Wood Stain Research Articles

Architecting layered double hydroxides: Exploring their structural mastery and transformative influence on wood staining

Traditional wood staining processes involve the extensive use of inorganic salts and fixing agents. The exploration of a low-concentration yet highly efficient wood staining method is crucial for the low-carbon, environmentally friendly, and high-quality development of wooden products. In this study, we employed metal-organic framework (MOF) as precursors for layered double hydroxides (LDHs), achieving control over the coloration of poplar wood towards a blue-green hue through the hydrolysis-induced exchange between MOF and hydroxide ions, using an ultra-low concentration (0.016 mol/L) Cu2+ solution. Exploiting the unique micro-nano structure of LDHs and their anion exchange properties, we successfully engineered a superhydrophobic surface (WCA=151.8°) for wood by introducing hydrophobic long chains. The resulting stained wood exhibited superior water resistance, self-cleaning ability, wear resistance, resistance to UV aging, and mold prevention. A key highlight of our preparation process lies in the utilization of extremely low concentrations of metal ion solutions, emphasizing its environmentally friendly, efficient, and multifunctional characteristics. This research provides a novel and efficient green staining approach for wood, opening up new avenues for the high-quality and sustainable development of wood materials.

Training of a Neural Network System in the Task of Detecting Blue Stains in a Sawmill Wood Inspection System

This article presents the operation of an automatic pine sawn timber inspection system, which was developed at the Woodinspector company and is offered commercially. The vision inspection system is used to detect various wood defects, including knots, blue stain, and mechanical damage caused by worms. A blue stain is a defect that is difficult to detect based on the color of the wood, because it can be easily confused with wood defects or dirt that do not impair its strength properties. In particular, the issues of detecting blue stain in wood, the use of artificial neural networks, and improving the operation of the system in production conditions are discussed in this article. While training the network, 400 boards, 4 m long, and their cross-sections of 100 × 25 [mm] were used and photographed using special scanners with laser illuminators from four sides. The test stages were carried out during an 8-hour workday at a sawmill (8224 m of material was scanned) on material with an average of 10% blue stain (every 10th board has more than 30% of its length stained blue). The final learning error was assessed based on defective boards detected by humans after the automatic selection stage. The system error for 5387 boards, 550 m long, which had blue staining that was not detected by the scanner (clean) was 0.4% (25 pieces from 5387), and 0.1 % in the case of 3412 boards, 610 mm long, on which there were no blue stains, but were wrongly classified (blue stain). For 6491 finger-joint boards (180–400 mm), 48 pieces were classified as class 1 (clean), but had a blue stain (48/6491 = 0.7%), and 28 pieces did not have a blue stain, but were classified as class 2 (28/3561 = 0.7%).

Study on the dyeing properties of Chinese fir with Cinnamomum camphor pigment by premordant dyeing

ABSTRACT Wood staining can improve the quality of Chinese fir. In this study, Cinnamomum camphora natural plant pigment was used as a substitute for synthetic dyes to stain Chinese fir, and the staining performance was enhanced through pre-mordanting with alum. The dyeing effects of direct dyeing and mordant dyeing were compared, and the factors and levels influencing color difference, wash fastness, and light fastness were investigated through an orthogonal experimental design. The results showed that mordanting time had the greatest influence on color difference and lightfastness, while mordanting temperature had the greatest influence on washfastness. After pre-mordanting, the washfastness of Chinese fir improved to a level of 2–3, while the improvement in lightfastness was not significant. Pre-mordanting increased the dye uptake rate by 6.67%. Scanning electron microscopy revealed that NaOH pretreatment opened the wood pores and increased the flow channels for dye liquor. Infrared analysis indicated that O-H in wood fibers formed complexes with Al3+ in the mordant, resulting in a decrease in the characteristic peak intensity of O-H. X-ray diffraction analysis showed that the attractive effect of Al3+ vacant orbitals on O-H partially influenced the ordered arrangement structure in the crystalline region.

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.

