TIRES are made up of synthetic rubber, natural rubber, fabric and wire, along with carbon black and other chemical compounds. Natural rubber is harvested mainly in the form of the latex from the rubber tree. The latex is a sticky liquid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". Synthetic rubber are mainly polymers synthesized from petroleum byproducts.
There are environmental issues concerning tire manufacturing and use. Rubber tires are non-recyclable and non biodegradable. Disposal after end-of-life use is a major concern. Tires are also mostly made of petroleum which is a non-renewable resource. I read one article that says one passenger car tire contains around 7 gallons of oil. With these issues, there are efforts being made to make tires more eco- friendly.
One such research is from the Ohio State University. Interestingly, scientists have discovered that food waste can partially replace the petroleum-based filler that has been used in manufacturing tires. What sort of food waste? Believe it or not - egg shells and tomato skin. It addresses two issues-less waste going to landfills and less dependence on non-renewable resource.
In the tests, rubber made with these food waste fillers exceeds industrial standards for performance. This may ultimately open up new applications for rubber. As the researchers explained, the technology will make the manufacture of rubber products more sustainable and will reduce American dependence on foreign oil and keeps waste out of landfills.
According to the United States Department of Agriculture, 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. The shells don’t biodegrade in landfills so they stay there forever.
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 again end up as waste.
In another study, the University of Minnesota invented a new technology to produce automobile tires from trees and grasses. The car tires produced from biomass that includes trees and grasses would be identical to existing car tires with the same chemical makeup, color, shape, and performance.
A tire manufacturer, Goodyear Tire & Rubber Company, is using silica derived from rice husk ash to increase the fuel-efficiency of its tires. Around 700 million and 800 million tons of rice is harvested each year. About 20 percent of a rice kernel is the inedible husk, which can be burnt to generate electricity, producing ash that is rich in silica. Silica is used as a reinforcing agent in tire tread compounds.