Constructional masterworks in glass / sedak at BAU 2019

Extreme and unusual glass constructions resulting from technical advances: at BAU 2019 sedak (hall C3 / stand 100) shows what the transparent material is capable of.

The unusual exhibits include a 17.8 metre long glass fin that stretches over the stand, a ten-metre glass “seesaw” and an all-glass parapet with a special feature. After buying into the Italian specialist Sunglass Industry, sedak’s portfolio now includes hot bending – there is a five metre high example of this.

The sedak stand is straddled by a filigree construction that demonstrates the know-how of the company in dealing with glass in very large formats: a 17.8 metre long and 60 centimetre wide glass fin. It is constructed from five laminates, weighs 1.5 tonnes, and is held by only two 30 centimetre long stainless steel arms with a thickness of just 38 millimetres, which are laminated into the fin.

The durability of the material is demonstrated by a “seesaw” made entirely from glass. The ten-metre-long component balances on a single acrylic glass post. Weighing 0.6 tonnes and with eleven laminates, it moves effortlessly around its central axis and is representative of the exceptional load-bearing capacity of glass – each side can be loaded with 150 kilograms. The completely transparent seesaw was created in a collaboration between the engineering office Eckersley O’Callaghan (London) and sedak.

Latest competence: hot bending

In cold bending, individual panes of glass are laid into a bending rig alternating with SG interlayers to form a glass package and then melted together to form a laminated glass element in an autoclave at around 140 degrees Celsius.

The interlayers provide the necessary shear stiffness, so that the glass package remains in its curved form unaided after lamination in the autoclave. In contrast, with hot bending (also know as sag bending or gravity bending) the glass panes are heated to their melting point at around 600 degrees. At this temperature gravity causes them to bend into a predefined form, after which a controlled cooling process takes place.

By purchasing a stake in the Italian company Sunglass Industry s.r.l., which is one of the market leaders for curved architectural glass, sedak has extended its portfolio to include hot bending technology. A hot-bent glass laminate consisting of two 1.35 x 5.0 metre panels demonstrates this technology on the sedak stand.

The two eight-millimetre-thick glass panes were curved into cylinders and then laminated. They are a replica of the glass elements used in the façade of the new Sunglass Industry headquarters in Villafranca. The modern, new building is shown in large pictures in the background, enabling the visualization of the exhibit in a larger dimension.

Specialist for size with attention to detail

In addition to large-format glass products of up to 3.51 x 20 metres, sedak develops glazing details that open up new worlds of architecture with great effect. In this context the company from Gersthofen (Bavaria) presents an innovative completion for glass edges that can be used, for example, in glass parapets or handrails: a laminated-on glass strip provides a clean conclusion to the glass parapet.

At 17 millimetres wide, 6 millimetres high and 2.5 metres long the filigree masterpiece with its highly polished sides forms an absolutely even glass edge that sets aesthetic accents and is also functional: the otherwise open edge of the glass laminate is protected from the effects of the weather.

The laminated-on glass also acts as protection against impacts and enables the use of two-layer laminates where previously the building regulations required three-layer laminates to be used.