Integrity of Melamine Formaldehyde Bonds in Ponderosa Pine Cross-Laminated Timber: Isolating Adhesive Compatibility Effect

Abstract The integrity of melamine formaldehyde bonds in prototype cross-laminated timber (CLT) specimens was tested as part of a project on utilization of ponderosa pine (Pinus ponderosa) from forest restoration programs in the western United States. Bond integrity tests, block shear, and cyclic delamination are prescribed by ANSI/APA PRG-320 (ANSI/APA 2019) and ANSI 405 (ANSI 2018) to qualify new products. Of these, the cyclic delamination criterion is particularly challenging for layups developed in research labs and pilot plants. Delamination is often blamed on poor compatibility between adhesive and wood species, clamping pressure, or distribution of adhesive, neglecting other potential factors. One of the study objectives was to separate the effect of adhesive compatibility from other potential factors affecting bond integrity in CLT. Bonding integrity tests were conducted on prototype specimens bonded with melamine formaldehyde adhesive. Three types of specimens were studied: (1) specimens harvested from panels fabricated in an industrial CLT plant, (2) specimens harvested from panels fabricated in a pilot-line, and (3) short blocks cross-laminated from 102 by 102-mm sections. The short blocks included sections with juvenile wood and blue stain on bonded surfaces. All samples passed the PRG-320 block shear criteria. All short blocks passed the delamination criterion, demonstrating sufficient adhesive compatibility with the surfaces regardless of heavy presence of blue stain and juvenile wood. Specimens harvested from panels did not meet the delamination criterion. Delaminations developed near preexisting interlaminar gaps observed in prototype panels, which may be related to thickness variation or to inconsistent clamping pressure.

Public Abstract Wooden Sculpture Park: From tree abundance to important environmental art

This research uses a lot of tree trunks to build an abstract art studio sculpture of a four-legged animal. Sketched, drawn, and scaled animal trait models represented human vegetation management at a highway and byway road site. Use the right tool and joiner wooden technique with screws and nails in the studio. The 'running forest' series was created after finishing and cleaning, using wood stain to preserve the wood and enamel paint for artistic purposes before the artist's impression technique stimulated or relocated the sculpture to its real location. This symbolic project politely communicated with the community through wooden sculpture-based environmental art.

Assessment of color and contact angle change of weathered wood in relation to wood species and different coating types

Color change was compared through artificial and outdoor weathering tests according to wood species and stain type. In the artificial weathering tests, the color change DE was the highest for the initial 200 hour, and teak solvent-based stain was the most effective in preventing color change. Outdoor weathering tests also showed a rapid color change until the initial 60 days, and the uncoated larch specimens exhibited graying after 120 days. Teak solvent-based stain had the highest preventing color effect, whereas water-based white semi-transparent stain had the highest contact angle. It is difficult to check the color change of wood due to the addition of pigment in teak, as its resistance to moisture is rapidly reduced and its surface protection effect is poor. Water-based white semi-transparent stain prevented color change and maintained a contact angle of 57.1° for up to 150 days, confirming the effect of moisture resistance. This study aimed to provide basic data on weather resistance by wood species and to suggest that the development direction of outdoor exposed wood is a water-based semi-transparent stain.

A Note on Wood Pocket Disease of Lime on Bearss Lime (Citrus latifolia Tan.) in Shambat, Khartoum State, Sudan

Symptoms of wood pocket disease of lime on Bearss lime trees (IVIA 124),kept in Shambat Research Station, Khartoum State, Sudan were described. These wereyellowing of foliage and death of branches, in addition to sectoring of fruits, brownstreaks on fruits and finally the death of the tree. Death of several potted seedlings wasalso observed, irrespective of the rootstock, accompanied by suckering of the rootstock.Branches showed cracking and wood staining with dark substance, typical symptoms ofwood pocket. As the disease is a genetic disorder, clones of Bearss lime tolerant towood pocket should be introduced and evaluated under Sudan conditions. This is thefirst record of wood pocket disease of lime in Sudan.

Antifungal effects of staining process on wood: Hardness, gloss, and color change

This study determined the effects of wood staining on wood-destroying fungi. To achieve this goal, different types of wood samples were used, including Scotch pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis Lipsky), sessile oak (Quercus petraea Liebl.), and mahogany (Entandrophragma cylindricum). Aniline (C6H2NH2), chemical (tannin (C14H10O9) + potassium dichromate (K2Cr2O7)), and Van Dyke brown stains (Fe2O3MnO2 + K2Cr2O7 + H2O) were applied to the samples, because a walnut color (brown) is preferred by customers. The stained samples were exposed to Fomitopsis palustris and Coriolus versicolor, and mycelium growing on wood was observed for 3 months. Hardness, gloss, and total color change tests were applied to the samples to determine the antifungal effects. The results showed that staining increased the total color change values of the wood, while decreasing in the gloss and hardness values. The chemical stain showed antifungal effects against both fungi.

