The effect of the soak temperature applied to the classification of the water resistance grade of wood adhesives

Abstract Classification of thermoplastic wood adhesives for non-structural applications in the durability class according to EN 204:2017 is significantly influenced by the water temperature used during the test. When using dispersion with durability class D3 and D4 the bonding strength will decrease as the temperature rises. The temperature selected within the water temperature range specified in the standard can reduce the strength value by nearly a third, which can modify the classification regarding the corresponding durability class. Inappropriate classification is misleading the users which can cause their application on an inadequate field. Therefore the modification of standard in this field is recommended.