Beech Wood Samples Research Articles

Physical, mechanical, and thermal properties of heat-treated poplar and beech wood

Air-dried density, weight loss (WL), impact bending strength (IBS), Shore-D hardness, and thermal conductivity values were determined for heat-treated poplar (Populus nigra L.) and beech (Fagus orientalis Lipsky) wood and compared with those for untreated samples. The test samples were heat-treated at 140, 160, 180, and 200 °C for 2 h. The results showed that density decreased and WL increased with increasing temperature for all temperatures. Additionally, during the heat treatment, the IBS increased in beech wood samples at 140 °C, but at higher temperatures, these values gradually decreased in both wood species. The highest decline in IBS values, found at a temperature of 200 °C, was 66.5% for beech and 55.7% for poplar. The Shore-D hardness of both wood species increased after heat treatment and regarding beech wood, the hardness increasing rate at temperature at 140 °C, 160 °C, 180 °C and 200 °C, 8.94%, 14.19%, 8.27% and 11.7%, respectively according to control samples. Regarding poplar wood, hardness increasing rates were 6.20% at 140 °C, 4.41% at 160°C, 5.88% at 180°C and 5.31% at 200°C according to control samples. The thermal conductivity of poplar and beech wood samples decreased after heat treatment, except for samples heat treated at 160 °C.

BIO PROTECTIVE TREATMENT OF WOOD

The article covers issues related to biological protection of wood. It is shown that wood, especially chopped (dead) wood is exposed to both external natural factors and the action of various microorganisms. Natural factors, especially ultraviolet rays of solar radiation, change the chemical composition of wood and destroy lignin as the least stable part of wood. Wood is more intensively destroyed by various microorganisms ‒ bacteria and fungi. Wood contains many nutrients - starch, sugar, fats, compounds of nitrogen, phosphoric acid, sulfur, potassium, calcium and magnesium. All of them are an excellent environment for the settlement and reproduction of various microorganisms. It is noted that among hardwoods, beech wood is most negatively affected by microorganisms, especially in the warm period of the year. This wood is a valuable breed from which furniture, planed veneer and various parts and products in the construction industry are made. Therefore, it is very important to keep it intact and attractive for a long time by treating it with bioprotective agents. The purpose of the research is to determine the biostability of beech wood after its treatment with bioprotective agents. An analysis of the biological destruction of wood and the use of protective materials was conducted and it was established that the paucity of data to explain and describe the bioprotection process, the neglect of environmentally safe means leads to the biodestruction of wooden structures under the action of microorganisms. A bioprotective agent based on copper oxychloride, nickel sulfate and soda ash was used in a certain ratio of components. Control and treated samples of beech wood were placed in the prepared soil and after 60 days the weight loss of the samples was determined. Studies have shown that the biostability of beech wood treated with a bioprotective agent is 4.3 times higher than that of untreated samples. The idea of the reproduction of microorganisms in the material and their death has been revealed, which, accordingly, shows changes in the metabolic processes of the vital activity of microorganisms. It has been established that the use of treated surfaces oil-wax and azure reduces the biodegradation process by more than 8 times for untreated samples. Keywords: beech wood, bioprotective treatment, bioprotective agents, biostability determination method, mass loss, treatment efficiency.

Study of the Influence of Heat Flow on the Time to Ignition of Spruce and Beech Wood

