How is bulletproof glass made? Interested in the technology for producing bulletproof glass?

The history of bulletproof glass began in 1910, when the French scientist Edouard Benedictus invented a method of producing especially strong glass by placing a special celluloid film between two sheets of glass. Such glass, now known as laminated glass, was patented by Benedictus under the name “triplex.” However, do not expect to sit behind bulletproof glass during a serious shelling. Absolute armor that protects against all firearms simply does not exist, especially glass armor...

Triplex is the most reliable and safe glass. In the century that has passed since the Frenchman made his epoch-making invention, the glass industry has moved far forward, and now the technology for manufacturing triplex is approximately the same. Two sheets of tempered glass are glued to each other over the entire surface with a polymer film or laminating liquid. (By the way, I myself worked at the Macromer Research and Production Enterprise in the production of such a liquid - indeed Gin is right, this is Acrolat: http://www.macromer.ru /him.shtml?base=5&...) Moreover, the sheets can be made of either one glass or different types, can be straight or bent (they are shaped before gluing). Lamination itself is enough difficult process, it is performed on an automated line in several stages. On last stage sheets of glass fall into an autoclave, where high temperature the film polymerizes and, like glue, bonds the glass. As a result, the impact strength of conventional triplex is 10–15 times higher than that of conventional sheet glass. If the triplex still manages to be broken or pierced by a bullet, the fragments will not splash in all directions - they will hang on the intermediate film without causing harm. This laminated glass looks like a monolith.
However, polymer film can glue not two glasses, but more. But three-layer triplex is still considered the best option– further addition of layers significantly increases the cost of the product, although, of course, the protective properties also increase. But on by and large It makes sense to use multilayer triplexes only where there is a serious threat to human life or to material and museum values.

But safety can be ensured not only by the use of triplex. There is also alternative way strengthening and protecting glass in glass structures - gluing window films onto ordinary high-quality glass.
Professional window films (for example, Courtaulds Performance Films made in the USA), when glued to glass, avoid the risk of damage from shrapnel. Glass reinforced with such a film successfully withstands even a shock wave - and if it is damaged, it will remain in the frame or fall out in one piece without breaking into sharp fragments.

The US Air Force is testing a new transparent material that could soon replace bulletproof glass in the military. vehicles. Aluminum oxynitride (ALON) is a transparent material similar in optical and structural characteristics to sapphire. It is very durable and much lighter than regular bulletproof glass.
The windshield, which consisted of three layers (ALON, glass, ALON again), during tests successfully withstood, for example, fire from armor-piercing cartridges from an M-44 sniper rifle. Regular bulletproof glass must be several times thicker than ALON windshield to withstand a similar load.

One day in 1903, the French chemist Edouard Benedict was preparing for another experiment in the laboratory - without looking, he reached out for a clean flask standing on a shelf in the closet and dropped it. Taking a broom and a dustpan to remove the fragments, Edward went to the cabinet and was surprised to discover that although the flask had broken, all its fragments remained in place, they were connected to each other by some kind of film. The chemist called the laboratory assistant - he was obliged to wash glassware after the experiments - and tried to find out what was in the flask. It turned out that this container was used several days ago during experiments with cellulose nitrate (nitrocellulose) - an alcohol solution liquid plastic, a small amount of which, after the alcohol evaporated, remained on the walls of the flask and froze as a film. And since the layer of plastic was thin and quite transparent, the laboratory assistant decided that the container was empty.

A couple of weeks after the story with the flask that did not shatter into fragments, Eduard Benedict came across an article in the morning newspaper, which described the consequences of head-on collisions of a new type of transport in those years - cars. The windshield shattered into pieces, causing multiple cuts to the drivers, depriving them of their vision and normal appearance. The photographs of the victims made a painful impression on Benedict, and then he remembered the “unbreakable” flask. Rushing into the laboratory, the French chemist devoted the next 24 hours of his life to creating unbreakable glass. He applied nitrocellulose to the glass, dried a layer of plastic and dropped the composite onto the stone floor - again and again and again. This is how Edward Benedict invented the first triplex glass.