METODE IDENTIFIKASI KERUSAKAN ELEMEN FISIK BANGUNAN HERITAGE DENGAN BUILDING INFORMATION MODELING (BIM) STUDI KASUS ISTANA ALWATZIKHOEBILLAH SAMBAS

Heritage buildings as architectural heritage assets that describe the identity of a region and the architecture of the past are important to be conserved and maintained. One of the cultural heritage buildings in Indonesia is Alwatzikhoebillah Sambas Palace. This building was built with wood construction. The condition of wood with age will experience changes in characteristics due to its interaction with various factors, especially biological and non-biological factors. Changes in any form cannot be underestimated, so documentation of cultural heritage buildings is needed. One way of documenting cultural heritage buildings is Building Information Modeling (BIM). BIM documentation can record various building information that is inputted in it. This research aim was to mapping and assessing the damage to the physical elements of wood on one of the accompanying buildings on the north side of the Alwatzikhoebillah Palace using BIM. BIM information contains the color code, mapping code, and the extent of the damage that occurs in the 2D view. The variables of this study were limited to biological damage caused by fungi and moss, also non-biological factors due to mechanical, weather, and chemical factors. The results of this research is the wall elements are dominantly damaged caused by wood staining fungus or mechanical erosion and weather changes of 1,64% with the effect of gray stains left on the elements.

Pest categorisation of Platypus apicalis.

The EFSA Panel on Plant Health performed a pest categorisation of Platypus apicalis (Coleoptera: Curculionidae: Platypodinae), an ambrosia beetle, also known as a pinhole borer, for the EU territory. P. apicalis is a polyphagous pest native to New Zealand. The majority of its life cycle is spent inside tree wood, but it does not directly feed on plant tissue, instead larvae and adults feed on a symbiotic fungus (Sporothrix nothofagi which is pathogenic to Nothofagus spp.) vectored by adults and introduced when they bore tunnels into the host. P. apicalis feeds within a wide range of live, often stressed trees, in dead or dying hardwood and softwood trees, and fallen or felled trees. Successful reproduction can occur inside a number of living tree species including Castanea sativa, Pinus spp. and Ulmus spp. P. apicalis is not known to have established outside of New Zealand although findings have been reported in Australia. Whilst there are no records of interceptions of this species in the EU, platypodines are intercepted with solid wood packing material (SWPM) and Platypus species, but not P. apicalis, have been intercepted with wooden logs in Japan. Host plants for planting also provide a potential pathway. Hosts are grown widely across the EU in areas with climates comparable to those in New Zealand where the pest occurs suggesting that conditions in the EU are suitable for its establishment. If introduced into the EU, adults could disperse naturally by flight, perhaps tens or hundreds of metres. The movement of infested wood and host plants for planting within the EU could facilitate spread. Economic impacts in forestry and timber industries would result from the galleries created by P. apicalis and from wood staining caused by the symbiotic fungus. Phytosanitary measures are available to inhibit the entry of P. apicalis. P. apicalis satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Natural dye extracted from Dalbergia cochinchinensis residue with water fastness, mildew resistance and permeability properties for wood staining

Natural dyes (ND) are gaining increasing interest due to their outstanding merits of being eco-friendly, biodegradable and non-toxic. Wood dyed with extracts from Dalbergia cochinchinensis residues as ND exhibited desirable color appearance and anti-UV property, while the other potential properties of ND dyed wood in terms of water fastness, mildew resistance along with the penetrability of the ND on wood blocks dyeing have not yet been exploited. The present study was aimed at exploring these aspects for multifunction assessment of the ND dyed wood. The results showed that the total color difference (ΔE*: 4.58) and color intensity reduction (PR: 14.01%) of the ND dyed wood declined slightly after washing fastness test in comparison with that of acid red (ΔE*: 32.82; RP: 76.14%) and reactive red (ΔE*: 26.85; RP: 66.52%) dyed wood, which is indicative of its preferable water fastness, which can be ascribed to the hydrophobicity improvement of the wood surface after ND dyeing. In addition, the ND ameliorated the mildew resistance against Aspergillus niger and Trichoderma viride infection. Interestingly, the wood blocks can be completely impregnated with ND under atmospheric pressure dyeing process without any pretreatment and auxiliary. This study provided a promising approach for multifunctional ND dyed wood preparation.

Effectiveness of European oak wood staining with iron (II) sulphate during natural weathering

Artificial graying of wood can be solution for contemporary trends of using uncoated wood for the arrangement of external architecture. The presented work was aimed at investigation of colour changes of European oak (Quercus sp.) wood surface treated with iron (II) sulphate. Three different procedures differing in time (2 h and 24 h) and temperature (20 °C and 70 °C) were used, as well as three different concentrations of aqueous iron (II) sulphate solutions (10 %, 20 %, 30 %). Beside the colour itself, it was evaluated the stained oak wood discolouration due to natural weathering. Thanks to iron (II) sulphate, wood colour changed to dark grey. In general, the colour changes on tangential section of wood were higher than those on radial section what was result of wood structure, in particular parenchyma cells arrangement in wooden rays. Contrary to expectations, the concentration of the iron (II) sulphate solution was not of significant importance for wood staining. Usage of concentrations higher than 10 % for the modification of the colour of wood gives the same effects. However, with increasing solution used to wood staining, the colour stability of the wood decreases during external exposure. The parameters of the procedure were not significantly affected. This allows the application of the simplest and least time-consuming modification method to be considered.

Thermo-Vibro-Mechanic® (TVM) wood densification method: Mechanical properties

A densification method is proposed and developed to improve the mechanical properties of Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) woods. The method, called Thermo-Vibro-Mechanic® densification, is derived from the hypothesis that the vibration added to the traditional thermo-mechanical densification process can cause the wood cell walls to interlock with each other at the micro-level via the friction effect. In addition, it aims to remove the cell cavities under lower pressure compared to other densification methods via the shaking effect. To test this hypothesis, the samples, obtained in both the radial and tangential directions, were pre-treated with wood stain and preservative before undergoing the densification process. Thermo-Vibro-Mechanic® densification was performed at varying temperatures (100, 120, and 140 °C), pressures (0.60, 1.00, and 1.40 MPa), and durations (20, 60, and 100 s). The changes in the values of the bending strength, modulus of elasticity, and compression strength parallel to the grain in the radial and tangential directions were determined accordingly. The results showed that the Thermo-Vibro-Mechanic® densification process increased the bending strength and modulus of elasticity values up to 50%, while the compression strength reached 67% higher than the untreated wood.

UJI EFEKTIVITAS FUNGISIDA NABATI SEBAGAI BAHAN PENGAWET UNTUK MENCEGAH SERANGAN JAMUR PEWARNA KAYU

Woods which have low natural durability are easy to be attacked with wood staining fungi (blue stain) so can decrease its wood quality. Syzygium aromaticum, Melia azedarach and Piper betle contain of active components (botanical fungicide) that can be used as natural preservative to prevent staining fungi attack. The purpose of this research is to know effect of botanical fungicide species and preserved wood investigated, i.e Paraserianthes falcataria and Toona sureni on the attack intensity of wood staining fungi. Results of the research showed that interaction between botanical fungicide and wood species gived very significant effect on the attack intensity of wood staining fungi. The lowest of attack intensity was resulted on Toona sureni that had preserved by Melia azedarach leaf extract. The leaf extract of Syzygium aromaticum, Melia azedarach and Piper betle could keep Paraserianthes falcataria and Toona sureni wood against staining fungi. Toona sureni wood was more resist against wood staining fungi than Paraserianthes falcataria, it was due to higher extractive in Toona sureni than Paraserianthes falcataria. To preserve woods which had bright colour such as Paraserianthes falcataria, more suitable to use Melia azedarach leaf extract which not change wood colour. 
 Key words: Botanical Fungicide, Preservative, Wood Staining Fungi

Self-assembly of biopolymer films for UV protection of wood

There is an increasing need for materials with tunable physical and chemical properties that are relatively non-toxic and efficacious for their intended application. Many wood stains and finishes emit toxic chemicals which may have serious implications to one’s health. A novel alternative material is realized between xanthan gum and Neodol, a non-ionic surfactant. The resulting three-dimensional film is evaluated as a free-radical scavenger for the protection of wood at different ratios. Atomic force microscopy visualizes the topography and quantifies the local nanomechanics, while rheological measurements showcase a shift from viscoelastic material to gel. Electron plasmon resonance confirms the free-radical reducing ability (3.5 times), while liquid chromatography mass spectroscopy quantifies the UV degradation of sinapyl alcohol. This material has potential, not only in coating industries as a safer option, but also in those industries requiring flexibility and tenability, namely for biosensors and anti-inflammatory therapeutics.Graphic abstract

Polyvinyl acetate/reduced graphene oxide-poly (diallyl dimethylammonium chloride) composite coated wood surface reveals improved hydrophobicity

Wetting is a key problem in wood finishing because water causes deterioration and reduces the durability of wood. Herein, hydrophilic wood has been modified into a hydrophobic wood through simple surface coating using polyvinyl acetate (PVAc) / reduced graphene oxide (rGO)-poly (diallyl dimethylammonium chloride) (PDDA). The synthesized graphene oxide (GO) from graphene flakes is used for chemical modification with urotropin in presence of sodium borohydride. The hydrophobic property of PVAc has been increased by modified graphene oxide dispersed at the presence of PDDA in methanol. The synthesized polymer composite is used coating on the various wood surfaces (radial and cross-sectional). Synthesized materials are characterized by extensive characterization techniques. The water contact angle of wood surface coated with PVAc/rGO-PDDA shows 187.8 % better than uncoated wood and 20.7 % better than PVAc coated wood and 2.4 % better than commercial wood stain coated wood. This facile, low cost and eco-friendly approach could be used in a variety of applications.

Influence of Traditional Wood Surface Modification Methods on Changes in Aesthetic and Resistance Properties

For ages, furniture makers have been using various methods to accelerate the natural process of wood aging, in order to achieve a more sophisticated colour and to provide a uniform appearance for furniture parts replaced during restoration. Nowadays, wood aging is popular due to its aesthetic value associated with naturally aged wood, which can be enjoyed in conjunction with favourable mechanical properties of contemporary wood. Methods of wood surface modification used in wood aging can be divided into mechanical ones, consisting in changing the structure of wooden surfaces (eg. sanding, brushing, paint rubbing or structuring with chisel or other tools) and chemical ones, involving the use of chemical substances to change the colour of wood (eg. greying; application of lye, paint or wood stain; and ammonia fuming). The purpose of our study was to determine the influence of traditional wood modification techniques used in furniture-making − such as: structuring, whitewashing, rubbing, greying, dyeing with potassium permanganate solution and ammonia fuming − on the aesthetic and resistance properties of wooden surfaces (colour, gloss, roughness, abrasion resistance and resistance to scratches). Tests were performed on wood species most frequently used in Poland to produce artificially weathered wood: Scots pine (Pinus sylvestris L.) and common oak (Quercus Sp).

Evaluation of the antagonistic effect and influencing factors of Bacillus subtilis against wood stain fungi: A systematic literature review and meta-analysis approach

Wood sapstain is a serious problem caused by the wood stain fungus, and it has a great influence on the international wood industry. The utilization of biological methods has good prospects for wood conservation. The objective of this study was to systematically estimate the antagonistic effect and influencing factors of Bacillus subtilis against wood stain fungus by using meta-analysis of literature data. Through report retrieval, a total of 992 references on B. subtilis related to wood were obtained. After strict screening, 163 data items from 7 articles were integrated. Estimated by the random-effects model, the combined effect Odds Ratio of the overall antagonistic effect was 0.15 (95% confidence interval [0.06, 0.34]). The results showed that B. subtilis could produce significant antagonistic effects against wood stain fungi. The inhibitory effect of wood stain fungi was affected by the strains of B. subtilis, species of wood stain fungi, the B. subtilis dosage, the type of mixed reagent, and the amount of mixed reagent on different wood stain fungi. The results of this study may provide a reference for biological control experiments, field tests, and practical applications of wood conservation.

Effects of Thermo-Vibro-Mechanic® densification on the density and swelling of pre-treated Uludağ fir and black poplar wood

The radial and tangential swelling as well as the fully dried density of low-density wood materials densified via the Thermo-Vibro-Mechanic® method were evaluated in response to applying wood stain and preservative. The samples obtained from Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) in the radial and tangential direction were pre-treated with wood stain and preservative before undergoing Thermo-Vibro-Mechanic® densification. Thermo-Vibro-Mechanic® densification was performed at three different temperatures (100 °C ± 3 °C, 120 °C ± 3 °C, and 140 °C ± 3 °C), three different vibration pressures (0.60 MPa, 1.00 MPa, and 1.40 MPa), and three different vibration times (20 s, 60 s, and 100 s). Afterwards, changes in the fully dried density and swelling amounts in the radial and tangential directions of the samples were determined. The fully dried density increased by 15.4% to 38% and the radial and tangential swelling amounts increased by 73.2% to 242.6%, when the densified samples were compared to the control samples. In general, the fully dried density and swelling values increased depending on the Thermo-Vibro-Mechanic® densification parameters; higher values were found as the compression ratio and total application time increased.