Glass: From Start to Finish

After canceling last year due to COVID-19, there was hope for AIA’s Conference on Architecture to return to an in-person format this year. With remaining uncertainties surrounding the pandemic, the organization opted for a virtual platform instead. The event is taking place over four days, including several seminars, demonstrations and various other virtual activities.

Amid a July 12 session, Jacob Kasbrick, regional architectural manager of Guardian Glass, discussed how glass is made and how the parts of a glass facade work together, while identifying important design considerations.

“Glass is a chameleon,” he said, explaining that, at different times of day, shadows and the environment can affect how buildings and glass look.

Kasbrick began with how glass is made – starting with soda ash, salt cake and iron oxide, with 50% being silica sand and 15-20% cullet (recycled glass).

The material then undergoes technical processes to achieve specific qualities and performance, he pointed out.

Raw materials enter a furnace and are heated to produce molten glass at 2900 degrees F. The molten glass then floats on a tin bath at 2000 degrees to become a flat ribbon. It is then cooled in a lehr to become annealed glass. Scanners then identify imperfect pieces and discard them, to package only perfect sheets of glass.

“Older generation coating,” according to Kasbrick, such as pyrolytic coatings, are added during this process.

Sputter coating, or soft coats, are done when glass enters a vacuum chamber where metals are sputtered onto the glass surface in microscopic layers of metal, adding performance attributes and a wide range of aesthetics.

The process begins with high-intensity scrubbing, rinsing and drying to clean glass. The surface is then inspected in a positive pressure room to ensure contaminants are removed, after which vacuum chambers reduce atmospheric pressure and then add sputter coatings. High performance coatings are ultra-thin and can consist of more than 12 layers.

The process of selecting the right type of glass requires consideration of performance, like keeping buildings insulated and measuring the heat gain or loss, or the U-factor.

In order to achieve desired performance and aesthetics, Kasbrick recommends using samples to visualize the end result of a project and to view them in different lighting conditions, angles and distances. Glass is not a one-size-fits-all medium, he suggested.

The AIA Conference on Architecture is an ongoing series. Sessions will continue July 29 and August 19. Stay tuned to USGNN for the latest updates.