Wooden Boards Research Articles

Sound environment design using flexible wood-based sound absorbers

A sound-absorbing material made of flexible wooden boards with air permeability was developed to improve the indoor sound environment of buildings. The flexible wood-based material has sound absorbing characteristics with the Helmholtz resonator by its air permeability. In other words, various sound absorption characteristics could be realized owing to the cross-sectional shape (flat or curved) and machining conditions (cut width, cut pitch, and plate thickness). In this paper, the application of flexible wood-based sound-absorbing materials to acoustic design in actual buildings (nursery schools and a church) where acoustic considerations are required is presented. In their application to a newly built nursery school, one of the considerations was to prevent the loss of design by installing sound-absorbing materials. In their application to acoustic renovation, the sound environment improvement effect was confirmed by measuring sounds before and after the installation, and it was also confirmed that the users were able to feel the improvement effect. These results will lead to the development of sound-absorbing wooden boards as an interior material and the promotion of the use of wood in buildings to contribute to the realization of a decarbonized society.

ANALYSIS OF IGNITABILITY AND COMBUSTION RATE OF SELECTED INTERIOR FURNISHING MATERIALS

The first part of the article presents the issue of apartment fires and describes materials used inthe final stage of interior finishing. The second part discusses the research method and procedureas well as the stand where, using two surface and edge methods in accordance with the PN-ENISO 11925-2:2020 standard, the ignitability and burning rate of selected eight finishing materials,such as: laminated chipboard, varnished MDF, PVC wall panel, pine wooden board, ash woodenpanel, carpet, laminated panel and vinyl panel, were determined. The test results are summarizedin a table with the following values or answers to questions (Yes or No) for both methods used:whether ignition after 15 s, or ignition after 30 s, whether combustion was self-sustained, whetherthere were drops or waste, whether they caused ignition of the tissue paper, flame height after20 s and 2 min. The last column contains the general characteristics of smoke released duringcombustion. Moreover, a separate table lists the average lengths of the burned sample and theirlinear burning velocities in the surface and edge methods for selected interior finishing materials.The study comprises an analysis of the obtained results, based on which several conclusions wereformulated important from the viewpoint of fire safety of apartments. For example, it turned outthat the highest combustion speed was observed in carpet samples and an ash wooden panelprotected with clear varnish, while the lowest flame spread speed was recorded in the case ofa vinyl panel and a varnished MDF board.

WD-1D-VGG19-FEA: An Efficient Wood Defect Elastic Modulus Predictive Model.

As a mature non-destructive testing technology, near-infrared (NIR) spectroscopy can effectively identify and distinguish the structural characteristics of wood. The Wood Defect One-Dimensional Visual Geometry Group 19-Finite Element Analysis (WD-1D-VGG19-FEA) algorithm is used in this study. 1D-VGG19 classifies the near-infrared spectroscopy data to determine the knot area, fiber deviation area, transition area, and net wood area of the solid wood board surface and generates a two-dimensional image of the board surface through inversion. Then, the nonlinear three-dimensional model of wood with defects was established by using the inverse image, and the finite element analysis was carried out to predict the elastic modulus of wood. In the experiment, 270 points were selected from each of the four regions of the wood, totaling 1080 sets of near-infrared data, and the 1D-VGG19 model was used for classification. The results showed that the identification accuracy of the knot area was 95.1%, the fiber deviation area was 92.7%, the transition area was 90.2%, the net wood area was 100%, and the average accuracy was 94.5%. The error range of the elastic modulus prediction of the three-dimensional model established by the VGG19 classification model in the finite element analysis is between 2% and 10%, the root mean square error (RMSE) is about 598. 2, and the coefficient of determination (R2) is 0. 91. This study shows that the combination of the VGG19 algorithm and finite element analysis can accurately describe the nonlinear defect morphology of wood, thus establishing a more accurate prediction model of wood mechanical properties to maximize the use of wood mechanical properties.

