Scientists have created a flexible, naturally derived material from crab shells and trees that could replace plastic wrap.
The world has produced 9 billion tons of plastic since the material was first invented in the 1950s. The vast majority of it does not get recycled. Today, single-use plastics and packaging are a major contributor to global plastic waste. About 25 million tons of plastic packaging, including plastic wrap, flows into oceans every year.
But researchers at the Georgia Institute of Technology have created a new material that could help curb the world’s plastic usage and prevent food waste. But instead of wrapping food in the plastic alternative, the material is built around food using two alternating sprays. The spray contains chitin — which can be found in the shells of crabs, lobsters, and shrimps — combined with cellulose found in tree fibers. The layers of sprays form a protective layer around food that is transparent and fully compostable when dried.
The biodegradable material may even be more effective than plastic wrap at keeping foods fresh, the team found.
"Our material showed up to a 67% reduction in oxygen permeability over some forms of PET [polyethylene terephthalate, commonly used in plastic],” researcher and professor J. Carson Meredith explained in a press release. “Which means it could, in theory, keep foods fresher longer."
The scientists were inspired to create the material after studying chitin’s use as part of a different project. But soon found that the plant properties of tree fibers provided a great complement to chitin.
“We recognized that because the chitin nanofibers are positively charged, and the cellulose nanocrystals are negatively charged, they might work well as alternating layers in coatings because they would form a nice interface between them,” Meredith said.
The team hopes the material will help cut down on food packaging, which is likely to increase as the world’s population grows without greener alternatives.
“We had been looking at cellulose nanocrystals for several years and exploring ways to improve those for use in lightweight composites as well as food packaging, because of the huge market opportunity for renewable and compostable packaging, and how important food packaging overall is going to be as the population continues to grow,” Meredith said.
However, the material is unlikely to publicly available any time soon. Although cellulose can be sustainably harvested from wood pulp, mass-produced cellulose is unavailable, and the costs of producing the material are too high to make it widely available for now.
In the meantime, several plastic film alternatives already exist and could help the world earn another victory in the fight against pollution and climate change.