This work examines the effect of thermal modification temperatures in the production of thermally modified wood on the cutting and fracture parameters when cutting heat-treated spruce wood by a circular sawblade machine. The samples were thermally modified at 160, 180, 200, and 220 °C. One sample was unmodified and was used as a reference sample. On the basis of the performed experiments, the fracture parameters (fracture toughness and shear yield strength) were calculated for the axial–perpendicular direction of cutting. In comparison with the theoretical assumptions, the influence of temperature on the cutting and fracture parameters was confirmed. Thermally treated wood is characterized by increased fragility and susceptibility to crack formation, as well as reduced density, bending strength, and shear strength. These properties significantly affect the size of the cutting force and feed force, as well as the fracture parameters. As the temperature increases, the values of these parameters decrease. The mentioned material characteristics could be useful for the optimization of the cutting process, as well as for the issue of energy consumption during the machining of heat-treated wood.

When used in construction, the properties of wood-based materials they are mainly affected by moisture. Moisture sorption and the associated swelling has an impact on the resistance of materials to biocidal attacks, on their mechanical properties or air permeability, and on comfort of use and durability of the structure. Equilibrium moisture content (EMC) and thickness swelling (TS) depending on the relative humidity for plywood (PW), particleboard (PB) and oriented strand board (OSB), for load-bearing purposes in humid environments and bonded with melamine-urea-formaldehyde resin (MUF), are studied in detail in this paper. Equilibrium moisture content and thickness swelling are influenced by the type of material, density, quantity of adhesive composition, and paraffin. The highest values of equilibrium moisture content were found in plywood, whilst the highest thickness swelling was achieved by OSB. A high dependency of nonrecoverable thickness swelling on the equilibrium moisture of the material was also ascertained. The proportion of nonrecoverable thickness swelling increases exponentially, in particular if the material’s equilibrium moisture content exceeds 12%.

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The withdrawal strength of plain dowels with nominal diameter of 8 mm was compared with the spiral dowels manufactured from beech (Fagus sylvatica L.) and oak wood (Quercus robur L.). The test specimens were tested after conditioning at relative humidity (RH) 25%, 45%, 65%, and 85% at a constant temperature of 20 °C. Therefore, the influence of relative humidity (respective moisture content), dowel structure, and wood species of the dowels on the withdrawal strength was determined. The structure and low humidity (RH 25%) caused the highest strength (8.6 MPa) of spiral dowels. Compared to plain dowels, the higher withdrawal strength of spiral dowels was statistically significant. Adversely, the lowest withdrawal strength was found for plain beech dowels (3 MPa), which, in addition to higher relative humidity (RH 85%), was also caused by a combination of plain structure and greater diameter of the dowels, thereby decreasing the amount of adhesive in the bonded joint. The influence of the wood species of the dowels was not statistically significant overall.

The production of three-layered cement-bonded particleboards (CBPB) differs in most cases from that of adhesively bonded particleboards. However, one production step is quite similar: mat forming. A homogeneous mat is formed by aerodynamic or by mechanical spreading or by a combination of both methods. The distribution of the particles is influenced by their separation and flight characteristics. Those characteristics are in turn influenced by particle size and the combination of the particle’s surface area and weight. Because density of cement is higher than that of wood, the cement/wood (c/w) ratio will influence the particles’ separation and flight characteristics significantly. In the current study, laboratory-made particles of different sizes were mixed with different amounts of cement. An aerodynamic former was then used to help determine the influence of the different particle types and the c/w ratio of the mix on mat forming. The strewn particles were analysed for their distribution of mass, size and cement content as a function of spreading distance. The particle size decreased with increasing spreading distance. In addition, the cement content and spreading distance were positively correlated. For a c/w ratio of 1.9, increasing cement content correlated with increasing distance. This means, large particles and less cement tended to fall earlier than smaller ones and more cement. This corresponds to the observation that the specific surface area of the particles increases with increasing spreading distance. Vice versa, the density of the particles decreases with increasing spreading distance. The effect is more apparent when the particle mixture is heterogeneous in size at constant process parameters (e.g., air velocity). Looking at the density profile of a CBPB board, the surface layers consist of small particles with a higher cement fraction, and the core layer consists of large particles with smaller cement fraction. Thus, the production of CBPB requires two aerodynamic formers working in opposite directions. With the results of this study, it is possible to optimise production parameters, such as the speed of the transport caul and the air velocity with regard to the infeed raw material parameters in order to create a symmetrical particle distribution from top to bottom of the mat, resulting in an optimized and application-oriented density profile.