Effects of Gmelina bark content and particle size on the characteristics of a recycled polypropylene composite

Bark plastic composite is a composite wood board consisting of a plastic matrix and bark in the form of powder or fibers as a filler. This research aimed to determine the influence of ratio and particle size on the characteristics of the composite made of Gmelina bark mixed with recycled polypropylene. Bark plastic composites were made with variations in powder: plastic ratio, namely 40:60% (P60), 30:70% (P70), 20:80% (P80), and 0:100% (P100), as well as variations in filler particle size, namely 40 to 60 mesh (M40), 60 to 80 mesh (M60), and 80 to 100 mesh (M80). Maleic anhydride (MAH) as a compatibilizer was added at 5% of the matrix’s weight. The reference testing standards were JIS A 5908:2003 and SNI 03-2105-2006. In the physical property testing, including density, moisture content, water absorption, and thickness swelling, all boards with different treatments met the standards. In the modulus of elasticity (MOE) testing, none of the boards with different treatments met the standards, while in the internal bond testing, all boards with different treatments met the standards. As for the modulus of rupture (MOR) testing, hardness, and screw-holding power, some samples met both standards. The M40P80 treatment produced the best bark plastic composite.

Performance of structural insulation panels under eccentric axial and racking loads with varying opening ratios

Structural insulation panels, which are actively applied in the housing market in North America and Europe by utilizing wood, an eco-friendly material, as the main material, are composed of OSB (Oriented Strand Board), EPS (Expanded Polystyrene), and SPF (Spruce-Pine-Fir), which is used as a connection between the panels. Structural insulated panels are used as a load-bearing wall to resist external forces without installing separate columns. The production of structural insulation panels consists of applying adhesive to both sides of EPS, which acts as an insulation material, and pressing wood boards (OSB), which exert strength as a structural material. The OSB on the outside resists compressive and tensile forces, while the EPS on the inside resists shear forces. The joints and openings of the structural insulation panels are reinforced with SPF (Spruce-Pine-Fir) structural wood. When structural insulated panels are used as an exterior wall structure, the installation of openings is essential. Based on the opening size that is popularly used in wooden structures, the performance evaluation of structural insulation panels under eccentric axial load and repeated lateral load due to the reduction of the cross-sectional area by installing the opening was carried out, and the behavior analysis through variable analysis and comparison analysis with the design equation was carried out.

Microblasting with vegetable and cellulosic media for heritage wood cleaning: effects on surface morphology

In this research, microblasting with powdered vegetable particles (almond and hazelnut husks, cork saw dust and rice husks) and cellulosic fibres was used to analyse their usefulness for cleaning unpainted wooden cultural heritage and their effects on surface morphology. Tests were made on mock-ups of old pine wood from wooden boards with original soiling. Before cleaning powdered particles were characterised by SEM–EDS to analyse their morphology and elemental composition. Wood surfaces were analysed before and after cleaning by means of digital microscope (white and UV light) and SEM–EDS to evaluate cleaning effectiveness, assess effects on the wood surface, and determine eventual soiling and powdered particles larger than 1 µm that might remain in the surface after the procedure. Results indicate that microblasting with powdered vegetable and cellulosic media is a useful and safe technique to remove soiling from wood, including micrometric particles embedded in its texture, with negligible surface changes. Furthermore, residues left after the cleaning procedure are very scarce and chemically compatible with the substrate because they are mainly composed of cellulose, hemicellulose and lignin, the main components of wood.

