On the night of February 9, 1998, Georgian President Shevardnadze was driving home in a Mercedes-Benz car. Suddenly, more than 20 killers jumped out of the dense forest shrouded in the night and fired wildly at the presidential car. and killed him. The car was smashed by thrown grenades, but fortunately, Shevardnadze remained unharmed! What protected the president from this disaster? Thanks to this, Mercedes-Benz gave him the German government Bulletproof cars for $ 500,000. So why can a bulletproof car be bulletproof? It turns out that it is equipped with a kind of protective glass - bulletproof glass.
Automotive bulletproof glass
Bulletproof glass was accidentally discovered by French scientist Benetiuk. He accidentally dropped a glass beaker on the ground in the laboratory, but the beaker did not break, only cross-shaped cracks appeared on the body of the beaker. Benetiuk's research showed that the glass was filled with a solution of nitrocellulose, and a thin film was attached to the glass, which acted as a glue and prevented the glass from breaking.
After many experiments, Benetiuk finally made glass by adding a mixture, sealing and gluing. After it is broken, glass shards get stuck, which can protect personal safety. Since then, this kind of glass has been widely used in automobiles, aircraft, and even spacecraft. With the development of science, bulletproof glass is now widely used, and technology has also made great progress.
Modern bulletproof glass is a composite bulletproof transparent material synthesized by special processing of glass or polycarbonate, polyurethane and special plastics, usually thermoplastics such as PVB and SGP. Synthesized glass also retains the characteristics of transparency and light transmission.
Bulletproof glass is generally divided into three layers: carrier layer, transition layer and protective layer. Among them, the carrier layer is cannon fodder, which is used to destroy the warhead, deform or break the warhead after impact, and greatly slow down the speed of the warhead. This layer is mainly made of high-strength tempered glass. or plexiglass. The transition layer is basically a polycarbonate fiber that uses the strength of the transition layer to absorb some of the kinetic energy of the warhead and ensures that the front and back intermediate layers can still be joined together without falling off after breaking. High-strength tempered glass or plexiglass is generally used as the protective layer and carrier layer, which requires high strength, impact resistance and impact resistance, and has a certain strength to ensure that bullets or fragments do not penetrate it, so how to ensure the security protection effect.
According to the different degrees of protection of the human body, bulletproof glass can be divided into two types: safe and safe for life. After the safety bulletproof glass is fired, there is no splash on the non-impact surface, and it does not cause harm to the human body; after bulletproof safety glass is fired, spatter remains on the non-impact surface, but the bullet cannot penetrate the glass, may cause secondary damage to the human body. Bulletproof glass has different requirements for its bullet resistance depending on the type of weapon. Bulletproof glass is divided into three series: the first is bulletproof glass for aviation, the second is bulletproof glass for vehicles and ships, and the third is bulletproof glass for banks. Thickness from 18 mm to 40 mm.
At present, the production of bulletproof glass in the world is increasing from year to year. In 2009, it exceeded 10 million square meters. The main production areas are Europe, Japan, North America and China. At present, China's bulletproof glass enterprises are developing rapidly. Now it has become the second largest bulletproof glass production base in the world after Europe.