Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100426
A. C. C. Viana, P. Moraes, W. Weingaertner
Rotary friction welding produces joints by inserting wood dowels, with a specific rotation and feed rate, into pre-drilled holes made in wood substrates. Studies on the welding of fast-growing Eucalypts from Brazilian planted forests are recent. Therefore, this research aimed to evaluate the macro and microstructural and thermochemical changes at the dowel/substrate interface of Eucalypts welded joints from Brazilian planted forests and to determine the mechanical strength of two-piece Eucalypts welded joints. Specimens formed by eucalypts dowels and substrates were produced. Subsequently, visual evaluation and scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric, differential scanning calorimetry and tensile tests were performed. The results reveal that the rotary friction welding parameters adopted contribute to the densification of the welded interface and the formation of a structure responsible for joining the dowel and the substrate, providing mechanical strength to the joint. The cellulose crystallinity index and the apparent crystallite size of the Eucalypts welded sample increase due to thermal degradation of amorphous components. The rupture of the welded joints is ductile and their average strength is 2,1 MPa. Welded joints of fast-growing Eucalypts, from Brazilian planted forests, are suitable when the rotary friction welding parameters are similar to those used for Eucalypts woods from Australian forests.
{"title":"Evaluation of the interface of Eucalyptus specimens welded by rotary friction","authors":"A. C. C. Viana, P. Moraes, W. Weingaertner","doi":"10.4067/s0718-221x2023000100426","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100426","url":null,"abstract":"Rotary friction welding produces joints by inserting wood dowels, with a specific rotation and feed rate, into pre-drilled holes made in wood substrates. Studies on the welding of fast-growing Eucalypts from Brazilian planted forests are recent. Therefore, this research aimed to evaluate the macro and microstructural and thermochemical changes at the dowel/substrate interface of Eucalypts welded joints from Brazilian planted forests and to determine the mechanical strength of two-piece Eucalypts welded joints. Specimens formed by eucalypts dowels and substrates were produced. Subsequently, visual evaluation and scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric, differential scanning calorimetry and tensile tests were performed. The results reveal that the rotary friction welding parameters adopted contribute to the densification of the welded interface and the formation of a structure responsible for joining the dowel and the substrate, providing mechanical strength to the joint. The cellulose crystallinity index and the apparent crystallite size of the Eucalypts welded sample increase due to thermal degradation of amorphous components. The rupture of the welded joints is ductile and their average strength is 2,1 MPa. Welded joints of fast-growing Eucalypts, from Brazilian planted forests, are suitable when the rotary friction welding parameters are similar to those used for Eucalypts woods from Australian forests.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72430479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100431
O. Goktas, Yasar Tahsin Bozkaya, Mehmet Yeniocak
The aim of this study was to determine the usability of selected natural dye extracts as environmentally friendly colorants that are used in painting of MDF based furniture and evaluate their resistance to scratch resistance, adhesion resistance, and surface hardness properties. In this study, the water-based lacquer coatings were prepared with natural dyes obtained from purple cabbage ( Brassica oleracea ), safflower ( Carthamus tinctorius ), Red beetroot ( Beta vulgaris ) and three synthetic paints that were black, blue and light blue as a comparison. Coated MDF test panels used for evaluation of performances of dyes to abiotic factors that are determined by mechanical tests such as scratch resistance, adhesion resistance, and surface hardness. As a result of the study, it has been observed that, except for scratch resistance, natural dyes perform as well as synthetic ones as alternative colorants in the lacquer coatings. Thus, natural and aesthetic raw materials that are environmentally friendly dyes can be used safely especially in children’s furniture and for wood-based products that are especially used indoors.
{"title":"The use of herbal extracts in lacquer paint coloring and determination of some mechanical resistance properties on wood-based surfaces","authors":"O. Goktas, Yasar Tahsin Bozkaya, Mehmet Yeniocak","doi":"10.4067/s0718-221x2023000100431","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100431","url":null,"abstract":"The aim of this study was to determine the usability of selected natural dye extracts as environmentally friendly colorants that are used in painting of MDF based furniture and evaluate their resistance to scratch resistance, adhesion resistance, and surface hardness properties. In this study, the water-based lacquer coatings were prepared with natural dyes obtained from purple cabbage ( Brassica oleracea ), safflower ( Carthamus tinctorius ), Red beetroot ( Beta vulgaris ) and three synthetic paints that were black, blue and light blue as a comparison. Coated MDF test panels used for evaluation of performances of dyes to abiotic factors that are determined by mechanical tests such as scratch resistance, adhesion resistance, and surface hardness. As a result of the study, it has been observed that, except for scratch resistance, natural dyes perform as well as synthetic ones as alternative colorants in the lacquer coatings. Thus, natural and aesthetic raw materials that are environmentally friendly dyes can be used safely especially in children’s furniture and for wood-based products that are especially used indoors.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85851568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100425
R. H. Martins, G. Barbirato, Luiz Eduardo Campos Filho, J. Fiorelli
The production of wood-based materials is currently being expanded by the furniture industry and civil construction sector. In order to find new alternatives for the panel market, new configuration possibilities (geometry) of panels and the use of renewable raw materials must be explored. In this scope, the objective of this research was to evaluate OSB sandwich panels with an undulated core and flat faces (OSBUC panels) made of Balsa wood waste strands ( Ochroma pyramidale) bonded with two-component castor oil polyurethane resin for use in civil construction. Two types of panels were produced with 13 % resin and varying the density of the core (OSBUC-T1 - faces 550 kg/m³ and core 400 kg/m³) and (OSBUC-T2 - faces 550 kg/m³ and core 500 kg/m³). The water absorption and thickness swelling of the face panels were determined based on the Brazilian standard NBR 14810 and the bending test properties of the OSBUC panels determined by the recommendations of the ASTM C393 standard. The results obtained were compared with the specifications of the PS-2-10 – “Performance Standard for Wood-Based Structural-Use Panels” that provides bending stiffness (EI) values and maximum bending moment (FbS) requirements for OSB panels according to different classes of use. The sandwich panels had maximum values of EI 6,48 x 106 N ·mm²/mm and FbS 3065 N·mm/mm. The OSBUC-T1 treatment proved to be the most efficient, as it has mechanical properties that meet the normative recommendations for structural use and as flooring, with lower material consumption (lower density).
