During the bus ride, many people found that the edges of the glass were black and there were some small transitions from large to small. A careful driver will find a small area around the window or behind the rear view mirror windshield. There are many small black dots that are densely arranged. But have you ever thought about what these little black spots are for? What is the use of small black spots on the car glass?
First of all, for the sake of beauty. There is a sealant between the window and the body (especially the front windshield), and the sealant also provides a better seam for the window. But the disadvantage is that it is not beautiful, and you can see the traces of glue without blocking, so these black areas can play a role of shielding and aesthetics.
Second, protect your vision. The small black dots next to the rearview mirror can reduce the direct sunlight of our eyes while trying not to obstruct our driver’s line of sight, which helps to alleviate driving fatigue.
Finally, prevent the car glass from bursting. The state has expressly stipulated that the front door of the car can not be made of tempered glass, and the current car glass is generally made of laminated glass. The glass itself has a strong light transmission. Although the temperature in the center of the glass is not too high under the sun exposure, the metal body is in contact with the glass. The temperature of the metal body is very high under the scorching sun. Naturally, it will be transmitted to the edge part of the glass, which will cause the temperature of the whole glass of the car to be uneven. After the glass is heated and expanded, it will be very easy to burst. The use of some small black spots can gradually increase the heat absorption and disperse the expansion force. Avoid glass damage. Simply put, the window frame is hot, the glass is hot, and a small black dot is needed to transfer heat to reduce the pressure on the window.
