When choosing glass for your retail store there are 3 basic types available, regular float glass, tempered glass and laminated glass. Each type offers different qualities for different uses and each has its pros and cons. Below is listed a summary of each type to help when choosing a glass for your project. But first, don’t forget to watch “Breaking Glass,” where we put all 3 types of glass to the test.
Regular Float Glass:
Float glass is a sheet of glass made by floating molten silica (glass) on a bed of molten metal (tin). This method gives the sheets a uniform thickness and very flat surfaces. This process is also known as Pilkington process.
Price, This is the most economical glass type.
Ability to cut down or rework if required at any time in the process.
Flexible, because the glass is not under stress from the manufacturing process it will allow for some flex or bend (very minimal) after or during installation.
Edge strength, because the glass is not under stress from the manufacturing process it is less prone to breakage if hit on the edge as compared to tempered.
No size and hole placement restrictions. (as compared to tempered)
When broken it leaves large sharp jagged shards that can be very dangerous and act as a knife edge. These pieces can also act as a guillotine if installed in a vertical position and the bottom has broken away the falling pieces are a very serious danger.
Will crack more easily if impacted on “face surface” of glass.
Tempered glass is a type of safety glass made from regular float glass but processed by controlled thermal treatments to increase its strength compared to normal glass. Tempering puts the outer surfaces into compression and the inner surfaces into tension, these stresses cause the glass to crumble into small pieces instead of splintering into shards, these small pieces are less likely to cause injury.
Safety, when broken the glass will break into small squares, these small squares are only minimally sharp and do not have a large enough surface area to do any major harm.
Hard, resists breakage when impacted on the “face surface” of glass. Installation method will affect how much impact the glass can take, because tempered glass is under stress from the tempering process if allowed to flex it will break up into the previously mentioned “small squares”.
Scratch resistance, because the tempering process hardens the glass it also gives the surface a “slightly” better resistance to abrasion.
Clear, because of the tempering process removes many imperfections in the float glass.
Cannot be cut or drilled after tempering process.
Broken easily if heavily impacted on edge.
Broken easily if allowed to flex.
Laminated glass is another type of safety glass that holds together when broken. When broken it is held in place by a separate layer of plastic (PVB) between its two or more layers of glass. The plastic layer keeps the glass layers bonded even when broken and because of its high strength prevents the glass from breaking up into large shards. Many configurations can be made depending upon which glass is used and what type of plastic is used. Car windshields, Bullet proof glass and self-darkening (LCD) glass are all examples of other specialty laminated glass.
Holds glass pieces if broken.
Good Security, because the plastic layer holds the glass together, so it still provides a barrier of protection.
Plastic layer can give glass many options and properties such as UV protection and security.
Expensive, and can cost more because of the extra pieces and manufacturing times.
Longer lead times as there are a limited number of suppliers who can make this type of glass.
Inconsistent thickness, because of the manufacturing process they cannot guarantee a consistent thickness, though the tolerances are quite small.
Disposal, can be difficult because in some areas landfill will no longer accept this type of glass and may require an extra fee for disposal.