Upcycled polyurethane panels used in composite façade

Through its involvement, the competence network for sustainable building initiated by Bayer MaterialScience is making a valuable contribution to the research and development of sustainable building concepts that cover a building's entire life cycle. With 20 partners across Europe, the ECB offers decision-makers in the building industry comprehensive consulting services and material solutions for energy-efficient, economical and ecological building.[image_1_right]

Experimental structure with sustainable material mix
As part of the research project, 20 students have successfully designed and built a "White Pavilion” from timber and demonstrated new ways of using polyurethane in a composite facade: They used compressed polyurethane panels using recycled polyurethane insulation scrap to construct the facade.  A white, shiny container dubbed the "White Pavilion” now stands at the very center of the Technology and Innovation park in Berlin-Wedding. With just 5 x 7 m of floor space and a 3-m high ceiling, it makes for an interesting contrast to the old brick buildings surrounding it on the former AEG company grounds. The container's four doors each can be rotated 360° to make the green inside walls visible on the outside, and to signal from a distance when the pavilion is open.The side is outfitted with vertical, transparent slats constructed of twin-wall polycarbonate sheets made of Makrolon from Bayer MaterialScience[image_2]The individual modules of the pavilion consist of pinewood frames with OSB walling. Wooden structures are always subject to very strict moisture protection requirements. The students therefore chose a high-performance but also sustainable building material for the pavilion: Polyurethane compressed panels made of recycled PU insulation scrap, reclaimed from Purenit in a special upcycling process, were used for the first time to construct the outer skin of the facade. Purenit, a functional material manufactured by Puren, displays very high resistance not only to moisture, mold and rot, but also to chemicals. The PU compressed panels serve as insulation, effectively reducing heating energy losses. To protect the panels against weathering, they were also treated with a 2 -3 mm PU spray coating manufactured by AB Polymerchemie, which likewise is the first of its kind. In the last step, the pavilion was painted white.

Researching building concepts for the future
For the students, the pavilion is their own on-campus event location and café. For TU Berlin, the building simultaneously gives researchers an opportunity to test and evaluate the innovative facade system under practical conditions. Shear and pull-out tests conducted by the students themselves at the Institute of Civil Engineering's testing center helped to compile initial information on the load-bearing capacity of the PU compressed panels and the Purenit/wood screw connections. The results ultimately will provide some indication of the durability of the new facade design.