Brief Overview of the Thermal and Mechanical Properties of Wood, Steel, and Gypsum Board for Structural Connections

Brief Overview of the Thermal and Mechanical Properties of Wood, Steel, and Gypsum Board for Structural Connections

Measurement of air permeance in mass timber elements assembled through the dovetail technique

Adhesives and metal fasteners are important components in engineered wood products (EWPs), but the petroleum-based nature of adhesives raises environmental concerns and metal fasteners lead to challenges with end-of-life disposal and reusability. However, there is a promising solution in the form of ‘mass timber elements assembled through the dovetail technique (MTADT)’, also called ‘dovetailed massive wood board elements’, which is entirely composed of wood and devoid of adhesive or metal connections. However, existing literature on MTADT has focused on insufficient structural analysis and model testing of connection details rather than assessing the performance of a structural component. In this study, air permeance measurement in MTADT was conducted in accordance with the Finnish building code as part of the DoMWoB project (Dovetailed Massive Wood Board Elements for Multi-Story Buildings). The research aimed to explore the impact of storage conditions and moisture content on the air permeance values of three massive wood elements with varying dimensions. The smallest element had dimensions of 1160 mm × 1160 mm x 200 mm, while the other two were approximately 1300 mm × 1300 mm x 200 mm in size. The results from the air permeance tests indicated significant variability among the three test pieces, with q50 values of 1.4 m³/(m2h) for sample O, 2.9 m³/(m2h) for sample K, and 9.9 m³/(m2h) for sample Y. This data suggested that test piece Y demonstrates substantially higher air permeability compared to the other samples because it was the driest of these test elements.

Super Lightweight, Scalable, High-Strength, Thermal Insulating Molded Corrugated Wood Boards for Cold Chain Transport Construction

Super Lightweight, Scalable, High-Strength, Thermal Insulating Molded Corrugated Wood Boards for Cold Chain Transport Construction

Preparation of multifunctional flame-retardant wood composites by crosslinking chitosan-based polymers with phytic acid functionalized UiO-66-NH2

Bio-based composites can mitigate the pollution issues linked to petroleum-based materials due to their eco-friendly properties. On the other hand, bio-based functionalized metal-organic frameworks have gained attention in the field of flame retardants due to their multi-pathway flame retardant mechanism and environmentally friendly synthesis process. However, its application in wood industry is less. In this work, a novel functional adhesive and coating (ACS-MACS/PA-UiO66-NH2) was developed by using phosphorus-rich biomass phytate functionalized metal-organic framework (MOF) PA-UiO66-NH2 as a flame retardant and mixed with modified chitosan. Furthermore, using ACS-MACS/PA-UiO66-NH2 and three-layer wooden boards, a tight cross-linked network was formed through hot pressing dehydration and condensation reactions to prepare multifunctional wood composites. The experimental results indicated that the mechanical properties of the multifunctional wood composites are excellent. Additionally, these wood composites exhibit high levels of charring and graphitization, leading to excellent flame retardancy. The preparation process of these multifunctional wood composites is straightforward, and their excellent properties provide a foundation for the development of high-performance green composite materials.

Quality of comply boards from the industrial waste of palm and bamboo

Requisite of boards as a material for furniture is increasing. Therefore, alternative materials are needed to replace wooden boards such as comply boards. This study aims to determine the quality of comply board from palm and bamboo waste using PVAc adhesives. The treatment used is 12% and 14% adhesive percentages. Parameter tests of comply board of physical properties include moisture content, density, and thickness development; mechanical properties include modulus of elasticity (MOE) and modulus of rupture (MOR). The mechanical properties of adhesive content have a significant effect on the mechanical properties of comply board palm and bamboo namely MOE and MOR the Physical Properties of the resulting comply board meet SNI 03-2105-2006 standards, namely for the parameters of Water Content, Density, Water Absorption. The mechanical properties of comply boards, namely Modulus of fracture (MoR) are not included in these standards. The condition of the results of this study is thought to be.