Laminated glass

Glass formed by several layers of silicate or organic glass, connected by a special polymer film, is called triplex. Polyvinyl butyral (PVB) is commonly used as a glass bonding polymer. There are two main methods for producing triplex laminated glass - poured and laminated (autoclave or vacuum).

Jellied triplex technology. The sheets are cut to size and, if necessary, given a curved shape (bending is performed). After thoroughly cleaning the surfaces, the glass is stacked on top of each other so that there is a gap (cavity) no more than 2 mm high between them - the distance is fixed using a special rubber strip. The combined sheets of glass are placed at an angle to the horizontal surface, polyvinyl butyral is poured into the cavity between them, and a rubber insert around the perimeter prevents its leakage. To achieve uniformity of the polymer layer, the glass is placed under a press. The final joining of glass sheets due to the curing of polyvinyl butyral occurs under ultraviolet radiation in a special chamber, inside which the temperature is maintained in the range from 25 to 30 o C. After the triplex is formed, the rubber tape is removed from it and the edges are turned.

Autoclave lamination of triplex. After cutting the glass sheets, processing the edges and bending, they are cleaned of contaminants. Upon completion of the preparation of the float glass sheets, a PVB film is placed between them, the formed “sandwich” is placed in a plastic shell - in a vacuum installation, the air is completely removed from the bag. The final connection of the sandwich layers occurs in an autoclave, under a pressure of 12.5 bar and a temperature of 150 o C.

Vacuum lamination of triplex. Compared to autoclave technology, vacuum triplexing is performed at lower pressure and temperature. The sequence of work operations is similar: cutting glass, giving it a curved shape in a bending oven, turning edges, thoroughly cleaning and degreasing surfaces. When forming a “sandwich”, ethylene vinyl acetate (EVA) or PVB film is placed between the glasses, then they are placed in a vacuum machine, after having been placed in a plastic bag. Soldering of glass sheets occurs in this installation: air is pumped out; The “sandwich” is heated to a maximum of 130 o C, polymerization of the film occurs; the triplex is cooled to 55 o C. Polymerization is carried out in a rarefied atmosphere (- 0.95 bar), when the temperature drops to 55 o C, the pressure in the chamber is equalized to atmospheric pressure and, as soon as the temperature of the laminated glass reaches 45 o C, the formation of the triplex is completed.

Laminated glass, created using poured technology, is stronger, but less transparent than laminated triplex.

Car windshields are made from glass sandwiches made using one of the triplex technologies; they are necessary for glazing high-rise buildings, in the construction of partitions inside offices and residential buildings. Triplex is popular among designers - products made from it are an integral element of the Art Nouveau style.

But, despite the absence of fragments when hitting a multilayer “sandwich” made of silicate glass and polymer, it will not stop a bullet. But the triplex glasses discussed below will do this quite successfully.

Armored glass - history of creation

In 1928, German chemists create new material, which immediately interested aircraft designers - plexiglass. In 1935, the head of the Plastics Research Institute, Sergei Ushakov, managed to get a sample of “flexible glass” in Germany, Soviet scientists began researching it and developing technology serial production. A year later, the production of organic glass from polymethyl methacrylate began at the K-4 plant in Leningrad. At the same time, experiments were started aimed at creating armored glass.

Tempered glass, created in 1929 by the French company SSG, was produced in the USSR in the mid-30s under the name “Stalinite”. The hardening technology was as follows - sheets of the most common silicate glass were heated to temperatures in the range from 600 to 720 o C, i.e. above the softening temperature of glass. Then the sheet of glass was subjected to rapid cooling - flows of cold air in a few minutes lowered its temperature to 350-450 o C. Thanks to tempering, the glass received high strength properties: impact resistance increased by 5-10 times; bending strength - at least twice; heat resistance - three to four times.

However, despite its high strength, “Stalinite” was not suitable for bending to form an aircraft cockpit canopy - the hardening did not allow it to be bent. In addition, tempered glass contains a significant number of internal stress zones; a slight blow to them led to complete destruction of the entire sheet. “Stalinite” cannot be cut, processed or drilled. Then Soviet designers decided to combine plastic plexiglass and “Stalinite”, turning their disadvantages into advantages. Pre-formed aircraft canopy coated small tiles made of tempered glass, polyvinyl butyral served as glue.

