6.2.5.c Cord
Cord is a special fabric, which consists mainly of longitudinal threads with a diameter of 0.6-0.8 mm with very rare transverse threads. Depending on the type and purpose of the tire, the cord can be cotton, viscose, nylon, perlon, nylon and metal. The cheapest of all is cotton cord. But it has the least strength, which, moreover, decreases significantly when the tire heats up.
The strength of nylon cord is approximately 2 times higher than that of cotton. And the strength of perlon and nylon cords is even higher. The most durable is a metal cord, the threads of which are twisted out of high-quality steel wire with a diameter of 0.15 mm. The strength of the metal cord is more than 10 times higher than that of the cotton cord, and it does not decrease when heated. Tires that are made out of such a cord have a small number of layers (1-4), less weight and rolling losses*. They are more durable. The cords are placed at a certain angle to the plane drawn through the axis of the wheel. The angle of inclination of the threads depends on the type and purpose of the tires. It is 50-52 ° for regular tires.
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