Bulletproof glass looks completely ordinary, but it does not break on impact, and if you shoot at it, the bullet will not break through such glass, it will get stuck in it. It is impossible to make bulletproof glass on your own, as it is a complex industrial process, but it is very interesting to learn how it happens.
The invention of bulletproof glass
The idea that you can strengthen glass by making it bulletproof came to the mind of the French scientist Edouard Benedictus in 1910. He came up with the idea of placing a celluloid film between two sheets of glass, which significantly increased the strength of the resulting product. Today this method is called "lamination" of glass, and Benedictus once called it "Triplex".
Currently, the same technology is used, but it has improved significantly since then, and instead of celluloid, various types of polymers are used. Sometimes bent glasses are even glued together. Bend them before connecting.
Making bulletproof glass today
Bulletproof glasses come in different thicknesses, it depends on this whether the glass will eventually stop a bullet. The thickness of such glasses ranges from 7 mm to 75 mm. Today, most often for the production of bulletproof glass, several layers of ordinary are used, between which layers of polycarbonate are poured. Polycarbonate is a transparent plastic and is quite tough, albeit laminated. When a bullet penetrates the thickness of such glass, successive layers of polycarbonate absorb its energy, and it stops.
Currently, a special modification of bulletproof glass is being made - one-sided. A special type of plastic is used, the properties of which differ, depending on the direction in which to interact with it. One side of such glass stops bullets, but if you shoot from the other side of the glass, you can hit the enemy. This allows those behind the glass to be able to respond to an attack. At the same time, the glass surface bends without collapsing.
Lamination of glass (applying a plastic film on it) is a very complex process from a technical point of view. It is done on automated equipment, in several stages. The last stage takes place at a high temperature, the plastic film polymerizes and acquires approximately the same properties as stationery glue. It is at this time that the glasses are finally connected.
Although bulletproof glass is very durable, there is no perfect glass. The impact strength of laminated glass is about 15 times higher than that of ordinary flat glass. But even if such a sheet is destroyed, the fragments will remain on the film, and will not fly in all directions, causing injuries to people.
Three-layer bulletproof glass is considered ideal for production. The reason is that with each new layer, not only the protective properties increase, but also the cost of glass production. Laminated glass is used in extreme cases where there is a serious threat to human life or in museums to protect very expensive exhibits.