It is known from theory and practice that the workability of wood depends on structural parameters that are closely related to the physical, mechanical and chemical properties of the type of wood itself, and disturbance parameters that refer to the technological and geometric parameters determined by the specific processing regime. That machinability, in addition to the mechanical output sizes, is often expressed by the quality, that is, the roughness of the processed surface. By defining a mathematical model in the process of planing solid wood in which the input sizes are processing parameters: wood density (ρ), feed rate (m/min) and number of cutting spirals (z), and the spilled sizes are praamters of roughness of the treated surface (Ra and Rz), and by applying optimization methods, optimal solutions for the process of planing solid wood on planer machines will be determined, so that the obtained Yoptim model will aim to improve the workability of solid wood, specifically its roughness of the processed surface.

We consider the machinability of the material as a technological feature that expresses the ability of the material to remove the maximum number of shavings from its machined surface in the minimum time with satisfactory processing quality, with as little cutting force as possible and as little tool wear as possible. The aim of the experimental research in this work is to examine the significance of the influential kinematic parameters of the roughness of the machined surface, i.e. of wood density (ρ), feeding speed (s’) and the number of spiral cutting knices (z) in the process of planning massive wood on the roughness of the newly created processing surface, which will vary in 14 trials, of which 6 are repetitions in the central point of the compositional plan, where the roughness parameter Ra is obtained as an output value, and the analysis of experimental data from the point of view of possible achievement of a better quality of the processed surface. The obtained mathematical model is essentially applicable and can be used to optimize the machinability parameters in the planning process of solid wood, and the experimental results can be used in further research into other parameters of the machinability of solid wood in the planning process.

In Europe, wood is a crucial construction material that has experienced a surge in use for building applications in recent years. To enhance its dimensional stability and durability, thermal modification is a widely accepted commercial technology. Thermal modification is a popular technique that alters the properties of wood, improving its resistance to decay and increasing its dimensional stability. The process involves heating wood to high temperatures under controlled conditions, leading to chemical reactions that result in various physical and mechanical changes. This paper will discuss the effects of thermal modification on the physical properties of wood, such as density, moisture content, and color, as well as its impact on the mechanical properties, including strength, stiffness, and hardness. Additionally, the review will examine the factors that influence the degree of modification, such as temperature, duration, and wood species. Finally, the paper will conclude with an overview of the current state of research in this field and identify potential avenues for future investigation.

• The roughness of the machined surface is a crucial factor in the woodworking process because it influences the quality of future operations like gluing, sanding, pressing, surface treatment and protection, and assembly. The quality of the machined surface is determined by a number of machining process parameters as well as material properties, and their proper selection and optimization will yield the best results. The purpose of this article is to demonstrate how specific parameters and wood species affect surface roughness. In the experiment, three species of wood: beech (Fagus sylvatica), fir (Abies alba), and poplar (Populus alba) with the same moisture content were used, and combinations of feed speed (5 and 8 m/min) and cutting depth (2 and 4 mm) were created. The processing was done on a wood planer (thickener) machine of the SD-B-510 series manufactured by Robland Machines Belgium. Following that, roughness measurements of Ra, Rz, Rt, and Rq were taken with a focus on the mean deviation of the profile Ra, and an analysis of the results was presented, revealing that different roughness values are obtained with the same processing parameters depending on the wood species. The difference between the greatest (5.36 µm) and lowest (2.41µm) roughness values (Ra) for beech is 2.95 µm, 1.25 µm for poplar, and 1.34 µm for fir.