Just how do manufacturers make millions of safe tyres?
Tyres are perhaps the most essential piece of equipment on your vehicle. They are paramount to your safety and driving experience. They provide the grip needed for traction on the road and must perform in all road and weather conditions. Most are pneumatic (they contain air under pressure) and there are hundreds of millions manufactured every year. So, how do tyre manufacturers produce the black circles that you depend upon?
Tyre jargon explained
Before I explain how tyres are made, I should uncomplicate some of the tyre jargon we use.
The plies enable the tyre to be flexible and help to provide the strength needed to operate under extreme road conditions. They are usually made by weaving fibre cords together and then coating them with rubber. They are like the bones of your body – they provide the skeleton that the tyre is built around.
Belts are formed around the tyre as strength reinforcers. Where plies provide flexibility, belts provide rigidity. They are made of steel wires, and then, again, coated with rubber. Manufacturers have spent a lot of money, time, and effort in the development of belts that resist punctures and now provide the backbone for tyres that can last 80,000 km and more.
Generally considered to be the ‘business’ part of the tyre, the tread is softer than the rest of the tyre and provides grip and cushion. Different tread patterns provide different levels of grip.
Grooves and sipes
When you look at the surface of a tyre that comes into contact with the road, you’ll notice deep grooves between the tread blocks. These act to expel water. Look a little closer, and you’ll see small grooves cut into the tread blocs. These are called sipes, and provide extra grip.
Manufactured from extra strong steel and coated with rubber, beads form an airtight seal between the tyre and wheel rim.
The sidewall runs from the bead to the tread. It’s made of extra thick rubber to provide strength and stability. You’ll find all the information about the tyre is embossed on this part of the tyre.
Where the sidewall and tread meet, you’ll find the shoulder of the tyre. This is the part of the tyre that provides extra strength when cornering.
How are tyres manufactured?
There are five steps in the tyre manufacturing process:
Raw materials are blended to form the rubber that will be used to make the tyre. There could be as many as 30 types of rubber used to form the rubber compound. Other ingredients used include:
- Carbon black
- Various chemicals
The rubber compound is allowed to cool before being cut into strips. These strips are used to form the basic structure of the tyre.
The tyre is built working from the inside. This is completed in machines, which form the belts, beads and plies. An ‘extruder’ is used to form treads and sidewalls, which are then rolled and cut into strips. Once all these parts have been assembled, you’ve got something that looks like a tyre.
The tyre is now vulcanised, compressing it into its final shape. It is also here that the tread is finalised, and the sidewall markings are embossed on the tyre.
5. Controlling quality
The manufactured tyres are tested, with specialist X-ray machines used to inspect for bubbles and voids in the rubber. A test wheel is used to inflate and spin the tyre to determine balance and ‘straightness’.
Once the tyre has been fitted to your vehicle, the responsibility for inspection is all yours. If a tyre is compromised by a cut, bulge, or wrong pressure, so is your safety. See our article “How do Australia’s drivers know they need new tyres?” for tips on checking tyres and the signs that a tyre is past its useful life.
If you have any doubt that your tyre is no longer fit for purpose, please, please bring it into our tyre shop in West Brisbane. A few minutes could save your life.
Keeping you safe on the roads,