Wood Panels Research Articles

Cement-bonded wood panels filled with duroplast sanitary ware wastes

Cement-bonded wood panels filled with duroplast sanitary ware wastes

Application of Hybrid Absorptive–Diffusive Panels with Variable Acoustic Characteristics Based on Wooden Overlays Designed Using Third-Degree-of-Freedom Bezier Curves

This manuscript describes the application of novel hybrid acoustic panels with variable acoustic properties that could be used in the design process. Despite the significant growth in the modern acoustic absorbing and diffusing panel sector in recent years, there is still a need for sustainable and original designs that will fit standard interior design trends. The most significant requirement is satisfying the design needs of variable acoustic venues. The availability of acoustic panels with variable properties is minimal, as most designs are based on textiles in the form of rolling banners; therefore, there is no market diversity. The current paper presents an original solution for a novel perforated wooden panel based on third-degree-of-freedom curves. Due to the possibility of exchanging the front panel, the acoustic surface can be varied and adjusted to the room considering different requirements for the acoustic climate, for example, by modifying the attenuation range from low to mid–high frequencies. The novel panels have unique esthetic properties with functional acoustic features regarding sound diffusion and absorption. In this paper, sound absorption and diffusion measurements will be presented for the different variants of the panels, presenting the option to modify the parameters to adjust the panel’s features to the room’s needs. In situ acoustic measurements in a laboratory were conducted to test the variable acoustic panels’ influence on the room’s acoustic parameters, such as T30 and C80. In summary, the advantages of this kind of design will be discussed, alongside the possible impact on modern construction materials’ utilization in architecture.

Research on the veneer defect image enhancement algorithm based on AMEF-AGC.

Aiming at the veneer defect image acquisition process is prone to the problems of blurred edges, inconspicuous contrast and distortion, which cannot show the defects clearly.To improve image analyzability and clarity, a veneer defect image enhancement method based on AMEF-AGC is proposed herein. First, a veneer defect image is subjected to Gamma correction to obtain multiple underexposed image sequences for which Gaussian and Laplacian pyramids are constructed to determine the weights of the multiple exposure sequence group images.Multiscale fusion is then performed based on these weights. Second, the fused image is converted into the HSV color space, where contrast and brightness enhancements are performed for the luminance component, and then converted back to the RGB color space to obtain an enhanced veneer defect image. Solid wood panels selected herein were pine, poplar and birch with defects including live knots, dead knots, and cracks.Compared with those obtained using several algorithms including AMEF, AGC, improved AGC and GC, this algorithm achieved 6.93% and 5.4% improvements in PSNR and SSIM metrics, respectively.Results demonstrated that the proposed method effectively enhanced veneer defect images with blurred and distorted edges, improved image clarity and visual quality, and made defect parts and details of the image clearer.

Green adhesives for wood panel products: a review

Green adhesives for wood panel products: a review

Structural Properties of Globulin: A Critical Parameter for Sunflower Meal as Wood Panel Adhesives.

Alternative biobased adhesive formulations are currently being investigated to replace urea-formaldehyde (UF) as wood panel adhesives. In this regard, oilseed meals are valuable alternatives, as it is anticipated that the sticky potential of these meals is linked to their protein content. This work focuses on the protein parameters (primary and/or secondary structures) that could impact the adhesiveness of sunflower meals. The proteins contained in these meals were first separated from the other components and identified using electrophoresis. Oilseed meals contain several families of proteins: globulins, albumins, prolamins, and oleosins. Sunflower meal is mainly composed of globulin (53%) and albumin (45%). The protein structures have then been either oxidized with H2O2 (in the presence or not of NaOH) or physically treated by microwave (MW). The oxidation treatment cleaves the protein backbone and creates smaller peptides, while the MW process converts α-helices into random coils. The adhesive potential of these treated proteins was evaluated by using shear tests onto wood panels. The results demonstrate that the primary and secondary structures of globulins are key parameters toward the sunflower protein meal adhesivity.

