Painted Wood Research Articles

Modelling of the deterioration and conservation costs of polychrome painted wood in two Norwegian medieval stone churches

EnvCul (https://envcul.nilu.no/) modelling was performed of condition changes of painted wooden panels and related conservation cost in indoor climate and object response scenarios in two Norwegian Medieval stone churches: Kinn (mean relative humidity = 79%) on the humid west coast, and Ringsaker (mean RH = 49%) in the drier eastern part of the country. It was found that, hypothetical, building measures in Kinn, and conservation heating measures in Ringsaker, to approach an indoor RH of about 65% in the two churches, could probably increase conservation intervals with 20–100%, and correspondingly reduce conservation costs between 10% and 50%. This is in reasonable agreement with an available report of observed conservation requirements in differently heated Norwegian churches. A situation between a linear and accelerating development of the deterioration of the painted wood on approaching a new conservation intervention gave the best correspondence to the observed values. The large modelling uncertainty was mainly due to lacking observations of the deterioration development, but also lacking understanding of the complex mechanisms and phases of the environmental dose-deterioration response of painting conservation treatments.

Antibacterial efficiency over time and barrier properties of wood coatings with colloidal silver

This work aims to represent a standard application for understanding the extent of the antibacterial efficacy of coatings with different amounts of colloidal silver on wooden surfaces over time. The key variable that was intended to be evaluated in this study was the “time efficiency,” with concerns about the possible efficacy in the durability of the surfaces. By highlighting the “expiry date” of the agents, as in the case with other products, the study aimed to confirm the validity of the simulation tests conducted in the laboratory with degradation tests. Furthermore, the role of the silver amount on the barrier performance of the coatings was assessed by liquid resistance, water uptake, and perspiration tests, evaluating the aesthetic durability of the coatings by means of colorimetric analyses. Ultimately, this work demonstrates that these coatings may represent alternatives in terms of prolonged antimicrobial activity when compared with the biocide agents currently in use, capable to offer good resistance to detergent solutions and to water. Nevertheless, due to silver’s susceptibility to extended exposure to acidic solutions, the findings of the research discourage the utilization of colloidal silver in wood paints intended for use in public settings.Key points• Colloidal silver does not alter the deposition process and does not introduce defects in the wood paint.• Coatings containing silver show high antimicrobial activity over time, against both E.coli and S.aureus.• The silver-based filler resists contact with detergents and aqueous solutions but suffers oxidation processes in acidic environments.

The Painted Wooden Tomb Effigies at Goudhurst to Sir Alexander Culpepper (d. 1541) and his Second Wife, Dame Constance Culpepper, and their Comparators

Wooden tomb effigies are now rare in England and Wales, although it is likely that they were once relatively common. Of the total of 120 known examples, only ninety-three survive. The other twenty-seven documented figures have been lost or destroyed owing to woodworm, fire, iconoclasm, theft and the general misuse that has beset this monumental type. Most remaining examples are mere skeletons of their original state, with any surface decoration worn away or cleaned off over the centuries, leaving only bare wood with perhaps traces of polychromy in crevices. A minority are now painted, but most do not display the original surface finish. The effigies at Goudhurst (Kent) to Sir Alexander Culpepper (d. 1541) and his second wife were thought to have been similarly overpainted, but new evidence from recent pigment analysis using polarized light microscopy shows that this was probably only partial. Physical and documentary evidence throw much light on the dating of the monument, the two effigies of which were produced at different times, the older parts dating to 1537. A detailed assessment of the memorial and its comparanda underlines the unique nature of the pair.

Synergistic contribution of bio-based additives in wood paint: The combined effect of pigment deriving from spirulina and multifunctional filler based on carnauba wax

This work aims to reveal the synergistic behavior of two bio-based additives on the durability and protective behavior of a bio-based wood paint. The powder extract form spirulina was introduced as a natural pigment, while carnauba wax was used as a multifunctional filler. The impact of the two additives on the morphology of the coatings was investigated by scanning electron microscopy observations, while their role on the durability of the paint was assessed by exposing the samples to UV-B radiation and continuous thermal shocks. Infrared spectroscopy analysis, colorimetric inspections, adhesion test and scanning electron microscope observations were employed to investigate the impact of the synergic behavior of the bio-based additives. Furthermore, the role of the spirulina and wax powders on the barrier performance of the coatings was evaluated by liquid resistance test ad water uptake test. Finally, Buchholz hardness indentation test and the scrub test were employed to estimate the effect of the additives on the mechanical properties of hardness and abrasion resistance of the coatings. Ultimately, this work demonstrates the interesting synergy of spirulina and wax, able to provide an intense coloring and certain aesthetic features to the paint, to improve the water-repellent properties of the surface and to increase the abrasion resistance of the composite layer.

