‘Toughened Glass’, this term is banded around so often in our industry, we sometimes forget whether or not our customers/partners fully understand its meaning. So here’s a short blog post to hopefully crystallise any definition you might currently have – Enjoy!
What is Toughened Glass?
Toughened glass is a type of safety glass processed by controlled thermal (or chemical) treatments to increase its strength compared with normal glass.
How is Glass Toughened?
Toughened glass starts life as normal/float glass. Any cutting must be completed before the glass is toughened as it would likely shatter if it was cut in its toughened state.
In the toughening process, the surfaces of the glass are heated in a furnace. Temperatures vary but the glass normally reaches temperatures of over 600°C. The hot glass is then cooled rapidly by a blast of air over a period of between 3 -10 seconds. Here’s the science-y part: As the bulk of the glass begins to cool, it contracts. The already solidified surfaces of the glass are then forced to contract, and consequently, they develop residual compressive surface stresses, while the interior zone develops compensating tensile stresses. The tension zone in the core of the glass takes up about 60% of the glass surface.
Why Toughen Glass?
Here at Deco Glaze, we toughen our glass whenever and wherever possible, making our products extremely durable and safer for our customers.
When Float glass, breaks it shatters into shards, which are extremely sharp, this makes it unstable for domestic applications.
As well as being up to 5 times stronger than the equivalent thickness of float glass thermally toughened glass safely fractures in to smaller pieces with blunt edges.
Lastly toughened glass offers greatly increased resistance to both sudden temperature changes and temperature differentials up to 200°C compared with 40°C for non-toughened.