Adherence to fire safety regulations for wood is one of the most important tasks in its use in structural and architectural applications. This article deals with determining the influence of heat flux on the ignition process of spruce (Picea abies L. Karst.) and beech wood (Fagus sylvatica L.). The heat flux was generated by an electric radiant panel. The analysed parameters included the ignition time of the spruce and beech wood samples, the influence of wood density, and sample moisture, and the course of sample combustion, both with and without flame, was observed. The heat flux was maintained at constant values, depending on the distance of the examined sample from the panel, along with the specific power of the radiation panel. The power of the radiation panel was set to constant values of 5 kW and 10 kW. The samples were placed at distances of 50, 70, 100, 150, and 200 mm from the heat source, and heat fluxes in the range of 13–92 kW·m−2 were observed. At a power of 5 kW and a heat flux of 64 kW·m−2, neither the sample of beech nor that of spruce wood, placed at the distance of 100 mm from the radiation panel, exhibited flaming combustion. The ignition time for the beech wood was approximately twice that of the spruce wood, likely due to the higher average wood density. It can be stated that wood density, as one of the main factors, significantly influences the ignition phase of burning. The statistical analysis examined variables including wood type, radiant panel output, distance, and heat flux in relation to ignition time. The analysis revealed a significant difference between ignition time and distance (p-value = 0.0000, H = 37.51583) as well as between ignition time and heat flux (p-value = 0.0000, H = 37.69726). Similarly, the time to ignition for all tested beech wood samples was longer than for spruce wood.

Determining thermal properties of beech and fir wood samples in longitudinal direction via modified transient plane source method

The increasing use of wood leads to the need for a better understanding of its thermal properties with the aim of quantitatively identifying the exchange of thermal energy between wood and the surrounding solar radiation as precisely as possible. Reliable and rapid measurement of thermal conductivity is one of the most important current industrial requirements. The aim of this study is to examine the validity of using the modified transient plane source method (MTPS), which uses the principle of one-sided heating of the sample, and is defined by the ASTM D7984-21 (2021) standard, for determining the thermal conductivity of complex biocomposite composite materials such as wood. The analysis of the available literature shows a lack of data on the thermal conductivity of the type of wood originating in Croatia. In this study, the thermal conductivities of beech and fir wood samples in the longitudinal direction was determined by the MTPS method depending on the temperature and moisture content in the samples. Measurements were made on samples with a moisture content of 0%, 10%, and 20% in the temperature range from 20 to 80 °C.

Spray Coating of Wood with Nanoparticles from Lignin and Polylactic Glycolic Acid Loaded with Thyme Essential Oils.

Ensuring the longevity of wooden constructions depends heavily on the preservation process. However, several traditional preservation methods involving fossil-based compounds have become outdated because they pose a significant risk to the environment and to human health. Therefore, the use of bio-based and bioactive solutions, such as essential oils, has emerged as a more sustainable alternative in protecting wood from biotic attacks. The entrapment of essential oils in polymeric carrier matrices provides protection against oxidation and subsequent degradation or rapid evaporation, which implies the loss of their biocidal effect. In this work, lignin as well as PLGA nanoparticles containing the essential oils from two different thyme species (Thymus capitatus and T. vulgaris) were applied on beech wood samples using spray coating. The prepared coatings were investigated using FTIR imaging, SEM, as well as LSM analysis. Release experiments were conducted to investigate the release behavior of the essential oils from their respective lignin and PLGA carrier materials. The study found that lignin nanoparticles were more effective at trapping and retaining essential oils than PLGA nanoparticles, despite having larger average particle diameters and a more uneven particle size distribution. An analysis of the lignin coatings showed that they formed a uniform layer that covered most of the surface pores. PLGA nanoparticles formed a film-like layer on the cell walls, and after leaching, larger areas of native wood were evident on the wood samples treated with PLGA NPs compared to the ones coated with lignin NPs. The loading capacity and efficiency varied with the type of essential oil, while the release behaviors were similar between the two essential oil types applied in this study.

