How it Works

GJ ToughLam hi-performance laminated glass consists of two or more sheets of heat strengthened or toughened glass bonded together by heat and pressure with an interlayer of either standard PVB or a specialist high strength SentryGlas® ionoplast to ensure the highest strength and structural performance.

Toughened glass is produced by heating the glass close to its softening point in the toughening furnace and then relatively cool air rapidly cools the outer surface of the glass while the inner layer of the glass cools at a slower rate. This process induces compressive stress in to the surface of the glass.

When the glass is placed under load, this compressive stress must first be overcome before tensile stress can be induced in the glass. The result is that glass subject to this process is much stronger than annealed glass. It also has different breakage characteristics.

If one layer of GJ ToughLam glass is broken, the combination of the strength of the unbroken glass and the tough plastic interlayer will help to retain the glass in the frame.

Performance Options

GJ ToughLam can be engineered to suit the most demanding requirements.


GJ ToughLam is available in a range of interlayers including PVB as standard, or a specialist high strength SentryGlas® ionoplast. The result is a durable, adaptable high performance glazing material that meets the most demanding requirements.

It can also incorporate high performance acoustic interlayers for enhanced sound control or toned interlayers for increased solar performance.

Heat strengthened or toughened glass

GJ ToughLam can be specified with either Heat Strengthened or Toughened glass or a combination of both.

Heat strengthened glass is 1½ times stronger than annealed glass of the same thickness. When broken, heat strengthened glass breaks into fewer, larger pieces.

When heat strengthened laminated glass is broken, the combination of the tough plastic interlayer and the relatively large pieces help the glass stay in the frame.

Toughened glass is 2½ times stronger than annealed glass of the same thickness. When broken it breaks into a large number of very small pieces.

Find out more about GJ ToughLam