The influence of air movement in providing thermal comfort in naturally ventilated old Mosque Gunong Kleng, West Aceh, Indonesia

Abstract Mosques were created to fulfill the needs of Muslims in prayer, therefore thermal comfort is critical to consider so that the congregation is comfortable and can focus and feel at home while praying. The typology of ancient mosques reflects the community’s traditions and culture, as well as local knowledge values. Natural ventilation, which acts as a natural air exchange mechanism, is one facet of thermal comfort. The Gunong Kleng Mosque, founded in 1927, is one of West Aceh Regency’s ancient mosques. However, design adjustments have been made, such as the installation of wooden boards to on terraced roof. The air flow from the building’s roof is blocked, resulting in inefficient air exchange. The goal of this study is to determine thermal performance and the effect of air movement on thermal comfort at the Old Gunong Kleng Mosque. This study employed a quantitative approach using field measurements of air temperature, relative humidity, and air velocity. An anemometer and a USB data logger were utilized to collect data. Field measurements revealed that ET comfort in the mosque was 78% too hot, 16% warm comfortable, and 6% for optimal comfort. Ansys Fluet simulation with two types of situations was used to forecast air speed, demonstrating that changes in the design of the stepped roof had a significant impact on the air speed within the mosque. When opposed to an open roof, a closed roof slightly lowered the ambient temperature in the prayer room.

Printing and imprinting the Missale Nidrosiense: a multidisciplinary investigation of the first printed book of Norway

In our study, we employed an interdisciplinary approach to study the diverse parts of the Missale Nidrosiense, published in 1519. Our aim was a thorough investigation of the materials used and the manufacturing methods that may give indications on dating and provenance of the components of the book and where the book was bound. Initially, visual and multispectral methods were employed to investigate the books’ components, printing technology and bookbinding structure. Subsequently, other methods were applied: the composition of metallic components was determined by X-ray fluorescence spectroscopy (XRF). Pigments, printing inks and binders were characterised by using a combination of XRF and synchrotron-based infrared microscopy. Non-invasive dendrochronology based on X-ray tomography was utilised, to indicate date and provenance of the wooden boards of the book. Additionally, we used a biocodicological approach to identify the species of animal used in the parchment. This resulted in a complete biography of the book. We were able to acquire new information about the materials used and their provenance. This provides new information about craft, economy, trade and commercial exchange in the beginning of the sixteenth century in North-west Scandinavia, despite the lack of written documentation from this period.

Promoting Circular Economy of the Building Industry by the Use of Straw Bales: A Review

Over the past decade, the concept of a circular economy has increasingly gained attention as a framework for guiding businesses and policymakers. Given its significant environmental impact, the building industry plays a pivotal role in the transition toward a circular economy. To address this, our review proposes a bio-based building material, specifically straw bale, which elaborates on the circularity of bio-based buildings based on the 3R principles of a circular economy: reduce, reuse, and recycle. In terms of the “reduce” principle, straw-bale buildings can reduce construction waste, the environmental impact, energy requirements, and carbon emissions. Regarding the “reuse” principle, straw-bale buildings utilize agricultural waste resources and are easily disassembled due to their prefabrication. As for the “recycle” principle, straw-bale buildings can undergo physical, biological, and biochemical conversion processes (thermochemical conversion), yielding both wooden composite boards and potential biogas and biomass fuels for electricity and heating. This study evaluates the contribution of straw packaging construction and the use of straw as a raw material, using the 3R principles to determine future research opportunities for the construction industry to achieve a circular economy. The results of this study offer circular economy solutions and interdisciplinary research insights for researchers and practitioners interested in the building environment.

High-amylose starch-based gel as green adhesive for plywood: Adhesive property, water-resistance, and flame-retardancy

The escalating demand for environmentally sustainable and cost-effective adhesives in the wood processing and manufacturing sector has prompted exploration into innovative solutions. This study introduces a novel gel adhesive composed of chemically unmodified high-amylose starch (G70, with 68 % amylose content) with a minimal proportion of urea-formaldehyde (UF) (UF/starch = 1:10, w/w). This G70/UF gel demonstrates remarkable adhesive capabilities for wooden boards under both dry conditions (with a shear stress of 4.13 ± 0.12 MPa) and wet conditions (with a shear strength of 0.93 ± 0.07 MPa after 2 h of water soaking). The study unveils that the elevated amylose content in the starch, coupled with a meticulously controlled isothermal process during bonding, is crucial for these enhancements. Specifically, the robust cohesion of amylose chains expedites phase separation between starch and UF, while the isothermal process facilitates the migration and enrichment of UF molecules at the gel-board and gel-air interfaces. Lacking these mechanisms, conventional amylopectin-rich starch/UF gels (27 % amylose content) show minimal improvement. Moreover, the G70/UF gel showcases exceptional fire retardancy. In all, the G70/UF gel presents a promising alternative for plywood production, reducing reliance on unhealthy UF resin while offering satisfactory bonding resistance in diverse conditions and superior flame retardancy.