Gama-aminopropiltrietoksisilan ile Modifiye Edilmiş Kayın ve Göknarın Fiziksel, Mekanik ve Biyolojik Özellikleri

Silanes have potential for modifying wood materials to improving their properties. The aim of this study was to determine the physical and mechanical properties of beech (Fagus orientalis Lipsky) and fir (Abies bornmülleriana Mattf.) wood samples impregnated with gamma-aminopropyltriethoxysilane (APTES) as well as their performance against decay fungi. Beech and fir wood samples were impregnated with APTES at 20% and 40% concentrations. Control and treated samples were subjected to water uptake, bending strength and thermogravimetric analysis (TGA) tests as well as exposure to the white-rot fungus Trametes versicolor and the brown-rot fungus Coniophora puteana. Weight percentage gain (WPG) was higher in fir samples than in beech samples after APTES treatment. Water uptake was higher in fir samples than beech for control and impregnated samples. Water uptake decreased with higher APTES concentrations. APTES treatment slightly increased modulus of rupture (MOR) and modulus of elasticity (MOE). Mass loss caused by decay fungi was much lower in APTES treated timbers.

Antifungal protection of beech wood using plant extracts

In this research, the antifungal efficacy of dry plant extracts of Chinese cinnamon bark (Cinnamomum cassia L.), Rtanjski tea herb (Satureja montana L.) obtained by water extraction and extract of Thyme herb (Thymus serpyllum L.) obtained by ethanol-water extraction was investigated against the fungi Coniophora puteana and Serpula lacrymans, which cause brown rot, and the fungus Trametes versicolor, which causes white rot of hardwood and conifers. Five different concentrations of plant extracts were tested, and water was used as a solvent. Samples of beech wood (Fagus sylvatica ssp. moesiaca (Maly) Czeczott.) were treated by the immersion method with solutions of plant extracts and exposed for 60 days to the action of the test fungi. The smallest mass loss (%) of beech wood when affected by each of the test fungi was in samples treated with Thymus serpyllum extract at a concentration of 25%, followed by Satureja montana at the same concentration. Cinnamomum cassia bark extract did not show significant antifungal activity against the test fungi at any concentration. The obtained results can affirm the use of dry plant extracts as ecologically acceptable agents in the preventive protection of non-resistant wood species against rotting fungi.

Optimization of chitosan adhesive properties by means of genipin crosslinking

ABSTRACT Chitosan is a polysaccharide resulting from chitin deacetylation. It has demonstrated interesting characteristics in the field of adhesion but loses most of its adhesive resistance in moist environment. A chemical crosslinking of chitosan with genipin has been implemented to improve its adhesive properties in the presence of water. The study of crosslinking kinetics using rheology revealed its dependency on crosslinking rate and chitosan concentration. The capacity of the chitosan-genipin systems for water absorption has been quantified as their Free Swelling Capacity. The cross-linkage of chitosan by genipin (1% w/w) decreased significantly its ability for water absorption. Finally, the adhesive strength of several chitosans be they supplemented or not with genipin and/or glycerol used as plasticizer have been performed on Thick Adherent Shear Test samples of beech wood according to standard EN 204:2016 and EN 205:2016. The chitosan adhesive formulation containing genipin and glycerol exhibits the better adhesive properties on wood and presents higher water resistance compared to the native chitosan formulation.

Water Vapor Sorption Kinetics of Beech Wood Modified with Phenol Formaldehyde Resin Oligomers

Beech is an important tree species in Europe. This study aimed to elucidate the influence of four molecular weights of phenol formaldehyde (PF) resin (266, 286, 387, and 410 g/mol) on the sorption behavior of unmodified and modified beech wood samples using a dynamic vapor sorption (DVS) apparatus. The variations in the environmental relative humidity and moisture content (MC) of the samples were recorded, and the DVS isotherms were plotted from the equipment. During the sorption process, the MC of the modified samples decreased in comparison to that of the unmodified samples, and both apparently decreased with the increasing molecular weight of the PF resin. The DVS isotherm hysteresis plot illustrated a reduction in sorption hysteresis for the modified wood with varying PF resins compared to the unmodified samples. Based on the DVS isotherm adsorption and desorption plots, the decrease in the equilibrium of the MC can be attributed to there being fewer sorption sites in the modified samples, which exhibited the lowest hygroscopicity. Overall, the moisture sorption mechanism for both types of samples was clarified, highlighting a clear correlation between the molecular weight of the applied PF resin and its influence on moisture sorption behavior.

