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The aim of this work was to investigate the fire resistance of silver fir (Abies alba L.) and European ash (Fraxinus excelsior) boards charred using the traditional yakisugi method and to compare the results with the fire resistance of non-charred boards as a reference and exploit its potential as a material with fire protection properties. After the boards were surface-charred on one side, specimens with different char thicknesses, resulting from their different position in the chimney, were selected from each wood species and subjected to analysis. Specimens with dimensions of 250 × 90 mm underwent a small flame test, those of 220 × 170 mm received indirect flame exposure by constant heat flux radiation from an infra-red emitter and those of 600 × 600 mm were subjected to a fire resistance test according to EN 1363-1:2020. The results of the small flame tests showed statistically significant fire resistance enhancement of specimens with 6 and 3 mm char-layer thickness in fir and ash wood, respectively, and a 110% and 75% improvement when compared to reference specimens. The constant heat flux radiation tests did not reveal any significant differences between the reference and charred specimens. The up-scaled fire resistance test, in which an assembled panel was exposed to flame, also indicated significant improvement. The reference burn-through time of fir and ash specimens was improved significantly with increasing char layer thickness, resulting in 10%–26% of fire resistance improvement for fir and 5%–12% for ash wood specimens. These results, based on the tests performed, suggest that the one-sided surface-charring of wood can enhance its fire resistance; however, this was mostly achieved in boards with the thickest char layer in both wood species studied and not all fire resistance indicators were considered. Further in-depth studies are required to better understand the complex behaviour of charred wood in response to fire. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of substituting core layer strands of randomly oriented strand boards (OSB) with waste wood particles with respect to CSA 0437–Series 93 Standards on OSB and Waferboard requirements. Standard core layer strands have been substituted with four different levels (0, 25, 50 and 100%) of waste wood particles. Several mechanical properties of the OSB have been tested. Overall, it could be demonstrated that waste wood particles can successfully be used in the core layer of OSB. All properties met the requirements of CSA 0437-Series 93, except for thickness swell (TS) and water absorption (WA). From a mechanical and physical board properties perspective, it is possible to substitute up to 100% of the core layer strands in randomly OSB panels with unsorted contaminated waste wood particles. However, results showed high density variability within boards and between different core compositions. Internal bond (IB) met the standard's requirements, showed significant differences between the waste wood proportions and increased with the level of waste wood particles. The modulus of elasticity (MOE) and modulus of rupture (MOR) also met the requirements, and decreased with increasing waste wood particle levels. [ABSTRACT FROM AUTHOR]

Raw materials of annual plants fibres are not easily usable for industrial production applications. Pretreatment of the annual plant fibres is necessary to increase the homogeneity of the material and to improve the material properties. This study deals with the influence of steam explosion treatment on the quality of annual plant fibres used as insulating material. Wheat straw material was selected for production of insulating panels and bulk insulation material. To clarify the changes within the structure of the plants due to the pre-treatment process material analysis was carried out using FT-IR spectroscopy and light microscope. The results showed that the pre-treatment process homogenizes the materials and the processes could be used for the production of bulk insulation and panels. A comparison of the results from other studies were done to show the potential of innovative materials and applications. [ABSTRACT FROM AUTHOR]

The current trend for sustainable utilisation of limited resources is stimulating the scientific research for previously neglected raw materials that could also be used for new value added products. Bark, which is a natural insulation material of trees, could be used as technical insulation material. This paper focuses on the effects of particle orientation in light larch (Larix decidua) bark insulation boards on their physical–mechanical and thermal properties. The experimental design is based on the variation of the particle orientation (orthogonal or parallel to the panel plane) and the board density (200–500 kg/m3). The mechanical properties, water absorption, thickness swelling and thermal conductivity of the boards were tested. The results showed a significant influence of the particle orientation and the density on the measured properties of the bark panels. This implies that the bark particle orientation is an important factor when producing insulation panels with specific characteristics. Suggestions for efficient use of bark particleboard are given. [ABSTRACT FROM AUTHOR]

Wood products curriculum and education in North America have been changing last two decades. Some of the universities are loosing their wood products programs while some are merging with other bionamed departments. It is still fact that wood products graduates are still in demand but with a different perspective than several 10-15 years ago. It is important that expectation of industry should be taken into consideration to revise and develop new curriculum of the current programs. This article briefly reviews some of the wood science programs in North America and their background within the scope of overall trend and development. [ABSTRACT FROM AUTHOR]

