Triplex: how safety glass was invented
In 1903, Benedictus knocked a flask off a shelf during one of the experiments. The vessel fell to the floor and cracked, but, to the scientist's surprise, did not crumble, but retained its former shape. Benedictus recalled that earlier in this flask were stored the remains of collodion - an ether-alcohol solution of cellulose nitrate. The volatile mixture evaporated, leaving a thin, transparent, almost invisible layer of cellulose nitrate on the walls.
At that time, car windshields were made of ordinary glass, which, breaking, breaks into thousands of long and extremely sharp fragments, in the event of an accident seriously injuring drivers and passengers.
After reading about one of such accidents in the newspaper, Benedictus remembered the flask that had fallen, but had retained its shape. After several experiments with laminated glass, he made a “sandwich” of two glasses and a layer of cellulose nitrate between them. When heated, the plastic layer melted, sticking the glass together. Such a “sandwich” could be beaten with a hammer - it cracked, but retained its shape and did not give fragments. In 1909, Benedictus received a patent for safety glass, which he called "Triplex" (Triplex).
In those same years, the Englishman John Wood worked on the problem of safe glass. He received a patent for his development in 1905, but it did not go into mass production - Wood suggested using natural rubber as the middle layer, which was expensive, and the glass came out not quite transparent.
After obtaining a patent for triplex, Benedictus appealed to car manufacturers to use his invention. But automakers, in an effort to make cars cheaper, refused. But the military paid attention to the new material, and the triplex received a real baptism of fire during the First World War - they made glass of gas masks from it.
But already in 1919, Henry Ford began using triplex in his cars, and another 10-15 years later, all other automakers followed his example. And modern safety glass, through which millions of drivers look at the road, is a distant descendant of the invention of Eduard Benedictus.The article “Safe Glass” was published in the journal Popular Mechanics (No. 1, January 2005).