Toughened glass is now required by regulation for every building project due to its increased strength and safety characteristics.
When all proprietary operations are completed from drilling, notching, edgework including any printing if required, the glass is passed through our oscillating furnace and heated to around 630 C. Once the heating process is completed, the glass is transferred to the quenching chamber where it is rapidly cooled. The structure of the glass is then transformed creating very high permanent surface compressive stress. In conclusion, if the glass is broken the contained stress is released and results in the glass breaking into small harmless particles. The glass also becomes stable against thermal fracture caused by partial shading once in situ.
The whole production process is controlled and monitored to ensure the product conforms to the required standard BS EN 12150 and is subsequently tested to BS EN 12600. The prime function of any toughened glass is to ensure if broken, then it breaks safely. The process increases the strength of the glass and makes it 4 - 5 times stronger than normal annealed glass, it is ideal for many applications especially when incorporated into lamination.
To maintain product quality ToughGlaze only purchase from 3 main suppliers, Pilkington, Guardian and AGC (All products conform to BS EN 572). Although manufacturers carefully select and grade raw materials, impurities will exist in float glass. It is only in the toughening process that the impurities / inclusion like nickel sulphide becomes a problem. Please refer to the heat soaking section of our website or contact ToughGlaze for more technical information.
ToughGlaze recommend all glass that will be glazed in critical areas or places where replacement could be difficult, for the glass to be heat soak tested prior to final assembly or installation.
Please note any inclusions of this type is not considered a fault. It must also be noted this is not the only reason glass breaks without warning or initial impact.