Oak Veneer Research Articles

User Preferences on the Application of Wooden Wall Coverings in Interiors Made of Oak Veneer Residue

Guided by the principles of visual perception and basic design, this research was conducted to examine users’ preferences on how they perceive natural unique wood phenomena of Pedunculate Slavonian Oak veneers (Quercus robur L.) such as color changes, wood rays, sapwood, and knots, which in the production and technical sense represent defects and wood residue, but could be used in the design of sustainable and ecological wall decorations. The goal was to detect samples with the most positive attributes and to observe their connection with activities and functional space if they are viewed as wall coverings in the interior. The results confirm that discoloration and wood rays are considered the most harmonious (“prettiest”) decors. Discoloration is associated with quiet cognitive or medium-intensity activity that can be used in libraries, hotel rooms, and classrooms. Wood rays are connected with very quiet activity in ambulance waiting rooms or religious buildings and museums. Knot decors are considered the most natural and are recommended for interiors with very or medium-intensive activities such as restaurants, cafes, and hotel receptions, but attention should be paid to the way the wall decors are arranged on the walls. Sapwood–hardwood decors are the subject of further research and improvement concerning the relationship between the dark and light parts of the veneer. In conclusion, the results provide useful guidelines for manufacturers with a large veneer residue in production and who want to design decorative wall panels, as well as for designers and architects designing interiors for a specific purpose and function where certain user behavior and psychological stimulation are desired.

Biofilms on plastic litter in an urban river: Community composition and activity vary by substrate type.

In aquatic ecosystems, plastic litter is a substrate for biofilms. Biofilms on plastic and natural surfaces share similar composition and activity, with some differences due to factors such as porosity. In freshwaters, most studies have examined biofilms on benthic substrates, while little research has compared the activity and composition of biofilms on buoyant plastic and natural surfaces. Additionally, the influence of substrate size and successional stage on biofilm composition has not been commonly assessed. We incubated three plastics of distinct textures that are buoyant in rivers, low-density polyethylene (rigid; 1.7 mm thick), low-density polyethylene film (flexible; 0.0254 mm thick), and foamed polystyrene (brittle; 6.5 mm thick), as well as wood substrates (untreated oak veneer; 0.6 mm thick) in the Chicago River. Each material was incubated at three sizes (1, 7.5, and 15 cm2 ). Substrates were incubated at 2-10 cm depths and removed weekly for 6 weeks. On each substrate we measured chlorophyll concentration, biofilm biomass, respiration, and flux of nitrogen gas. We sequenced 16S and 23S rRNA genes at Weeks 1, 3, and 6 to capture biofilm community composition across successional stages. Chlorophyll, biomass, and N2 flux were similar across substrates, but respiration was greater on wood than plastics. Bacterial and algal richness and diversity were highest on foam and wood compared to polyethylene substrates. Bacterial biofilm community composition was distinct between wood and plastic substrates, while the algal community was distinct on wood and foam, which were different from each other and polyethylene substrates. These results indicate that polymer properties influence biofilm alpha and beta diversity, which may affect transport and distribution of plastic pollution and associated microbes, as well as biogeochemical processes in urban rivers. This study provides valuable insights into the effects of substrate on biofilm characteristics, and the ecological impacts of plastic pollution on urban rivers. PRACTITIONER POINTS: Plastic physical and chemical properties act as forces of selection for biofilm. Biofilm activity was similar among three different types of plastic. Community composition between plastic and wood was different.

Static and dynamic crushing of sandwich tubes with composite skins and three plywood cores (poplar, birch, and oak)

This paper presents the results of static and dynamic crushing of sandwich tubes with carbon or glass skins and different wood cores. Wood cores were made with poplar, birch, or oak veneer. The core thicknesses of the tubes were equal even if the thicknesses of the species veneers were different for availability reasons. For a tube with a birch core and carbon skins, the Specific Energy Absorption was 50.4 J/g in quasi-static tests and 66.6 J/g in dynamic, and the energy absorbed was 5427 J in quasi-static and 7025 J in dynamic. The birch layers were shown to make a very significant contribution although they were 40 times less expensive than carbon layers. Results from the research work described here show that these materials are appropriate candidates for energy absorption at low carbon emission and with renewable materials.

