Almost unheard of a century ago, safety glass has made its way into our daily lives, from the windshield on our cars to the frameless shower doors in our bathroom, it’s made the wide use of glass possible.

In our follow up to our two part series on safety glass, we’ll be looking at laminated safety glass.

The origin of laminated safety glass, Edouard Benedictus’s accidental discovery:

“Benedictus climbed a ladder to fetch reagents from a shelf and inadvertently knocked a glass flask to the floor. He heard the glass shatter, but when he glanced down, to his astonishment the broken pieces of the flask still hung together, more or less in their original contour.

On questioning an assistant, Benedictus learned that the flask had recently held a solution of cellulose nitrate, a liquid plastic, which had evaporated, apparently depositing a thin coating of plastic on the flask’s interior. Because the flask appeared cleaned, the assistant, in haste, had not washed it but returned it directly to the shelf.” (Source)

Upon his accidental discovery in 1903, Edouard Benedictus thought it would be perfect for the recently popularized automobiles driving around Paris. It turned out being hard to convince automobile makers to use it in their cars, which caused it to see limited use until the outbreak of World War I, where is was used in gas masks. After its battlefield use proved its effectiveness, it was finally picked up by automotive manufactures where it has since been the standard in automotive windows.

The modern day process of creating laminated safety glass has changed from the coating of glass with a liquid plastic, to the stronger method of sandwiching a thin sheet of PVB between glass sheets. PVB also known as polyvinyl butyral is a clear, flexible plastic film that will hold the glass in its form upon breaking, severely lessening the chance of flying glass shards.  Due to the layer of PVB, laminated glass is also quite hard to penetrate, in fact bullet-proof glass essentially an extremely durable, highly layered piece of laminated safety glass. Besides being hard to physically break through, it holds the extra benefits of blocking most UV radiation and high frequency sound.  This added strength unfortunately makes laminated safety glass very difficult to cut, and nearly impossible if it is made using tempered glass.

So the next time you look through a piece of glass you might want to ask yourself just what went into it’s creation. There’s a good chance it’s not just super heated sand…