Study of the quality of impregnation and structural features of birch wood using the method of micro-X-ray computed tomography

Quality control of the internal structure of wood is an urgent task from both scientific and practical points of view. Existing control methods mainly imply a destructive approach associated with the destruction of a part of the product, which in some cases is impossible. In this study, the morphological features of the void space of wood were studied with an assessment of open porosity, pore size distribution, as well as a separate analysis of the void space with spatial determination and assessment of the sizes of pores filled with impregnation and empty pores using the method of micro-X-ray computed tomography. To assess the porosity, the approach of pore segmentation by X-ray density was used. The total porosity of the wood sample used for the study was 42.96%. The largest number of pores as a percentage of the total volume was 7 to 14 micrometers in size, which corresponds to the distance between the main structural components of the cell wall (vessels, tracheids, libriforms). After impregnation of wood, according to the micro-X-ray tomography data, the percentage of filled pores was 75.1%, the volume of the remaining void spaces in the wood not filled with the impregnation composition was 26.9%. In addition, 3D modeling of wood without impregnation and with impregnation with separate segmentation of the impregnation composition in the pores was carried out. It was found that this method allows to estimate with a high degree of accuracy the degree and depth of impregnation, the distribution of liquid along the anatomical structures of wood, and the use of the segmentation method by X-ray density allows to increase the accuracy of the study. It should be noted that the accuracy of the measurement is directly dependent on the size of the sample.