ВСТАНОВЛЕННЯ ВПЛИВУ ВОЛОГОСТІ ТА СТУПЕНЯ СТИСКУ ДЕРЕВИНИ БУКА ВЗДОВЖ ВОЛОКОН НА ЗАЛИШКОВУ ДЕФОРМАЦІЮ ПІСЛЯ РОЗВАНТАЖЕННЯ

Степан Грицак

doi:10.36930/42265203

Authors

S.S. Grytsak Ukrainian National Forestry University https://orcid.org/0009-0006-4668-2459

DOI:

https://doi.org/10.36930/42265203

Keywords:

beech wood; wood densification; mechanical modification; moisture content; compression ratio; residual defor-mation; mathematical modeling; regression analysis; Box experimental design; process optimization

Abstract

The paper presents the results of an experimental study on the influence of wood moisture content and longitudinal compression ratio on the residual deformation of beech wood after unloading. The relevance of the research is associated with the need to improve the efficiency of mechanical wood modification technologies through optimization of densification parameters and prediction of the final properties of compressed wood. The object of the study was the longitudinal densification process of beech wood (Fagus sylvatica L.), while the subject of the research was the relationship between residual deformation, moisture content, and compression ratio. A second-order two-factor Box experimental design was applied to investigate the process. The independent variables were wood moisture content (6–12%) and compression ratio (20–40%), whereas the response variable was residual deformation after unloading. Experimental data were statistically processed using Cochran’s, Student’s, and Fisher’s criteria. A second-order quadratic regression model was developed and verified as statistically adequate for describing the investigated process and predicting residual deformation within the selected factor space. The obtained results showed that residual deformation varied from 17.20% to 35.81% depending on the technological parameters. It was established that the compression ratio is the dominant factor governing the densification process, while moisture content increases the plasticity of the cellular structure and enhances the efficiency of permanent deformation formation. A statistically significant interaction between the investigated factors confirmed the synergistic effect of their combined influence. The maximum residual deformation (35.81%) was achieved at a moisture content of 12% and a compression ratio of 40%. The developed mathematical model can be used for predicting the results of longitudinal wood densification, selecting rational technological parameters, optimizing mechanical modification processes, and improving the dimensional stability of densified beech wood products. The obtained findings expand current knowledge regarding the formation of permanent deformation during longitudinal compression of hardwood and provide a scientific basis for the development of advanced resource-efficient wood processing technologies and digital process optimization in the woodworking industry

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