Anyone who has purchased any new tyres he will certainly have noticed the presence of little “hairs” made of rubber. But what are they for? It is sometimes said that their purpose is to indicate thetire wear, or reduce noise while driving, or again improve ventilation…but the reality is different and has to do with the production of the tyre! The hairs, in fact, do not have a specific function but are only the result of a technical step during production.
When one is produced tire in fact a first version was created without it tread. To impress these grooves on the surface it is necessary to push the tire against a mold using air or, more commonly, hot water. This allows the rubber to spread into all the nooks and crannies of the mold itself, although there is a risk of rubber forming during this process. air bubbles. To prevent this from happening and to ensure a good adhesion between the rubber and the mold it is necessary to let out the excess air.
For this reason the mold is equipped with small vent holes through which excess air is expelled, although a small amount of rubber may be sucked in along with it. When the rubber cools, this excess part forms i “hairy” visible on the tire surface. With use, these hairs gradually wear out and disappear.
In summary, we can say that these hairs do not have a function in daily use of the tyre. However, their presence can be an indicator that the tire is new or anyway little used.
To learn more about the tire production process, here is a video ad hoc on the topic:
