Vorbehandlung von Fichtenholz mit Chemikalien mit dem Ziel der Verbesserung der Imprägnierbarkeit

Dried sprucewood (Picea abies L. Karst) is hardly penetrable with liquids, p.e. wood preservatives. The aim of this research was to improve the penetrability by means of pretreatments with chemicals. Small specimens (20×20×50 mm) were treated with different acids, alkali and chelating agents. Concentration, temperature and duration were varied. Subsequently, the specimens were impregnated with a water based preservative. The penetration and the retention of the liquid were determined. The pre-treatments with ammoniumoxalate, acetic acid and formic acid improved the penetrability slightly without attacking the wood structure. For further work with sawn planks, acetic acid, hexametaphosphate and oxalate were selected (see part 2).