods is most common in the interior of potato chips and candy bags. Many people may not realize that the familiar silver coating makes this package very difficult to recycle because the metal film must be removed from the plastic, which means that most of the metal film is rolled up in the landfill. In this new effort, researchers have proposed a replacement for a fully and easily recyclable metallized film.

The new film is manufactured in an inexpensive process that produces films made from water and amino acids. More specifically, they are made by first making nanosheets of non-toxic synthetic clay. The amino acid stabilized nanosheets are then used. The resulting film is transparent and, most importantly, does not allow gas or water vapor to pass. In practice, the film will be applied to plastics, such as those already used in packaging, such as polyethylene terephthalate, the same type of plastic used in water bottles. Researchers have tested the package by exposing it to several gases used in current foods and found that its permeability is reduced by about 50%. They also pass physical abuse tests to ensure that it can withstand the process that packaged foods must withstand. They reported that it has withstood this abuse and the metallized film currently in use.

The researchers pointed out that because these films are synthetic, their final cosmetics are controlled by companies that use it as a packaging substitute. But they also admit that they need to test the film more before the company is willing to switch to it instead of the more familiar metallized film.