Effect of Variable Conditions of Exposure on the Physical and Mechanical Properties of Blockboards

The growing demand for wood and the continued increase of the raw material price have resulted in companies using more efficient wood resources in wood-based products such as blockboard. These boards are used in the field of interior design, especially. The aim of this research was to evaluate the effect of variable environmental conditions on the physical and mechanical properties of blockboard (BK). Two types of commercial BK were exposed in variable environmental conditions (kitchen, bathroom and climatic chamber) for three months. The BK structures were composed of veneer (V) and high-density fibreboards (HDF) for the face sheets and glued, solid wood, resinous strips for the core. The temperature and relative humidity of the air (RH) ranged from 18 °C to 25 °C and from 25% to 90%, respectively. In the climatic chamber (CC), the dynamics of the parameter variations were different than in the other two exposure climates, being determined by the programmed cyclic changes in RH. The changes observed on physical and mechanical properties were more extreme for the blockboards tested in the CC than in the kitchen (K) and bathroom (Ba). After 3 months of exposure in the CC, the thickness and weight of the boards increased by 1.8 and 1.1 times, respectively, for veneered BK, and by 4.4 and 0.4 times, for BK with HDF faces, compared to values recorded in the kitchen. The panels exposed in the CC exhibited the highest increase in moisture content (MC): 41% for veneered BK and 82% for BK with HDF faces after three months of exposure, followed by those exposed in the bathroom and kitchen. Increases in MC determined decreases of flexural properties and soundness surfaces, more evident for HDF face structures compared to V ones.

Archaeological Evidence of Migration from the Southern Taiga of Western Siberia to the Urals in the Early Middle Ages: The Vodennikovo-1 Cemetery

We describe 15 burials at the Vodennikovo-1 group of mounds in the northern Kurgan Region, on the Middle Iset River, relevant to migration processes during the Early Middle Ages. On the basis of numerous parallels from contemporaneous sites in the Urals and Western Siberia, the cemetery is dated to the late 7th and 8th centuries. Most of single and collective burials are inhumations in rectangular pits with a northwestern orientation, with vessels, decorated by carved or pricked designs, placed near the heads. These features, typical of the Early Medieval Bakalskaya culture of the Tobol and Ishim basins, are also observed at the Pereyma and Ust-Suerskoye-1 cemeteries in the same area. However, there are innovations such as inlet burials, those in blocks of solid wood and plank coffi ns, western orientation of the deceased, and placing vessels next to the burial pits. These features attest to a different tradition, evidenced by cemeteries of the Potchevash culture in the Tobol and Ishim basins (Okunevo III, Likhacheva, and Vikulovskoye). Also, Potchevash and Bakalskaya vessels co-occur at Vodennikovo-1, and some of them (jugs with comb and grooved designs) are typologically syncretic. To date, this is the westernmost cemetery of the Potchevash culture, suggestive of a migration of part of the southern taiga population from the Ishim and Tobol area to the Urals.

An Ontology Based Approach for Regulatory Compliance of EU Reg. No 995/2010 in Greece

Illegal logging has always been considered as a major environmental and social global concern, as it is directly associated with deforestation and climate change. Nowadays, EU Regulation No 995/2010 has been successfully enforced to impede the placement of illegally produced timber within the EU market and therefore to efficiently enhance sustainable forest management and restore ecosystem balance. However, EU 995 regulatory compliance and enforcement itself is quite complex, since it requires long-term conformity, on a common basis for various heterogeneous groups and communities of stakeholders, in a global, even beyond EU, rule regulation framework. To make things worse, such a framework must be applied to the entire supply distribution chain and a wide variety of wood products, ranging from paper pulp to solid wood and flooring. Hence, in such complex and multivariate information environments, an ontological approach can more efficiently support regulatory compliance and knowledge management, due to its openness and richness of semantics for representing, analyzing, interpreting and managing such kind of information. In this paper, a rule-based regulatory compliance ontology is proposed, which fully captures EU Regulation No 995/2010 concepts and compliance rules and guidelines, as well as Greek legislations governing wood trade. The proposed ontology can be the basis for a computerized system providing automated support for illegal wood trade and monitoring EU regulation information provision and audit information storage and analysis.

The quality of the wood bonding depending on the method of applying the selected thermoplastic biopolymers

The quality of the wood bonding depending on the method of applying the selected thermoplastic biopolymers. The aim of the research was to determine the effect of the method of applying the biopolymer on the surface of bonding solid wood elements on the quality of the obtained adhesive connection. The results of conducted mechanical research show that the highest average value of shear strength was observed for birch lamellas bonded with PLA, both with the first and second method of application. In case of estimating the quality of the bonding of wooden elements, better results were achieved for PLA and the second method of application the "green" adhesive.

Defect Removal and Rearrangement of Wood Board Based on Genetic Algorithm

Defects on a solid wood board have a great influence on the aesthetics and mechanical properties of the board. After removing the defects, the board is no longer the standard size; manual drawing lines and cutting procedure is time-consuming and laborious; and an optimal solution is not necessarily obtained. Intelligent cutting of the board can be realized using a genetic algorithm. However, the global optimal solution of the whole machining process cannot be obtained by separately considering the sawing and splicing of raw materials. The integrated consideration of wood board cutting and board splicing can improve the utilization rate of the solid wood board. The effective utilization rate of the board with isolated consideration of raw material sawing with standardized dimensions of wood pieces and board splicing is 79.1%, while the shortcut splicing optimization with non-standardized dimensions for the final board has a utilization rate of 88.6% (which improves the utilization rate by 9.5%). In large-scale planning, the use of shortcut splicing optimization also increased the utilization rate by 12.14%. This has certain guiding significance for actual production.

