The composite materials are combined to make constituent parts of a tire. The rubber and the pre-treated steel cords that are delivered on wire reels are fed into a calender. The steel cords are encased in one layer or multiple layers of rubber. This produces a long, continuous sheet of cord and rubber that is cut to the correct length at a certain angle depending on the tire size and then rolled up for further processing.
For the tread that forms the connection to the road and the sidewall, kneadable rubber material that has been made in a mixing plant is made into a long, continuous strip by a screw-type extruder. After the extrusion process, the weight per meter is checked and the tread is cooled in an immersion bath. The tread strip is then cut to the correct length for the tire size, at which point a further unit weight check is carried out. The extruder also makes sidewall sections that are cut to suit the tire size.
The textile threads are fed into the calender where they are embedded in a thin layer of rubber. This long, continuous sheet is cut to the desired width at a 90° angle to the threads’ direction of travel and wound up for further processing. It forms the textile cord ply that holds the internal pressure and keeps the tire in the correct shape.
The air-tight inner liner is made into a wide, thin layer by a calender. This component seals the air-filled inner chamber and regulates the tire pressure. In modern tubeless tires, the inner liner replaces the tube.
The bead core is the connection between the tire and the rim and consists of many ring-shaped steel wires, each of which has its own rubber coating. We subsequently fit this ring with a rubber profile.
