What factors are related to the hardness of tire rubber?

The hardness of tire rubber is one of the important indicators of tire performance, which is related to multiple factors, mainly including the following aspects:

1、 Rubber formula

Rubber types: Different types of rubber have different hardness characteristics. For example, natural rubber is usually softer, while synthetic rubber can adjust its hardness by adjusting the formula.

Rubber composition and ratio: Different components and ratios in rubber can also affect hardness. For example, increasing the proportion of synthetic rubber usually makes the tire rubber harder, while increasing the proportion of natural rubber makes the tire rubber softer.

2、 Filling material

Carbon black: Carbon black is a commonly used filling material in tire rubber, which can significantly improve the hardness and wear resistance of tires. The type and amount of carbon black have a significant impact on the hardness of tire rubber.

Other filling materials: In addition to carbon black, other filling materials such as silica can also be used to adjust the hardness of tire rubber. These materials affect hardness by altering the cross-linking structure and intermolecular interactions of rubber.

3、 Production process

Sulfurization process: Sulfurization is an important step in the production process of tire rubber, which determines the cross-linking structure and properties of tire rubber. The process parameters such as vulcanization temperature, time, and pressure can all affect the hardness of tire rubber.

Mixing process: Mixing is the process of uniformly mixing rubber, filling materials, additives, etc. The quality of the mixing process directly affects the uniformity and hardness of the tire rubber.

4、 Environmental factors

Temperature: As the temperature increases, the pressure inside the tire also increases, making the tire feel harder. This is because under the condition of constant volume, there is a proportional relationship between temperature and pressure.

Humidity: Humidity has a relatively small impact on the hardness of tire rubber, but under certain specific conditions (such as high temperature and high humidity environments), humidity may affect the cross-linking structure and properties of tire rubber, indirectly affecting hardness.

5、 Tire usage and performance requirements

Different types of tires require tire rubber of varying hardness based on their intended use and performance requirements. For example:

Racing tires usually use rubber with higher hardness to improve the handling performance and grip of the vehicle.

Cars driving on highways require good comfort and stability, so tires with lower hardness are usually used.

Off road vehicles require good durability and tensile resistance, usually using tires with higher hardness.

In summary, the hardness of tire rubber is determined by multiple factors including rubber formula, filling material, production process, environmental factors, as well as tire usage and performance requirements. In the process of tire design and production, it is necessary to choose the appropriate tire rubber hardness based on specific usage conditions and performance requirements.