Effects of different incising pretreatments in improving permeability in two refractory wood species

Abstract

For many product and applications, the penetration of preservatives or modification substances into wood species should be deep and homogeneous. Caucasian spruce and European larch are resistant to impregnation. This study compared how different incising pre-processes increased the retention of impregnation materials and the depth of their penetration into the structures of these refractory wood species. Mechanical, biological, and laser incising pretreatments were applied to increase the permeability of sapwood samples before the impregnation. To compare the uptake of the wood preservatives transverse and longitudinal to the axial tracheids in the samples, the cross-sections of some of the samples that had been subjected to different incising pretreatments were covered with a polyurethane-based paint. All wood samples were impregnated using a vacuum method with Celcure C4 new generation preservatives. The study compared the possible effects of these different incising pretreatments on the uptake of preservatives into the tracheids in the spruce and larch woods in both longitudinal and transverse directions. The results showed that the copper (Cu) uptake levels increased in these refractory wood species, especially in the transverse direction, after the different incising pretreatments. Moreover, the results showed it is very important to choose the most suitable pretreatment method for the refractory tree species before impregnation.