What is the Difference Between Laminated Glass and Tempered Glass

Laminated glass and tempered glass are both types of safety glass. They share the benefit of increased strength compared to regular glass. However, there is a distinct difference between laminated glass and tempered glass in their composition, breaking, and usage.

What is the difference between laminated glass and tempered glass? Laminated glass consists of two or more layers of glass bonded together with a plastic interlayer, whereas tempered glass is a single pane of glass.

Key Areas Covered

1. What is Laminated Glass
      – Definition, Features 
2. What is Tempered Glass
      – Definition, Features 
3. Similarities Between Laminated Glass and Tempered Glass
      – Outline of Common Features
4. Difference Between Laminated Glass and Tempered Glass
      – Comparison of Key Differences
5. FAQ: Laminated Glass and Tempered Glass
      – Answers to Frequently Asked Questions

Key Terms

Laminated Glass, Tempered Glass

What is Laminated Glass

Laminated glass is a type of safety glass made by bonding two or more glass layers together with a tough plastic interlayer. This interlayer is usually made up of polyvinyl butyral. The composition of these panes is mainly silicon dioxide (SiO2) with minor amounts of other oxides for properties like clarity and strength. PVB is a thermoplastic polymer, meaning it softens under heat and pressure during the lamination process. This allows it to flow between the glass layers and form a strong bond upon cooling. The chemical structure of PVB includes vinyl alcohol groups (CH2-CHOH) that form hydrogen bonds with themselves and the glass surfaces, creating a resilient adhesion. This type of glass holds its shape even when cracked.

Laminated glass has many uses. It is mainly used in safety applications due to its ability to hold its shape even when cracked. It is used in car windshields, preventing dangerous shards from injuring occupants in an accident. Similarly, skylights and overhead glazing in buildings benefit from laminated glass, minimizing the risk of falling glass in case of breakage. This glass is also used in security solutions. Jewellery stores, museums, and banks use these types of glasses for protection.

What is Tempered Glass

Tempered glass is a type of safety glass made by heating regular glass to a high temperature (around 1100°F) and then rapidly cooling it with forced air. This creates internal stress within the glass. The outer surfaces are compressed, while the inner core becomes tensile (under tension). This internal stress makes tempered glass several times stronger than regular glass and alters how it breaks.

Tempered glass breaks into small pieces instead of large chunks when it faces a strong force. This property makes it useful in the production of safety applications. Tempered glass is a component in car windows (except windshields, which use laminated glass for added protection). It ensures that in case of an accident, shattering glass poses minimal risk to occupants. It is also used in shower doors, glass table tops, and side panels in furniture.

Similarities Between Laminated Glass and Tempered Glass

1. Both are considered as safety glasses.
2. They are stronger than regular annealed glass and more resistant to impact.
3. They both look alike.

Difference Between Laminated Glass and Tempered Glass

Composition

• Laminated glass has two or more glass pieces bonded with a clear plastic interlayer, typically polyvinyl butyral (PVB), while tempered glass is a single sheet of glass heat-treated and rapidly cooled, creating internal stress that makes it shatter into small, blunt pieces.

Cracking

• In laminated glass, cracks may appear on the surface, but the plastic interlayer holds the glass together, preventing it from shattering and falling out. However, tempered glass shatters into small, pebble-like pieces upon impact.

Cost

• Laminated glass is generally more expensive than tempered glass.

Penetration

• Laminated glass is more resistant to penetration due to the plastic layer, while tempered glass is easier to break through.

Conclusion

In conclusion, both laminated and tempered glass are safety options, stronger than regular glass. Laminated glass consists of two or more layers of glass bonded together with a plastic interlayer, whereas tempered glass is a single pane of glass. Laminated glass is more resistant to penetration due to the plastic layer, while tempered glass is easier to break through.

FAQ: Laminated Glass and Tempered Glass

1. What are the disadvantages of laminated glass?

Laminated glass has several disadvantages. The added plastic layer in laminated glass can slightly impact visual clarity. It is also heavier than standard glass, which may pose logistical challenges during installation or transportation. In addition, laminated glass is more expensive.

2. Does laminated glass crack easily?

Laminated glass does not crack easily. This is because laminated glass consists of multiple layers bonded together with a flexible interlayer. This design helps distribute impact forces across the glass surface.

3. Is laminated glass more expensive than tempered glass?

Yes, laminated glass is more expensive than tempered glass. This is because the process of creating laminated glass is more complex and requires more materials and specialized tools.

4. Why would the laminated glass fail?

The failure of laminated glass generally occurs due to the cohesive failure of the interlayer material or due to issues with the connectivity between the glass panels and the interlayer. When the bond between the layers weakens or breaks, it compromises the structural integrity of the glass.

5. How to tell if the glass is tempered or laminated?

It’s not hard to tell tempered glass and laminated glass apart. Tempered glass often has a certification mark etched in a corner while laminated glass has a visible plastic interlayer between the glass panes.

Reference:

1. “Tempered Glass.” Wikipedia. Wikipedia Foundation. 
2. “Laminated Glass.” Wikipedia. Wikipedia Foundation. 

Image Courtesy:

1. “Safeguard Glass Markings 1” By Scheinwerfermann – Own work (Public Domain) via Commons Wikimedia
2. “Shattered laminated glass in broken window in railway tram train carriage Close-up Cracks fragments visual effects patterns..” By Wolfmann – Own work (CC BY-SA 4.0) via Commons Wikimedia