Basque House in Araucanía-Chile: A Reflection from the Importation and Development of Its Regionalist Architecture

The study of the Basque House, which was commissioned for construction by Basque-French settlers in the year 1930 in the town of Nehuentúe, Chile, allows us to delve into the value that the residential architectural heritage of Basque settlers brings to the rural area of the La Araucanía region, which was heavily populated by groups of European settlers since the second half of the 19th century. This house features a replica of the neo-Basque style from the French region of the Atlantic Pyrenees, from where rationalist architecture and symbolism in its forms and decorative elements were imported. On the facades of the Basque House in Nehuentúe, we observe a generous number of openings with square windows that are arranged under the asymmetry of the roof, geometric shapes that try to lighten the weight of this large compact volume. Simple construction bodies, organized according to the functionality of natural light and sun exposure of the rooms. Decorative elements that evoke the facades of the farmhouse stand out, overhangs and frameworks of red-garnet painted wood on white walls that transfer the popular origin of the Basque farmhouse structure to a bourgeois architecture that shows them as a decorative trend. This study delves into the history, place, and architecture of the house, comparing it to its origin, to understand how the settler, through architecture and symbols, felt closer to their roots. It is possible to delve into the history, observe the place, carry out a survey, classify and interpret a home, which, together with the analysis of its original architecture, allows it to be valued in a complete way so that it can be preserved. We can understand the territory of colonization through the deep analysis of its architecture. This knowledge of the past leads us to a learning process filled with symbolism, stories, and memory.

COMPARATIVE ANALYSIS OF FIRE PROTECTION CHARACTERISTICS OF TWO TYPES OF COATINGS

Materials from natural raw materials are always of great demand in the sphere of construction, both large-sized structures and the smallest decoration elements. Regardless of the area of use, wood needs to be processed, whether it is protection from excessive heat and possible sources of ignition, protection from biological influences, including natural conditions, or processing in order to give an object aesthetic features, or create interior compositions. Each type of coating – enamel or paint – has a number of individual characteristics. The aim of research is to identify the relationship between the special fire-retardant paint «Pirex», which provides the first fire protection group, and general-purpose wood paint «Luxart» without a certificate of belonging to one or another fire group security. Referring to State Standard R 53292-2009, which is the basis of the research, wood samples were treated with potential fire protection, after which conclusions were presented on the effectiveness of all tests. In addition to examining the difference between fire retardant paint and general purpose paint, the effect of applied agent layers on the fire retardant properties of wood was investigated. The results of the studies carried out allow us to draw conclusions about each method of applying paint and to identify correlation dependences for each paint on the number of coating layers.

Preparation and Properties of a Novel Cross-Linked Network Waterborne Polyurethane for Wood Lacquer.

Waterborne polyurethane (WPU) is a waterborne coating with excellent physicochemical properties. Its deficiencies of water resistance, chemical resistance, staining, and hardness have limited the wide application of polyurethane in the wood lacquer market. In this study, polycarbonate diols (PCDL) were used as soft segments and WPCU was modified by cross-linking using Trimethylolpropane (TMP) to prepare polycarbonate type WPU (WPCU) with cross-linked network structure. The new wood lacquer was prepared by adding various additives and tested by applying it on wood board. The successful synthesis of WPCU was determined by FTIR testing, and the cross-linking degree of WPCU was probed by low-field NMR. The viscosity of the cross-linked WPCU emulsion showed a decreasing trend compared to the uncross-linked WPCU emulsion, and WPCU-2 had the smallest particle size. Compared with the uncrosslinked WPCU film, the crosslinked WPCU film had lower water absorption (2.2%), higher water contact angle (72.7°), excellent tensile strength (44.02 MPa), higher thermomechanical, and better water and alcohol resistance. The effect of crosslinker content on the microphase separation of WPCU chain segments on the surface roughness of the film was investigated by SEM. The wood paint prepared by WPCU emulsion has good dry heat resistance, chemical resistance, and adhesion, and the hardness of the wood paint when the TMP content is 3% reaches H. It also has good resistance to sticky stains, which can be used to develop new wood lacquer.

