When people began to send potato chip bags back to the manufacturer, Vaux, to protest that the bags were not easily recycled, the company noticed this and launched a collection point. But the reality is that this special plan only solves a small part of the garbage mountain. Every year, Vox Corporation alone sells 4 billion packaging bags in the UK, but only 3 million packaging bags are recycled in the above-mentioned program, and they have not yet been recycled through the household recycling program.
Now, researchers say they may have come up with a new, greener alternative. The metal film used in current potato chip packaging bags, chocolate bars and other food packaging is very useful for keeping food dry and cool, but because they are made of several layers of plastic and metal fused together, they are difficult to recycle. use.
“The potato chip bag is a high-tech polymer packaging.” said Dermot O’Hare of Oxford University. However, it is very difficult to recycle it.
The British waste disposal agency WRAP stated that although technically speaking, metal films can be recycled at the industrial level, from an economic point of view, it is currently not feasible for widespread recycling.
The alternative proposed by O’Hare and team members is a very thin film called a nanosheet. It is composed of amino acids and water and can be coated on plastic film (polyethylene terephthalate, or PET, most plastic water bottles are made of PET). Related results were published in “Nature-Communication” a few days ago.
This harmless basic ingredient seems to make a material safe for food packaging. “From a chemical point of view, the use of non-toxic materials to make synthetic nanosheets is a breakthrough.” O’Hare said. But he said that this will go through a long regulatory process, and people should not expect to see this material used in food packaging at least within 4 years.
Part of the challenge in designing this material is to meet the industry’s requirements for a good gas barrier to avoid contamination and keep the product fresh. To make nanosheets, the O’Hare team created a “torturous path”, that is, to build a nano-level labyrinth that makes it difficult for oxygen and other gases to diffuse in.
As an oxygen barrier, its performance seems to be about 40 times that of metal thin films, and this material also performs well in the industry’s “bending test”. The film also has a great advantage, that is, there is only one PET material that can be widely recycled.
Post time: Oct-09-2021