Free Phone Wellington. |
0800 777 007 |
Phone. |
04 5287 007 |
|
|
ARTICLESOrdinary Annealed Glass – when broken, has a jagged pattern with lethal slivers of glass which either fly out or remain precariously intact. Many homes have sliding doors, glass side panels, glass conservatories, ceiling-to-floor windows and glass shower cubicles. These are at-risk areas, where impact could cause severe injuries. If your home was built prior to 1993 you may have annealed glass in these at-risk areas. From 1993, the building code has required Grade A safety glass to be installed in all new houses where specified by AS/NZ Standard 2208. Safety glass must also be used when replacing glass in these at risk areas. Identification of Safety Glass NZS 4223:Part3:1999 requires safety glass to be permanently marked, for both building inspectors' and consumers' peace of mind. The marking is usual Permanently marked does not mean removable labels of any kind. It can be very difficult to identify safety glazing if it is not permanently marked at the time of manufacture. Where there are no markings you cannot tell if it is safety glass or not, so always assume it is not safety glass. Types of Safety Glass There are two main types of safety glass; these are Laminated Glass and Toughened Glass. Laminated Glass consists of two or more glass sheets permanently bonded together by a plastic or resin interlayer. Although it will break on impact, the bond between the glass and interlayer adhere any broken fragments, keeping the glass intact and resisting any penetration. The layered nature of laminated glass means that it blocks more noise and UV light than ordinary glass. Laminated glass offers greater protection for people and property by providing an effective barrier from attack. Although the glass will break if hit with a solid object, the interlayer will resist penetration, ensuring any attempt to enter a premises will be slow and noisy. In addition, the attacked glass will tend to remain in the frame keeping wind and rain out of the building until it can be replaced. Laminated glass can be made with a tinted interlayer or be made with tinted or reflective glass to reduce glare and heat gain. It can also be made with Low E glass or be processed into double glazed units thereby reducing heat loss and saving on energy costs. Laminated glass can also be manufactured with a special interlayer that can reduce noise transmission by up to 62%. For this and many other applications of laminated glass please contact us for further information. Toughened Glass is ordinary annealed glass that, after cutting and processing, is loaded into a furnace and heated to a plastic state at around 600oC. The glass is then rapidly cooled by a series of high pressure air nozzles. This rapid cooling induces high compression stress in the in the glass surface, while the centre remains in tension. Although the physical characteristics remain unchanged, the additional stresses created within the glass increases its thermal and mechanical strength making it 4 to 5 times stronger than annealed glass of the same thickness. Toughened glass can withstand a temperature differential of 250OC. In the unlikely event of breakage, toughened glass fractures into small particles, significantly reducing the risk of injury. Prior to the toughening process the glass can be processed to produce holes, curves and notches to a wide range of shapes and sizes. However, once toughened the glass cannot be further cut or processed apart from by sandblasting or applying window films. Typical applications for toughened glass include: · Splashbacks · Shower doors and screens · Double Glazed Units · Balustrades and fences · Frameless glass doors and entries · Doors and side panels · Internal partitions · Glass canopies · Furniture · Structural glass walls |
