Glass Solutions for Curved Facades
How is curved glass made?
Curved glass, also referred to as bent glass, is glass that has been heated past its softening point and formed into a curved shape, either by annealed gravity bending, or by heat-treated (tempered or heat-strengthened) bending. In case of gravity bending, the softened glass is placed over or into a mould and cooled down slowly after the required shape is achieved.
Although it allows many shapes, gravity bending is time consuming and the coating must withstand a longer heating period. With the heat-treated bending process, the glass is cooled down very quickly immediately after the desired curvature is reached to increase its strength. The main challenges here are how to avoid optical distortions caused by the production process and the limitation to cylindrical shapes and concave shapes when coatings are involved.
Design freedom without sacrificing aesthetics or performance
Curved glass gives architects and designers more freedom to create innovative, aesthetically pleasing curved glazed facades where straightness, corners and edges can be enhanced with soft curves. Curved glass allows transparent views on the corner of a building, without visually disturbing frames. These curves can be in the form of simple cylindrical shapes to the more complex 3D free form shapes.
Whilst curved glass opens up many more design possibilities, the challenge is to choose a curved glass that still provides the required thermal and solar performance in its curved shape. A crucial factor here is the coating, which has to withstand the bending process without reducing the glass’ visual appeal.
Curved glass that meets all your project needs
For commercial curved façades, the Guardian SunGuard® range of coated solar control glass products are some of the highest performing bendable glass products available. Guardian SunGuard® glass coatings are designed to withstand the bending process, maintaining their high performance and aesthetic appeal. Using Guardian glass coated products allows to achieve uniform and homogeneous appearance of curved and flat parts of a façade.
This is backed up by technical support and SunGuard® glass coatings’ application advice from Guardian specialists, who are on hand to help through the various stages of a project. We work collaboratively with glass processors during the initial design phase to help them define key parameters such as the minimum bending radius, process tests and to produce mock-up samples, regardless of the type of bending process used. During the construction phase, we provide on-site support to glass processors with the goal to minimise the visual disturbances in the glass such as roller wave, distortion or discolouration of the coating.
Meeting the challenge: a complex curved façade
The Elbphilarmonie building in Hamburg, Germany, is one of the largest and most acoustically advanced concert halls in the world. The building’s stunning glass façade is one of the most complex ever produced, consisting of both flat and curved IGUs for the windows, as well as triple laminated curved single glazing for the covered exterior galleries.
Developing the curved glass elements of the façade was a challenge. Guardian Glass worked closely with the glass processor to meet the architect’s requirements for curved glass in terms of performance and aesthetics (i.e. the shapes of the curved glass, appearance and colour reflections). Read the full story.