Gulf Construction Online - 'Anchors' keep glass secure

Safety & Security

'Anchors' keep glass secure

FrameGARD anchoring systems make glass and glazing more secure and safe to use. Martin Webb, managing director of the UK firm, elaborates.

01 August 2002

Glass, a contemporary building material, is not without its risks. In explosions, over 80 per cent of all injuries are caused by flying glass.

In recent years, glass in overhead applications such as airports, shopping malls and railway stations have shown signs of nickel sulphide inclusions or 'glass cancer'. This is a problem in toughened or tempered glass where the impurity, nickel sulphide, causes the sheet of glass to spontaneously explode and drop onto the people below.

Another problem with glass is the ease with which intruders can enter the premises. Annealed or float glass breaks extremely easily, toughened glass, although four times stronger than annealed glass, can shatter completely when struck with a small implement, and laminated glass unless bonded into deep rebate frames also fails under attack.

FrameGARD Anchoring System has a selection of products that are used in conjunction with window film to anchor the glass to the surrounding frame or structure. The products have been tested in explosion situations up to 15 psi for 85 psi msecs, which is 100 kg of TNT at a distance of 23 m. This was tested on 6 mm annealed glass at recent government tests in the UK. Most requirements, however, are for protection for 4 psi for a 28 psi msecs or 100 kg of TNT at 50 m. All the FrameGARD solutions, including the new GullWING profile, meet this requirement.

GullWING can be used for explosion, riot and overhead problems with all types of glass. Existing daylight window film applications can also be upgraded to the higher performances by using the GullWING profile.

FrameGARD products have been used for overhead glazing problems at the Eurostar railway station, various retail chains for burglar protection, government buildings, banks and key businesses worldwide.

Recent door tests on a standard retail door show that an attacker can gain entry through 6.4 mm laminated glass in 4 seconds. With FrameGARD, attacks involving a sledgehammer, intruders have been kept out for 10 minutes.

Window film has been used for many years to hold glass together in the event of failure. Normally the window film is applied with adhesives to the glass and a small gap, up to 3 mm, called the 'daylight' gap is left at the edge. The equivalent strength of window film is that of steel. The film does not interfere with the optical quality of the glass. The problem is that the 'daylight' gap allows the glass to fail at that point.

The patented solutions developed by FrameGARD are to anchor this film by various means to the surrounding structure. FrameGARD has developed solutions to apply to almost any glazing problem including the popular 'planar' fittings for toughened glass. The products are used as a retrofit solution and cause minimal disruption to the occupants of the building as they are fitted normally to the inside of the glass. They can be used for all types of glass to achieve dramatic improvements in performance.