Enhancing the lateral performance of Chuan-dou timber frame infilled with vertical wood panels

Chuan-dou timber frame system represents a prevalent form of traditional wooden architecture, extensively employed in Southwest China. The wood infilling wall stands as a primary manifestation of infill wall construction in Chuan-dou timber frame system, and the existence of infilled walls significantly impacts the lateral behavior of Chuan-dou timber frames. In this paper, the internal force analysis of the timber frame specimen infilled with vertical panels (TFVP) had been undertaken by the credible finite element model, elucidating the detailed enhancement mechanism of wood vertical infilled panels on the lateral performance of the timber frame. 10 models with diverse geometric parameters were formulated to investigate the influence of geometric factors on the vertical panels, including width and thickness. The research findings showed that the presence of Dijiaofang and wood infilled walls could result in a substantial enhancement in the load capacities and initial lateral stiffness of the timber frames. Among them, the enhancement effect of Dijiaofang comes from half-tenon joints (HTJs), while the reinforcement of wood vertical infilled panels arises from the interplay between adjacent panels, as well as the squeezing and friction behavior between the infilled wall and Chuan-dou timber frame. Furthermore, the parametric analysis indicated that the geometry of vertical panels has discernible effects on the lateral performance of TFVP specimens.

Hybrid panels produced with particles and veneers of pine wood in different compositions

Hybrid wood panels can be produced with different particle or veneer sizes, forest species or even mixtures of synthetic materials, with the aim of reusing wood particles and generating new products. The present study aimed to verify the production process of hybrid panels formed with particles and veneers of Pinus taeda wood and urea‒formaldehyde resin. The panels were produced in four different compositions, with a nominal density of 0.65 g/cm³, and their quality was evaluated through their physical and mechanical properties. The addition of veneers in the traditional particleboard system increased the density of the hybrid panels and improved the mechanical properties. The properties of the MOR and MOE in static bending and screw withdrawal were favored using veneers on the panel faces. The internal bonding of the panels was not affected by their composition. The addition of veneers to the particleboard improved the dimensional stability of the panel.

Construction Tasks for Children With Blindness: Analyzing the Completion Ratio of Six Puzzles

Introduction: There are major differences when children with blindness perform construction tasks using haptics, without relying on sight, compared to when children with typical vision perform them through sight. When using sight, in all of the processes, the overall image can be grasped simultaneously while executing the task. When using haptics, the construction must be made by touching each piece sequentially and successively. In this study, framed block puzzle construction tasks that can be implemented by haptic means are developed with the objective of considering the order of difficulty of the task. Methods: In all, six framed block puzzle construction tasks were performed by 39 children with blindness, and the analysis was conducted from the perspective of the task-completion ratio. These six tasks were established on the basis of factors such as wood panel division and dimension, symmetry and asymmetry, and the number of block patterns. Results: A significant difference was observed in the completion ratio between one- and two-dimensional tasks, between two-dimensional symmetrical and asymmetrical tasks, and between two-dimensional asymmetrical tasks with multiple and single correct patterns. Discussion: This study clarified that the task order of difficulty is influenced by the factors of division and dimension, symmetry and asymmetry, and number of block patterns. Thus, we identified a task order wherein difficulty increases in the order of one- and two-dimensional symmetrical tasks and two-dimensional asymmetrical tasks with multiple and single correct patterns. Implications for Practitioners: Based on these hypotheses, providing instructions to children with blindness, in the order of simple to difficult tasks, is vital after ascertaining each child's level of capacity for spatial cognition.

The Physical Properties of Cross-Laminated Wood Panels Made with Tropical Hardwoods and Domestic Temperate Woods

The Physical Properties of Cross-Laminated Wood Panels Made with Tropical Hardwoods and Domestic Temperate Woods

Recruitment and growth of the xylophagous bivalve Bankia martensi ( ) with different levels of wood biofouling species cover

