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Tempered and laminated safety glass. Two important materials briefly explained.

Konventionelles Glas
Conventional glass © pixabay.com / kiragrafie

According to Duden, “glass” is briefly and concisely defined as follows:

A translucent, usually transparent, easily fragile substance made from a molten mixture and used as a material (e.g. for panes, glasses).

We are all familiar with this substance and yet we know very little about it. Perhaps this often transparent material does not catch our eye enough. It is also possible that we have simply become accustomed to this versatile material.

Glass is used as a tasteless container for breakfast juice and on the way to work this material protects us from environmental influences - regardless of whether we travel by car or train. Glass is also immune to most acids and alkalis, which guarantees a wide range of applications.

While showering at least, most of us come into contact with glass again. In this case not simply with glass, but with two differently refined special forms of it, which we will briefly discuss in the following.

ESG (tempered safety glass) © pixabay.com / wilhei

ESG (tempered safety glass)

First presented to the world public in 1927, the idea behind tempered safety glass is still as ingenious as it was nearly 100 years ago. Since glass in its natural form produces dangerously sharp fragments during shattering, the glass surface is “quenched” with cold air during the production process. The resulting temperature difference between the outer skin and the core remains in the glass as internal tension. These new forces are called pre-stressing and improve the material properties noticeably. For example, the bending, impact and shock resistance is increased, but the fracture pattern also changes positively. If the pane breaks, the pre-stressing escapes in milliseconds and produces thousands of small fragments. In contrast to large, pointed glass fragments, these are harmless to humans and make it clear why ESG is used for shower walls.  

Verbundsicherheitsglas (VSG)
VSG (laminated safety glass) © Wikimedia Commons

VSG (laminated safety glass)

Around 1950, the combination of two ESG discs and a non-breaking, tough elastic film found its way into the automotive industry. The advantages of the pre-stressed panes were known, only the problem of the thousand small fragments had to be solved. At least for windscreens, it became more and more necessary to find a new glass solution that would break down into harmless pieces under the effect of force, but still absorb the forces that occur. The solution was a sandwich composite consisting of two ESG panes and a film glued in between. Thus the two ESG panes shatter as desired, but are held together by the bonded film. This creates the spider's web, which is known far and wide. We are now also using this laminated safety glass for our Air Colours walk-in solutions, which are available in four different colours thanks to the integrated and coloured films.