Joint Durability of Steam-Treated Beech Wood.

Steaming beech wood is one of the most commonly used eco-based processes for wood color equilibration. In addition to color equalization, steaming has also been noticed to stabilize the final product (solid wood panels). The beech wood samples used in this study were steamed for two different periods. PVAc and polyurethane (PU) adhesives were used to analyze bonding strength and durability. The bonding strength was measured according to the EN 13354 standard. The samples were treated before testing according to the first part of the standard, i.e., immersion in water. The durability of the bonded joint was tested according to the ISO 9142 standard. The samples were treated before testing with two methods. The results of the bonding strength show the influence of the steaming process on the bonded joint. Short exposure to steam decreased bonding strength, and prolonged exposure increased bonding strength. From the results given and the statistical analysis, it can be concluded that a prolonged steaming period increases the stability of the beech wood and thus the durability of the bonded joints.

Swelling of beech wood (Fagus sylvatica L.) during gaseous ammonia treatment as a function of pressure

AbstractThis paper deals with the optical observation and evaluation of the swelling of beech wood samples (Fagus sylvatica L.) during gaseous ammonia treatment. The pressure level was varied in several experiments from ambient pressure to almost saturated steam pressure at isothermal conditions at 20 °C. The initial moisture content of the wood was oven dried and also conditioned (65% RH/20 °C). All experiments were carried out in a self-developed experimental setup. It consisted of three parts: a pressure vessel with a glass pane at the top, a camera with additional lighting above it and an algorithm for the semi-automatic evaluation of the data. Parallel investigation of the maximum swelling in water of specimens of the same origin showed that ammonia leads to a higher swelling in tangential direction (up to 23%). The swell-inhibiting influence by the wood rays can be observed on the basis of the comparison to the water swelling in radial direction. Furthermore, the results visualise the change in crystal structure from cellulose I to ammonia-cellulose I.

Analysis of stress development during kiln drying of beech timber

Before use, timber must have reduced moisture content. Kiln drying causes cracking risk. This study aims to evaluate the risk of cracking during the drying of beech wood samples using the response surface methodology. Additionally, we aim to develop an empirical model that describes critical tensile stress during the early drying stages and the air parameters commonly used in kiln-drying schedules for beech timber, specifically, the effects of dry-bulb temperature (DBT) and wet-bulb depression (WBD). Nine options of drying conditions were analyzed in the study according to the Central Composite Design assumptions; they were combinations of three options of DBT (30, 40, and 50 °C) and three options of WBD (4, 5, and 6 °C). During the experiments, tangential shrinkage of the wood samples was completely restrained with a load cell that measured generated tensile drying stresses. The results of the ANOVA analysis confirmed that the DBT is the only factor significantly influencing the tensile stress at failure (σf). The second-order effect between DBT and WBD has also been confirmed. The drying condition causing the highest risk of cracking was shown using the multiple contour plots of tensile stresses and the moisture content at failure (MCf). Reliability theory was used to predict the cracking risk of wood tissue. The analysis confirmed the dependence of the cracking risk of wood tissue on drying conditions. When DBT is equal to 30 °C, the cracking risk increases as the air relative humidity (RH) decreases. However, during the drying of beech wood samples at a temperature of 50 °C, decreasing the RH in a range corresponding to the increase of WBD from 4 to 6 °C reduces the cracking risk, which is indicated by the lower moisture content at failure (MCf) of the wood samples.Graphical

Anisotropic wood–water interactions determined by gravimetric vapor sorption experiments

