A Brief History of Windshields Part Two
This system worked well in preventing injuries as there were no large sharp edges to cut the drivers or passengers. However it did present a different problem in that it would shatter very easily when hit by a small stone that would have just cracked the old glass. This lead to many expensive replacements and the need for another new system.
That system eventually came in 1919, again introduced by Henry Ford. Now the windshields would use safety glass that was more akin to the normal glass originally used, only instead of a single pane it would utilise two exactly identical sheets of glass that would be attached on top of each other with a thin layer of lamination running the middle. This laminated plastic had the useful advantage of allowing the glass to crack normally while remaining held in place rather than landing on the driver or the dashboard – leading to the ‘spider’s web’ cracks we see today.
This system was used on top of a new glue called urethane that would powerfully bond the glass to the frame at a molecular level. This worked to attach the windows far more securely and meant that the glass in the windshield would actually aid the structural integrity of the vehicle in the case that it should roll over.