Multi-modal sorting in plastic and wood waste streams

Addressing the escalating waste crisis necessitates innovative waste management strategies, particularly valorisation techniques, the efficiency of which is dictated by the purity of the feedstock. In order to mitigate the segregation challenges encountered in complex and non-homogeneous waste streams, this work proposes a vision-based architecture ample for effective sorting of parts based on shape and material-related properties. The proposed work encapsulates a novel deep learning multi-modal approach, in which multiple parallel auto-encoders are used to extract spatio-spectral information from the RGB and multi-spectral sensors and project them in a common latent space. By decoding the latent space representations, the class of each object is picked out, thus guiding the robotic sub-system accordingly. To support the proposed deep architecture, a dataset, called Multispectral Mixed Waste Dataset (MMWD) was produced, containing multi-spectral data from the visible (16 bands), near-infrared (25 bands) regions of the electromagnetic spectrum and RGB (3 bands) data. The dataset includes the following seven plastic and wood wastes: Polypropylene (PP), PolyEthylene Terephthalate (PET), Low-Density PolyEthylene (LDPE), High-Density PolyEthylene (HDPE), Medium Density Fibreboard (MDF), Melamine Faced Chipboards (MFC), and Oak Veneer samples. For the localisation of waste along the conveyor belt, YOLO v8 is used to achieve 99.5% mean average precision (mAP50). In the classification task, where the multi-modal approach was followed, the overall accuracy achieved is 96% with the prediction recall being greater than 95% for the majority of classes under examination.

DISCOLORATION OF OAK VENEER INDUCED BY METAL IONS

The 3 mm thick oak veneers were discolored by single ions of Fe2+, Cu2+, and Mn2+ and mixed ions of Fe2+-Cu2+, Fe2+-Mn2+, and Cu2+-Mn2+. The brightness (L*), red-green index (a*), and yellow-blue index (b*) of the veneers changed by varying degrees with the changes in ion mass fraction, temperature, heating time, ion species, and ion mass fraction ratio. The maximum values of total color difference (△E*) of the veneers were 38.94, 11.79, and 9.42 for Fe2+, Cu2+, and Mn2+. Moreover, the total color difference (△E*) values of 24.07, 13.71, and 4.45 were observed for Fe2+-Cu2+, Fe2+-Mn2+, and Cu2+-Mn2+ mixed ions. The veneers showed different degrees of vibrational peaks after discoloration. According to the ultraviolet spectrum, Fe2+ had a red shift in the ultraviolet absorption band of the unsaturated carbonyl compound and benzene ring compound. Moreover, the dark effect of Fe2+, Fe2+-Cu2+, Fe2+-Mn2+, Mn2+, Cu2+-Mn2+, and Cu2+ gradually decreased. The surface of the veneer was flat, without any rupture or deformation, and the pores were clear after treatment.

International supply chain handling practices and the quality of heat-treated, white oak veneer logs

The most promising alternative to the methyl bromide fumigation of exported logs is steam-heating the log in a vacuum. Research has confirmed that steam heating to 56 °C for 30 minutes kills all viable propagules of oak wilt pathogen (Bretziella fagacearum) in the sapwood of oak logs. The purpose of this study was to determine whether this heat-treatment method has any effect on the quality or value of white oak veneer logs shipped between the US and EU. Seventeen steam- and vacuum-treated and seventeen untreated control logs were shipped from Baltimore, Maryland to the Czech Republic, for processing into veneer, between December 2021 and February 2022. The treated and untreated logs were sawn into flitches, soaked in hot water vats, sliced, dried, and the veneer from each log was graded for quality. Each log was assigned a value based on the veneer quality and yield. The average value of treated log was 1,547 €/m³, and the average value of the untreated logs was 1,539 €/m³. The null hypothesis was statistically confirmed. Therefore, it is concluded that the 56 °C/30 min, sapwood heat treatment using vacuum and saturated steam had no adverse impact on the value of the white oak veneer logs.

