Tyres seem like relatively simple objects, right? After all, they are just big, black doughnut-shaped pieces of rubber to help your car roll. While this is true from a simply observational perspective, there is actually a lot more to a tyre than you might think.
From the history of the humble tyre to the modern manufacturing process, there is plenty to learn.
You may or may not be surprised to know that the first tyres were actually bands of iron that lined the wooden wheels of carts in the old days. However, in the mid 1800’s rubber made its way onto the scene for the first time. While this was a marked development, it was still just solid rubber that replaced the iron bands. It wasn’t until 1895 that the first air inflated rubber tyres started to appear on vehicles.
The next major progression came in the mid 1900’s when steel belted radial tyres were invented to provide greater tyre life and longevity. This brought inflated rubber tyres into the mainstream of vehicle production, and provided vehicle manufacturers with a new resource.
So with the broad history of the tyre out of the way, how are the tyres on your modern vehicle actually made? The entire manufacturing process is extremely complicated due to the materials and the machinery involved, but we will outline the general process.
The materials needed to make a standard tyre include:
- Synthetic rubber
- Natural rubber
- Carbon black
- Nylon belt
- Steel belt
- Antioxidants and antiozonants
- Vulcanisation accelerators
Compounding and mixing
The first step in the tyre manufacturing process (after sourcing the raw materials) is to create the rubber compound by mixing the materials together. This process is usually done in three of four stages, and is similar to the process of mixing cake batter ingredients together in a big mixer.
Cords are then manufactured to help the tyre to withstand the loads imposed on them. These can be either fabric cords or steel cords. After this, the cords are put through a machine that allows them to be securely bonded with the rubber compound.
The inner layer of the tyre goes through a separate but similar process.
The next step in the process is for the tyre bead to be prepared. This is a crucial part of a tyre, as it keeps a tyre mounted onto a wheel. For this reason it is made from steel and hard rubber, and is fastened securely. The reason this process must be done accurately is because any any errors can make it unsafe or difficult to fit to a wheel.
After this, the rubber is put through a machine that effectively marks out the tread pattern (often the part which we most identify with when thinking about a tyre) and the sidewalls, based on the different compounds used.
The curing process then gets underway, which involves chemical treatment of the rubber and fitting the tyre to a mould, which will ultimately determine the shape of the tread. The tyre is inflated on this mould and then heated (known as the vulcanising process) to an extreme temperature, causing the tread to be formed on the outside and solidified.
The result of this process is what we see on our cars.
All that is left now is for the tyre to be inspected for quality assurance purposes, to ensure that the performance and safety of the tyre will be up to Australian safety standards.
Tyre development and manufacturing is constantly undergoing innovation, and it’s interesting to know what goes into the process. So the next time you go for a drive, think about the process that was required to create each of your tyres.