New developments in European wood adhesives

After a rapid overview of the most salient new developments in wood adhesives in Europe, the utilization of accelerated phenolic adhesives for panel products, both synthetic and natural(such as tannins), is described. This paper will also discuss results from experiments using laboratory and industrial panel production runs in which a synthetic phenol-formaldehyde adhesive has been used at pressing times of 7 sec/mm of panel thickness, as fast as urea-formaldehyde and melamine urea-formaldehyde adhesives, without any loss of performance and while achieving full exterior properties of the panels. Then we will discuss the development of oriented strandboard (OSB) panels bonded with tannin adhesives. This development has allowed preparation at an industrial level of fully exterior-grade OSB panels satisfying the requirements of Class 4 (marine) of the relevant European Norm specification. This is achieved under standard factory conditions without factory alterations and at industrially significant pressing times and temperatures. At present, no other adhesive in Europe has proven capable of satisfying the Class 4 (marine) requirements; isocyanates and PMUFs satisfy Class 3 only. The results of the development of tannin adhesives for exterior grade medium density fiberboard are presented.