경남내륙지역 목관·목곽묘의 구조적 특징과 축조양상

This study examined the wooden gasket tombs and wooden chamber tombs in Gyeongnam Inland areas from two main perspectives. It summarizes recent excavation cases to review the structural characteristics of these tombs and infers the construction style and burial methods through the example of the Jeongjang-ri Tomb No. Ⅲ-86. Firstly, the wooden gasket tombs consist of ① burial area (tomb pit), ② wooden gasket, ③ backfill soil, ④ topsoil, ⑤ wooden fence, and ⑥ mound, which are not significantly different from those found in the Yeongnam region. However, the wooden gasket tomb at Jangchon-ri B-25 is a unique half-cut chamber type. What is particularly noteworthy is that the lower part of the tomb pit is excavated about 10° eastward from the top, where the wooden gasket is placed. Additionally, the wooden gasket tomb at Dohang-ri #48 lacks backfill soil and exhibits a distinctive structure with retaining walls. The structure of the wooden chamber tombs consists of ① burial area (tomb pit), ② wooden chamber, ② wooden gasket, ③ pedestal, ④ backfill soil, ⑤ topsoil, ⑥ capstone, and ⑦ outer wall. There are various types of wooden chamber tombs, including single-chamber style, double-chamber style, and compound chamber style. Among them, the wooden chamber tombs in Jeongjang-ri is notably distinct because it has separate compartments on both walls for the relics among the double-chamber style tombs that have both the inner and outer walls and the single-chamber style tombs. Additionally, the floor surface is excavated to install a pedestal, and two to five wooden planks are placed across it. And it is clear that the inside and outside are installed on the wooden board. Second, the architectural features and burial styles have been reconstructed by inferring the procedure of construction based on the structural features of the Jeongjang-ri Tomb No. Ⅲ-86. The assumed procedure is as follows: Excavation of the ① burial area and ② tomb pit and installation of the pedestal → Installation of horizontal wooden planks and longitudinal planks → ④ Installation of inner and outer walls and backfilling → ⑤ Placement of body and artifacts → ⑥ Closing and sealing of the wooden gasket and mound construction. Therefore, the Jeongjang-ri Tomb No. Ⅲ-86, among others, holds significance as it provides an opportunity to comprehensively reconstruct the structural characteristics and construction processes of wooden chamber tombs in the Gyeongnam Inland region.

Comparative Study of Coffee Wood and Fern Board Planting Media on Phalaenopsis amabilis Vegetative Growth in the Seedling Phase

Latar Belakang: Phalaenopsis amabilis or referred as the moon orchid, is a popular type of orchid with high market demand. Planting media is factors that can be successful in caring for the Phalaenopsis amabilis, which is an epiphytic orchid type or attaches to other plants. Most orchid planting techniques have not adapted to their natural habitat in nature. Metode: Research method used comparative studies between coffee sticks and fern boards as planting media for Phalaenopsis amabilis on their vegetative growth according to their natural habitat by attach on other plants. The analysis result by statistical tests (t – test upaired) using SPSS. Hasil: The results of the analysis showed that p ≤ 0.05 on the four parameters consisting of the number of leaves 0.01 ≤ 0.05; leaf span parameter 0.001 ≤ 0.05; leaf width parameter 0.0002 ≤ 0.05; root length parameter 0.032 ≤ 0.05. There are differences in the use of planting media types of coffee logs (M1) and fern boards (M2) on the vegetative growth of Phalaenopsis amabilis orchid plants. Kesimpulan: The vegetative growth on M1 and M2 significantly different. The fern board planting media (M2) tends to be more recommended for use because it can be optimal in providing vegetative growth consists of the number of leaves, leaf span, leaf width and root length because its growth is more stable.