Teredinid bivalves (shipworms) are the main wood degraders in marine environments. However, little is known about the biological interactions between these marine wood borers and wood-associated biofouling species. Filter-feeding species and seaweeds are frequent biofoulers on the submerged wood. Using the marine xylophagous bivalve Bankia martensi (Stempell, 1899) as a model, we hypothesized that increasing the abundance of biofouling species on wood will decrease the recruitment and subsequent growth of the shipworm B. martensi. During the springs of 2020 and 2021, experiments manipulating biofouling cover were carried out using pine panels in Bahía Metri, southern Chile. Three experimental levels of biofouling cover were established (low: 0%–10%, intermediate: 40%–50%, and high: 90%–100%). After five months, the number of B. martensi perforations (as proxy as larval settlement density) and specimen sizes (length, width and volume) in the panels were measured. An inverse relationship between the perforation densities of B. martensi and biofouling cover on the wooden panels was observed. The most frequent biofouling species were mussels and seaweeds which tended to settle on the upper and lateral surfaces, while acorn barnacles and bryozoans were more frequent on the lower surface. Bankia martensi perforations were reduced with increasing biofouling cover. The number of perforations varied according to the panel surface, higher density on the upper and lateral surfaces and lower on the underside. Bankia martensi specimens were larger, both in length and in volume, in panels with low biofouling compared to intermediate and high biofouling cover, while width did not vary with treatment. Our results suggest that the biofouling cover decreases B. martensi recruitment and growth rates, which in turn reduces the wood degradation rate caused by this teredinid. Future manipulative experiments with selected biofouling species (filter-feeders, such as mussels and barnacles), as well as incorporating measurements of reproductive traits of shipworms could help in understanding the biological interactions between these marine communities of wood-boring and biofouling species.

Seismic design rules for lightweight steel shear walls with wood panel sheathing within the Eurocode format

Within the 2nd-generation of Eurocodes several new lateral force resisting systems (LFRS) typically used in lightweight cold-formed steel (CFS) buildings have been introduced, including shear walls with wood sheathing (SWWS). Therefore, extensive studies have been carried out to define the seismic design parameters according to the format of European code for seismic design, i.e. Eurocode 8. In current version of the 2nd-generation Eurocode 8 (prEN1998-1-2, CEN 2022), in case of SWWS the behaviour factor has been defined based on the FEMA P695 (FEMA, 2009) [3] methodology, whereas the other seismic design parameters have been set based on assumption validated with analyses on limited case studies. To overcome this lack, specific research devoted to defining the main seismic design parameters for SWWS belonging to Ductility class 3 (DC3) according to prEN1998-1-2 (CEN 2022) has been carried out at the University of Naples “Federico II”. The research shows that the Easley et al. (1982) method gives consistent in-plane horizontal wall resistance predictions if the shear resistance of wood panel-to-steel sheet screw connections (sheathing connections) is evaluated with reliable approaches and formulas for the evaluation of the shear resistance of sheathing connections have been calibrated. Based on the results obtained from this research, a partial safety factor for resistance evaluation of SWWS according to limit state design (LSD) equal to 1.3 is proposed and an overstrength (expected resistance) factor for the design of non-ductile elements according to capacity design equal to 1.7 is recommended.

Research on structural optimization of high-density wood panel equilibration chamber based on computational fluid dynamics

Research on structural optimization of high-density wood panel equilibration chamber based on computational fluid dynamics

Predicting the elastic properties of Norway spruce by its morphology

Models for the elastic material properties of wood aim to predict the mechanical response of wooden structures to external loading. Traditionally, the variability of these properties in trees is described by a taxonomy of growth defects that is typically based on visual indicators in the material. This includes curvature, knots, and spiral grain models. Existing meso- and macro-scale models fail to describe the uncertainty connected to the local heterogeneity of the material. In this paper, we propose a novel meso-scale model that describes the natural variability of Norway spruce morphology and material properties based on random field theory. Our approach removes the need for a taxonomy of growth defects and enables uncertainty quantification of the stiffness and density in a straightforward fashion using simulations. This may enhance confidence for stiffness-graded applications, where the dynamic resonant behavior of wood structures is relevant and growth anomalies are present. Further, our stochastic models can generate images that realistically mimic wood patterns, which is relevant for applications like synthetic wood panels and flooring.

Anatomy of the Painting: The Study of the Serbian Orthodox Icon from the Turn of the Seventeenth to the Eighteenth Century

The paper presents the results of the multi-analytical study of the painting on a panel from the icon collection of the Gallery of Matica srpska museum in Novi Sad, Serbia. It is part of the research aiming to set the methodology for the museum’s database on artistic materials and techniques present in the collection. Computer tomography (CT) scanning was used to understand the structure of the wooden panel support. Ultraviolet (UV) and infrared (IC) imaging, as well as visible (VIS) macro photography, were used to study the paint layer, both the original part and restoration treatments, as well as the coat of varnish. Energy dispersive X-ray fluorescence (EDXRF) and Fourier-transform infrared (FTIR) spectroscopy revealed the pigments, binders, and metal leaf, defining the artistic technique. Optical microscopy (OM) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) were used to disclose the stratigraphy and composition of layers in the artwork. The multi-analytical approach confirmed that protein-based binder, gilding, silver leaf, and traditional pigments were used. The data gathered from this research are important for studying the artistic materials and techniques in icon production and defining the methodology setting for the museum collection’s databases as the reference material.

