The Tire

Project

Tire's Composition

Tire is one of the most important components of any motor vehicle, supporting its weight, its cargo and making direct contact with the ground. It is responsible for turning the motor power into traction, as well as for the stability of the vehicle and its efficiency of braking.
They are mainly composed of different types of rubber, fillers - such as clay and silica - carbon black and minerals and chemicals that speed up the vulcanization process, making these materials very difficult to recycle. Each of the different rubber types present very different properties which require great precision in manufacturing. Normally, mean quantities are showed in Figure 1.

Figure 1: Tire composition

Tire's Structure

Let´s take a look inside the tires:

Tire structure

Inner Liner

The inner liner has the function of holding high-pressure air inside. It is composed of rubber layer with low air permeability, and generally consists of butyl, synthetic rubber, or polyisoprene type.

Crown Belt or breaker

The breaker has the function of absorbing external shock and helps prevent any tread injury from coming into direct contact with the carcass. In order to do that, the breaker is placed in between the tread and carcass and it is made of chord. Also, the breaker prevents the separation from the rubber layer and the carcass.
The belt is a strong reinforcement layer placed in between the tread and carcass in radial tires. The belt’s functions are similar to the breaker’s but it also tightens the carcass reinforcing the strength of the tread.

Tread

The tread is highly resistant to protect the carcass and belt. It consists of a thick layer of rubber which comes into direct contact with the road surface. Besides, rubber with strong anti-inner abrasion features is used to increase tire’s driving lifespan.

Casing Ply and Crown Plies

This provides more strength to the tire and are alternate layer of rubber-coated fabric.

Sidewall

The sidewall has the function of protecting the carcass on the inside and providing a comfortable riding experience due to its flexibility during driving.

Shoulder

The shoulder dissipates heat that is accumulated inside tires while driving.

Bead

The bead is in contact with the rim, then, in the case of sudden reduction of air pressure while driving, the tire will not become loose from the rim. The bead is made up of various parts including the bead wire, core, rubber and flipper.

Referências

1.http://www.wrap.org.uk/sites/files/wrap/2%20-%20Composition%20of%20a%20Tyre%20-%20May%202006.pdf Acessed at 09/17/2015.
2. 2. Composition of main materials used in automobile tires in Japan in 2012. Source: Kunioka, Masao; et al; “Biobased Contents of Natural Rubber Model Compound and Its Separated Constituents”; Polymers 2014, 6(2), 423-442; doi:10.3390/polym6020423
http://www.mdpi.com/2073-4360/6/2/423/htm 3. http://www.hankooktire.com/global/tires-services/tire-guide/tire-structure.html Acessed at 09/17/2015.

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Team:Brasil-USP/Project/TireComposition