Gravimetric vapor sorption experiments were performed on beech wood samples to determine the directional permeability, diffusion and sorption coefficients in the three orthotropic wood directions. Dynamic Vapor Sorption (DVS) experiments allowed for the direct evaluation of the diffusion coefficient from the analysis of the kinetic sorption profile using a double stretched exponential model with values ranging from 0.10 × 10−10 to 1.52 × 10−10 m2/s and depending on the wood direction of the sample and the RH-values. Moisture sorption isotherms (MSIs) were constructed and fitted to a modified Guggenheim-Anderson-de Boer and a Sorption Site Occupancy model, which allowed for the calculation of the sorption coefficient which was found to be between 2.4 and 3.0 mol/(m3 Pa). Dynamic Vapor Transport (DVT) experiments were performed to calculate the permeability coefficient from the vapor flow rate and it ranges between 0.56 × 10−10 and 4.38 × 10−10 mol/(m s Pa) as a function of the flow direction and RH conditions. These results indicate that such an experimental approach is suitable for determining wood–moisture interactions.

Size- and temperature-dependent oxidative pyrolysis and auto-ignition of spherical beech and spruce wood

Abstract Opposed to piloted ignition, where a substance is ignited by an external flame or spark, the term auto-ignition describes the onset of combustion by spontaneous ignition without an external source. In this study, the influence of the size of spherical wood samples and the temperature surrounding the samples was investigated by performing ignition experiments in a muffle furnace with beech and spruce wood. On a specially constructed rig, spheres with four different diameters (8 mm, 12 mm, 18 mm, and 25 mm) were put into a preheated furnace at five isothermal temperatures (240 °C, 270 °C, 300 °C, 330 °C, and 360 °C). For every temperature, diameter, and wood species, the experiments were repeated eight times, and positions of the spheres on the rig were changed for every measurement. Temperatures inside the samples were recorded with thermocouples (TC) positioned in holes drilled to the middle of the spheres. With rising size and temperature, samples were more prone to auto-ignition in a glowing mode, due to a larger, highly reactive pyrolyzed surface and internal overheating. During heating and oxidative pyrolysis, isothermal phases were present at approximately 360 °C in the recorded temperature curves. The comparison to simultaneous thermal analysis (STA) measurements shows decomposition of hemicelluloses, and cellulose is highest around 360 °C. It is concluded that pyrolysis and disintegration of the main wood constituents use up all arising energy. Due to differences in the composition of the wood polymers, beech wood samples already ignite at lower temperatures compared to spruce wood samples with the same diameter. It can be concluded that the size is a critical factor for auto-ignition at the used temperatures. Larger samples will produce more volatile compounds during pyrolysis and have a larger pyrolyzed, porous surface area where heterogenous oxidation reactions can happen. The influence of the size is already critical at differences on the millimetre scale.

Impact of different polyethylene glycol wood treatments on the adhesive properties of beech wood

ABSTRACT Modified beech wood, treated with polyethylene glycol (PEG), was examined regarding its adhesive properties. Therefore, beech wood was modified with various molecular weights and amounts of PEG. All variants of the PEG treatment lead to an improved dimensional stability of beech wood samples. Afterwards, three different kinds of adhesive systems were tested on the modified wood. The three adhesive systems were based on phenol-resorcin-formaldehyde (PRF), emulsion-polymer-isocyanate (EPI) and melamine-urea-formaldehyde (MUF). The adhesives were tested according to a delamination test between layers (DIN EN 16351 annex A) and a determination of the longitudinal tensile bonding strength (DIN EN 302-1 A1). The achieved results showed an effective wood modification with suitable bonding properties. The usage of PEG-modified beech in constructive applications such as cross-laminated-timber (CLT) seems to be possible.