Australia in Oak, Copper, and Quartz

This article describes a map I made based on a trip to Western Australia I took with my wife in 2014. The map is sculptural, constructed using a combination of wood, metal, and semi-precious gemstones. For the base of the map, I used a 44.5 × 40.5 in (113 × 103 cm) piece of quarter-sawn white oak veneer plywood. Guided by a 1-inch (2.54 cm) grid system, I drilled 773 holes of four different diameters to show the land area and general shape of the continent. I chose two different gauges of copper wire to represent driving and train routes. Amethyst stones represent alkaline saline lakes that Holly—an extremophile microbiologist—sampled for resident microbiota. For the one acidic saline lake she sampled (pH 3.5), I used rose quartz instead of amethyst. I highlighted the stromatolites we observed at Shark Bay (Western Australia) with a green diopside mineral. Finally, anywhere we stayed of note is represented with one (or more) red map pins. The final product is 44.5 × 40.5 in (113 × 103 cm) at a scale of 1:4,118,400 (1 in = 65 mi; 1 cm = 41.2 km).

Quality Research of Edge Banding of Unit Furniture

Edge banding is used to cover cut sides of wood materials such as plywood or particleboard. The quality of two different furniture edge banding materials and their thickness were studied in this paper. The research was focused on most widely used in the Lithuanian furniture industry acrylonitrile butadiene styrene (ABS) and oak veneer. The experiments were performed to investigate the mechanical properties of materials and SolidWorks Simulation were made as well. The conclusions and recommendations can ensure the improvement and optimization of the processes of furniture industry. Structure of the paper: introduction, review of literature, methodology of experiment, results of research and their consideration, conclusions, references.

JUSTIFICATION OF THE POSSIBILITY OF USING THERMOMODIFIED VENEER IN AN ENVIRONMENT WITH HIGH HUMIDITY

Thermally modified wood is widely used in the woodworking industry, as it has increased resistance to environmental factors (humidity, temperature). The effect of high temperature on wood causes a decrease in water adsorption by reducing the available free hydroxyl groups of carbohydrates. The reduction in hygroscopicity contributes to the treated material size stability, as swelling and shrinkage are mainly associated with the phenomena of absorption and water desorption. The study of natural weathering always takes many years. Therefore, to study the resistance of thermodified wood to environmental influences, artificial weathering is used - modeling of external factors (cyclic change of UV light and moisture). The effectiveness of the thermodified veneer use as a material for lining the furniture facades which working in different temperature and humidity conditions was established. The values of moisture and water absorption on the samples of oak veneer, which have previously undergone the heat treatment process, have been determined. It was found that the samples of oak veneer gained the most moisture from the environment in the first two days. The weight of unmodified veneer increased by 0.06 g, similar results showed veneer modified at temperatures of 160 and 190 °C. Thermodified veneer at a temperature of 250 °C for the first two days gained twice less. By the end of the experiment (next 11 days), the samples of ordinary and modified veneer at all temperatures absorbed the same amount of moisture. Untreated veneer and thermodified at temperatures of 160 and 220 °C absorbed 50-66 % of its initial weight, and modified at 250 °C – 20-36 %. Control samples of veneer during the determination of water absorption gained 98 % of the initial weight. Samples modified at 160 °C – 10, 20, 30 min showed the best result – reducing the value to 94 %, 93 % and 91 %. There is a slight improvement in water absorption after exposure to temperature 220 °C for 10, 20, 30 min – 91 %, 91 % and 90 %. Values water absorption at the level of 90 %, 89 % and 86 % were recorded in veneer samples modified at 250 °C.

