Page 71 - Between light and shade

Light, transparency and reflection

Erkrath reduce light transmission, they provide
a certain degree of sun protection during the day
and reflect artificial light at night while being
filled with light from the outside. Conversely,
as the tower in Lommel exhibits glass works of
art along its spiral staircases, it needs to provide
transparency and sparkle at night.

Polycarbonate 71 has the same light transmis-
sion properties as glass but is 35 times as flexible,
6 times as expandable, twice as light and, above
all, more impact resistant. Used in the form of
multi-walled panels, it offers thermal insulation
of 0.875W/m²K with a color rendering index
(CRI) above 97%, which also makes it a suitable
material for canopies, despite its lower resistance
to ultraviolet light.

As a result, I have used it for the walls of
sports halls at the Fire Stations in Enschede
(p: 2003, c: 2005-2007; 01/450) and in Charleroi
(p: 2014, c: 2015-2016; 01/569), but it is primarily
to provide wonderful light in the small studio
belonging to the artist Erik Salvesen in Ekenäs-

71 Polycarbonate, discovered in 1953 by Schnell, Bottenbruck
and Krimm at Bayer AG, appeared on the market in 1958. Yet
again, we had to wait for decades to witness the development
of multi-walled panels with excellent insulating properties.
It has a density of 1.2, a yield strength of 60 MPa, a modulus
of elasticity of 2 GPa and a thermal expansion coefficient of
70.10-6 °K-1 (compared to 2.5 – 40 MPa – 70 GPa and 1.2. 10-6
°K-1 respectively for ordinary glass).
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