scholarly journals Durable protection of the surface of wood used outdoors: material constraints, problems and approaches to solutions

2018 ◽  
Vol 149 ◽  
pp. 01016
Author(s):  
A. Merlin ◽  
B. George ◽  
L. Malassenet ◽  
L. Podgorski
Keyword(s):  
Solid Wood ◽  
Wood Products ◽  
Premature Aging ◽  
Added Value ◽  
Aesthetic Perception ◽  
Surface Appearance ◽  
Protective Function ◽  
Surface Protection ◽  
Wood Processing ◽  
Wooden Structures

The aesthetic durability of wooden structures is a major challenge for the use of this material in construction. Wood is used for its technical performances but also for its architectural qualities and its aesthetic perception. The premature aging of the wooden structures is detrimental because these disorders, even if they do not affect the strength of the structures, are mostly irremediable. The surface protection of wood is generally ensured by the use of a finish, whose essential role is to protect wood from climatic aggressions (water, solar radiation, oxygen, ...). The secondary wood processing industry consists of a series of manufacturing and processing activities, each containing a portion of the added value of the product. The application of a finish on a wood-based work is usually the last and most visible step in this value chain.In outdoor use, the protection of the wood surface with transparent finishes is not yet sufficiently durable to be able to compete with materials used in industrial carpentry such as PVC or aluminum. Opaque finishes generally provide more durable protection but they mask the appearance of the wood sought by users.With the aim of positioning wood in this construction sector, research on transparent finishes has focused on the efficiency and improvement of the durability of the protection of the surface appearance of structures. Faced with climatic aggressions, the optimum conservation of a structure is not only linked to the performance of the finish but also to the characteristics of the wood material. In particular, in order to fulfill its protective function, the finish film must be able to follow the dimensional variations of the wood it covers without breaking and without detachment. In addition to the criteria for the effectiveness of finishes in the protection of structures, the environmental impact must be considered with increasing attention. Currently, more than 80% of composite or solid wood products are still protected with solvent-based liquid products, which are an important source of VOC emissions. Does the solution come from photo-polymerizable systems that can be formulated with 100% dry matter either in liquid phase in reactive diluents or powdered?

Kiln-drying lumber quality of hybrid poplar clones

Holzforschung ◽  
2007 ◽  
Vol 61 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Kyu-Young Kang ◽  
Slobodan Bradic ◽  
Stavros Avramidis ◽  
Shawn D. Mansfield
Keyword(s):  
Global Climate ◽  
Hybrid Poplar ◽  
Value Added ◽  
Solid Wood ◽  
Wood Products ◽  
Kiln Drying ◽  
Wood Processing ◽  
Hybrid Poplars ◽  
Short Rotation

Abstract Hybrid poplars are currently used in North America primarily for the production of pulp fibre and in the manufacture of engineered solid wood products. Recently, the deployment of poplars as a short-rotation fibre crop has been of interest to mitigate the increasing amount of plantation-grown short fibre resources (hardwoods) derived from the Southern Hemisphere, as well as in the context of global climate change, both as a means to rapidly sequester carbon and as a feedstock for potential bioenergy production. Knowledge on the utility of hybrid poplars in the value-added secondary wood-processing sector, however, is very limited. To improve this situation, the variation in kiln-drying quality of five hybrid poplar genotypes of similar age, harvested from a common site in British Columbia, Canada, was evaluated for three different kiln-drying schedules. The results clearly demonstrate that the drying schedule has a greater effect on grade recovery and the degree of deformation than the hybrid poplar genotype. Furthermore, it was shown that many of the deformations inherently associated with wood derived from fast-grown trees can be reduced or removed with drying, in particular with an aggressive drying schedule.

scholarly journals Physico-mechanical properties of thermally modified Eucalyptus nitens wood for decking applications

2019 ◽  
Vol 70 (3) ◽  
pp. 235-245 ◽  
Author(s):  
Maximilian Wentzel ◽  
Óscar González-Prieto ◽  
Christian Brischke ◽  
Holger Militz
Keyword(s):  
Brinell Hardness ◽  
Good Alternative ◽  
Solid Wood ◽  
Thermal Modification ◽  
Wood Products ◽  
Added Value ◽  
Eucalyptus Nitens ◽  
Plantation Species ◽  
The Moment ◽  
Quality Material

Eucalyptus nitens is a fast growing plantation species that has a good acclimation in Spain and Chile. At the moment it is mainly used for pulp and paper production, but there is a growing market for solid wood products made from this species. Thermal modification offers a good alternative to produce high quality material to manufacture products with high added value. This study used unmodified and thermally modified E. nitens wood from Spanish and Chilean plantations to elaborate external decking and examine if it complies with the necessary properties to be a competitive product. A process similar to ThermoWood® was applied at the following temperatures: 185 °C, 200 °C and 215 °C. For each modification and for an unmodified specimen mass loss, volumetric swelling, anti-swelling efficiency (ASE) and equilibrium moisture content (EMC) were determined. Brinell hardness, dynamic hardness, screw and nail withdrawal resistance, and abrasion resistance according to the Shaker method and the Taber Abraser method were also determined. According to this study, thermally modified E. nitens from both countries showed high potential to be used as decking material, particularly when modified at 200 °C.