The effect of heat treatment method and process temperature on the glossiness of polyurethane varnishes applied to wood material surfaces

Bu çalışmada, farklı yöntemlerle ve farklı sıcaklık seviyelerinde ısıl işlemli ağaç malzeme yüzeylerine uygulanan poliüretan verniklerin parlaklık özellikleri incelenmiştir. Kayın (Fagus sylvatica L.) ve sarıçam (Pinus silvestris L.) odunu örnekleri üç farklı yöntem (ThermoWood, yağlı işlem ve sıcak hava) ve üç farklı sıcaklık (170 °C, 190 °C ve 210 °C) uygulanarak ısıl işleme tabi tutulmuştur. Daha sonra örnek yüzeyleri endüstriyel uygulamalara göre poliüretan vernik ile kaplanmıştır. Parlaklık ölçümleri TS EN ISO 2813 esaslarına uyularak gerçekleştirilmiştir. Verniksiz örnekler için, yağlı işlem yöntemi ile ısıl işlem görmüş örneklerde daha düşük parlaklık değerleri belirlenmiştir. ThermoWood ve sıcak hava yöntemleri ile muamele edilmiş örneklerde parlaklık değerleri benzer bulunmuş ve bu örneklerde, düşük sıcaklıktaki (170 °C) ısıl işlem sonrası parlaklıklar kontrol örneklere göre artmıştır. Vernikli örneklerde ise ısıl işlem yönteminin etkisi parlaklık üzerinde önemsiz bulunmuştur. Diğer taraftan, hem verniksiz hem de vernik uygulanmış örneklerde ısıl işlem sıcaklığı artışına bağlı olarak yüzey parlaklık değerleri azalmıştır.

Farklı yöntemlerle ısıl işlem uygulanmış ağaç malzemelerde yoğunluk ve eğilme direncinin belirlenmesi

Bu çalışmada, ağaç malzemelerin hava kurusu yoğunluk ve eğilme direnci üzerine farklı yöntem ve sıcaklık koşullarında uygulanan ısıl işlemlerin etkisi analiz edilmiştir. Sarıçam (Pinus silvestris L.) ve kayın (Fagus sylvatica L.) odunu örnekleri ThermoWood, yağlı işlem ve sıcak hava yöntemleri kullanılarak üç farklı sıcaklıkta (170 °C, 190 °C ve 210 °C) ayrı ayrı ısıl işleme tabi tutulmuştur. Deney örneklerinin yoğunluk ve eğilme direnci sırası ile TS 2472 ve TS 2474 esaslarına uyularak belirlenmiştir. Araştırma sonuçlarına göre, ısıl işlem yöntemi ve işlem sıcaklığındaki farklılaşma ahşap örneklerin yoğunluk ve eğilme direnci değerleri üzerinde önemli bulunmuştur. Isıl işlem yöntemi açısından, her iki ağaç türü için en yüksek yoğunluk ve eğilme direnci yağlı ısıl işlem görmüş örneklerde elde edilmiştir. Ayrıca, sıcak hava yöntemine göre ThermoWood yöntemi ile işlem görmüş örneklerde daha yüksek direnç değerleri bulunmuştur. Tüm yöntemler için, ısıl işlem sıcaklığındaki artışa bağlı olarak ahşap örneklerde yoğunluk ve eğilme direnci değerleri azalmıştır. Sıcaklık artışından kaynaklanan yoğunluk ve direnç kayıpları yağlı ısıl işlem yönteminde en az seviyede iken, sıcak hava yönteminde en fazla orana sahiptir.

Slow thermal decomposition of lignocelluloses compared to numerical model: Fine particle emission, gaseous products analysis

This paper is focused on aerosol fine particle release during the thermal decomposition of beech wood samples with identical mass under an oxidizing and inert atmosphere. This thermal degradation of wood is a significant part of the biomass combustion and pyrolytic process. This contribution focuses on nanoparticles emission with specifying sizes and concentrations in the range of 18–545 nm during thermal degradation processes and determining correlations between individual thermal degradation processes of a wood sample with the same weights but with different heating rates. The flue gases' chemical composition was simultaneously analyzed using a quadrupole mass spectrometer during the thermal degradation process. The weight loss of the sample and its derivation were monitored using a thermogravimeter. This combination made it possible to identify the ranges with the highest particle emission concerning the wood sample and the sample's heating rate. The fine particle identification apparatus uses a Scanning Mobility Particle Sizer and a condensation particle counter. This experimentally obtained data were then compared with the numerical model CPD-Bio. In this case, the comparison was focused on the prediction of the temperatures of the individual pyrolysis stages, at which gaseous products and especially tars are formed.