Entry of exes Soviet republics Since the beginning of the 90s, capitalism has sharply increased the demand for the protection of cash collectors' vehicles and currency exchange offices with armored glass. At the same time, a need arose for “transparent armor” for passenger cars businessmen. Since the production of real armored glass was expensive, as was the final product, a number of companies began producing imitation armored glass - it was triplex of rather mediocre quality, polymerization of film PVB was carried out in an accelerated mode, using ultraviolet irradiation. The finished product was capable of withstanding a pistol bullet from a distance of 5 meters, i.e. corresponded only to the 2nd class of protection (there are six in total). Massive armored glass of this type did not withstand temperature changes of more than +20 and below -22 o C - after just six months, the layers of triplex were partially delaminated, their already low transparency was seriously reduced.

Transparent armor

Modern bulletproof glass, also called transparent armor, is a multilayer composite formed by sheets of silicate glass, plexiglass, polyurethane and polycarbonate. Also, the composition of armored triplex may include quartz and ceramic glass, synthetic sapphire.

European armored glass manufacturers produce mainly triplex, consisting of several “raw” float glasses and polycarbonate. By the way, non-tempered glass among companies producing transparent armor is called “raw” - in triplex with polycarbonate it is “raw” glass that is used.

The polycarbonate sheet in such laminated glass is installed on the side facing the inside of the protected room. The purpose of the plastic is to dampen vibrations caused by the shock wave when a bullet collides with armored glass, in order to avoid the formation of new fragments in sheets of “raw” glass. If there is no polycarbonate in the triplex composition, then the shock wave moving in front of the bullet will break the glass even before it actually comes into contact with them and the bullet will pass through such a “sandwich” without hindrance. Disadvantages of armored glass with a polycarbonate insert (as well as with any polymer in the triplex composition): significant weight of the composite, especially for classes 5-6a (reaches 210 kg per m 2); low resistance of plastic to abrasive wear; peeling of polycarbonate over time due to temperature changes.

Quartz glass. It is made from silicon oxide (silica) of natural origin (quartz sand, rock crystal, vein quartz) or artificially synthesized silicon dioxide. It has high heat resistance and light transmittance, its strength is higher than that of silicate glass (50 N/mm 2 versus 9.81 N/mm 2).

Ceramic glass. Made from aluminum oxynitride, developed in the USA for the needs of the army, patented name - ALON. The density of this transparent material is higher than that of quartz glass (3.69 g/cm3 versus 2.21 g/cm3), the strength characteristics are also high (Young’s modulus - 334 GPa, average bending stress limit - 380 MPa, which is practically 7-9 times higher than similar indicators of silicon oxide glasses).

Artificial sapphire (leucosapphire). It is a single crystal of aluminum oxide, and as part of armored glass it gives triplex the maximum strength properties possible. Some of its characteristics: density - 3.97 g/cm 3 ; average bending stress limit - 742 MPa; Young's modulus - 344 GPa. The disadvantage of leucosapphire is its significant cost due to high production energy costs, the need for complex machining and polishing.

Chemically strengthened glass. “Raw” silicate glass is immersed in a bath with an aqueous solution of hydrofluoric acid. After chemical tempering, glass becomes 3-6 times stronger, its impact strength increases sixfold. Disadvantage - the strength characteristics of strengthened glass are lower than those of thermally tempered glass.

Armored glass frame

The use of armored triplex in glazing does not mean that the opening blocked by it will be bulletproof - a frame of a special design is required. It is created mainly from metal profiles, most often aluminum. Steel linings are installed in the grooves located along the junction line of the triplex and the frame profile, protecting the weakest point in the armored window design from impact or contact with a bullet.

Protective armor plates can also be installed externally frame structure, however, this will reduce the aesthetic characteristics of the window. For achievement maximum level frame protection can be made entirely of steel profile(overlays are not needed in this case), but they will become very bulky and expensive.

The weight of an armored window often exceeds 300 kg per m2; not every building and structural material can withstand it. Therefore, installation of an armored window structure is permissible only for reinforced concrete and brick walls. It is not easy to open the sash of an armored window due to its high weight; servo drives are used for this purpose.

