A tire provides a cushion between the vehicle and the road, to reduce the transmission of road shocks.
The air in the tire supports the vehicle’s mass, and the tread provides frictional contact with the road surface, so the vehicle can maneuver for normal use.
Radial ply tires are usually manufactured in stages.
The casing is initially formed by laying the rubber inner liner, and the first layer of textile ply cords, around a flat drum mold.
The rubber-covered bead wire and sidewalls are then locked into position.
The rubber sidewalls protect a finished tire from kerb damage and weathering.
At the second stage-building machine, the tire is shaped. Belts of steel wire are guided into place.
The tread is then positioned and the uncured tire is consolidated by rollers, before it is placed in the mold.
During the molding and curing stage, the tire is subjected to high temperature and pressure, and it takes on its final fixed identity, with its own distinctive tread pattern.
It is then trimmed and checked for balance and quality before it is inflated, and run under load against a rotating drum.
This is a final check for ride uniformity.