You may have seen high end homes or commercial building with curved window glass installed. While it looks pretty cool; I have often wondered how curved window glass is made. Would it be feasible to incorporate the curved glass into the average home? The answer is yes it can be done, but you better have deep pockets. Each individual piece of glass can take upwards of 6 hours to manufacture. So for the average homeowner, it sounds like flat glass windows is the way to go. Of course you can still obtain the curved effect using flat glass in the construction of a bay window.
Manufacturing Curved Window Glass
The first step is to manufacture a precision mold to control the shape of the glass and match the architectural design. To get the curve just right, the fabricators cut a flat piece of glass with an outside radius that matches the intended curve. They then make several supports using steel plate. Each plate has a concave radius that perfectly matches the curve of the glass template.
The supports are placed vertically on a rolling cart to form the support structure. Then a series of slats are stacked side by side to create the shape of the mold. The entire mold is then placed into the oven for about an hour to preheat the steel. This is a critical step in that the glass heats up much quicker than the steel and if it came in contact with the cold steel it would shatter.
After cutting the glass to size it is imperative that it is perfectly clean. Just a small speck of dust could cause the glass to shatter during the firing process. After carefully cleaning the glass it is thoroughly inspected using a UV light to expose any contaminants.
To ensure that the glass can easily be removed from the mold, it is coated with a mixture of detergent, clay, calcium carbonate. The glass is now ready to be placed in the mold. By this time the furnace should have reached a temperature of 900 degrees Fahrenheit.
Three hours later, and at a temperature of about 1300 degrees Fahrenheit, the glass molecules begin to move and the flat glass sags into the curved mold. The final step is to cool the glass slowly over a period of about 2 hours. This step is known as annealing, and is critical to prevent the glass from cracking. Voila! You now know how to manufacture curved window glass.
Curved Window Glass Video
I came across this awesome video that demonstrates how curved window glass is manufactured. Take a peek: