Wood Grain Research Articles

Surface Morphology and Chemical Changes of Maple and Beech Cut Through by CO2 Laser Under Different Angles Relative to the Wood Grain

This paper examined the surface morphology of maple and beech cut through by CO2 laser under different angles relative to the wood grain: 0°, 15°, 30°, 45°, 60°, 75°, and 90°. In the analysis, stylus measurements, stereo-microscopic images, and chemical changes were considered. Laser uncovers more wood anatomical details, with enhanced clarity, when the cutting transitions from along the grain to across the grain. This is particularly noticeable in the earlywood and is more pronounced in maple compared to beech. The first tissue of earlywood was deeply ablated by the laser, leading to a wavy anatomical pattern, which is more visible for higher angles of laser cutting in relation to the wood grain. The anatomical structure of beech was more affected by carbonization in comparison to maple and had a significantly higher core roughness, Rk. For both species, the worst surface roughness occurred when cutting at 15°. In maple, the laser caused more degradation of the polysaccharides compared to beech, and this impact was particularly noticeable parallel to the grain rather than at a 90° angle. The degradation of hemicelluloses occurred in parallel with more advanced cellulose degradation for beech compared to maple and for cutting along the grain compared to across the grain. Structural changes in lignin, such as condensation processes, were observed for both species.

Effect of Two Pomelo Peel Flavonoid Microcapsules on the Performance of Waterborne Coatings on the Surface of Poplar Boards

Two types of microcapsules were added to the coating separately. The specifications of the poplar board were 50 mm × 50 mm × 8 mm. The antibacterial rate of the poplar board surface gradually increased with the increase in the microcapsule content, and the antibacterial activity for Staphylococcus aureus was slightly higher than that against Escherichia coli. Influenced by the change in the wood grain’s color on the poplar board itself, both microcapsules had no significant effect on the chromaticity value and color difference of the poplar board surface, as well as the reflectance of the visible light band. The glossiness decreased with the increase in the microcapsule content, and the gloss loss rate increased with the increase in the microcapsule content. With the increase in the microcapsule content, the hardness of the poplar board surface in both groups increased slightly, and the roughness increased gradually. The adhesion of the poplar board surface coating with melamine-resin-coated pomelo peel flavonoid microcapsules was slightly reduced, and the impact resistance was not significantly affected. Chitosan-coated pomelo peel flavonoid microcapsules had no significant effect on the adhesion of the poplar board surface coating, and the impact resistance increased slightly when the content of microcapsules was higher. Comprehensively, the poplar board coating with 9.0% chitosan-coated pomelo peel flavonoid microcapsules had a better overall performance, with antibacterial activities for Escherichia coli and Staphylococcus aureus of 70.6% and 77.6%, respectively. The color difference was 6.70, the gloss loss rate was 53.9%, the reflectivity was 50.60%, the hardness was H, the adhesion was grade 1, the impact resistance was grade 2, and the roughness was 2.10 μm. The results provide technical references for the application of antibacterial microcapsules of pomelo peel flavonoids on the surface of wood materials.

Impact of Wood Structure Variability on the Surface Roughness of Chestnut Wood

Wood constitutes a unique and valuable material that has been used from ancient times until nowadays in a wide variety of applications, in which the surface quality of wood often constitutes a critical factor. In this study, the influence of different wood areas and therefore, of different anatomical characteristic areas of chestnut wood (Castanea sativa Mill.) on the surface quality, was thoroughly studied, in terms of surface roughness. Five different chestnut tree trunks were harvested, from which five different disks were obtained corresponding to five different trunk heights. Surface roughness was measured on these disks on the transverse, radial, and tangential planes, on the areas of sapwood and heartwood, measuring the roughness in each point both vertically and in parallel to the wood grain. The results revealed that the examined roughness indexes (Ra, Rz, Rq) follow a parallel path to one another. In the case of all surfaces (transverse, radial, tangential) of the disks examined, when the measurement was implemented perpendicularly to the wood grain, a significantly higher roughness was recorded, compared to the wood grain measurements being implemented in parallel with the wood grain. Significant differences between heartwood and sapwood roughness were not demonstrated, although sapwood often appeared to exhibit a higher surface roughness than heartwood sites. Among the roughness values of the three different surfaces, the highest roughness in the vertical-to-wood-grain measurements was recorded by tangential surfaces, with slightly lower values on the transverse surfaces and the lowest roughness on radial surfaces. Meanwhile, for the measurements in parallel with the wood grain, the transverse surfaces presented significantly higher roughness values compared to the tangential and radial surfaces. Significant roughness differences were not detected among the surfaces at different trunk heights. Although, significant differences in roughness were recorded among different trees, it was observed that all the studied trees align with the identified and described within-tree trends.

Increasing Mannequin Diversity in Museum Exhibitions to Address Social Equity

For too long, museums have used thin, white mannequins as the standard for body surrogates in dress and textile exhibitions. This article explores some of the issues surrounding this practice and the message these objects may convey. As an actionable step towards social equity, it offers an alternative called the “Forest People” that aims to address issues of diversity and inclusion in curatorial and display practices. Inspired by tree diversity, the Forest People is a solution that draws from the past to create a new version of artists’ wooden lay figures. It replicates different wood colors and grains and can lend itself to presenting a variety of different races while still fading in the background and conveying an aesthetically pleasing and visually coherent ensemble. The article reflects on the development of a prototype for the exhibition Woven Identities: Ghanaian and Guatemalan Textiles in the Face of Globalization (2023) at the University of Alberta, and its effectiveness and potential developments.

Effect of changes in surface visual properties of heat-treated wood on the psychological preference

Heat treatment of wood is an attractive, environmentally friendly modification, which can change surface visual properties of wood including color and grain, but it is unclear how heat-treated wood is perceived and evaluated compared with untreated wood. In this paper, Chinese fir was heat-treated at 160, 180, 200, or 220 °C for 2 or 4 h. The changes of wood surface color and grain contrast were measured. A subjective questionnaire and eye-tracking technology were used for psychological evaluation. The results showed that changes in the visual properties of heat-treated wood had a significant effect on psychological preference—heat-treated wood was generally more preferred than the untreated, particularly at 200 °C for 4 h. Grain contrast and hue played an important role in the preference for heat-treated wood. The preference gave people the positive psychological impression of warmth, weight, cost, prevalence, and comfort. Eye-tracking analysis showed that Chinese fir heat-treated at about 200 °C with high hue value and clear grain contrast was easier to gain more visual attention. The results would have a high technical reference value for the heat-treated wood in product visual design.

Cutting with Circular Saw of Traversal-Structured Panels Obtained from Spruce (Picea abies L.) Branches

Finding new wood resources is a permanent challenge nowadays, especially due to the fact that there is a crisis of these resources through the continuous degradation of forest areas that can be exploited. In this general context, the use of spruce (Picea abies L.) branches to create panels with a transverse texture becomes the main purpose of this research. Going beyond the current stage of research in the field, this research highlights the particularities of cutting panels with a transverse texture made from spruce branches, especially due to the cutting direction compared to the wood grain. In addition to the activities of collecting and sorting the branches, processing and joining, in order to obtain dimensionally stable panels, the workability of these panels with a transverse texture represents a new challenge in this field. The work methodology was based on the effective measurement of the cutting and advance power during cutting with a circular blade. The obtained results referred to the comparison of 10 working regimes from the point of view of the electrical power consumed, according to the two main parameters taken into account, which are the rotational speed of the circular blade and the advance speed. The final conclusion of the work highlighted the fact that the processing of panels with a transverse structure requires specific work regimes, namely an optimal regime of electric consumption of 2.2 kW, at a cutting speed of 79.2 m/s and an advance speed of 3.7 m/min.

Multiproxy palaeoenvironmental reconstruction of the Bathonian Castelbouc sauropod tracksite (Causses Basin, southern France): Insight into a Middle Jurassic insular ecosystem

We report lignitic fossil rich-beds from the Bathonian Castelbouc sauropod tracksite (Castelbouc Cave N°4, Causses Basin, southern France). Showing the co-occurrence of amber with plant, vertebrate and invertebrate remains, they are a precious tool to reconstruct Middle Jurassic dinosaur ecosystems. A multiproxy approach combining sedimentology, petrology, mineralogy and palaeontology led to determine that these fossil rich-beds were deposited in a range of insular coastal palaeoenvironments. They include protected backshore areas such as freshwater/brackish ponds and brackish bay/lagoon showing co-occurrence of terrestrial and marine inputs. The backshore environments were particularly rich in ostracods (Darwinula sp., Fabanella bathonica) and gyrogonites of charophytes (Porochara douzensis). The abundance of conifer remains including leafy axes (Brachyphyllum), cones (cf. Classostrobus), wood (Brachyoxylon) and pollen grains (Classopollis) shows that ponds and bay/lagoon were bordered by conifer-dominated forests in which Cheirolepidiaceae were the main component. Such a rich and relatively diverse flora was probably an attractive source of food for megaherbivorous dinosaurs. Vertebrate microremains mostly consist of fish scales (Ginglymodi indet.) and crocodylomorph teeth (Atoposauridae indet.), two groups that are common components of Middle Jurassic paralic faunas. The palaeobotanical assemblage suggests a warm subtropical climate probably tropophilous with marked alternation between a wet and a dry season.

Influence of the depth of friction-welded dowels on the strength of rotary welded joints

One of the important factors in rotary welding is the depth of welding of the dowel as well as the direction of welding of the dowel. In the studied interval (welding depth of 15 to 30 mm), the pull-out force increased when welding the dowel parallel to the wood grain and perpendicular to the wood grain. The strength of the welded joint increased from 15 to 20 mm, and then it continuously decreased towards a welding depth of 30 mm. The reason for this is that the tip of the dowel is intensively worn, and with a welding depth of 20 mm, it is approximately equal to the diameter of the hole. Therefore, by increasing the welding depth, the pull-out force increases slightly (due to the friction between the dowel and the hole wall), and the strength of the joint decreases. The highest joint strength was achieved at a welding depth of 20 mm for specimens welded parallel to the grain (PV) and specimens welded perpendicular to the grain (RTV). In welded joints where the dowels are loaded only by tensile force, it is recommended to use a welding depth of 30 mm.

Development of craquelure patterns in paintings on panels

Panel paintings are multi-layer structures composed of humidity-sensitive materials. Preventing or limiting stresses in these structures, generated by the loss or gain of moisture, requires an understanding of the relevant processes and risks. A three-dimensional elastic model of a panel painting was used to analyse surface stresses and understand how crack patterns are developed in the two-layer structure of the pictorial layer—the gesso and the paints. Two historically important paint types were considered—egg tempera and oil paints, laid on a gesso produced following historical procedures. Two scenarios of stress development were analysed: permanent cumulative drying shrinkage of paints or gesso, owing to gradual loss of water or evolution of the molecular composition of the binders, and moisture-induced cyclic swelling of the wood substrate. Ratios of distances between cracks in the tangential and longitudinal directions of a wood panel to the layer thickness were estimated for increasing magnitudes of materials’ dimensional change in the two scenarios. The critical values of the ratios for which stress in the midpoint between the cracks dropped below the value inducing strain at break in the materials and saturation of the crack patterns occurred, was approximately 3–4 or 5–6 for the paints and the gesso, respectively. The critical distance normalized to the gesso thickness between cracks parallel to the wood grain induced by cyclic swelling of the wood substrate due to relative humidity variation in the range of 50–70% was 6. The study demonstrated that crack spacings in the fully developed crack systems remain sensitive only to the thicknesses of paint or gesso layers which, therefore, can be derived from the crack pattern geometry. Existing flaws in gesso were found not to increase the risk of new crack development.

Study on the Process Optimization of Peanut Coat Pigment Staining of Poplar Wood

Wood staining is a crucial technique for enhancing the decorative effect of wood. Different mordants and mordant processes can influence the staining effect of wood. In this study, three types of mordants and mordant methods were selected to improve the color difference and colorfastness to the washing of poplar veneer, using green peanut pigment as the dye. An orthogonal test was conducted to investigate the effects of mordant temperature, mordant time, and mordant concentration on color difference and colorfastness to washing. Range and variance analysis were employed to determine these properties’ main factors. A fuzzy comprehensive evaluation method was used to evaluate and optimize the color difference value and colorfastness of washing. The results revealed that all three factors had significant impacts on both color difference and colorfastness to washing during the process of mordant staining. The optimal process conditions (temperature, concentration, time) for achieving desirable staining effects on poplar veneer were determined as 50 °C, 0.8%, and 2 h, respectively. Furthermore, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses demonstrated that the dye formed complexes with poplar wood, enabling it to adhere to wood grain apertures and tube walls effectively. Mordant treatment increased the crystallinity of stained wood significantly while improving its overall staining performance considerably. This study provides substantial data support for future optimization processes involving natural pigment coal staining in wood.

Documenting Border Barriers

Documenting Border Barriers is an ongoing research-based artwork in etching and relief printmaking that addresses the exponential rise in fences and walls that have been built on the borders of nations and territories to keep people out. Each print details a specific border barrier in the world today, based on documentary photos, texts, and reports.
 The technique combines drypoint etching and relief printmaking. Drawings are scratched into a rectangular plexiglass plate using an etching needle and abrasive tools. A thick ink is then spread on the scratched surface and wiped clean, leaving ink in the abrasions. Finally, the plate is pressed on paper with a manual etching press. Surrounding details are omitted to portray the razor wire, cement, and steel with visceral immediacy. An impression of landscape and sky are evoked with an under-printing of wood grain patterns. In some prints, printed window screen creates the impression of chain link. The prints, each unique in detail yet similar in composition, bear witness to the violent policies of exclusion and lack of concern for the lives of people on the move.

On the high fracture toughness of wood and polymer-filled wood composites – Crack deflection analysis for materials design

Cracks oriented in the toughest direction across the grain of wood (0°) tend to deflect at 90° to the precrack rather than extending in 0° direction. Fracture toughness data across the grain are therefore difficult to interpret. Crack growth mechanisms and effects from replacing wood pore space with a polymer are investigated. Crack growth is analyzed in four-point bending fracture mechanics specimens of birch and two different polymer-filled birch composites using strain-field measurements and finite element analysis (FEA). Calibrated cohesive zone models in both precrack and 90°-directions describe fracture process zone properties in orthotropic FEA-models. Conditions for 0° crack penetration versus 90° crack deflection are analyzed based on cohesive zone properties. Stable, subcritical crack deflection takes place at low load, reduces crack tip stress concentration, and contributes to high structural toughness, provided the 90° toughness is not too low. Polymer-filled neat birch composites have the best structural toughness properties in the present investigation, since 90° toughness is not compromised by any chemical treatment.

Texture Inspection using the Voice Based Biometric Authentication in the Quantum Computation

Texture inspection has remained an important substance throughout the whole history because with the advances of the mobile graphics and many hardware, high-quality image processing for the basic wood texture in the Wolfram mathematical. We also used wood in the building material and household furniture to find out the type of wood that can be used as a specific material and to help in the development of the different wood texture in the android studio. Cedar is a fibrous and a porous structural tissue found in the roots of trees and other woody plants. The colour of the wood has been depend on the reflection of the most important component of the wood grain may be the process of refining or protection of the wooden surface in the production of the manufacturing cost 5 and 30%. Various Woods textures having the appearance of the wood that require the wood joints for the great variation between sapwood and heartwood.

Effect of Wood Specimen Length on Uniaxial Stress–Strain Curve along the Grain Direction

Abstract The axial compression test was carried out on the basis of three different-size specimens of white wax (Fraxinus chinensis), fir (Abies fabri), and Yunnan pine (Pinus yunnanensis) to explore the influence of specimen length on the compression strength parallel to grain, peak strain, and elastic modulus of wood. Weibull’s weakest-link theory, Bazant’s law of size effect, and Carpinteri’s multiple fractal size effect were used for the analysis. The results showed significant size effects on theses parameters of wood along the grain. Using the three theories to predict the compressive strength of 100-mm-length specimens, the predicted value of Bazant’s law of size effect has the smallest error with the measured value, followed by Weibull’s weakest-link theory and Carpinteri’s law of multiple fractal size effect. The size-effect coefficients of the down-grain compressive strength of the three woods obtained using the slope method were 0.06, 0.11, and 0.09, respectively, which were consistent with the values of m in the Weibull fitting function.

Impact of surface finishing technology on slip resistance of oak lacquer wood floorboards with distinct gloss levels

ABSTRACT The choice of surface finishing technology for floorboards can significantly influence the risk of slipping. This study aimed to assess the impact of surface finishing technology on the likelihood of slippage, focusing on lacquered floorboards made of northern red oak (Quercus rubra L.). Four finishing methods were applied to the floorboard surfaces, with the primary distinction between the tested variants being the level of glossiness in the top layer, ranging from 3 to 20 gloss units (GU). To evaluate slip risk, tests were conducted using the British portable skid resistance tester (BSRT), providing numerical values in the form of the British pendulum number (BPN) and the slip resistance value (SRV) for qualitative comparisons. The analyses revealed that depending on the type of lacquered wood surface layer, the difference in BPN could vary from 46% to 77% for dry tests and from 48% to 60% for wet tests. Matte lacquer finishes, specifically at 19 GU, exhibited the smallest slip risk, while glossy finishes (4 GU) demonstrated the greatest slip risk, especially when the surface was wet. In terms of wet test results, the least slip risk, regardless of wood grain direction, was observed for variant No. 4 (low glossiness at 4 GU), with an SRV value ranging from 51 to 53. Conversely, variant No. 1 (high gloss at a mean of 19 GU) recorded the poorest slip resistance properties, with an SRV between 29 and 31. These findings suggest that matte lacquer finishes generally provide a safer option compared to glossy finishes, and the inclusion of brushing during production can enhance slip resistance. Furthermore, the direction of the wood grain was identified as a contributing factor to slip risk, with a 0° grain orientation presenting the highest risk. These insights can be valuable for flooring manufacturers and installers in selecting and applying finishes that effectively minimize the risk of slipping. These findings can be used by flooring manufacturers and installers to select and apply finishes that minimize slip hazard.

Experimental Study of Physical Properties of Laminated Veneer Lumber Made by Three Cameroonian Hardwoods with Two Adhesives

This work deals with the determination of some properties of laminated veneer lumber (LVL) made from tropical hardwoods, specifically focusing on Cameroonian woods. The LVL samples are manufactured using veneer from three tropical wood species: Ayous, Ilomba, and Bete. Two types of adhesives are used: a neoprene contact adhesive (Magpow) and a white vinyl adhesive (Nemo). The specimens have undergone multiple drying cycles, and hundreds of samples from each species have been selected with dimensions of 1 cm × 1 cm × 1 cm. These samples are then machined according to the specific wood grain of each species. The experiments conducted aim to determine properties such as moisture content, densities, volume swelling, shrinkage coefficients, and the hygroscopic point of equilibrium of the samples. Swelling and shrinkage measurements allow for the visualization of sample dimensions in relation to humidity levels, and the hysteresis of the adsorption phenomenon of the LVL is also obtained. The results show that regardless of the type of adhesive or veneer used, LVLs are denser than the wood they are made from. For each type of LVL, the ratio between the mass of a sample saturated in water and the mass of the dried sample remains constant. The rule of mixture is investigated, and the density properties of materials and the vacuum rates of LVL samples are compared with experimental data.

Sensitivity of lap-shear test to errors in groove cutting and influence of wood type/treatment

EN 302-1 and EN 205 are among the most commonly used standards for the approval as well as research of wood adhesives to evaluate bond strength. The present study investigates the sensitivity of the lap-joint samples to a possible error in groove cutting as well as the influence of using steam-treated and untreated beech wood on tensile shear strength. The lap-joint specimens cut with 0.5 mm too shallow and 0.5 mm too deep grooves was compared with samples cut precisely within the tolerances mentioned in the standards. A comparison of tensile shear strength between the joints manufactured out of steam-treated and untreated beechwood has been made.The results show a significant influence of groove depth on the resulting tensile shear strength. While deep groves (+0.5 mm) underestimate, shallow grooves (−0.5 mm) overestimate it dramatically. Additionally, the joints with steam-treated beech wood delivered lower tensile shear strength than those of untreated beech wood bonds when there is a considerable wood failure percentage. When the ultimate tensile shear strength of the adhesive bond approaches the shear strength parallel to the grain of wood, the impact of steam-treated beech wood on the estimation of adhesive bond strength is higher.

Non-Destructive Evaluation of Downy and Silver Birch Wood Quality and Stem Features from a Progeny Trial in Southern Sweden

This study investigated whether improved downy birch could perform as well as improved silver birch, and whether there was sufficient genetic variation and control for non-destructive testing (NDT) values to include them as selection traits in breeding programs. NDT tools were applied to a 15-year-old downy birch family trial intermixed with improved silver birch. Average diameters, fissured bark height, and grain angle were higher for silver than downy birch. The genetic analysis for downy birch provided estimates of narrow-sense heritability (h2) for acoustic velocity and Pilodyn penetration depth that were above 0.3 but had low genetic variation. Grain angle had relatively high genetic variability (18%) and an h2 of 0.20. A subsample of 49 trees had 4 mm cores x-rayed for wood density estimates, and 34 stems had 12 mm cores macerated for cell measurements. t-tests revealed that average wood density and cell measurements were not significantly different between species. For silver and downy birch, fiber length and vessel length increased between inner and outer measurement positions, and fiber length was reasonably correlated with acoustic velocity. Silver birch tended to have denser and stiffer wood, while downy birch had less rough bark and straighter grain, and these results are in agreement with existing knowledge. The h2 values were similar to those observed in other birch species and indicate there is potential to breed for improved wood density and grain angle in downy birch.

Exploring Architectural Shapes Based on Parametric Shape Grammars: A Case Study of the “Three Lanes and Seven Alleys” Historic District in Fuzhou City, China

With the development of information technology, the introduction of information technology into architectural modelling and façade design and the systematic definition of historic districts is a problem that the architectural industry continues to explore and pursue. As a shape-based and self-defining generation rule, shape grammar provides significant help in the process of the automatic generation of architectural shapes to obtain design results that meet the requirements of the original historic district. Based on the simple combination of the application of shape grammar in architectural design, combined with the field investigation method, the representative buildings in the “Three Lanes and Seven Alleys” historic district are investigated and understood in detail, and the corresponding shape grammar rules are established. The courtyard types of the historic district are divided into: “” shape, “T” shape, “=” shape, “” shape, “” shape, “” shape, “” shape, “U” shape, “” shape, and garden. In detail, the façade components include the entrance, patio, main seat, wings, cloister, pavilion, etc. The elements of its façade include saddle walls, grey sculptures, carved stones, grey tiles, wooden grilles, wooden railings, wood grain flowers, etc. On this basis, parametric design is introduced to convert the design syntax into parametric programs. Grasshopper in Rhino is mainly used to visualize and simulate the regulation, and finally, achieve the purpose of automatically generating the architectural shape and façade of the “Three Alleys and Seven Alleys” historic district by adjusting its parameters.

OPALIZED WOOD FROM CLOVER CREEK, IDAHO: HOW AN 1895 FOSSIL TREE DISCOVERY BECAME THE STANDARD OF QUALITY FOR WOOD-OPAL IN MINERALOGICAL COLLECTIONS

ABSTRACT Opalized oak specimens with striking beauty, attributed to Clover Creek, Lincoln County, Idaho, can be seen in numerous museums around the world. Even the casual observer notes the fossil wood grain, reminiscent of modern oak. The provenance of these ‘golden oak’ specimens was a small, unique deposit. Historical documents, photographs and oral histories provide insights into the 1895 fossil discovery, its subsequent excavation, promotion, and distribution. Land surveys in the years immediately following Idaho statehood in 1890 are linked to the fossil discovery. Local farmers, related by marriage, excavated and promoted the fossil wood. A spectacular longitudinal cut specimen was featured on the cover of A. E. Foote’s 1897 mineral catalog. Archived correspondence establishes that specimens were promoted privately before being offered publicly. Current research indicates some specimens suffered fungus damage while the tree was alive. Previously unknown museum specimens are described and incorporated into a hypothetical reconstruction of the fossil tree.