Have you ever wondered what’s the purpose of the black dots on the edges of your car’s windshield? Many people believe they are stickers or plastic to protect them from the sun, but nothing far from the truth. Actually, they are made with a special ceramic paint which is resistant to heat and the passage of time and, therefore, they are not easy to remove.
Even though they seem like a simple decorative detail, those black points have an important purpose: strengthen the windshield making it safer. So, let’s learn more about these black dots’ purpose.
The real purpose of the black dots
In the automotive industry those dots are known as ‘’frit’’ or ‘’frit band’’. Even though they seem like they don’t have any mechanical function, they do have a key role in the way in which the windshield is maintained on the car. When a windshield is replaced, mechanics use that frit band as an area to join both the frame of the car and the glass.
Before, car brands used to use rubber seals and chrome borders to attach and secure the windshield. This method helped reduce vibration and made the car look polished. However, around the 1950s, manufacturers began using adhesives instead of rubber seals. These adhesives were faster and cheaper to use but had a major problem: they didn’t hold up well under sunlight and started to lose strength over time.
Origin of the ‘’frit band’’
To solve this issue, engineers created the ‘’frit band’’, a long area of black dots we see today on the edges of the windshield. The main purpose of this is to keep the windshield in place:
- The outer part of the frit band acts as a barrier against ultraviolet (UV) rays from the sun, which can damage or weaken the adhesive that keeps the windshield in place. By blocking UV rays, the frit band helps the glue last longer and stay strong.
- The inner part of the band has a slightly rough texture that helps the adhesive stick better to the glass. This ensures a solid bond between the windshield and the car frame, making it safer for passengers.
Why dots instead of lines?
The first question that might come to your mind now is: why dots? And the answer is a functional purpose. If the transition between the dark part of the edge and the transparent glass were a straight line, it would create a visual distortion that would bother drivers.
So, the black dots create a soft transition between the dark area and the transparent part, which allows drivers to better adapt to the darkness inside the car and the light outside.
What’s more, the dots also have an aesthetic purpose: they hide the adhesive that keeps the windshield making the edge of the glass look cleaner and uniform.
Importance of a right sealed windshield
If the adhesive that holds the glass isn’t applied correctly, the car’s structure can become weaker. In fact, poor sealing can reduce the overall strength of a vehicle by as much as 30%. This means that if the car rolls over during an accident, the roof could collapse and injure or even crush the passengers. Additionally, if the windshield isn’t properly sealed, the airbag on the passenger side might not deploy correctly, reducing its ability to protect you in a crash.
For this reason, experts recommend checking the windshield of your car regularly. If you notice cracks, leaks, or any sign that the adhesive might be failing, it is important to visit a professional repair shop as soon as possible. Isn’t it curious how everything has a reason no matter how insignificant it might seem?