Why do we need black dots around the edges of car glass

Have you noticed black dots on car windows? Many see them every day, but wonder about their purpose. In fact, they are drawn not only for beauty, but also perform some functions. Let's find out what they do and how they are called correctly.

What are black dots on glass called?

Black stripes and dots on the edges of car windows are correctly called frits.

Frits are coated with ceramic paint on glass and hardened in a special furnace. The result is a rough, indelible layer of frits that perform 4 important functions.

Sealant protection

The first and most important function of frits is to protect the urethane sealant that holds the windshield of the car from UV rays.

If these dots were not there, then sunlight falling on the glass would destroy the sealant. And this, in turn, will lead to the fact that the glass will no longer hold on and just fly out.

Automakers have taken care of this problem by coming up with this clever solution. The rough surface allows better adhesion of the adhesive.

Improve Appearance

By itself, the sealant leaves ugly defects that are visible when the glass is installed, and therefore the second function of the frits is to improve the appearance. Large dots smoothly turn into small ones and then turn into a strip. This approach gave a pleasant appearance. Now it's hard to imagine what cars would look like without them.

Until the 50s and 60s, automakers used special rubber seals to hold the glass in place. And only later came the pasting technology.

But at first, not frits, but metal plates were used as protection. Take a look at a 60s rarity like a 1967 Ford Mustang and you'll see how the plates wrap around the entire windshield and rear window. However, this approach has shown its imperfection. And now they began to replace them with the usual black dots.

Uniform heat distribution

The black band causes more heat absorption. And this is not surprising, because dark colors heat up and retain heat more than light ones.

To evenly distribute the temperature and reduce the load on the glass from such thermal unevenness, a dotted image is used. This is the third function.

Sun glare protection

The fourth important function of frits is to protect the driver from blinding by the sun. Take a look at the part of the windshield where the rearview mirror is located. There are many black dots around it. They play the role of sun visors so that the driver is not blinded by the sun entering the center.

Now you know why you need these black dots on your car windows. They are used not only on cars, but also on any type of transport.