scholarly journals Increasing the Strength of the Glue Line in the Production of Thermally Modified Wood Paneling

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 253
Author(s):  
Ruslan Rushanovich Safin ◽  
Aigul Ravilevna Shaikhutdinova ◽  
Ruslan Khasanshin ◽  
Shamil Mukhametzyanov ◽  
Albina Safina
Keyword(s):  
Wood Products ◽  
Ultraviolet Rays ◽  
Surface Activation ◽  
Wood Block ◽  
Two Stage ◽  
Adhesion Properties ◽  
Wood Processing ◽  
Ultraviolet Treatment ◽  
Thermally Modified Wood ◽  
Modified Wood

This work is devoted to the study of the effect of ultraviolet rays for the surface activation of pine wood thermally modified at temperatures of 180−240 °C in order to increase the surface roughness, enhance the wettability of thermal wood and the adhesive strength of the glue in the production of wood block furniture panels. Studies were carried out to measure the contact angle of wettability of thermally modified wood samples of pine, as a result of which it was determined that the ultraviolet treatment process contributes to an increase in the adhesion properties of the surface layer of thermally modified wood by more than 13% due to the reactivity of ultraviolet rays to oxidize and degrade ligno-containing wood products. At the same time, the most active process of surface activation takes place during 60 min of ultraviolet irradiation of wood with a total irradiation of at least 125 W/cm2. It was revealed that the combined effect of two-stage wood processing, including preliminary volumetric thermal modification followed by surface ultraviolet treatment, causes an increase in the moisture resistance of glued wood products by 24%. So, if the strength of the glue seam when gluing natural wood samples after boiling decreased by 46%, then the samples that underwent two-stage processing showed a decrease only by 22%. In connection with the results obtained, an improved technology for the production of furniture boards for the manufacture of moisture-resistant wood products is proposed.

Study on Application of Stress Wave for Nondestructive Test of Wood Defects

2013 ◽  
Vol 401-403 ◽  
pp. 1119-1123 ◽  
Author(s):  
Wen Shu Lin ◽  
Jin Zhuo Wu
Keyword(s):  
Nondestructive Test ◽  
Stress Wave ◽  
Significant Influence ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Wood Products ◽  
Propagation Time ◽  
Propagation Parameters ◽  
Wave Technique ◽  
Wooden Structures

The elm wood samples were tested by the technique of stress wave, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. Under the same specifications, the propagation time of the stress wave was longer in the wood with holes or cracks than the perfect wood samples, and the time become longer with the increasing the sizes and numbers of holes or cracks. The studying results of the thesis will provide a sound background for the application of stress-wave technique in detecting the inner defects of wood products and other wooden structures.

scholarly journals Variations in Essential Oil Chemical Composition and Biological Activities of Cryptomeria japonica (Thunb. ex L.f.) D. Don from Different Geographical Origins—A Critical Review

2021 ◽  
Vol 11 (23) ◽  
pp. 11097
Author(s):  
Ana Lima ◽  
Filipe Arruda ◽  
Jorge Medeiros ◽  
José Baptista ◽  
João Madruga ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Cryptomeria Japonica ◽  
Current Knowledge ◽  
Biological Activities ◽  
Forest Biomass ◽  
Biological Properties ◽  
Added Value ◽  
Endogenous Factors ◽  
Wood Processing ◽  
Social Environmental

The scientific community is paying increasing attention to plant waste valorization, and also to “greener” practices in the agriculture, food and cosmetic sectors. In this context, unused forest biomass (e.g., leaves, seed cones, branches/twigs, bark and sapwood) of Cryptomeria japonica, a commercially important tree throughout Asia and the Azores Archipelago (Portugal), is currently waste/by-products of wood processing that can be converted into eco-friendly and high added-value products, such as essential oils (EOs), with social, environmental and economic impacts. Plant-derived EOs are complex mixtures of metabolites, mostly terpenes and terpenoids, with valuable bioactivities (e.g., antioxidant, anti-inflammatory, anticancer, neuroprotective, antidepressant, antimicrobial, antiviral and pesticide), which can find applications in several industries, such as pharmaceutical, medical, aromatherapy, food, cosmetic, perfumery, household and agrochemical (e.g., biopesticides), with manifold approaches. The EOs components are also of value for taxonomic investigations. It is known that the variation in EOs chemical composition and, consequently, in their biological activities and commercial use, is due to different exogenous and endogenous factors that can lead to ecotypes or chemotypes in the same plant species. The present paper aims to provide an overview of the chemical composition, biological properties and proposals of valorization of C. japonica EO from several countries, and also to indicate gaps in the current knowledge.

