BY: DUSTIN BATTY
An innovative research team at The Ohio State University decided to use food waste to make car tires and the newly created rubber outperforms normal petroleum-based tires.
According to an OSU article on the experimental product, most rubber tires use petroleum-based filler that has been largely unchanged for the past century. Katrina Cornish, a researcher at OSU who has been developing new sources of rubber for years, wanted to find a way to make rubber from materials found in America. She decided to try using food waste—specifically, eggshells and tomato skin—in place of the petroleum filler.
Including eggshells gives rubber “unusual properties,” like an increased flexibility.
Eggshells are a common sight at the landfill and Americans wouldn’t even have to dumpster dive to get them. According to the article, about 50 billion eggshells come from commercial sources every year, from which they are shipped directly to the landfill. Eggshells are useful as tire filler because they “have porous microstructures that provide larger surface area for contact with the rubber and give rubber-based materials unusual properties.”
Tomato skin is another commodity that commercial sources could easily provide. Anywhere tomato sauces or juices are made, the skin is peeled and discarded. Apparently tomatoes are “the second most popular vegetable in the United States,” providing millions of tons of material. Tomato skin is useful in tire filler because it is “highly stable at high temperatures and can also be used to generate material with good performance.”
Tomato skin makes a good rubber filler because it is “highly stable at high temperatures.”
Car tires usually use a petroleum-based filler called “carbon black,” which makes up about 30 per cent of the tire. This fossil-fuel filler is getting harder to import as the worldwide demand for automobiles is steadily increasing, so people are looking for a domestic solution. This is only one of the benefits of food-based filler; it also increases the sustainability of rubber production and keeps the waste materials out of the landfill.
According to the article, the rubber made with the food waste filler “exceeds industrial standards for performance.” Although fillers make rubber stronger, most of them—including carbon black—also make the rubber less flexible. The researchers found that mixing eggshells and tomato skin in with the carbon black allowed “strong rubber to retain flexibility.”
The demand for tires is constantly increasing, and this new sustainable rubber will help meet that demand.
These properties have the researchers thinking about possible applications for this new rubber that would be impossible for the old, less flexible rubbers. We may be seeing the red tinge of tomato rubber in many innovative new products in the near future.
Now that the researchers have proven the viability of the product, they have “licensed the patent-pending technology to Cornish’s company, EnergyEne, for further development.” They are testing various proportions of eggshell, tomato skin and carbon black in order to find the best combination.
It looks like the future will be rolling in on red-tinged food waste tires.