In the case of protection with "explosive resistant security" films, usually only one single (or multi-layered) film is laminated onto the internal side of the glazing; the other components of the door, the window or the facade are still unsecured. During an explosion extreme pressure waves are released. At an explosion with pressure waves of e.g. 0.1bar, a load of about 1t/m2 will impact on the whole element. In order to withstand this high pressure, the complete element must be designed blast resistant. If only films are laminated onto the glazing and all other components are unsecured and are not designed for such a strong pressure, the element will fail in emergency case in a variety of ways:
- The glazing which is held together by the film can be pressed completely out of the frame construction in ‘one piece’.
- Window and door wings without special heavy duty security hardware and locking systems can be pulled of the frame.
- Unsecured door and window wings and above all the facade constructions can’t withstand statically the pressure and would break apart.
- Installation materials, e.g. dowels or screws are undersized and can shear-off, the whole element incl. frame would be torn out of the anchoring.
In all cases, the protection by films is completely inadequate. The film is only splinter binding. There is still the risk that in case of an explosion, the pressure wave will enter the building, thereby tearing uncontrollably debris from the building, the window or from the door into the interior. The risk of fatal injuries to persons inside the building is only minimized slightly by using such films. SAELZER only produces complete blast resistant constructions. The individual components of the windows, doors and facades e.g. frame, wing, glazing, hardware are all blast-resistant, so the whole element can withstand the enormous pressure wave. The complete elements are tested in open range tests under real conditions. The installation situation is modelled on the reality, the elements are either installed in masonry, concrete or in a steel construction. Please see photo 1, it shows an aluminum façade after a blast test with a charge of 500kg. The test result has the addition NS = no splinters (GSA2), which means that in case of an explosion no fragments of the glass or the profiles would fly into the inside and so no humans will be injured.