scholarly journals Improving the accuracy of wood moisture content estimation in four European softwoods from Spain

2021 ◽  
Vol 30 (1) ◽  
pp. e002
Author(s):  
Juan I. Fernández-Golfín ◽  
Maria Conde Garcia ◽  
Marta Conde Garcia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Moisture Content ◽  
Accurate Estimation ◽  
Wood Moisture ◽  
Mathematical Functions ◽  
Measured Moisture Content

Aim of study: To obtain improved models to predict, with an error of less than ± 2.0%, the gravimetric moisture content in four different softwoods commonly present in the Spanish and European markets, based on electrical resistance measurements. This improved moisture content estimation is useful not only for assessing the quality of wood products, especially in the case of laminated products, during the transformation and delivery process, but also for accurately monitoring the evolution of moisture in wood present in bridges and buildings, which is of great importance for its maintenance and service life improvement.Area of study: The study was carried out on samples of Scots, laricio, radiata and  maritime pines of Spanish provenances.Material and methods: On 50x50x20 mm3 solid wood samples (36 per species, 9 per condition), conditioned at 20ºC (±05ºC) and 40±5%, 65±5%, 80±5% or 90±5% Relative Humidity (RH), electrical resistance and oven-dry moisture content was measured. The Samuelsson's model was fitted to data to explain the relationship between the two variables. The accuracy of the model was evaluated by the use of an external sample.Main results: With the proposed mathematical functions the wood moisture content can be estimated with an error of ±0.9% in the four species, confirming the effectiveness of this nondestructive methodology for accurate estimation and monitoring of moisture content.Research highlights: our results allow the improvement of the moisture content estimation technique by resistance-type methodologies.Keywords: Resistance-type moisture meter; species correction.Abbreviations used: MC: Moisture content; RH: relative Humidity; R: electrical resistance; RP: wood electrical resistance measured parallel to the grain; RT: electrical resistance measured perpendicular (transversally) to the grain; GM-MC: gravimetrically measured moisture content.

scholarly journals Studi Perbandingan Analisis Struktur Rumah 2 Lantai Menggunakan Kayu Glulam dan Kayu Solid Terhadap Beban Gempa. (Hal. 85-94)

2019 ◽  
Vol 5 (1) ◽  
pp. 85
Author(s):  
Ramdhan Taufik ◽  
Erma Desmaliana ◽  
Amatulhay Pribadi
Keyword(s):  
Construction Material ◽  
Pushover Analysis ◽  
Solid Wood ◽  
Wood Products ◽  
Basic Material ◽  
Class Iii ◽  
Base Shear ◽  
Non Linear ◽  
The Difference ◽  
Immediate Occupancy

ABSTRAKKondisi geografis Indonesia memiliki struktur tektonik kompleks. Kondisi ini membuat perencanaan rumah tinggal 2 (dua) lantai membutuhkan pertimbangan khusus dari segi kekuatan dan kekakuan. Penggunaan material kayu sebagai bahan konstruksi di Indonesia masih jarang digunakan. Kayu glulam adalah suatu produk kayu rekayasa yang dibuat dari beberapa bilah kayu yang direkatkan dengan arah sejajar serat menggunakan perekat berupa lem. Penelitian ini bertujuan untuk mengidentifikasi respon struktur pada rumah tinggal menggunakan material kayu glulam dan solid dengan bantuan program ETABS 2016. Berdasarkan analisis yang telah dilakukan, diperoleh nilai periode struktur, gaya geser dasar, dan simpangan antar lantai antara seluruh model menunjukan hasil yang berbeda, perbedaan diakibatkan dari hasil konversi berat jenis dan modulus of elastisity berdasarkan BS EN 1194:1999. Berdasarkan analisis non-linier pushover didapatkan bahwa kayu glulam Nyatoh (kayu kelas III) berada pada level pada kinerja B to IO (Immediate Occupancy), dimana hasil tersebut tidak berbeda jauh dengan kayu solid Bangkirai (kayu kelas I).Kata Kunci: rumah tinggal, kayu glulam, non-linier pushover ABSTRACTGeographical condition of Indonesia has a complex tectonic structure. These conditions create  2-storyhome-planning that require special consideration in terms of strength and rigidity. The use of wood as a construction material in Indonesia is still rarely used. Glulam wood is a wood products engineering made from wooden slats several glued with the direction of the parallel fibers using adhesives. This research aims to identify the structure of the response at home using basic material glulam and solid wood with the help of ETABS 2016 programs. Based on the analysis that has been done, obtained the value of the structure periode, base shear force, and interstory drift between all models show different results, the difference is due to the results of specific gravity conversion and modulus of elasticity base on BS EN 1194:1999. Based on non-linear pushover analysis, it shows that Nyatoh glulam wood (class III wood) was at the level of the B to IO (Immediate Occupancy) performance, where the results were not much different from Bangkirai solid wood (class I wood).Keywords: home livingstructure, glulam wood, non-linear pushover

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