Researchers at Ohio State University believe food waste can partially replace the petroleum-based filler used in car tyres.
The usual filler, carbon black, makes up around 30% of the tyre, and gives tyres their colour, as well as their strength. It is getting harder to source with the decrease in oil reserves which means prices of tyres regularly fluctuate.
However, the Ohio researchers created a new filler using local food waste of egg shells and tomato skins, and found they made a more efficient rubber than petroleum. Cindy Barrera, one of the researchers found, "Fillers generally make rubber stronger, but they also make it less flexible. We found that replacing different portions of carbon black with ground eggshells and tomato peels caused synergistic effects – for instance, enabling strong rubber to retain flexibility.”
Researchers Katrina Cornish (left) and Cindy Barrera (right) examining ground eggshells, ground tomato skins and the developed rubber. ©Kenneth Chamberlain, The Ohio State University
The research found that eggshells' porous microstructures provided a larger surface area for contact with the rubber, and that tomato skin was very stable at high temperatures.
If this technology was to expand, it could help reduce waste across the US, reduce dependence on oil, and help create sustainable rubber products.
The dried and ground tomato skins (top) and eggshells (bottom) as coarse, medium, and fine processing before being added to rubber. © Kenneth Chamberlain, Ohio State University
"According to the USDA, Americans consume nearly 100 billion eggs each year. Half are cracked open in commercial food factories, which pay to have the shells hauled to landfills by the ton. There, the mineral-packed shells don’t break down.
"The second most popular vegetable in the United States - the tomato - also provides a source of filler, the researchers found. Americans eat 13 million tons of tomatoes per year, most of them canned or otherwise processed. Commercial tomatoes have been bred to grow thick, fibrous skins so that they can survive being packed and transported long distances. When food companies want to make a product such as tomato sauce, they peel and discard the skin, which isn’t easily digestible." (https://news.osu.edu/news/2017/03/06/tomatotires/)
The university has licensed the patent-pending technology to Katrina Cornish’s company, EnergyEne, for further development.
For more information visit: https://news.osu.edu/news/2017/03/06/tomatotires/