Verification and Establishment of Techniques of Ajami Artwork

Ajami, a technique of painted wood paneling, was popular in the Ottoman Empire from the 17th to the late 18th centuries. Ajami art became prominent in Syria after the decline of tile production, and it rose to a sophisticated level of art in both local and global markets. Today, however, Ajami art has become almost forgotten and unknown by the modern generation, due to being an exclusive art that can be seen only in palaces, museums, and historical houses. This study investigates the traditional method and techniques of making Ajami, with a focus on the work of a renowned Syrian Ajami art master artisan named Mr. Abdulraouf. The study aims to identify and document the traditional method of Ajami production and determine the materials and techniques used for making Ajami. The study found that Ajami art consists of natural elements that are utilized in four main stages; foundation, design, painting, and finishing. The artisans have a strong preference for floral and geometric designs, influenced by Islamic religious beliefs. The findings of this study could serve as an educational guide to preserve heritage and make it presentable for the present and future generations.

Self-Neutralizing Melamine-Urea-Formaldehyde-Citric Acid Resins for Wood Panel Adhesives.

In this study, we used a self-neutralizing system to counteract too acidic a pH, unsuitable for wood adhesives, and tested it on MUF resins augmented by the addition of citric acid or other organic acids, based on the addition of small percentages of hexamine or another suitable organic base to form an acid-base buffer. In this manner, the pH of the adhesive was maintained above the minimum allowed value of 4, and the strength results of wood particleboard and plywood bonded with this adhesive system increased due to the additional cross-linking imparted by the citric acid. Thus, the wood constituents at the wood/adhesive interface were not damaged/degraded by too low a pH, thus avoiding longer-term service failure of the bonded joints. The addition of the buffering system increased the strength of the bondline in both the plywood and particleboard, both when dry and after hot water and boiling water tests. The IB strength of the particleboard was then increased by 15-17% when dry but by 82% after boiling. For the plywood, the shear strengths when dry and after 3 h in hot water at 63 °C were, respectively, 37% and 90% higher than for the control. The improvement in the bonded panel strength is ascribed to multiple reasons: (i) the slower, more regular cross-linking rate due to the action of the buffer; (ii) the shift in the polycondensation-degradation equilibrium to the left induced by the higher pH and the long-term stability of the organic buffer; (iii) the additional cross-linking by citric acid of some of the MUF resin amine groups; (iv) the already known direct linking of citric acid with the carbohydrates and lignin constituents at the interface of the wood substrate; and (v) the likely covalent linking to the interfacial wood constituents of the prelinked MUF-citric acid resin by some of the unreacted citric acid carboxyl groups.

A formaldehyde-free amino resin alternative to urea-formaldehyde adhesives: A bio-based oxidized glucose – urea resin

Urea-formaldehyde resins (UF) are the most commonly used wood-based panels adhesive in industry. These adhesives are more than 80 % by volume of the wood adhesives market. However, due to formaldehyde toxicicity and extreme volatility UF resins yield panels with formaldehyde emission problem both during wood panels preparation and their in-service use. In order to address this problem, to find an environment friendly replacement for formaldehyde to manufacture novel and safe aminoresins is essential research for wood adhesives. In this article, a bio-based amino resin wood adhesive (OGU) is developed by using oxidized glucose reacted with urea. The research work presented here tests the impact on the adhesive properties of a number of oxidation treatment parameters and of the glucose to urea molar ratio. The molecular structure and thermal properties of the OGU adhesive were studied by different analytical techniques. The results indicate that the bioaldehydes are obtained by glucose under mild oxidation conditions. The bioaldehydes obtained can then be reacted with urea to form a novel oxidized glucose-urea amino resin, suitable to manufacture plywood. Under the specified process conditions at pH 4 and at a urea-to-glucose molar ratio of 1, the OGU adhesive yielded plywood with a dry strength of 0.99 MPa, 24 h cold water soaking wet strength of 0.77 MPa, and 3 h hot water (63°C) soaking wet strength of 0.76 MPa. These results satisfy the requirements of the GB/T 9846–2015 standard. The OGU resin adhesive prepared has then a good market potential to replace the current UF resins used in the industrial production of wood-based panels and as a novel biomass amino resin adhesive.

