Sibyllenbad with PLEXIGLAS® columns

© Kurmittelhaus Sibyllenbad / Foto: Christina Schmidt, Wittmann Media, Waldsassen

Light as a factor for well-being

Many people visit spa resorts to relax and unwind. But bright light is not very relaxing. Light-scattering materials such as PLEXIGLAS® ensure pleasant lighting.

Simply entering Sibyllenbad already feels like a vacation. Pleasant lighting adds to the relaxing atmosphere. Columns with LEDs are clad in PLEXIGLAS® and provide indirect lighting, the intensity and color of which can be adjusted to suit different moods. This makes the columns an attractive design feature as well as a feel-good factor.

An illuminated eye-catcher

The Sibyllenbad health center at the German-Czech border, in the Upper Palatinate, combines spa and medical treatments. Visitors can relax and rest in various saunas, a bathing temple and the spa water bathing section. The heart of Sibyllenbad is the large bathing hall with three pools. However, until it was renovated in 2014, the space was dominated by drab concrete columns which did not fit in with the otherwise relaxing atmosphere.

We immediately knew we wanted to use PLEXIGLAS® Satinice, as it scatters light especially evenly.

Andreas Szak
Managing Director at Designpanel

Sibyllenbad’s operators therefore commissioned the experts for working with acrylic glass, plastics and composite materials from Designpanel. Their job was to clad the ceiling-high concrete columns to not only improve their appearance, but also illuminate the bathing area. In addition, the color and intensity of the lighting needed to be adjustable. “We immediately knew we wanted to use PLEXIGLAS® Satinice,” says Andreas Szak, who established the Designpanel brand with his brother Rüdiger Szak. “It scatters light especially evenly.” 

Design panel – elements for innovative architecture

In 2010, Andreas Szak (ACRYSIGN) and his brother Rüdiger Szak (axis GmbH & Co. KG) established the Designpanel brand to market innovative product developments from both companies. The combination of surface materials developed by ACRYSIGN Kunststofftechnik GmbH and axis’ Lightpanels creates unique design elements for architecture and object design.

Thermally molded and secured

Although Szak had used the brand acrylic glass from Evonik before for other projects, the size of the columns at Sibyllenbad posed a new challenge. Six columns, six meters in height, and eight columns with a height of 2.5 meters, each with a diameter of 80 centimeters, were to be clad. This required a total of thirty sheets of PLEXIGLAS® Satinice measuring 3050 x 2030 x 10 millimeters, satined on both sides.

Various processing steps were needed to turn the sheets into columns. Szak and his team thermally molded every single PLEXIGLAS® sheet using two hard shells. “PLEXIGLAS® is very well suited to this process because it retains its excellent light-scattering properties,” explains Szak. The curved sheets were then screwed to the columns and the concrete ceiling with locking rings. This was required to enable maintenance access to the LEDs which provide the illumination. As a result, the tall columns look as if they were made from a single cast. In truth, the columns have two layers of PLEXIGLAS® cladding, each of which consists of two half shells. The individual elements are connected with seams and screwed together with transparent polycarbonate screws.

Translucent with excellent light-scattering properties

“The heat and humidity in the bathing area place particular demands on the materials,” says Szak. While PLEXIGLAS® is impervious to the humidity in the bathing area, the LEDs needed to be coated in resin to prevent damage to them.” Yet the combination of PLEXIGLAS® and LEDs still has several advantages: The LEDs have a strong light intensity and, in combination with the light-conducting material, provide homogeneous lighting. As the PLEXIGLAS® Satinice is satined on both sides, it allows light to shine through without being fully transparent, so the illuminants remain an invisible light source. When not illuminated, the columns appear evenly white and translucent throughout the entire surface. Once they are illuminated however, up to 16 million colors are theoretically possible, allowing the bathing area to be illuminated in an enormous variety of ways.

The excellent look remains consistent. Even years later, PLEXIGLAS® retains its original color, does not yellow or lose any of its light-conducting properties. The material also shows no traces of wear or scratches and retains its velvety surface. “It was important to us to use a particularly durable material that would show no traces of wear, even years later,” explains Szak. Visitors to Sibyllenbad will therefore be able to enjoy the relaxing lighting for many years to come.