How to make bulletproof glass

Protecting your home, office, public places and private spaces is essential for the serenity and safety of the people who live there. Understanding how to make bulletproof glass, its technical specifications and the efficiency evaluation will make it become clearer how unparalleled resistance hides behind refined taste.

Quite often we have to defeat the prejudice that lies behind the idea of protection. Bulletproof glasses boast elegance like any other quality glass and can be inserted into windows that are perfectly integrated in the style of the building they belong to.

Everytime we make bulletproof glasses our study focuses on factors such as:

• risk level;
• stylistic, climatic, acoustic context;
• size.

This means that window and door experts make bulletproof glasses like a tailormade suit. They structure it in such a way as to make it resistant to the different types of firearm, always taking into account the fact that the glass and the window frame represent a furnishing element for the rooms. To this we add the assessments concerning housing well-being. Who makes bulletproof glass must take into account the thermal needs of the room, to ensure well-being inside the building and to align with the efficiency needs of the windows. The same happens to give a suitable acoustic insulation to the rooms.

An important consideration is about the dimension of the glazed sheet: the larger its surface, the greater the risk exposure is. Moreover, the product must also be considered from a technical point of view. The bigger it is, the more elastic and resistant it has to be, not only against bullets but also against gunshots.

Taking into consideration all these variables, attention is focused on glass resistance, on its structure and on a very important test phase that verifies the ability of the glass surface to withstand a gunshot.

What is bulletproof glass made of

First, let’s take a few minutes to understand what bulletproof glass is made of.

We could say that bulletproof glass is not only made of glass, but also of other transparent plastic or metallic materials, such as acrylic, polycarbonate or at least a combination of glass and plastics, generally considered particularly effective in resisting gunfire of firearms.

However, the most effective bulletproof glass has a special composition.

What distinguishes bullet-proof glazing from common glazing is the combination of different glass thicknesses assembled with interlayers of different thickness and composed of an internal anti-splinter film, designed to prevent the escape of splinters.

Each bulletproof window comes from the set of evaluations that we talked about above and that we now want to investigate in a more technical way.

Let’s focus on the risk, starting from the fact that there are two main categories of glass, and therefore bulletproof doors and windows, which comply with two different regulations:

• UNI EN 1522 (civil use);
• NATO AEP 55 (military use).

Each is classified according to several security levels:

• FB2-FB4-FB6-FB7 in the civil field, able to protect against gunshot from 9 mm to 7.62×51 caliber, armor-piercing;
• LEVEL 1-2-3-4 IN MILITARY FIELD, capable of blocking bullets from 7.62×51 to 14.5×114 B32 API.

To obtain ballistic protection certification, the glass and the window have to be made of suitable materials and have to pass a test carried out in a ballistic laboratory. It tests the system by verifying calibers and instruments that allow us to measure the resistance capacity in compliance with the technical and legal standards, as required by current safety standards.

Each type of bulletproof glass has a specific standard testing method. Since 1998 there has been a single testing system for all European countries, which makes the classification more understandable and ensures that the export of Made in Italy has an ever greater influence over the other countries.

It is extremely important that the bulletproof glass is inserted in a suitable window frame, in wood or metal, suitable to guarantee the protection of the internal rooms.

Differences from explosion-proof glass

In order to deepen these types of glass, we suggest you understand the differences between bulletproof and explosion-proof glass.

Often associated under the same definition, they are not quite the same.

Let’s start from the fact that both are stratified glasses, that is safety glasses, which in case of breakage do not break into fragments. This is an important feature in any context, not exclusively in the case of bullets.

Based on the stratification of the glass, it can perform various functions:

• • anti-injury and anti-fall;

• shatterproof;

• bulletproof;
• explosion-proof.

Analyzing the last two they have a fundamental difference that sees them placed in sites that are not always similar.

The bulletproof glasses are designed to withstand the impact of bullets fired by different types of weapons and identifiable by classification. Each class of glass protects against impacts of increasing power.

Instead, explosion-proof glasses have the ability to resist the shock wave due to an explosion. The different stratification makes them more or less resistant and ensures the safety of the people inside the building.

Following this analysis, it is clear that each context requires a specific glass, but above all it is evident how important it is to rely only on experts in the sector. In fact they are the only ones able to identify, design, manufacture and install the right product.