Research of technological processes of manufacture of legs of dining tables of various designs

A technical description of the legs of dining tables of various designs with the texture of oak wood with the following dimensions of 750 × 52 × 52 mm. A method for studying the production processes of production of dining table legs of various designs with the texture of oak wood. Necessary materials have been calculated to make three types of dining table legs with oak wood texture. The necessary equipment has been calculated and the routes of technological processes have been developed and the planning of the shops has been presented in order to make three varieties of modern dining table legs with oak wood texture. The comparison of technological processes of making dining table legs with the texture of oak wood is made. You have determined the rational technological process of making the legs of dining tables. It is estimated that the third option for making dining table legs with a wood texture of square cross-section is optimal, where the cost of equipment is 817.25 thousand UAH, the number of employees 10 people, total power is 34.8 kW. It should also be noted that the third option generates the least wood waste and residues, in particular in the amount of 103.37 m3, and the cost of materials for a set of legs in the amount of 4 pieces is the lowest, amounting to UAH 312, which is much less than other options. The highest value of economic efficiency is the third option of investment, which is 0.208. The payback period for this option is 4.8 years. Therefore, the technology of making dining table legs is recommended, in which the base is made of three laminated rails with chipboard with a thickness of 16 mm with a square cross section of 48 (16 × 3) × 48 mm, and the shank with a cross section of legs made of planed oak veneer with a thickness of 2 mm.

Selected Properties of Overlaid Magnesium Based Composite Panels for Flooring

The objective of this work was to evaluate some of the mechanical and physical properties of the flooring materials manufactured from panels having magnesia substrate overlaid with oak veneer (Querqus alba) and linoleum sheets. Commercially manufactured panels were used in this work. Bending characteristics, internal bond strength, thickness swelling, and surface quality of the samples were evaluated. The highest modulus of elasticity (MOE) value of 4406 MPa for the sample type-A2 was loaded in the direction of the substrate followed by 3478 MPa for linoleum covered samples which were loaded in the same direction. Internal bond strength values of the panels did not show any significant differences from each other. Dimensional stability of the specimens in the form of thickness swelling for both 2-h and 24-h water soaking tests resulted in values ranging from 0.11 to 0.19%. The surface quality of the samples was not substantially influenced as a function of water exposure. Based on the results in this work magnesium substrate overlaid with oak veneer and linoleum panels could have potential to be used as flooring material with accepted properties.

Impact of pressing regime and substrate type on bond quality of decorative veneer

The choice of optimal pressing regime for certain types of substrate is of great importance in production of veneered panels. In this paper, the impact of pressing regime on the bonding strength of beech and oak veneers, glued with urea-formaldehyde (UF) adhesive, on medium-density fiberboard (MDF), and moisture-resistant MDF (MR MDF) substrates was examined. The analyses showed a generally higher bond strength with oak veneer compared to beech veneer, which was also the case with regular MDF compared to moisture-resistant MDF. Multivariate analysis of variance (ANOVA) showed that with beech veneer, all of the used regimes produced better results on regular MDF compared to moisture-resistant MDF. In contrast, with oak veneer, the influence of pressing regime had a more noteworthy impact than the type of substrate used. These results indicated that the use of MR MDF as substrate in combination with UF adhesive was inadequate.

Polyglycerol- and sucrosebased green polyurethane adhesives for veneering

Veneering of particleboard with ABS foil and natural oak veneer was performed using polyglycerol- and sucrose-based polyurethane adhesives. Bonding strength between veneer and underlying board was determined according to EN 312 standard. Developed adhesive formulations exhibited bonding strengths between coating material and underlying board exceeding the surface soundness of particleboard (cohesive failure between 50 % and 100 %). Higher adhesion was found for natural oak veneers. Reactivity of the studied adhesives was comparable to those for commercial adhesives used in furniture industry. It has been demonstrated that biobased polyols can be considered environmentally benign and efficient components of polyurethane adhesives for furniture industry.

