Leverkusen, Germany - Use of wood in construction has been rising recently, with timber exploited more and more in larger buildings. High-performance adhesives, including polyurethane types, are needed for such a building approach, and Bayer MaterialScience AG, together with the Materials Testing Institute (MPA) of the University of Stuttgart and adhesives producer Purbond AG of Sempach Station, Switzerland, is evaluating better test methods for the adhesive bonds. These three organisations, "feel the methods underpinning current standards do not give sufficient consideration to the outstanding properties of polyurethane adhesives," said a 12 July statement from BMS. In a joint project, the trio will try to design better test methods for long-term prediction of behaviour of bonds between PU and wood,A resurgence of interest of wood means it is now being used to build offices, schools, apartments, and even bridges, theatres and transmission towers. According to BMS this trend is aided by a lumber industry which is keen to offer semi-finished goods that can be rapidly and precisely joined on site. This allows larger building blocks to be produced, making construction of "large and architecturally interesting structures fast and economical," BMS said. High-performance adhesives are vital for such work, with one-component polyurethane systems offering a number of advantages. They can be applied direct from a drum, need no mixing and have no pot life restrictions, BMS added.Purbond is the "market and technology leader for one-component polyurethane (PU) adhesives for the manufacture of load-bearing wood elements," said BMS. MPA is the body responsible in Germany for testing wood adhesives before they are marketed. It assesses adhesive strength, application properties and long-term bond durability. BMS itself supplies the isocyanate prepolymers used as raw materials for the one-part PU adhesives. PIC (l-r) Dr Heinz-Werner Lucas, head of Business Development Prepolymers at the Coatings, Adhesives, Sealants Business Unit of BMS; Dr Simon Aicher, head of the MPS; and Walter Stampfli, general manager of Purbond."
