Greener and quieter tires

A new European regulation requires manufacturers of new tires to limit the values ​​of resistance and rolling noise. The rolling resistance, ie the energy required to roll the tire, translates directly into fuel consumption. Therefore, if we reduce the resistance we save fuel. In turn, a reduction of noise generated by the tire results in less noise pollution.

Although this regulation is currently not compulsory for retreaded tires, the Valencian company Industrias del Neumático S.A., one of the leading companies in manufacturing of recycled tires in Europe, applied for public funding in order to conduct a study of possible improvements in their product.

The research group Applied Mechanical Engineering of the Elche University, directed by Miguel Sánchez Lozano, assessed the impact of new tire band drawings and innovative production processes. "Our collaboration has involved advising the company when selecting new equipment and then monitoring the manufacture of prototypes and testing them to see the benefits from the implementation of new systems," explains Professor Sanchez. The company has proved that not only can they reduce the noise the tire generates by 3%, but also that manufacturing is more precise and the wheel is more balanced.

In terms of rolling resistance, experimental formulations of rubber were tested. "We proposed three different compounds which introduced a new component which is silicon in various proportions to see its effects," explains the researcher. His research group collaborated in the development of these new rubber compounds, and then made a series of tests to evaluate their mechanical behavior. The researchers also tested the strength of the prototypes.

After about 200 trials, they drew conclusions about the best mix of rubber, verified that the prototypes met all the required values, and compared results with recycled tires made of traditional materials and with various brands of new tires. "We concluded that the reduction of rolling resistance obtained is between 3 and 5% depending on the type of tire, which has a direct impact on fuel economy that the consumer could get through this new rubber. The company is now studying the economic feasibility and when to implement the new rubber composition in the production chain," comments Miguel Sánchez.