Results of experimental researches into process of oak veneer drying in the solar dryer

A new design of solar drying plant with the active solar energy system is developed. It is proposed to use the K1-102 automated control system to diagnose the key parameters of air exchange in the solar dryer and to predict the intensity of heat exchange processes of oak veneer drying. This allows increasing the technological and power efficiency of the process of oak veneer drying in the solar dryer 2 times. The regularities of the influence of the physical parameters of the environment and weather-dependent factors on the heat, mass, and moisture exchange processes of oak veneer drying in the solar dryer are determined. Estimation of energy, kinetic and dynamic parameters of the oak veneer drying process is given. The duration of the drying process in the solar dryer is experimentally determined. Performance characteristics of the drying object are investigated, depending on the set technological tasks (heating or drying) under standard insolation and meteorological conditions. It is found that it is necessary to regulate air exchange, moisture release, rational moist coolant removal, solar energy flow in relation to the predicted changes in the minimum and maximum variation peaks of weather-dependent factors. This is important for intensifying the oak veneer drying processes and reducing the specific power consumption of the drying process due to solar energy. The obtained results can be used in the development and improvement of technical means of oak veneer drying, to improve the technological and power efficiency of the process

Factors influencing the production of structural plywood in Tasmania, Australia from Eucalyptus nitens rotary peeled veneer

Harvested logs supplied from five fibre-managed Eucalyptus nitens plantation coupes with different growing environments were assessed for quality and stiffness. Billets extracted from the logs were rotary peeled for veneer. When averaged across the five coupes, 30% of veneer recovered could be used directly in structural plywood production and an additional 20–25% could be used after further processing. In visual assessment most veneer was assigned an Australian/New Zealand Standard AS/NZS2269.0:2012 Quality D. Acoustic testing during processing showed veneer peeled from a drier and lower elevation coupe had significantly higher dynamic MOE values than veneer processed from logs harvested from wetter higher elevation coupes. To examine the utility of the E. nitens peeled veneer in the production of structural plywood, it was combined with veneer of a known higher stiffness, rotary peeled from regrowth forest Tasmanian oak species logs. Structural seven-ply panels were manufactured from the veneer prepared in three different ply arrangements. Mechanical testing of the panels in accordance with AS/NZS2269.0:2012 showed that an F17 target stress-grade panel product of 83% E. nitens and 17% Tasmanian oak species could be produced, if E. nitens veneer of higher stiffness were selected from veneer segregated by estimated dynamic Modulus of Elasticity value. Panels with 50% E. nitens and 50% Tasmanian oak veneer could be produced by selecting E. nitens veneer of lower stiffness after segregation. In the majority of panels tested stress-grade rating was limited by perpendicular bending strength. Outcomes from the study indicate that structural plywood can be manufactured using differing proportions of E. nitens veneer, rotary peeled from fibre-managed plantations, provided it can be segregated into stiffness categories and selected to achieve a target stress-grade.

The influence of log defects on the cutting yield of oak veneer

The quality of logs entering the production line is important because it controls the quality and yield of veneer. In Romania, Quercus species represent 18% of the total forests, and of which 2% is exclusively the pedunculate oak. The wood of pedunculate oak is hard and elastic, and it has a good natural durability. Due to such features it also has multiple uses in the furniture industry, construction, joinery, and cooperage works. The present work highlights the influence of some characteristics of the raw material on the cutting yield of veneer in the case of pedunculate oak logs purchased from different regions. Defects in the raw material had a certain negative influence on the veneer quality. The defects were identified and prioritized using the Pareto diagram.

Influence of Sessile Oak Log Characteristics on the Efficiency in Veneer Cutting

The sessile oak tree represents 10.5% of the forest area in Romania and is the most widespread indigenous oak species. To select the most suitable domain of use for sessile oak wood, certain dimensional and qualitative criteria were taken into consideration. The aim of the present study was to highlight the influence of some log characteristics (wood diameters and quality) on the efficiency in sessile oak veneer cutting. The authors used a group of sessile oak logs purchased from Targoviste in Southeast Romania. The results analysis indicates the influence of sessile oak log diameters on the veneer efficiency comparative with decorative veneer efficiency by estimation of the cumulative density function (CDF). Analyzing the quality of sessile oak logs, it was found that buds and insect holes were the most important defects that appeared. Also, the regression analysis indicates an acceptable level of the present defects and did not have a significant influence to the veneer cutting efficiency, upon the number of obtained veneer sheets and the surface area of special veneer sheets, respectively.