Effect of Pistachio Husks Powder Additive on Unsaturated Polyester Composites

In this study, polyester composites reinforced with pistachio shells powder (P.) with an averagediameter (150 – 200 μm) with different weight ratios (0.5%, 1%, 1.5%, 2%, and 2.5%) wereprepared to the resin. The Shore D hardness, thermal conductivity (K), and the glass transitiontemperature (Tg) of the samples were examined. The results showed that the Shore D hardnessincreases with the increase of the reinforcement ratio and its maximum value is (87.55) at (2.5%P.) While the value of hardness at (0%) is (86.5). The thermal conductivity increases slightly withthe increase in the percentage of reinforcement and its maximum value is (0.213253 W/ m. K) at(2.5% P.), while the value of K at (0% P.) is (0.170264W/ m. K), but with this slight increase inthermal conductivity, polyester composites remain from the insulating materials. The minimum(Tg) of (UPE/ P.) composites was the value (113.898°C) at (2.5% P.). Polyester composites areused in wood paints, either in primitive finishes or final finishes.

From wood waste to wood protection: New application of black bio renewable water-based dispersions as pigment for bio-based wood paint

This study aims to assess the effect of two different amounts of bio a renewable black pigment derived from wood waste on the durability of a bio-based wood paint. The effect of this eco-friendly pigment on the aesthetical features of the coatings was evaluated by colorimetric measurements and optical microscopy observations. The durability of the paints was assessed by exposing the samples to UV-B radiation and continuous thermal shocks, analyzing the influence of the presence of the pigment on the protective behavior of the paint by means of infrared spectroscopy analysis, colorimetric inspections, adhesion tests and scanning electron microscope observations. Furthermore, the coatings' durability was confirmed following tests of chemical resistance to liquids, where the pigment did not negatively influence the barrier performance of the polymeric matrix of the paint. Finally, the thermal test evidenced the behavior of the black pigment in increasing the heat absorption by the paint, which suggests its use in structural energy saving applications. Ultimately, this work demonstrates how this bio renewable water-based dispersion, derived by wood waste, can be applied as functional pigment in bio-based wood paint, capable of modifying the appearance of the coating without negatively affecting its protective performance.

Impact of High Concentrations of Cellulose Fibers on the Morphology, Durability and Protective Properties of Wood Paint

This work aims to reveal the effect of a high amount of cellulose fibers on the durability and protective behavior of a bio-based wood paint. The influence of the filler on the morphology of the coatings was investigated by scanning electron microscopy observations, while the durability of the paint was evaluated by exposing the samples to UV-B radiation and continuous thermal shocks. Infrared spectroscopy analysis, colorimetric inspections, adhesion tests and scanning electron microscope observations were employed to assess the role of the high concentrations of fillers in affecting the resilience of the acrylic matrix. Moreover, the impact of the filler on the barrier performance of the coatings was estimated using a liquid resistance test and a water uptake test. Finally, the mechanical properties of hardness and abrasion resistance of the layers were evaluated by means of the Buchholz Hardness Indentation test and the Scrub test. Ultimately, this study demonstrates the pros and cons of using large amounts of cellulose fibers as filler in wood paint: the work warns against the excessive use of these fibers, which need a threshold limit so as not to significantly change the coating’s structure and thereby weaken its protective properties.

