Impregnation of Pinus radiata, P. pinaster, P. pinea y P. halepensis wood: relationship among the absorption of water-soluble preservatives and their physical and anatomical characteristics.

The object of this work was to estimate the absorption levels of water-soluble preservatives in Pinus radiata D. Don, P. pinaster Ait., P. pinea L. y P. halepensis Mill. woods, applied by Bethell process using two different times of pressure, and its relationship with their physical and anatomical characteristics. The oven-dry density and the wood moisture content were estimated, according to IRAM 9544 and IRAM 9532 standards respectively. The initial and final vaccumm value applied during 15 min. was 600 mmHg each one, while two pressure times (3 kg.cm-²) 10 min. and 30 min. were used. The preservatives employed (2% weight/volume ) were CCA-C and CCB. The anatomical analysis was carried out with light and scanning electron microscopes, the last with dispersive x-ray analyzer. The results showed that a greater pressure time produced greater absorption levels. The absorption levels registered were, in descendent grade: P. halepensis, P. pinaster, P. pinea y P. radiata and they were inversely related with the oven-dry density values. The cuantitative anatomical characters were not correlated with the absorption levels. The presence of high resin amounts could explain the lower absorption level in P. radiata wood. The constitutive elements of the preservatives were identified. The ratio observed was chrome grater than copper and the last greater than arsenic in CCA-C, and chrome greater than copper in CCB.

Keywords: Preservation; Pinus spp.; Bethell method; water-soluble preservatives; physical and anatomical characteristics