Tire companies put a great deal of thought, planning, engineering and testing effort into each tire they produce. This is because so much rides on having effective and safe tires on your vehicle. Below, we take a look at how tires are made and why quality manufacturers are so trustworthy today.
Tires are essentially rubber casings that surround the rim of your vehicle wheels. This rubber is both strong and flexible to provide an appropriate grip for vehicle traction. Tires also cushion passenger rides, providing comfort as the car or truck travels on the roadway or other surface. Obviously, tires are fitted onto cars, trucks, buses, tractors and aircraft. But they also provide important functions on forklifts and other industrial vehicles. They are found on baby strollers, shopping carts, bicycles, motorcycles and wheelchairs, too.
Most tires for automobiles are pneumatic, meaning they maintain a certain air pressure on their interior. In the past, these tires had inner tubes that held the air. But modern styles feature a pressure seal that keeps the air within the wheel.
The first pneumatic tire was invented in Scotland in 1845. This design was ahead of its time, not widely needed until bicycles became popular after 1880. At that time, a second inventor from Scotland updated the design.
The primary material used in manufacturing of tires is natural rubber. But today’s tires also use synthetic rubber. Synthetics match natural characteristics of strength and durability through treatment by multiple chemicals, followed by heat processing. Vulcanization, the process of making rubber stronger, was invented by American Charles Goodyear in 1839. He was the founder of one of today’s most known tire companies, the one bearing his name.
Modern tire factories employ skilled workers who make almost 300 million tires annually. These factories also use advanced automation for many steps in the manufacturing of tires.
Materials Used in Tire Manufacturing
Tires consist of multiple raw materials, including natural or synthetic rubber. Natural rubber comes from the rubber tree, in the form of a milky liquid. This liquid is mixed with acids that create a solid rubber. Specially-designed presses extract excess water from this rubber, forming the material into sheets that are dried, pressed into bales and transported to factories. Synthetic rubber is made of crude oil polymers in lieu of the rubber plant’s natural liquid.
Along with rubber, carbon black made from crude oil or natural gas is used in the manufacturing process. Other key ingredients include sulfur and other chemicals that enhance high friction with low mileage or high mileage with low friction, depending on the tire’s purpose. Chemicals are used to maintain flexibility of the rubber and protect the material from the sun’s UV radiation.
The Tire Manufacturing Process
The tire manufacturing process starts with understanding of tire usage and driving habits. This understanding comes from intensive research in the field. After conducting research, a tire company starts developing and combining more than 200 materials that go into each tire for specific purposes, such as fuel efficiency, safety, performance and environmental friendliness.
Materials used in tire manufacturing fall into these categories:
- Natural rubber, such as for tread layers
- Synthetic rubber, for treads
- Carbon black and silica, for durability
- metallic and textile reinforcement cables, forming the shape and making the material rigid
- Chemical agents, each used for unique properties like grip or rolling resistance
After development and acquisition of appropriate materials and thorough design processes, testing and simulations, the manufacturing process can begin. A manufacturer can build tires efficiently through human and automated processes. The industry has developed a wide range of machines to suit their specific manufacturing needs.
Throughout tire manufacturing, quality control processes maintain quality standards. There are over one billion miles of tire tests performed each year. This equates to driving a vehicle around the planet more than 40,000 times.
Design and Performance Intertwine
Effective tread design is critical for tire performance. The patterns and grooves of tire tread help your tire grip the road in a variety of driving conditions. Tread also makes your ride safer and more comfortable.
For example, certain design elements impact how your tire grips a wet surface. These elements of design include:
- Groove ratio, how the tire pumps water away from it
- Shape and layout, making draining of water more effective and quicker
- Sipes, improving traction on ice or wet conditions
For a dry surface, design elements affecting grip include:
- Tire shape, called the profile, for support in turns
- Groove count, affecting level of grip
- Tread blocks, improving traction but affecting road noise
- Self-locking sipes, reducing rigidity of the tread
A tire typically consists of nine parts. These include:
- Inner liner, an airtight layer of synthetic rubber
- Carcass ply, above the inner liner and containing textile fiber cords or cables in the rubber for strength and pressure resistance
- Lower bead area, to grip the metal rim of wheels
- Beads, ensuring an airtight fit and keeping the tire in place on the rim
- Sidewall, protecting the tire’s side
- Casing ply, creating tire strength through steel cords bonded in the rubber
- Cap ply, to reduce friction heating and maintain tire shape at fast speeds
- Crown piles, providing a rigid tread base
- Tread, for traction and turning grip
With so many parts involved in the design and manufacturing of vehicle tires, it is easy to see why some manufacturers rise above the rest. Regulators also ensure tire manufacturers meet minimum standards for safety, durability and reliability in the manufacturing of their products. The industry is so closely regulated because of the role tires play on any motorized vehicle. They are essential auto parts that keep people safe, even at the highest speeds and during dangerous conditions.