Spectroscopic analysis for evaluation the nano silica as an inorganic and hybrid nano material in treatment of red cinnabar pigment – Based on case study at the Grand Egyptian Museum

One of the most important funerary objects during ancient Egyptian history was the canopic chests, which varied in shape and objective during different ages. Part of a painted wooden canopic chest which dated between the late 27th dynasty (525 BC - 404 BC) to the Greco-Roman period and stored now at the storage rooms of the Grand Egyptian Museum in Giza, Egypt; used as a case study to do an experimental study through designing mimic samples to the object structure, which mainly was wooden support of Ficus Sycamore wood species, covered with white preparation layer of Calcium Carbonates (CaCo3), with a variety of colors for the painting layer; but in our research we concentrate on the red pigment which has been identified as Cinnabar, which from its conservation state was suffering from darkening, cracks, microcracks, and fragility. The experimental study conducted mainly to evaluate the performance of the nano silica for the treatment of the red cinnabar pigment as a consolidation material in two different forms: the inorganic and hybrid; in the inorganic form the nano silica has been dispersed in 2-propanol organic solvent, and its hybrid form the nano silica dispersed in Klucel E organic polymer. and to get accurate results that can be reliable in the field of conservation, various analytical and examination methods have been applied such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FT-IR), and Laser-induced breakdown spectroscopy (LIBS). Prior to the elemental characterization of data samples, the local thermodynamic equilibrium (LTE) condition was established to guarantee the correctness of the LIBS analysis. The results revealed the high efficiency of using nano silica in the inorganic form (dispersed in 2-propanol) than the same material but in hybrid form (dispersed in Klucel E) in regard of absorption of the materials in the matrix and the final appearance of the samples surfaces.

Enhancing the Mechanical Properties of Waterborne Polyurethane Paint by Graphene Oxide for Wood Products.

Water-based polyurethane paint is widely used for wood furniture by virtue of the eco-friendliness, rich gloss, and flexible tailorability of its mechanical properties. However, its low solution (water or alcohol) resistance and poor hardness and wear resistance limit its application. The emerging graphene oxide has a high specific surface area and abundant functional groups with excellent mechanical properties, endowing it with great potential to modify waterborne polyurethane as a nanofiller. In this study, graphene oxide prepared by Hummers' method is introduced in the chemosynthetic waterborne polyurethane through physical blending. The testing results demonstrate that the appropriate usage of graphene oxide at 0.1 wt% could obviously improve water absorption resistance and alcohol resistance, significantly enhancing the mechanical properties of waterborne polyurethane paint. The corresponding tensile strength, abrasion resistance, and pendulum hardness of the graphene oxide-modified paint film increase by 62.23%, 14.76%, and 12.7%, respectively, compared with the pristine paint film. Meanwhile, the composite paint film containing graphene oxide possesses superiority, including gloss, abrasion resistance, pendulum hardness, and tensile strength in contrast with the commercial paint. The use of graphene oxide to enhance the waterborne polyurethane possesses strong operability and practical value, and could provide useful reference for the modification of waterborne wood paint.

Colloidal silver as innovative multifunctional pigment: The effect of Ag concentration on the durability and biocidal activity of wood paints

This study aims to assess the effect of two different colloidal silver amount on the durability and biocidal activity of a water-borne wood paint. The influence of this multifunctional pigment on the aesthetical features of the coatings was evaluated by colorimetric measurements and optical microscopy observations. The durability of the samples was investigated by means of different accelerated degradation tests, such as the exposure in a climatic chamber and to UV-B radiations. Scanning electron microscope observations, infrared spectroscopy analysis and colorimetric inspections were carried out to highlight the residual influence of silver in altering the protective behavior of the paint. Moreover, the Ag-containing samples exhibited excellent antibacterial activity against Staphylococcus aureus and Escherichia coli, while colloidal silver did not introduce effective fungicidal performances against Coniophora puteana and Trametes versicolor fungi. Ultimately, this work demonstrates how colloidal silver can be used as a functional pigment in wood paint, capable of modifying the appearance of the coating, improving its antibacterial performance, without negatively affecting its protective performance.

