What Are Cord Plies In a Tire?
Cord plies are the internal layers of tires consisting of rubberized textile materials, nylon, fiberglass, or polyester. They are responsible for providing strength and shape to the tire. Without cord plies, the tire loses its shape and becomes flexible.
Types of Cord Fabrics Used
The textiles used in making tire plies vary, including polyester, rayon, nylon, and aramid cord fabrics. Each of these materials provides dimensional stability and helps support the vehicle’s weight, thereby playing a crucial role in the tire’s functionality and safety.
Variations in Cord Ply Designs
Cord plies can differ in their arrangement within the tire’s structure. The ply design significantly impacts the performance and durability of tires. There are two primary types of ply arrangements in tires:
- Perpendicular arrangement: In radial tires, the cord plies are perpendicular to the direction of travel i.e. 90-degree angle. This design allows the sidewall and the tread to function independently and provide good handling characteristics to the tire. This design is common in all-season and touring tires.
- Diagonal arrangement: In contrast, bias tires feature plies that are laid diagonally (typically around 30 to 40 degrees) to the direction of travel, with each ply laid in a crisscross pattern. This arrangement offers more load-carrying capacity and strength to the tire on rough roads. This design is more common in all-terrain and performance tires.