Aqueous Cellulose Solution Adhesive.

In the context of sustainable development, research on a biomass-based adhesive without chemical modification as a substitute for petroleum-based adhesive is now crucial. It turns out to be challenging to guarantee a simple and sustainable method to produce high-quality adhesives and subsequently manufacture multifunctional composites. Herein, the inherent properties of cellulose were exploited to generate an adhesive based on a cellulose aqueous solution. The adhesion is simple to prepare structurally and functionally complex materials in a single process. Cellulose-based daily necessities including straws, bags, and cups were prepared by adhering cellulose films, and smart devices like actuators and supercapacitors assembled by adhering hydrogels were also demonstrated. In addition, the composite boards bonded with natural biomass wastes, such as wood chips, displayed significantly stronger mechanical properties than the natural wood or commercial composite boards. Cellulose aqueous adhesives provide a straightforward, feasible, renewable, and inventive bonding technique for material shaping and the creation of multipurpose devices.

Dynamic Control Method of Improving Extreme Learning Machine Algorithm in Wood Spinning Process

<p>The precise control of the feed system of the rotary cutting machine is the key to achieving uniform thickness rotary cutting of wood on the log-core veneer lathe. The application of Improving the Extreme Learning Machine Model in the feed system can effectively solve the problem of unstable feed rate matching in traditional control methods. This study analyzed the working mechanism of log-core veneer lathe and established a kinematic model of its feed system. Using the thickness and thickness variation of the wooden board as the control results of Improving the Extreme Learning Machine Model, in order to solve the optimal weight and threshold of Improving the Extreme Learning Machine Model, this paper uses an improved particle swarm optimization algorithm to solve. Finally, in the Matlab software environment, log-core veneer lathe motion model and control model are written, and simulation experiments are conducted to verify. The results show that Improving the Extreme Learning Machine Model effectively improves the control performance of the system, with stable feed rate changes, good real-time performance, fast convergence, high control accuracy, and strong adaptability.</p> <p> </p>

Evaluations of the effects of different flame retardants combinations on particleboards produced using urea–formaldehyde resin

Nowadays, using flame-retardant chemicals is gaining importance in chipboard production. Melamine resins to produce chipboard are preferred to provide flame retardancy properties with a cost of approximately 2.5 times the urea–formaldehyde (UF) resin. In this study, the UF resin to produce the chipboard was preferred due to its economical availability. To improve the flame retardancy properties of the chipboard, phosphate-based and inorganic flame retardants were used in the chipboards. In chipboard production, oak, pine, poplar, sawdust, urea–formaldehyde resin as adhesive, flame retardant chemicals like triphenyl phosphate (TPP), ammonium polyphosphate (APP), and calcium gluconate (CaG) were used. Flame retardant chemicals were added to chipboards in single and double compositions and prepared by pressing method. Mechanical (tensile, bending, and surface strength), physical (humidity, density, formaldehyde emission), and fire (limiting oxygen index (LOI), cone calorimeter, and UL-94 vertical) tests were performed on wooden boards. It has been observed that the use of different types of flame retardant and their combinations in chipboard does not significantly change the mechanical properties. It was seen that the free formaldehyde emission rate decreased by using flame retardant added compared to the control sample. The chipboard samples with added flame-retardant chemicals have entered the V-0 rating in the UL-94. LOI values of the chipboard samples containing 50% CaG-50% APP and 50% TPP—50% CaG were observed as 29.7% and 29.8%, respectively. Besides, the highest heat release rate (HRR) reduction was obtained in the chipboard sample containing 50% CaG—50% APP.