With a bid to control the heating costs while providing ideal insulation for Scandinavian detached wood houses, two companies have jointly devised a solution based on polyurethane rigid foam. MjøsCon AS - a subsidiary of Mjøsplast AS based in Moelv, Norway - has been working in cooperation with Bayer MaterialScience's Nordic BaySystems polyurethane systems house in Otterup, Denmark, to develop an intelligent solution for the year-round usage of wooden houses. The companies put two wooden beams - one with a cross-section of 98 by 47 mm, the other 40 by 47 mm - are in a mold and the space between them is filled with a liquid polyurethane system consisting of Desmodur® 44 V 20 L and Baydur® C-77-B-60/W. The mold is then sealed and the composite material is cured at a temperature of around 45 ºC. The polyurethane system adheres extremely well to the wood substrate, thereby ensuring that the composite is also mechanically stable. The finished wood/polyurethane beam can be removed from the mold after only a short time.
With the addition of the 60-mm-thick layer of polyurethane rigid foam, the composite timber now measures 198 by 47 millimeters. The company claims that the technology helps to significantly improve heat insulation and the thermal bridges between the interior space and the exterior are prevented. The inventors have applied for patents for the product and production process. The Norwegian Industrial Property Office has given a written reply that the invention will be patented. The application comes at a time when new energy conservation legislation has been introduced in Norway which calls for a substantial reduction in energy consumption.