해외 목조건축물 사례분석을 통한 생활SOC의 목재 적용방안 고찰

Purpose: This study aims to comprehensively analyze the effects of wood, structural problem solving method, carbon reduction, etc. used through overseas wooden construction precedents and use them as basic data to apply Living SOC wood in the future. Method: First of all, the theoretical consideration of the necessity of applying wood or wood structure to Living SOC was conducted. To this end, we reviewed the basic matters on the current status of Living SOC and the use of wood through previous studies. Next, we analyzed the case of overseas wooden buildings that were already completed to actively use wooden codes and wood in the future. Finally, based on the analyzed results, the possibility of wood use and wood painting for Living SOC was verified, and through this, a plan to apply wood for Living SOC in the future was presented. Result: In this study, the possibility of wood use and application to domestic Living SOC projects was verified through the structural possibility of overseas wooden buildings and carbon-neutral characteristics analysis. In most buildings in Korea, structures were mainly used as modern building materials instead of wood, and wood use is still insignificant. However, in developed countries, high -rise wooden buildings are already appearing, which proves structural stability and carbon neutral effects of wooden shafts. Therefore, in the case of Korea, it is necessary to actively revitalize the use of wood and the wooden architecture, focusing on public buildings including Living SOCs, with reference to these advanced cases.

Preparation of Cellulose Modified Wall Material Microcapsules and Its Effect on the Properties of Wood Paint Coating.

An orthogonal experiment with four factors and three levels was designed. Nine different microcapsules were prepared by changing four factors: the core–wall ratio, emulsifier concentration, reaction temperature, and rotation speed. Through an analysis of the microcapsule yield and morphology, it was determined that the microcapsule of sample 6 performed the best in the orthogonal test and that the core–wall ratio was the largest factor affecting the microcapsule morphology and yield. In order to further optimize the performance of the microcapsules, single factor independent tests were carried out using the core–wall ratio as a single variable. It was found that the microcapsules with the core–wall ratio of 0.75:1 had good micro morphology and yield. The properties of the coating were the best when the microcapsules were added into the primer and the topcoat at the same time with an additional amount of 10.0%. The mechanical properties of the coating containing cellulose microcapsules and the coating without cellulose microcapsules were tested. Cellulose can enhance the toughness of the microcapsules, inhibit the generation of microcracks, and enhance the performance of the coating to a certain extent. The elongation at break of the coating with cellulose microcapsules was 9.49% higher than that without cellulose and was 11.1% higher than that without cellulose microcapsules.

Universal Preparation Strategy for Ultradurable Antibacterial Fabrics through Coating an Adhesive Nanosilver Glue.

Microbiological protection textile materials played an important role in the battle against the epidemic. However, the traditional active antimicrobial treatment of textiles suffers from narrow textile applicability, low chemical stability, and poor washability. Here, a high-strength adhesive nanosilver glue was synthesized by introducing nontoxic water-soluble polyurethane glue as a protectant. The as-prepared nanosilver glue could adhere firmly to the fiber surfaces by forming a flexible polymer film and could encapsulate nanosilver inside the glue. The as-prepared nanosilver had a torispherical structure with diameter of ~22 nm, zeta potential of −42.7 mV, and good dispersibility in water, and it could be stored for one year. Further studies indicated that the nanosilver glue had wide applicability to the main fabric species, such as cotton and polyester fabric, surgical mask, latex paint, and wood paint. The antimicrobial cotton and polyester fabrics were prepared by a simple impregnation–padding–baking process. The corresponding antimicrobial activity was positively correlated with nanosilver content. The treated fabrics (500 mg/kg) exhibited ultrahigh washing resistance (maintained over 99% antibacterial rates for 100 times of standard washing) and wear resistance (99% antibacterial rates for 8000 times of standard wearing), equivalent breathability to untreated fabric, improved mechanical properties, and good flexibility, demonstrating a potential in cleanable and reusable microbiological protection textiles.

Studies on the Stability of Binding Media in Retouching Materials for Exterior Painted Wooden Decoration in Taiwan

The conservation of tradition polychrome in Taiwan adopted Western techniques from the beginning of twentieth century. However, the issue of whether such materials are suitable to the climate of Taiwan is a question that remains unanswered. The objective of this study was to assess the durability of three retouching binders under the external climate conditions of Taiwan. The binders that were tested included a watercolour coated with 5% acrylic resin Paraloid B72, an acrylic resin Paraloid B72 and a low molecule weight resin Laropal A81 using accelerated aging conditions that simulated the exterior climate of Taiwan. Alterations in colour, gloss, adhesion and solubility were measured to evaluate the stability and reversibility of the materials. The results showed that both watercolour coated with 5% Paraloid B72 and Laropal A81 had lower resistance to moisture, and thus are not recommended for use in exterior areas in Taiwan. Paraloid B72 remained more stable with good re-treatability after ageing, however it was still affected by UV/heat and condensation cycles. The observation of material behaviour in the study provides information for the selection of retouching materials for exterior Taiwanese traditional polychrome, and highlights the need for further systematic testing of suitable materials in the future.