Original or post-war paintings? The fixed wooden scenery of the Teatro Olimpico in Vicenza: a guided multidisciplinary approach based on scientific analyses and HBIM

Archival resources, a photogrammetric survey, analysis of materials and techniques, and evaluation of the state of conservation were interconnected phases in the interdisciplinary research on the perspective scenery of the Teatro Olimpico in Vicenza. To fill existing gaps related to the history of this unique artefact and to the undocumented retouching of paint layers on the scenery during post-war reconstruction work, a broad analytical approach (optical microscopy, XRPD, SEM–EDX, μFTIR and μRaman) was applied to micro-samples, the selection of which was guided by consolidated geometrical and archival data. The aims were to obtain a characterisation of the pigments and binders and to evaluate the microstratigraphic sequence, the state of conservation of the scenery flats, and the deterioration processes involved. The findings unveiled a discernible variability in the production techniques of the finishes, frequently lacking the classic microstratigraphic sequence associated with the traditional method for painting on wooden panels from the sixteenth century. Moreover, by identifying many pigments that could be used as temporal markers we were able unequivocally to establish, for the first time, that a significant part of the scenery designed by the architect Vincenzo Scamozzi was heavily repainted in the post-WWII period. These analytical results and all the data collected on the artefacts over time were related through an HBIM model, enabling the historical and technical-analytical information to be linked to the geometrical survey and thus to provide guidance for actions based on current and future knowledge for the maintenance and monitoring of the Teatro Olimpico.

Cage enrichment to minimize aggression in part-time group-housed female breeding rabbits.

In most rabbit farms, breeding does kindle and nurse their kits in single-litter cages throughout their entire reproduction cycle. However, the protective behavior can lead to aggressive displays and injuries when the does are housed in groups. This study aimed to evaluate cage enrichment for reducing the agonistic behavior in part-time group-housed does. A total of eighty does with their 22-day-old kits were allocated to 20 multi-litter cages, with each cage housing four does and their litters for 10 days. Each multi-litter group was subjected to one of four treatments: alfalfa blocks as distraction material (A), wooden panels underneath the platforms (P), both alfalfa and wooden panels (AP), or no extra enrichment (controls, C). This experiment was replicated for three consecutive reproduction cycles. The skin injuries of the does and the kits were scored with a tagged visual analog scale before grouping and at one, three, six, eight, and 10 days after grouping. Computer vision techniques were used to continuously monitor rabbit activity and agonistic behavior (aggression and fleeing/chasing) during the first 24 h after grouping, specifically during light hours. During the first day in the group, 67.2% of the does and 13.4% of the kits acquired new injuries. This increased to 82.0 and 33.2%, respectively after 10 days in the group relative to the onset of grouping. The injury scores of the does increased toward the sixth day after grouping compared to the first (p < 0.001) and were highest on the tenth day for the kits (p < 0.001). On all the observation days, the number of injured does was higher in C compared to A (p = 0.04) and AP treatment (p = 0.005). There were no other treatment effects observed on the doe or kit skin injuries. Rabbit activity was highest after grouping but decreased after the first and second days (p < 0.001). The agonistic interactions between the does involved more fleeing/chasing behavior (62.0%) rather than aggression (38.0%). Although hierarchy fights are likely when unacquainted does are group-housed, the many animals that sustained injuries and the high injury scores confirm that part-time group housing for does is challenging and possibly inevitable. This study has shown that alfalfa, with or without wooden panels, can slightly reduce the number of injured does.

An LCIA-based model proposal for the selection of building interior finishing materials

The increasing environmental impacts of buildings highlight conscious material selection as a pivotal aspect of sustainable building design. Most current life cycle impact assessment (LCIA) models on material selection focus on the main construction or insulation materials while often neglecting the environmental effects of finishing materials. Hence, this study seeks to present an LCIA-based model for selecting finishing materials based on their environmental impacts. Environmental Product Declaration (EPD) as a data source for the mandatory steps of LCIA is recommended for the model since it provides fast, reliable, and equivalent data on the environmental impacts of the materials. The model is validated by assessing three wall finishing materials in hotel bedrooms- gypsum board, paint, and wood panel. Findings revealed that the model has the potential to mitigate the environmental effects by guiding decisions made during the finishing material selection phase.