Tannine aus Fichtenrinde als Bindemittel in Holzwerkstoffen

Besides the synthetic binders also tannins can be used for the manufacture of wood-based materials. Results related to the development of natural binder systems make clear that also tannins from spruce bark are suitable for the manufacture of particleboards and medium density fibreboards (MDF). The tannins were obtained through extraction of spruce bark with water and/or sulphite waste liquor and then mixed with usual commercial quebracho tannin. The cross linking agent was formaldehyde. The strength properties of the MDF manufactured with these binder systems meet the requirements for their application in humid areas. MDF manufactured with pure spruce tannin formaldehyde resin as binder corresponded to the board type MDF (application in dry areas)