The hidden science behind car windshield black dots

Most windshields in cars have small black dots of varying sizes along their edges. These can be found in vehicles of every class from different manufacturers. What is their actual purpose?

Although they may seem insignificant, these dots serve an essential function. To understand their significance, we need to look at the process of installing windshields in cars. Before the glass panel is mounted, its edges are coated with ceramic paint and heated. This process ensures that the adhesive bonds better to the rough surface.

During heating, the paint reaches a higher temperature than the glass itself. These dots are used to protect the windshield from cracking due to temperature differences, which reduce the temperature difference on a small surface of the glass. The size of the dots changes gradually to protect the windshield effectively.

Additionally, the black frame of the windshield, known as the "frit," masks the adhesive used to install it. It also protects it from harmful UV radiation, which helps to extend its lifespan.