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Armored windows or how to secure your home in the 21st century

Armored windows for the home are already beginning to cease to be something unique and inaccessible. Today's realities show that only with their installation can you gain confidence in the absolute protection of your own home. It's 2016, and if you don't want to become a victim of modern criminals, then you need to keep up with the times and be informed the latest methods ensuring security. I will try to provide you with enough information for this.

Armor against bars

Owners of window bars can answer that they have already sufficiently taken care of the safety of their homes, and they do not need expensive window armoring at all. Then I recommend paying attention to the significant disadvantages of using steel barriers, which armored glass lacks:

1. Presence of vulnerabilities during hacking attempts. As I mentioned above, now it’s the 21st century and attackers are armed with more than just a crowbar and a set of master keys. For example, liquid nitrogen can be used to remove steel rods, with the help of which the problem will be solved quickly and silently;

1. Lack of bullet protection. The metal honeycomb structure will not stop bullets or small fragments. But who knows what can happen on the street? Recent unfortunate events in Europe have demonstrated that even the most prosperous areas can find themselves in the midst of a situation involving firearms and explosives;

1. Violation of panoramic view. Even beautiful Forged Products are not able to completely eliminate the oppressive feeling of a sky blocked by steel;

1. Level reduction fire safety . Blind bars not only do not let anyone in, but also do not let anyone out, which can play a fatal role in the event of a fire or other emergency. And even if a swing-type design with a lock is used, then, again, searching for the key will also take precious seconds, or even minutes.

The price of armored windows, although much higher than forged or grilled ones, is:

• Not subject to hacking methods available to most robbers;
• They will protect not only from penetration, but also from bullets and shrapnel;

• Will not affect the panoramic view in any way, as they have absolute transparency;

• Will not become an obstacle if you need to urgently exit through a window opening.

As you can see, the differences are quite significant to think about the possibility of allocating enough financial resources for the purchase and installation of armored double-glazed windows.

Booking options

There are two ways:

1. Purchase and installation armored glass unit;
2. Reservation of window glass with special film.

The first is undoubtedly more reliable and allows you to achieve maximum security, while the second, on the other hand, will be cheaper and can even be done with your own hands, although the process itself is quite complicated. I'll look at both:

Armored glass unit

To ensure absolute inaccessibility of your window opening Of course, it is necessary to install a fully armored window, that is, not to limit oneself to strengthening the strength of the glass alone, but to ensure the resistance to mechanical stress of the frame itself.

Thus, we can talk about two components of the entire structure:

1. Laminated glass, reinforced with polyvinyl butyral film or polymer filling;

1. Frame made of multi-chamber profile with hardened steel inserts. Wherein appearance the window is the same as a regular one.

When purchasing such a miracle modern technologies ask how protected the joints of the frame and glass are, since they are the most vulnerable places in this design and must be covered with the “filling” of the profiles. Otherwise, the level of protection of the entire glass unit can be considered incomplete.

Previously, glass was strengthened exclusively by pouring polymers into the spaces between them; now the use of PVB film is becoming more widespread. Why? To answer this question it is enough to do comparative characteristics some parameters of finished products:

1. Chroma:

• • With PVB, complete transparency is guaranteed without the appearance of any shades for ten years;
  • When pouring polymers, yellowness may appear already in the first year of operation as a result of exposure to ultraviolet radiation;

1. Optical distortion:

• With PVB they are completely absent;
• When pouring polymers, it is possible that the substance is distributed unevenly;

1. Delamination:

• With PVB it is completely absent;
• When poured over time, it occurs due to a weak level of adhesion between polymers and glass;

1. Loss of protective functions:

• PVB does not occur for at least ten years from the start of operation;
• When pouring is gradually carried out;

1. Increase in thickness:

• With PVB minimal;
• It's noticeable when pouring.

As a result, I came to the conclusion that if I order armored glass, then only those that are reinforced with polyvinyl butyral film. The cost of such double-glazed windows depends primarily on the protection class:

• 2nd class:

• 3rd grade:

• 5th grade:

• Class 5a:

• 6th grade:

• Class 6a:

Glass armoring with film

Reserving windows with film, as I noted above, is much cheaper. So, for example, if you order such a service from a relevant company, then everything including the work will cost you from 1000 rubles for one square meter, which is many times cheaper than installing armored double-glazed windows. Such a barrier, of course, will not save you from snipers, but it will protect you from hacking and even shrapnel.

