Flat glass, also called float glass is often processed to suit several different requirements and applications. With a wide range of technologies in the modern day glass industry, customers tend to get confused when they see the different types of glass available. The 4 main types of glass that could be used in various residential and commercial balustrade applications include:
#1 Annealed glass
This basic product is a result of the annealing stage in the float glass making process. Molten glass is first allowed to cool very slowly in a controlled manner, until it reaches normal room temperature, relieving the internal stresses within the glass. Without this specialized slow cooling, the glass would crack with the slightest mechanical shock and change in temperature. Annealed glass is utilised as a base product to form various advanced glass types.
#2 Heat-strengthened glass
This type of glass is also referred to as semi-toughened or semi-tempered glass. In the heat-strengthening process, annealed glass is heated to between 650°C and 700°C and then quickly cooled, although at a slightly slower rate than toughened glass. This specialised process increases the thermal and mechanical strength of annealed glass, giving it double the strength of the latter.
In case of a heavy impact, the broken fragments are very similar in size to the annealed glass fragments, but with greater chances of staying together. This type of glass isn’t commonly used in balustrades or any similar structures because it has limited strength compared to toughened or tempered glass,
#3 Toughened or tempered glass
This is the commonest type of glass used in balustrading and similar structural features. Annealed glass is first heated to about 700°C by the processes of convection, radiation and conduction. A simultaneous and uniform blast of air on both the surfaces accelerates the cooling process.
The variation in cooling rates between the surfaces and the inside of the glass panels produces varying physical properties, resulting in very high compressive stresses in the surface which are balanced by the tensile stresses within the glass’ body. This process makes the panels four to five times safer and stronger than untreated or annealed glass.
The surface compression or counteracting stresses gives toughened glass its higher mechanical resistance to breakage; even in the case of a very heavy impact, it will break into regular, smaller, squarish fragments rather than shards that are sharp and more likely to result in injuries.
#4 Laminated Glass
Any one of these types of glass mentioned above can be laminated. In most instances, the two sheets of toughened glass are laminated together with a PVB (Polyiynil Butyral) layer that’s 1.52mm thick. This type of glass offers a number of advantages’ it’s secure and safe and doesn’t shatter on impact. The glass is held together by the special interlayer. This significantly reduces the safety hazard common with shattered glass fragments; and to a certain degree security risks associated with easy break-ins.
A variety of different interlayers are available that apply a range of other advanced technologies to this application. The structural interlayers can be utilised to enhance the strength of these glass panels where high loadings are needed. Coloured interlayers can also be used for purely decorative purposes or added privacy. If required, other properties such as fire-resistance and sound dampening can also be incorporated into these interlayers.
We at Quantum Frameless Glass can provide excellent, customised solutions for residential and commercial spaces. For any more information about our glass balustrades, call us at this number – 1300 282 248. You can also contact us using this online form.
Thanks for reading,
Quantum Frameless Glass Team
1300 282 248