Analysis of Attributes that Become Consumer Preferences in Choosing Indonature Table Furniture Products

Ud. Indonature is a company engaged in furniture, especially coffee table located on the island of Lombok, West Nusa Tenggara. Furniture made of solid wood such as Teak and Trembesi wood. In recent years there has been a decrease in the company’s turnover therefore it takes product innovation to increase sales. With the need to develop coffee table furniture products more clearly, researchers decided to conduct research on Attribute Analysis that Becomes Consumer Preferences in Choosing Indonature Table Furniture Products. This study aims to find out and analyze the combination of attributes that become consumer preferences in purchasing Indonature coffee table products and to know and analyze the most important coffee table attributes for Indonature consumers. The problem formulation in this study is, firstly, what combination of attributes are the consumer preference in buying coffee table into nature products and the second is what are the most important attributes of coffee table products for indonature consumers. The results of conjoin analysis showed that the most preferred and most important combination according to consumers is made of trembesi wood material with arch form, has a natural wood finishing and rustic design.

Mapping the Supply of Colour Tones of Wood and Furniture Products in Slovakian Small and Medium-Sized Enterprises

The purpose of the surface treatment of wood products is not only to protect them, but also to make them attractive in relation to the visual aspect through their colour modification. It is therefore important that manufacturers of wood and furniture products pay particular attention to the supply of colour tones of wood. According to colours, wood is divided into groups: red woods (oak, cherry, pine, alder, etc.), brown woods (elm, ash, walnut, etc.), pale woods (hornbeam, spruce, fir, etc.) and green woods (acacia, etc.). The main objective of this paper is to identify the supply of colour tones of wood and furniture products of Slovak micro, small and medium-sized enterprises. An empirical survey was used to map the researched issue in the form of a questionnaire. The results show that Slovak micro, small and medium-sized woodworking and furniture enterprises prefer the quality of wood raw material to its price. At the same time, they mostly manufacture products made of solid wood. Where it is necessary to modify the colour of the wood, enterprises use a process of staining, which enhances the natural colour and grain of the wood. On the other hand, due to the lack of investment capital, they cannot use hydrothermal treatment of wood steaming, which is considered a modern way of modifying the colour tone of the wood. It is essential that Slovak micro, small and medium-sized woodworking and furniture enterprises constantly adapt their production supply in the changing market environment, where they must respond immediately to current trends. In this way, they can sustain and increase their turnover, which will help them overcome the current crisis.

Physical Properties of Rice Husk-Pine Wood Particleboard

Rice husk is one types of sustainable and economical agricultural wastes that could produce particleboard as the substitute for solid wood. The problems that encourage this research are due to the increasing of deforestation and the increment demand for solid wood in various industries. Malaysia produces a significant amount of agricultural biomass waste every year. It is noteworthy to mention that agricultural wastes can be fully used in an environmentally friendly way. This study aims to evaluate the properties of particleboard made from rice husk at different fibre loading and mixture. Different formulated composition of rice husk and pine wood shaving was prepared for the production of particleboard by hot pressing at temperature 160 °C for 6 min using Urea-Formaldehyde (UF) resin with additional of ammonium chloride (NH4Cl) as a hardener. The results showed the density values and moisture content of particleboards ranging from 0.547 to 0.660 g/cm3 and 8.072 to 8.929 %, respectively. The thickness swelling and water absorption were increased as the increment of soaking time. Besides, the colour of the rice husk-pine particleboards has no significant difference and changes except for particleboard made from 100% rice husk. While the more proportion of pine wood shaving has the better compaction of particleboards, and the addition of grinded rice husk also make the particleboards have fewer voids. This study is expected to reduce deforestation activities and to maximize the usage of agricultural wastes.

Critical load for buckling of solid wood elements with a high slenderness ratio determined based on elastica theory

Buckling tests were conducted using slender specimens of western hemlock. In the tests, the slenderness ratio was varied from 132 to 418 in which elastic buckling was induced, and the values of the critical load for buckling were obtained. When the deflection of the specimen was calculated from the loading-line displacement based on elastica theory, the value of deflection/load initially decreased because the compressive deformation was more dominant than the bending deformation. In contrast, when the load increased, the bending deformation became dominant, and the deflection/load-deflection relation exhibited linearity. These tendencies indicated that the transition from compression to bending was induced around the minimum value of the deflection/load. Therefore, it was recommended to determine the critical load for buckling using the load at the minimum value of the deflection/load where the deflection was calculated from the loading-line displacement.

Influence of Veneer Density on Plywood Thickness and Some Mechanical Properties

It has been common knowledge that as the density of wood increases, the mechanical properties also improve. In turn, the density of wood depends on many factors, including the wood moisture content, location and cross-section in the trunk, the type of treatment and the parameters of technological processes. There is a great deal of research reported in the scientific literature on the effect of solid wood density on mechanical properties for different wood species as well as for structural timber. However, no research data can be found related investigation of the influence of veneer density on the properties of the birch plywood. In the present study, researching the properties of 7-ply birch plywood (thickness 9 mm), it was concluded that as the density of veneers increases, the bending properties of plywood in the direction of wood fibers (covered veneers) increases. When determining the plywood gluing quality, similar tendencies have been observed. For plywood with a lower density in all veneer plies the gluing quality (tensile-shear test) for perpendicular wood fiber veneers increases in the direction from the symmetry axis or middle veneer to the plywood outer plies, which can be explained by the fact that the outer plies become denser at the time of the hot pressing process. The results of the study will allow birch plywood manufacturers in direct production, sort veneers by density, to produce plywood with very predictable gluing quality, plywood thickness and mechanical properties in bending.