Making tires from wood might seem like an idea that would be more at home on the Flintstones than in the early 21st Century, but that’s just what a team of wood science researchers at Oregon State University (OSU) are proposing. They aren’t suggesting constructing the tires solely from wood, but replacing silica with microcrystalline cellulose derived from plant fiber as a reinforcing filler in the manufacture of rubber tires. The result could be a tire that would cost less, perform better and save on fuel and energy.
As part of their study the OSU researchers replaced up to about 12 percent of the silica used in conventional tire manufacture with microcrystalline cellulose – a micrometer-sized type of crystalline cellulose with an extremely well-organized structure. This decreased the amount of energy needed to compound the rubber composite, improved the heat resistance of the product, and retained tensile strength.
The study also showed that the new tire possessed comparable traction to existing rubber tires in wet, rainy conditions and actually decreased the rolling resistance of the product in high temperatures. This would improve the fuel efficiency of tires made with the new approach in hot weather.
Cellulose fiber has been used for some time as reinforcement in some types of rubber and automotive products, such as belts, hoses and insulation – but never in tires, where the preferred fillers are carbon black, which is made from increasingly expensive oil, and silica, which is energy-intensive to process. Both products are also very dense and reduce the fuel efficiency of automobiles. Conversely microcrystalline cellulose is produced in a low-cost acid hydrolysis process.
The research team say that more research is needed to confirm the long-term durability of tires made using microcrystalline cellulose, but hopefully they’ll last longer and provide a smoother ride than these.
The OCU team’s research appears in the journal, Composites Part A: Applied Science and Manufacturing.