Mobility

Windshields are surrounded by small black dots, that are sometimes also found around the central rearview mirror to place toll badge. But what's their real use?

The days of single-glass (laminated) windshields at the beginning of the 20th century are long gone. Since the 1950s, they have been made of tempered glass. Since then, the windshield has become athermic, heated, a head-up display screen, a support for the rearview mirror, cameras and sensors of all kinds. However, it remains a fragile element subject to constraints of the weather, gravel and the sun. The sun is undoubtedly its greatest enemy, following projections of various objects of varying sizes. And on this high-tech curved glass, there are small black dots.

Smooth transition

The first function of the black dots is aesthetic. It offers a smooth transition between the black perimeter strip hiding the glue, frit, and the rest of the windshield. This is glued with a strong and durable urethane adhesive. The dots are baked directly onto the glass. Beyond their smooth transition effect, these black dots also create a stronger connection between the glass, the glue and the car frame. In particular, they prevent the glass from being distorted by the sun's rays, as they help disperse heat. Their black color also reduces the glue's deterioration by UV rays.

For toll collection

Those around the rearview mirror have another additional function. They can reduce the driver's glare by reflecting the light. They are also there for aesthetic reasons while providing a favorable area for the passage of waves through athermic windshields. This is why it's better to place toll collection badges there for France, Spain, Italy, Portugal or Scandinavia, for example.

(MH with Olivier Duquesne – Sources: Ca m’intéresse – Suzuki – Vinci Autoroutes – Picture: © Suzuki)