목재용 오일 마감재(오일스테인) 자연발화 위험성에 관한 연구

Recently, as natural interiors have been in the spotlight, there is a trend to produce and assemble interior accessories using wood or bark. For small items made in this way, an oil finishing material for wood must be used, and the most used currently is oil stain. Linseed oil, which is classified as a drying oil among vegetable oils, is used as the main ingredient in oil stain. Linseed oil, which is a drying oil, consists of unsaturated fatty acids, and many of them are composed of polyunsaturated fatty acids, so it oxidizes very quickly in the air. Because of these properties, there is a risk of spontaneous ignition due to oxidative heat in the process of improperly processing the painting tools generated after wood painting. Therefore, this study analyzes fire cases that occurred at the fire site, and based on this, deduces the possibility of spontaneous ignition due to oxidative heat in painting tools with oil stains through a re-enactment experiment, and suggests considerations for fire detection and fire prevention measures.

Clinical CT densitometry for wooden cultural heritage analysis validated by FTIR and Raman spectroscopies

The identification and characterization of wood material represent an ongoing challenge for artefacts of interest in cultural heritage. Fourier transforms infrared spectroscopy (FTIR) and micro-Raman (MRS) spectroscopies and more recently Surface-Enhanced Raman Scattering (SERS), being non-destructive techniques, have been largely used for the analysis of painted wood. In this work, for the first time, the X-ray Computed Tomography (CT), using a CT medical scanner, was adopted to discriminate three types of wood, usually used in the construction of heritage objects. Wood interior features have been identified in CT images processed through the volumetric rendering technique (VRT), without the need to destructively “take out” a piece of the sample. The information at the macroscopic level collected by CT (density, volumes, morphology, etc.) was enriched by the evidence, at the microscopic level, obtained by the Raman and FTIR spectroscopic techniques. So, the samples have been classified in softwood and hardwood, with the advantage with respect to the conventional analytical methods to be able to distinguish specific structures within the cell walls only through the CT diagnostic technique. Ultimately, a new non-destructive approach is proposed to analyze wood-based heritage objects, but which can be also extended to other materials (i.e., pigments, glues, consolidants).

The effects of cellulose nanofibers compounded in water-based undercoat paint on the discoloration and deterioration of painted wood products

Cellulose nanofibers (CNFs) have many potentials as filler to improve the properties of the other materials. We have developed the novel paints containing CNFs, and which controlled the discoloration of wood products. To clarify the discoloration mechanism of wood panels using an undercoat paint containing CNFs, prepared by an integrated process from Cryptomeria japonica, the composites and films made of CNFs and acryl resin that was a raw material for the paints were prepared. Observation of the surface of the CNFs/acryl resin composite film by atomic force microscopy showed that the fibers and the resin were uniformly mixed. The composite film prevented light transmittance in the ultraviolet (UV) light region, as well as oxygen gas permeation. The permeability coefficient of the oxygen gas decreased to 60% with the addition of 1.5 wt% of CNFs to the acryl resin. The addition of CNFs also increased the breaking stress by approximately 1.5 times compared with the acryl resin film. Electron spin resonance (ESR) analysis after UV irradiation resulted in the lowest radical formation of a piece of wood wrapped in the CNFs/acryl resin composite compared with the acryl-coated specimen and the wood as it was. Therefore, the CNFs composite film shielded the UV rays and oxygen more effectively than the original acryl resin, making it difficult for these factors to reach the wood’s surface, and thus, perhaps suppressing the generation of radicals from the wood. These actions would suppress the production of coloring substances caused by the radicals, resulting in the suppression of discoloration. Furthermore, the increase in the film’s strength by the addition of CNFs would have enhanced the stability of overall the paints with a CNF-containing undercoat. These effects might have contributed not only to the prevention of discoloration but also to the prevention of the occurrence of minute cracks caused by various weather deterioration factors.