Large research work is currently being performed concerning different elaborated new wood protection methods. However, combining industrially well-approbated processes is also considered potentially quite promising and such approach is being actively studied. The objective of the present study was to investigate peculiarities of interaction between liquids and thermally modified (TM) birch wood (Betula spp.). This knowledge is essential for proper TM wood post-treatments involving its impregnation as well as for evaluation of potential wood moisture dynamics in outdoor applications. Changes caused by TM (150–170 °C) in a closed system under elevated pressure in wood wettability, permeability, liquid absorption capacity, and drying characteristics were evaluated. The results concerning absorption capacity, which is mainly related to wood anatomical features and is density-dependent, indicated reduced absorption capacity of TM wood compared with unmodified birch of similar density. Permeability, which characterises the ease with which liquid is transported through a wood porous system, was evaluated by capillary absorption tests through the samples’ tangential and radial surfaces. TM made birch wood less permeable through both surfaces as well as less anisotropic regarding transverse absorption rates. Moreover, TM also caused a decrease in drying rates for birch wood impregnated with water. Reduction in permeability influences the impregnation process of boards and no full saturation was detected for TM boards when applying an impregnation schedule providing complete saturation for unmodified boards. On the other hand, less water was absorbed by TM boards exposed to rain on outdoor weathering racks.

目前正在开展有关不同的新木材保护方法的大型研究工作。然而，结合工业上认可的方法也被认为是很有前途的，并且这种方法正在积极研究中。本研究的目的是研究液体与热改性（TM）桦木（Betula）之间相互作用的特殊性spp。）。这些知识对于正确的TM木材浸渍后处理以及评估室外应用中潜在的木材水分动力学至关重要。评估了在较高压力下，密闭系统中TM（150–170°C）引起的木材润湿性，渗透性，液体吸收能力和干燥特性的变化。有关吸收能力的结果主要与木材的解剖特征有关，并且与密度有关，表明与同等密度的未改性桦木相比，TM木材的吸收能力降低。通过毛细管吸收测试，通过样品的切向和径向表面，评估了渗透率，该渗透率表征了液体通过木材多孔系统传输的难易程度。TM使桦木两面的渗透性降低，并且横向吸收率方面的各向异性也较小。此外，TM还会导致浸透桦木的干燥速率降低。渗透率的降低会影响板的浸渍过程，并且在应用浸渍方案为未改性的板提供完全饱和时，TM板没有检测到完全饱和。另一方面，TM板在室外耐候架上暴露在雨中的水吸收的水更少。渗透率的降低会影响板的浸渍过程，并且在应用浸渍方案为未改性的板提供完全饱和时，TM板未检测到完全饱和。另一方面，TM板在室外耐候架上暴露在雨中的水吸收的水更少。渗透率的降低会影响板的浸渍过程，并且在应用浸渍方案为未改性的板提供完全饱和时，TM板没有检测到完全饱和。另一方面，TM板在室外耐候架上暴露在雨中的水吸收的水更少。