Here is a classification demonstrating the level of this method of protection, taking into account the thickness of the glass, as well as the thickness and number of film layers:

Armored film on window glass can be installed independently. The task at first glance does not look very difficult, but in fact it has many pitfalls, to successfully overcome which you need to have at least some experience.

If you have doubts about whether you can cope with armoring glass on your own or not, then it is better to seek help from qualified specialists, or at least first practice on a small window somewhere in a closet or garage.
Otherwise, you risk simply ruining both the applied material, the cost of which starts from three hundred rubles per 1 m2, and the double-glazed window being processed, which will cause much more damage to your family budget than paying for hired services.

The glass booking instructions that I used look like this:

1. Measured the glass using a tape measure. To the data obtained I added 10 mm on each side for cutting, but if you have them without a frame, then 5 mm will be enough;

1. Performed calculations in relation to the roll, standard width which is 1524 mm;
2. On big table performed precise cutting canvases;
3. Prepared the solution by adding a few drops of shampoo to half a liter of distilled water;
4. I applied the cut pieces of film to the glass, checking compliance. In case of a positive result, further operations began;
5. Apply the mixed solution to the glass and carefully clean it from dirt with a scraper, after which, using a special remover, removed the remaining foreign particles from the smooth surface;

1. I repeated the procedure several times, achieving absolute cleanliness. The fact is that the smallest grain getting into the gap between the film and the glass can ruin the whole job;
2. I moistened the first fragment of the coating on both sides to prevent dust from getting on the adhesive layer and removed the lavsan from it;
3. Then again applied the solution to the side with glue and applied it to the glass;
4. The outer side was also treated with the prepared liquid, after which Use a yellow squeegee to remove all the water from under the film;

1. I trimmed the excess edges with a sharp knife;
2. Removed leftovers;
3. I left the coating to dry. During this period, the film and glass combine so strongly at the molecular level that they become one.

Depending on the thickness of the applied material, the time it takes to dry completely changes:

Conclusion

Metal, wooden and even plastic armored windows will become a reliable guarantee of safety for your home. If their cost is too high for your family budget, then you can stop at armoring the glass by applying a special protective film. This will be much cheaper and can also provide quite a decent level of protection.

The video in this article contains Additional information related to the topic under consideration. If you have any additional questions, ask them in the comments.

When preparing this article, material from the site roststeklo.ru was used

For a long time, armored glass has become an integral element of protecting a home, store windows, cars from intruders or from armed attack. This structural element is often called transparent armor. Armored glass has found wide application in life ordinary person, and in law enforcement and security structures. Their meaning in modern world cannot be underestimated.

Armored window design

Armored glass is a translucent product that protects people and material property, valuables from theft, destruction, damage, and also protects against penetration into the room from the outside through a window opening. These products include two elements:

1. Armored glass. It consists of several layers of transparent glass that are glued together polymer material, hardening under sun rays. The thicker the product, the higher the level of protection.
2. Frame. It is made of aluminum or steel profile, very rarely of wood. To give the system protective properties, it is reinforced with heat-strengthened steel plates. Such overlays must reliably cover the junction of the frame and glass.

The mass of finished armored structures can be more than 350 kg per square meter. This is ten times more than the weight of a conventional double-glazed window. To compensate for the weight, they are equipped with electric drives.

Types of armored glass

Armored glass is classified according to its ability to withstand a certain type of destructive influence.

According to this criterion, all structures can be divided into several groups:

1. Windows with anti-vandal protection.
2. Tamper-resistant products.
3. Designs that protect against firearms.

Automotive protective structures are included in a separate group, since they are subject to special requirements. armored glass and the requirements for their production are defined by GOST 51136-97 and GOST 51136-2008. Each type of transparent protection is installed for protection in specific conditions.

Anti-vandal glass

Anti-vandal windows protect people from splinters when attackers try to break it. They are a multilayer glass unit with an air chamber where a special one is glued to the glass. The film, in turn, is made of thick plastic. The fragments “stick” to it, thanks to which they do not fly apart in different directions.

