Physics and Technology
Heated to 620–650°C, then rapidly cooled (quenched) with high-pressure air. Creates compressive stress on surface and tensile stress in core — making it 4–5× stronger than annealed glass. Fractures into small, blunt fragments, reducing injury risk.
Heated to ~620–650°C, then cooled at a slower rate. Lower surface compressive stress than tempered glass — approximately 2× stronger than annealed glass. Less optical distortion. Fractures into larger fragments, ideal for laminated applications.
International Standards
To ensure safety and reliability, Glaspedia tempered and heat strengthened glass comply with most global standards.
Defines mechanical strength and fragmentation requirements for tempered and heat strengthened glass.
Specifies performance criteria for thermally toughened soda-lime silicate safety glass.
Specifies performance criteria for heat strengthened glass.
Governs tempered and heat strengthened glass under safety glazing materials.
Govern tempered glass use in Building Integrated Photovoltaics (BIPV) applications.
Aesthetics
The tempering or heat treating process can introduce optical effects that influence design. Roller wave, bow, or warp may cause reflections to appear uneven, particularly on large façades. Anisotropy, visible as rainbow-like patterns under polarized light, results from stress distribution within the glass. While not defects, these phenomena affect visual uniformity.
South Star mitigates distortion and anisotropy through advanced inspection systems, Osprey 10 Complete by LiteSentry®, and optimized cooling processes, ensuring heat treated glass meets both functional and aesthetic expectations.