Why are tyres black in colour?

 

 Source- Wikimedia

We all are using vehicles having tires which are black in colour. But have you ever wondered the reason behind this? Why don't tires have fancy colours such as mixture of red and yellow giving a flame like appearance? Infact automotive industries invest in making the car body as aesthetically pleasing as possible, but keep the tires black in colour which makes them look plain and dull.
Since tires are made of rubber, earlier tires were available in the natural colour of rubber- white. The working of tyres involve lot of friction with the road which increases the temperature of tyres and causes wear and tear. Natural rubber is soft and could not withstand the increased temperatures and the wear. Thus the rubber was mixed with other chemicals in order to increase the durability of tyre. The most commonly used substance was zinc oxide that helped to increase traction and also made the entire tyre more bright white.

Use of Carbon Black
In the 1900s the company Binney and Smith sold a substance carbon black to Goodrich Tire Company. The company Goodrich Tire found that using carbon black as a reinforcing filler in tyres increased its strength and durability. The black colour of tyres is typically due to the use of carbon black. If you have ever seen a burning tyre you would notice an extremely black smoke in the flames. This black smoke is due to the carbon content in the tyre. Tyres made with mix of carbon black show 50% significant increase in abrasion resistance due to friction and improved traction. Improved traction makes the black tyres more safe to use during rainy season when the roads are slippery. Carbon black being a good conductor also helps to conduct heat generated when the tyre rubs on road. This helps to maintain its temperature and tyre damage due to heat is thus reduced.

Colourful Tyres

 

Source- Bikerumor

Though black tyre has its own benefits you will still find colourful tyres which are used in custom cars, sports bicycles etc. In order to make tyres colourful some additives are needed to be added which can effect the quantity of carbon black used, thereby decreasing the tyre life. However with the increasing advancements in technology it is possible to see durable as well as colourful tyres in the near future.

Thanks for reading!

Other Facts:

• Carbon Black is produced due to incomplete combustion of petroleum products
• In addition to its use in tyres, carbon black is also use as a colour pigment in inks
• Carbon black is a general term used for its subtypes which are acetylene black, channel black, furnace black, lamp black and thermal black