Review of Recent Research Activities on One-Component PUR-Adhesives for Engineered Wood Products

Manufacture of engineered wood products requires safe adhesive systems. Since their introduction in the mid-1980s, one component polyurethane (1C-PUR) adhesives have proven to provide a reliable alternative to commonly water based aminoplast (UF, MF, MUF) and phenoplast (PR, PRF) adhesive systems. No formaldehyde, no mixing and fast curing at room temperature are some of the reasons, why 1C-PUR adhesives have continuously experienced increasing acceptance in the field of structural timber gluing. Driven by the intention to establish a highest possible level of adhesive performance and security, this successful development was accompanied by extensive scientific and industrial research activities. The present article aims at providing an understandable overview of the most relevant results from those research activities during the past years. Major aspects such as chemical and physical bondline integrity, adhesive behaviour at elevated temperature and fire, and gluing of alternative wood species will be addressed in order to present an insight into 1C-PUR adhesive-technology and an outlook to its future development.