Contact Us

Causes and Identification of Heat Generation in All Steel Radial Tires

Ⅰ. Reasons for heat generation of all steel radial tires

Whether all steel radial tires generate heat is determined by air pressure, load and speed.

At high temperature of 96°C, the strength loss of natural rubber is about 35%. It can begin to flow at 130-140°C. Above 150-160°C, it becomes a viscous fluid with great viscosity. It begins to decompose at 200°C, an

d then decomposes sharply at 270°C. When the heating of all steel radial tire reaches the temperature of rubber modification, the modified rubber will generate gas, resulting in delamination of rubber components.

When the temperature of the all steel radial tire is very high, it should be cooled slowly, not rapidly with cooling water, so as to avoid damage to the self-reinforcing property of the rubber (rubber self-healing function).

Ⅱ. How to identify shoulder gaps caused by heating of all steel radial tires

The thickest point of the tire is between the belt layer and the 0° belt, which is also the part with the largest heat generation and the slowest heat dissipation (so the shoulder rubber should have good heat dissipation performance). When the temperature reaches a certain level, the flow process of the rubber parts in this part is from inside to outside, which causes the loss of the rubber parts in the steel radial tire, and generates gas to form shoulder bulge.

If blasting occurs, there is viscous fluid. The rubber at the blasting mouth has aging phenomenon. Sometimes carbonized agglomeration occurs. This is also one of the ways to distinguish man-made heated shoulders.

Ⅲ. Reasons for the high probability of problems in the tire shoulder and tire bead of all steel radial tires

The rolling resistance of all steel radial tires is closely related to the use of tire performance.Because when the tire rolls, the energy dissipation distribution (also called stress or strain distribution) on the section produces hysteresis loss and heat generation, which will reduce the tire use performance, thus affecting the use of the tire.

Tire material hysteresis loss of energy (heat generation) is mainly concentrated in the tread area, followed by concentration in the bead area of all steel radial tires. That is, the proportion of energy dissipation distribution of the tread bead part of the material is the largest, so the resulting hysteresis loss is large, the corresponding heat is also large, while the corresponding parts are more likely to have problems.

1. When the tire is rolling, the alternating stress on the shoulder of the tire (that is, tensile, compressive and shear stresses exist simultaneously) is the largest and most complex, resulting in hysteretic loss. At this time, the generation of heat is the largest, the chances of problems are also large.

2. The belt ply bears 60-75% of the stress of the steel radial tire carcass, so the end point of the belt ply creeps the most, the heat generation is also large, and the end point of the cladding is easily detached. This causes shoulder delamination/belt ply endpoint loosening.

3. The energy consumption generated by friction inside the tire accounts for more than 80% of the total energy consumption of the tire.

4. The bead area has more problems for the same reason.

5. Due to the meridian(radial) direction of carcass ply cord, the radial deformation of sidewall of all-steel radial tire is large under load condition. Due to the low lateral rigidity, the stress on sidewall is high.

In this case, the rubber in the middle of the sidewall is stretched bidirectionally, while the bead area and the sidewall end of the all steel radial tire are compressed bidirectionally, resulting in bending cracks in the bead area or delamination of the belt layer from the sidewall end.