EFFECT OF UV RADIATION ON CHANGE IN COLOR OF STEAMED BEECH WOOD

The wood of the beech (Fagus Sylvatica L.) was steamed with a saturated steam-air mixture at a temperature of t = 95°C, or saturated steam at t = 115°C and t = 135°C to obtain a pale pink, red-brown and rich brown-red color. Subsequently, samples of unsteamed and steamed beech wood were irradiated with a UV lamp in a Xenotest Q-SUN Xe-3-HS after drying in order to test the color stability of steamed beech wood. The color change of the wood surface was evaluated by means of measured values on the coordinates of the color space CIE L*a*b*. The results show that the surface of unsteamed beech wood as well as steamed beech wood with a steam-air mixture at a temperature of t = 95°C and saturated steam with a temperature of t = 125°C darkened and turned brown to a brown-yellow color due to UV radiation. The deep brown-red color of the surface of beech wood steamed with saturated steam with a temperature of t = 135°C brightened to a brown-yellow color similar to the color of unsteamed beech wood. The analysis of the changes in the color space CIE L* a* b* shows that the greater the darkening and browning of the beech wood by steaming, the smaller the changes in the values of ∆L*, ∆a* ∆b* of the steamed beech wood caused by UV radiation. The positive effect of steaming on UV resistance is evidenced by the decrease in the overall color difference ∆E*. While the value of the total color difference of unsteamed beech wood caused by UV radiation is ∆E* = 15.3, for beech wood steamed with a saturated steam-air mixture at t = 95°C it decreased to ∆E* = 9.5, which is a decrease of 37.9%, for steamed beech wood steamed with saturated steam with temperature t = 115°C is ∆E* = 6.2 which is a decrease of 59.4% and for steamed beech wood steamed with saturated steam with temperature t = 135°C is ∆E* = 4.5 which is a decrease of 70.5%.

Indentation Hardness and Elastic Recovery of Some Hardwood Species

The purpose of the study was to measure the Brinell hardness (HB) of six wood species and evaluate the ability to recover the depth of the imprint (self-re-deformation). Straight-grain clear samples of ash, beech, alder, birch, iroko, and linden wood were prepared. Measurements were made in the three main reference timber cross-sections: radial (R), tangential (T), and axial/longitudinal (L) and with two measuring loads of 30 kG and 100 kG (294.2 N and 980.7 N). The tested wood species could be classified into hard (ash, beech), medium-hard (alder, birch, iroko), and soft (linden) wood species. The HBs of each tested wood species differed in the cross-sections, i.e., side hardness (R, T) and end hardness (L). Higher HB values were obtained at 100 kG load in all species and all three cross-sections. The lowest influence of the measurement force value on the HB value was revealed for the soft wood species (linden: 107–118%). This influence was visible for the other five medium-hard and hard wood species, ranging from 125% to 176%. The percentage of temporary imprint in total imprint depth (x/H) varied from 12 to 33% (linden 12–18%—the lowest self-re-deformation ability; beech 25–33%—the highest self-re-deformation ability). The results of this study underline that the higher the density of the wood, the higher the Brinell hardness, and, simultaneously, the greater the measurement force used, the higher the Brinell hardness measured. The ability of self-re-deformation in wood’s R and T cross-sections depends on the wood density and the measuring force used. In contrast, this ability only depends on the wood density in the L cross-section. Those observations imply that the compaction of the cell structure during side compression is mainly non-destructive, while the longitudinal deformation of the cell structure (the buckling of cell walls and fracture of ends of the cells) is to a great degree destructive and irreversible. These results can be used in the construction and furniture sectors, especially when designing products and planning the woodworking of highly loaded wood floors and furniture elements.