Modern tires are sophisticated engineered products made from dozens of components including natural and synthetic rubber, steel, fabric, and chemical compounds. The manufacturing process involves assembling these layers in precise stages before vulcanization permanently bonds them together.
A tire is made from multiple distinct layers: the inner liner (airtight rubber layer that replaces the inner tube), body plies (fabric cords coated in rubber that give the tire strength), steel belt package (reinforcing layers under the tread), bead wires (steel hoops that anchor the tire to the wheel rim), sidewall rubber, and the tread compound. Natural rubber, synthetic rubber, carbon black, sulfur, silica, and various chemicals work together in each layer.
Manufacturing begins with mixing rubber compounds on large calendar rolls that coat fabric and steel cord components. Individual components — inner liner, body plies, beads, belt package, sidewall strips — are assembled onto a cylindrical drum called a tire-building machine, which builds the tire layer by layer. The resulting "green tire" is then loaded into a curing press.
In the curing press, the green tire is heated under pressure for a precisely controlled time. Heat activates sulfur crosslinks between rubber polymer chains, permanently transforming the soft, sticky rubber into a durable, elastic finished tire. The tread pattern and sidewall lettering are molded into the tire during this process by the design of the steel mold.
After vulcanization, each tire undergoes a series of quality checks: uniformity testing (measures force variation around the tire's circumference), balance testing, X-ray inspection for internal defects, and visual inspection. Tires that don't meet tolerances are rejected before leaving the plant.