Such structures are most often used in commercial facilities and in the private sector to protect both windows and doors, as well as exhibition display cases. According to GOST, they are divided into three classes - from A1 to A3, each of which is characterized by resistance to impact of a certain force.

Burglar-resistant glass

Burglar-resistant armored glass differs from the vandal-resistant type only in its resistance to destructive effects. This product provides protection against repeated blows with a sledgehammer or hammer, and can withstand being rammed by a car. Most often, such structures are used to protect banking institutions, shops, and establishments with a large turnover. Money, as well as racks for storing narcotic drugs.

According to domestic standards, depending on how many impacts the burglar-resistant glass can withstand, it is assigned a protection class from B1 to B3. How large quantity The design withstands impacts from a blunt or sharp object, the higher the class.

Bulletproof glass

Bulletproof glass provides protection against penetration by bullets or their fragments. They are reinforced multilayer structures bonded with a special polymer material. Similar structures are installed at facilities where the risk of an armed attack is high: in departments of the Ministry of Internal Affairs, at security posts, checkpoints and other similar places.

Bullet-resistant glass is divided into protection classes from B1 to B6a. Testing of structures is carried out various types firearms - from the Makarov pistol and Kalashnikov assault rifle to the Dragunov sniper rifle. During the tests, bullets of various weights and with a steel, heat-strengthened or special core are used.

Armored glass for cars

The car is equipped with reinforced rear side and windshield windows. Their main distinctive feature is the service life. If a standard armored window can last for several decades, then products for a car last no more than 5-6 years. This is due to the nature of the loads to which glass is exposed every day.

Such translucent armored elements are a multi-layer glass unit, which is additionally reinforced with shockproof film. Some of them, in addition to protecting against flying fragments, protect against ultraviolet radiation. Windshields are often covered with a thicker film than the side and rear ones.

Hide

Armored windows are widely used in various fields: they can be found in banks, residential buildings, shops, cars. The design is thick glass made of triplex and polycarbonate. The layers are superimposed on each other and glued in a special way, resulting in a thick, heavy, but very durable structure.

Types of products

Armored glass has similar properties to tempered glass. Read what are the advantages of this type of glass.

Using an armored window

Not so long ago, armored ones were used exclusively in places associated with material or historical values, such as museums and banks, but later armored windows became more accessible, and it became possible to find them in ordinary private homes, and not necessarily representatives of government authorities.

Modern windows have become much more technologically advanced, more affordable and more functional. They can be installed instead of . Armored windows for a home are superior to standard double-glazed windows not only in strength, but also in all other indicators, such as protection from cold and noise.

Armored windows

What do you need to consider when purchasing an armored window?

Before purchasing armored windows for your apartment, you need to determine what you need it for. You may not be able to get by with the cheapest option that can withstand a rock strike, or you may not have to pay a premium because you don't need a bulletproof window.

Product functions may be as follows:

• Protection against stones and accidental mechanical damage.
• Security from criminal attacks and attempts to purposefully break a window.
• Protection from firearms.

The difference between designs lies not only in strength and cost, but also in functionality.

Possible options when choosing a window

Reserving double-glazed windows with film makes them more durable; triplex glass does not spill out when broken, since all the fragments remain on the film. If you really want to, this one can be broken, but it will take a vandal quite a lot of time. You don't have to be afraid of rowdy teenagers. Glass can prevent a thief from getting into the house, it will last much longer than usual, but it will not provide protection from a bullet.

Armored plastic windows for the home - this is most often an ordinary triplex, holding together several thin glasses. It makes the window stronger and safer, but such a product cannot be fully called armor. A glass unit of this type is suitable for standard plastic frames and is inexpensive.

Types and designs of frames

Bullet-resistant double-glazed windows are quite expensive, but they can be different options, from one relatively thin glass to a thick complex. It is worth noting that the lowest class glass unit can freeze and produce condensation. Thicker double-glazed windows will cope with shots from more powerful weapons and retain heat better, but they will weigh quite a lot. The higher the class of the glass unit, the stronger it is. To be clear, a class 5 product can withstand a shot from a 7.62 caliber.

Armored windows into the house can be different designs and meet different requirements and standards, which affects their thickness and price. Such windows are quite accessible to a wide range of buyers.