Concerning industrial timber, the measure of stacked logs with equal wood length is cubic meter with bark (FVA 1997). It is consequently a volumetric measure including the non wood-containing spaces. The following work determines by extensive tests the solid measure of several stacks of wood by the means of an electronically measuring system, and calculates the resulting conversion factor. It was possible to make a statement about how the mid-diameter of logs from a stack and particularly log-parameters influences the conversion factor. The measurements in 3D, the mid-diameter, the crook, the taper and the ovality are considered and their influence on the factor were analysed. The results are illustrated and evaluated by using a correlation and regression analysis. The greater influence had the mid-diameter and the crook, which show strong correlations on the factor. [ABSTRACT FROM AUTHOR]

The continuous trend to energy saving and sustainable constructions in buildings leads to an increasing demand of efficient and sustainable thermal insulation materials. One promising development is the usage of the natural “tree insulation material,” namely bark, for building insulations. Insulation boards out of larch bark were scanned with an industrial computed tomograph in order to study the structure of the boards. The computed tomograph images were segmented using a categorization algorithm based on ANOVA. Apart from gaining knowledge about panel porosity, understanding of the inhomogeneous bark boards was enhanced by finding that two main components are prevalent. That knowledge of the board's microstructure enabled the application of a numerical model for thermal conductivity based on the finite difference method. These findings give the direction for further developments of efficient bark insulation panels with well-defined pore structure. [ABSTRACT FROM AUTHOR]

This paper deals with the characterization of the properties of wood fibres leather shavings composite board by using the near infrared spectroscopy (NIRS) and multivariate data analysis. In this study fibreboards were manufactured with different leather amounts by using spruce fibres, as well as vegetable and mineral tanned leather shavings (wet white and wet blue). The NIR spectroscopy was used to analyse the raw materials as well as the wood leather fibreboards. Moreover, the physical and mechanical features of the wood leather composite fibreboards were determined to characterize their properties for the further data analysis. The NIR spectra were analysed by univariate and multivariate methods using the Principal Component Analysis (PCA) and the Partial Least Squares Regression (PLSR) method. These results demonstrate the potential of FT-NIR spectroscopy to estimate the physical and mechanical properties (e.g., bending strength). This phenomenon provides a possibility for quality assurance systems by using the NIRS. [ABSTRACT FROM AUTHOR]

The potential of tree bark, a by-product of the woodworking industry, has been studied for more than seven decades. Bark, as a sustainable raw material, can replace wood or other resources in numerous applications in construction. In this study, the acoustic properties of bark-based panels were analyzed. The roles of the particle size (4–11 mm and 10–30 mm), particle orientation (parallel and perpendicular) and density (350–700 kg/m3) of samples with 30 mm and 60 mm thicknesses were studied at frequencies ranging from 50 to 6400 Hz. Bark-based boards with fine-grained particles have been shown to be better in terms of sound absorption coefficient values compared with coarse-grained particles. Bark composites mixed with popcorn bonded with UF did not return the expected results, and it is not possible to recommend this solution. The best density of bark boards to obtain the best sound absorption coefficients is about 350 kg/m3. These lightweight panels achieved better sound-absorbing properties (especially at lower frequencies) at higher thicknesses. The noise reduction coefficient of 0.5 obtained a sample with fine particles with a parallel orientation and a density of around 360 kg/m3. [ABSTRACT FROM AUTHOR]

The paper presents the results of studies relating to the utilization of the grapevine rods remaining at the pruning of the vineyards. The main objective of the present research was to compare and analyze the obtained values of physico-mechanical indicators of different types of wood-based panels with the participation of grapevine rods in their composition. To be fulfilled the goal of the study in laboratory conditions were produced: - 7 different types of single-layer particleboards from grapevine particles based on UFR and PFR, the binder content varying between 8 è 12%, boards density was from 700 to 840kg/m3, at press temperature - 190°Ñ; - 7 types fiberboards from grapevine fibers - with 10% PFR, boards density was 900kg/m3, at varying the percentage of grapevine fibers from 0 äî 30% and press temperature - 190°Ñ; - 3 types three-layered particleboards with a face layer from wood particles and a core layer from grapevine particles, at ratio of FL:CL=40:60, based on PFR, the binder content varying between 8 è 12%, boards density was 700kg/m3, at press temperature 170°Ñ; - 4 types three-layered combined boards with a face layer from wood fibers and a core layer from grapevine particles (0; 15; 30 è 45%), based on 10% UFR in FL and 10% UFR in CL, at press temperature 170°Ñ. The summarized results for the physical and mechanical indicators of the manufactured boards with various participation of grapevine particles respectively grapevine fibers are presented in Tables 1 - 4. The results obtained within the present research demonstrated that the grapevine rods can be utilized as raw material for production of different type of boards - particleboards, fiberboards, combined boards. Increasing the content of this type of lignocellulosic material in the composition of the various types of boards leads to a deterioration in their physico-mechanical indicators, which can be offset to a certain extent by an increase in the binder content or a change in the type of binder. This, of course, must be done after taking into account the future use of the respective type of wood boards. [ABSTRACT FROM AUTHOR]