Wood in outdoor applications is susceptible to decay and degradation caused by various factors, and although this process might be important in carbon cycle, it is much less desirable phenomenon when wood is used in commercial applications. Copper-ethanolamine based wood preservatives are currently the most important group of preservatives for protection of wood in use classes III and IV. Fixation of these wood preservatives is generally good, although in some cases a decreased fixation can be noticeable. The main reason for this occurrence is presumably unsuitable conditioning of impregnated wood. In the research, spruce wood specimens with dimensions (1.5 x 2.5 x 5.0) cm3 (EN 113, 2006) were impregnated with the Silvanolin commercial solution of 2 different concentrations (0.25 % Cu and 0.125 % Cu). Impregnation of the specimens was performed in a vacuum-pressure chamber, and afterwards retention was determined gravimetrically. After the impregnation, the specimens were exposed to 10 different drying procedures. For each drying procedure 6 specimens were used. Afterwards, the specimens were leached according to the modified standard method ENV 1250-2. After the first and the last day of leaching, the amount of ingredients in leachates was analyzed withX-ray fluorescence spectroscopy (XRF, Oxford instruments) and atomic absorption spectroscopy (AAS VARIAN SPECTRA AA DUO FS240). The results showed that increased temperatures and high relative humidity during conditioning negatively influenced the fixation of copper-ethanolamine preservatives. In order to provide a proper fixation of afore mentioned preservatives in wood, it is suggested to expose them to moderate drying in the open air after impregnation, whereby the preserved wood should not be exposed to too high temperatures and oscillating weather conditions.
|
