Elastomers and Tire Compounding

The pneumatic tire consists oftwo basic areas the tread area, which is responsible for ground contact, and the casing whose function is to support load and transmit power to the tread area. Each of these areas has several components with markedly different properties and which serve specific and unique functions, and all of which must interact together for designed performance. The role of the rubber compounds used in these basic components is threefold  

1) to provide the contact area between the vehicle and the road surface  

2) to provide the cohesive material that holds the tire together so it acts as an integral unit  

3) to provide protection for the strength-bearing components, that is, the textiles, steel beads, steel cords, and steel breakers in steel belted radial tires. 

The steel belt, which provides strength and protection of the ply or plies, is encased in a compound that must possess adhesion to the steel and provide stress transfer from the very rigid steel to the many times more flexible tread, sidewall, and textile carcass components. The belt layup also provides a uniform tire tread footprint necessary for uniform wear. A wedge compound is formulated to reduce belt-edge shear stresses while tying the belt to the carcass and reducing hysteresis. 

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Elastomers and Tire Compounding 1173 Table 4.7 Typical tread compound formulations and quantities of raw materials [11]. 

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