JWF, Sec. Fim Facts, Retention Systems
Security film is normally applied just to the interior of a window to minimize the dangers of flying glass shards. It can also be anchored to the window frames themselves to increase the overall glass hazard mitigation performance. There are basically two types
of security film anchoring methods – mechanical and wet installations.
MECHANICAL ANCHORING
The mechanical anchoring technique applies the security film over the entire surface of the window, as well as the framing system. The film is then attached to the frame using
a special bar and batten system. Various systems are available that attach the film either from the top, top and bottom, both sides, or all four sides of the frame.
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| Single Base-Plate Attachment |
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Wrap-Around Base-Plate |
WET ANCHORING
The wet method doesn’t use a special attachment mechanism. Instead the security film
is applied edge-to-edge, making sure the surrounding rubber gasket is trimmed. A special sealant is then applied to all four sides, which locks the film in place to the glass and framing system. The sealant must extend onto the glass and frame by at least 3/16”.
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| Wet-Glazed Method |
Both the mechanical and wet anchoring methods significantly increase the glass mitigation performance of any glazing system. In fact, the overall performance is about the same as a laminated glass framing system (and is less costly).
Other Fragment Retention Systems
• Static Catch Bar – An aluminum or steel bar is bolted into the frame. If a major blast-load occurs, the bar will contain the broken glass and prevent the fragment retention film from entering the room.
• Energy Absorbing Systems – Cables, cords and/or aluminum tubing are used to attach the framing system to building structure itself (e.g. concrete wall). This method will help absorb the blast-load force from the framing system that would normally be directed to the film and glass.
• Catch Nets – Usually seen in places like industrial plants where the aesthetic look is not of great concern, cargo-type nets or straps are used to cover window openings in case of an explosion.
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