A tire is a complex structure that consists of numerous components. How exactly do we get from the rubber tree to the road? Tire production involves numerous steps. Let's follow a Continental tire through all five essential phases of tire manufacturing:
Material procurement and production of composite materials
Production of components
Step 1: High-quality raw materials are processed into important composite materials
Various branches of industry supply the tire industry with raw materials with which the necessary composite materials are produced.
Steel. The steel industry supplies high-strength steel, which is the starting material for the production of the steel belt (steel cord) as well as the wire cores (steel wire). Chemicals. The chemical industry supplies the tire industry with numerous and important components, such as synthetic rubber and other materials that improve the wear and aging resistance as well as the grip of a tire. Natural rubber. Rubber is obtained from special trees grown on large plantations. With the addition of acid, the milk-like liquid extracted from the trees clumps (latex). This is then cleaned with water and pressed into solid bales, which simplifies transport and storage. The natural and synthetic rubber bales are portioned, cut and weighed. They are then mixed with other additives according to a precise recipe. For a modern car tire, up to twelve different rubber compounds are used.
Textiles. The textile industry supplies the raw materials (rayon, nylon, polyester and aramid fibers) for corduroy production, which are used to reinforce the tire.
Step 2: Production of components
Steel cord. The steel cords supplied and pre-treated on wire rolls are inserted into a calendar that coats them with one or more layers of rubber. The result is an endlessly long corduroy rubber web, which is cut to the right length at a certain angle depending on the tyre size and then rolled up for further processing.
Treadmills. The kneadable rubber material produced in a mixing plant can now be processed into a tread strip. A screw press (extruder) forms the rubber material into an endlessly long strip. After the extrusion process, the weight per meter is checked and the tread is cooled in an immersion bath. The tread is then cut to the correct length according to the tire size, after which a further piece weight check is carried out. Textile cord. A large unwinding device inserts a large number of textile threads into the calendar, where they are embedded in a thin layer of rubber. This endlessly long web is cut to the desired width perpendicular to the yarn run and wound up for further processing.
Steel core. The bead core consists of several ring-shaped steel wires, each coated with rubber. A rubber profile is then placed on this ring. Sidewall. Sidewall sections tailored to the tire size are produced with the extruder.
Inner layer. The airtight inner layer is formed by a calender into a wide, thin layer.
Step 3: Tire construction
Now the tire construction can begin. All semi-finished products are assembled into a tyre blank by means of the tire construction machine. This is done in two phases: first the carcass and then the tread/belt. To prepare for vulcanization, the blank is sprayed with a special liquid.
Step 4: Vulcanization
This is the curing process. The tire gets its final shape after being vulcanized for a certain period of time at a certain pressure and temperature. During this step, the raw rubber is converted into bendable and elastic rubber. In addition, the tire receives its profile and sidewall markings in the shapes of the vulcanizing press.
Step 5: Quality control
Every single production step, from the testing of the raw materials to the delivery of the finished tire, is subjected to continuous quality control.
With a multi-stage process, Continental ensures that the quality of the tires is carefully checked. Finished Continental tires are subjected to the following tests:
Checking tire uniformity
Only if all examinations and controls have been successfully completed, the tires will be sent to the distribution warehouse.