Properties of Veneered Flat Pressed Wood Plastic Composites by One-Step Process Pressing

The aim of this study was to develop, manufacture and determine properties of veneer overlaid flat pressed wood plastic composite (WPC) panels from recycled low density polyethylene (rLDPE), wood particles and different kinds of veneer (rotary-cut birch veneer and sliced oak veneer) using various adhesives by one-step hot pressing. Food packaging polyethylene film (PE film) as recycled stretch wraps, recycled low density polyethylene (rLDPE) particles and phenol formaldehyde (PF) resin were applied as adhesive for the bonding of veneer to the surface of WPC. No modification additives were used for the manufacture of WPC. It was found that compared with non-veneered WPC, the panels sandwiched with natural veneers greatly improved their properties. The bending strength was improved in 1.9–2.6 and 7.9–10 times across and along veneer fibers respectively for both types of investigated veneer. The highest values of bending strength were observed in WPC panels veneered with rotary-cut birch veneer. However, the water resistance of veneered WPC panels was reduced in comparison with non-veneered. The WPC specimens veneered with both types of veneer using PE film had better mechanical properties and water resistance than those of the specimens made with other two types of adhesives. The veneering of WPC panels enables to significantly improve adhesion properties of these veneered surfaces for their further finishing. In addition, the veneering of WPC panels hides the surface defects and provides a uniform application of different paints, varnishes and films to the surface of such materials. Overlaying WPC panels with wood veneers improves their appearance and properties resulting in eco-friendly value-added products.

Evaluation of Color Variability of Oak Veneers for Sorting

Veneers are used as overlaying material for various types of composite substrates for the production of veneered panels and furniture. There is a strong correlation between color and quality for the acceptability of a product, which is currently an industrial preoccupation. The aim of the present study was to evaluate the color variability of veneers produced from high-quality European oak logs exhibiting the best production yield. Defect-free logs cut from a Quercus spp. forest in Romania were sliced into veneers. Color measurements were made at various locations on veneer sheets. All data were statistically analyzed. As expected, heartwood highly influenced the final color of decorative oak veneers, in which yellow and red were highlighted. The statistical analysis also revealed the homogeneity of lightness and yellow degree within the veneer collectivity. The color homogeneity within the sectors confirmed the wood quality for veneer production. Therefore, individual veneer sheets can be segregated based on color measurement to provide accurate results for sorting pieces of different colors.

Wettability and Impact Performance of Wood Veneer/Polyester Composites

Fiber-reinforced thermosetting composites have been of interest since the 1940s due to their ease of use in processing, fast curing times, and high specific stiffness and strength. While the use of plant fibers in a polyester matrix has been thoroughly studied, only limited information is available regarding using wood as reinforcement. In this study, composites of thin wood veneer and a polyester matrix were made and the difficulties in the lamination and curing processes were investigated. Sheets of Douglas fir, maple, and oak veneers using a catalyzed polyester resin were assembled as unidirectional, balanced, and unbalanced cross-ply laminates. These were compared to control specimens using glass fiber as reinforcement. The impact properties of the samples, with respect to the laminate thicknesses, were characterized using a drop-weight impact tester. The wettability and surface roughness of unsanded and sanded wood veneers were also investigated. Results showed that Douglas fir cross-ply laminates had an impact energy equivalent to glass fiber laminates, making them an interesting alternative to synthetic fiber composites. Wood/polyester laminates absorbed a considerable amount of energy through a higher number of fracture modes. The balanced lay-up limited twisting of the wood/polyester composites. The lowest contact angle and highest wettability were observed in unsanded Douglas fir veneers.