“Once a float glass process line begins it stays online between 10-15 years, and a lot of glass is moving through these lines – about 6,000 kilometers annually,” Erica Clouse, Pilkington North America business development manager, said at this year’s Auto Glass Week held in Indianapolis. The glass process is crucial, according to Clouse, as she explains how the slightest glass distortion can alter a vehicle’s viewing area for cars with ADAS features.
She noted the float glass process hasn’t really changed in the past 70 years, but the speed at which glass goes through this process is important. According to Clouse, there are several steps that must be followed in order to create safe automotive glass. Some of the steps she highlighted included:
- The melting furnace – where the company puts all of the ingredients in. Sand is the base material and other things are added, according to Clouse, to have an easier time to melt. “It’s about 2,700 degrees Fahrenheit.”
- The float bath- which is typically 60 meters long and 7 meters wide and is where a glass ribbon, or a large piece of uncut glass, flows through the melting furnace.
- The cooling process – which Clouse stated is one of the most important steps, because if you go too slowly or too quickly “you run the risk of having a lower glass quality, the aim is to try and minimize distortion in the glass the glass ribbon.”
“It’s important to note the levels of acceptable distortion are even lower with [windshields with] ADAS,” Clouse said. She said acceptable distortion levels come down to driver/customer safety, of which many in the audience agreed with. Distortion, according to Clouse, has real-life implications, as it could make the detected object in the camera’s view move in an unexpected way.
“Why are we talking about this — about calibration and ADAS and how it affects us? It’s because the specifications for a windshield isn’t just about making the driver comfortable,” she said. “With the new comfortability needs that started about 10 years ago people wanted more features and we had to adapt,” Clouse added. Now with ADAS, more adaptation is necessary.
“If you don’t calibrate the vehicle it doesn’t know anything has changed. We like to say if you don’t calibrate it you’re stealing a range of tolerance from your customers. When you don’t do this step you’ve shortened the vehicle’s tolerance range which can increase the changes of drivers having an accident,” she said.