Some like it dot: windshield markings, explained
If you’ve ever been sitting in Tucson traffic, bored out of your mind, you may have noticed all those little dots around the fringes of your windshield. You may have even wondered, what are those even FOR? You’re not the only one. Jalopnik’s David Tracy thought the same thing, so he did some digging and found what we in the glass industry already knew: they’re more than just decoration:
Rick told me that the black band around the edge of the glass is called “frit,” a baked-in ceramic paint that’s essentially impossible to scrape off. That frit band along the edge of the glass, he told me, serves three main purposes.
Most importantly, it acts to prevents ultraviolet sun rays from deteriorating the urethane sealant. That matters, because the sealant doesn’t just keep rain out of the car, it actually holds the glass in place. The last thing you want is the sun to cook your adhesive, and send your window flying out the next time you hit a speed bump.
The frit band also acts to provide a rougher surface for that adhesive to stick to, and it’s a visual barrier, preventing people from seeing that nasty glue from outside.
There are other purposes to the ‘frit’, like helping to dissipate heat during the glass curing process. The more you know!