Wood fibreboard paraffin hydrophobization and the impact of this treatment on the board surface finishing quality

Wood fibreboard paraffin hydrophobization and the impact of this treatment on the board surface finishing quality. The aim of this paper is to analyse the causes of surface treatment defects in commercially produced wood fibreboards (FB). The analysis of: the obtained (measured and calculated) thermodynamic characteristics and of the results of microscopic examinations demonstrated that the excessive FB hydrophobization with paraffin may cause the paraffin to release from the FB surface and to migrate into the first primer layer. For the sanded FBs, similar paraffin migration was also observed into the second primer layer. This entailed lowered drying rate for the coating materials applied on FB, lower adhesion of the coating materials to the substrate and also lower adhesion between the particular coating layers applied. At the same time, the occurring frequency of surface treatment defects increased.