What is the primary characteristic of laminated safety glass upon breakage?

It cracks into a spider-web pattern but the fragments remain tightly adhered to the PVB interlayer, preventing dangerous free-falling shards.

What is the purpose of the boil test?

To test the durability of the interlayer against high temperatures (100°C for 2 hours) and check for signs of delamination, bubbling, or cloudiness.

How is the impact resistance tested?

By dropping a specified steel ball (e.g., 227g) from a set height to ensure the glass limits penetration and maintains fragment adhesion.

IS 2553 Part 2

: 1990

Safety Glass - Part 2: Laminated Safety Glass

CurrentFrequently UsedSpecificationBIMArchitectural · Doors, Windows and Shutters

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Specifies the requirements and testing methods for laminated safety glass used in architecture and transport. It ensures the glass resists environmental degradation and does not shatter into dangerous shards upon impact.

Specifies requirements for laminated safety glass for use in buildings.

Quick Reference Values

boil test temperature100 °C

boil test duration2 hours

small ball impact mass227 g

minimum visible light transmission70% for windscreens

Practical Notes

Laminated safety glass relies heavily on the quality of the PVB interlayer; delamination or bubbling during the boil test indicates poor manufacturing or moisture ingress.

When specifying for building facades, ensure edge sealing is compatible with the interlayer to prevent long-term weathering damage.

Unlike toughened glass, laminated glass stays largely intact within the frame after breaking, offering post-breakage safety and security.