{"title":"OSB sandwich panel with undulated core of balsa wood waste","authors":"R. H. Martins, G. Barbirato, Luiz Eduardo Campos Filho, J. Fiorelli","doi":"10.4067/s0718-221x2023000100425","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100425","url":null,"abstract":"The production of wood-based materials is currently being expanded by the furniture industry and civil construction sector. In order to find new alternatives for the panel market, new configuration possibilities (geometry) of panels and the use of renewable raw materials must be explored. In this scope, the objective of this research was to evaluate OSB sandwich panels with an undulated core and flat faces (OSBUC panels) made of Balsa wood waste strands ( Ochroma pyramidale) bonded with two-component castor oil polyurethane resin for use in civil construction. Two types of panels were produced with 13 % resin and varying the density of the core (OSBUC-T1 - faces 550 kg/m³ and core 400 kg/m³) and (OSBUC-T2 - faces 550 kg/m³ and core 500 kg/m³). The water absorption and thickness swelling of the face panels were determined based on the Brazilian standard NBR 14810 and the bending test properties of the OSBUC panels determined by the recommendations of the ASTM C393 standard. The results obtained were compared with the specifications of the PS-2-10 – “Performance Standard for Wood-Based Structural-Use Panels” that provides bending stiffness (EI) values and maximum bending moment (FbS) requirements for OSB panels according to different classes of use. The sandwich panels had maximum values of EI 6,48 x 106 N ·mm²/mm and FbS 3065 N·mm/mm. The OSBUC-T1 treatment proved to be the most efficient, as it has mechanical properties that meet the normative recommendations for structural use and as flooring, with lower material consumption (lower density).","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79712603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100421
Lincoln Audrew Cordeiro, Bruno de Miranda, M. E. Carneiro, A. Missio, U. Klock, P. Cademartori
The finishing quality of wood products depends on the material’s surface and its intrinsic properties. Dynamic wettability is a simple and efficient way to understand the behavior of materials related to solid-liquid interactions according to theoretical and practical perspectives. Thus, we sought to investigate the wettability of Imbuia ( Ocotea spp.), Red oak ( Quercus spp.), and Pine ( Pinus elliottii ) woods and its effects before and after sanding. Through the sessile drop technique, we evaluated contact angle and work of adhesion. Sanding changed the samples’ surface quality due to the decrease in contact angle and the increase in the work of adhesion. In addition, the droplet spreading and adsorption observed on the surface of the woods are an indicator of wettability. Pine and Red oak had their dynamic contact angle reduced by up to 43 %. However, Imbuia was less susceptible to the effects of sanding, since it was found to be a more hydrophobic species; thus, this wood has a more stable surface in terms of dynamic wettability. This may be a result of the effect of low molecular weight compounds on the surface of Imbuia wood. The preparation of the wood surface depends on a synergy between the finishing processes and the chemical composition of the surface. Therefore, the results found can indicate which coatings are more suited to these woods.
{"title":"The effect of sanding on the wettability and surface quality of Imbuia, Red oak and Pine wood veneers","authors":"Lincoln Audrew Cordeiro, Bruno de Miranda, M. E. Carneiro, A. Missio, U. Klock, P. Cademartori","doi":"10.4067/s0718-221x2023000100421","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100421","url":null,"abstract":"The finishing quality of wood products depends on the material’s surface and its intrinsic properties. Dynamic wettability is a simple and efficient way to understand the behavior of materials related to solid-liquid interactions according to theoretical and practical perspectives. Thus, we sought to investigate the wettability of Imbuia ( Ocotea spp.), Red oak ( Quercus spp.), and Pine ( Pinus elliottii ) woods and its effects before and after sanding. Through the sessile drop technique, we evaluated contact angle and work of adhesion. Sanding changed the samples’ surface quality due to the decrease in contact angle and the increase in the work of adhesion. In addition, the droplet spreading and adsorption observed on the surface of the woods are an indicator of wettability. Pine and Red oak had their dynamic contact angle reduced by up to 43 %. However, Imbuia was less susceptible to the effects of sanding, since it was found to be a more hydrophobic species; thus, this wood has a more stable surface in terms of dynamic wettability. This may be a result of the effect of low molecular weight compounds on the surface of Imbuia wood. The preparation of the wood surface depends on a synergy between the finishing processes and the chemical composition of the surface. Therefore, the results found can indicate which coatings are more suited to these woods.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81116075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100428
E. P. Amorim, E. Longui, M. Freitas, F. Yamaji, Francides Gomes da Silva, Marcela Aparecida de Moraes Silvestre, J. Cambuim, Mario Luiz Teixeira de Moraes, P. Gonçalves
The use of wood as a bioenergetic source requires knowledge of its technical properties. The rubber tree Hevea brasiliensis has an economic life cycle of 25 to 30 years in Brazil. It is used for extracting rubber and generating residual wood for fuel. Our goal was to characterize the wood quality of 10 clonal progenies as a source of raw material for bioenergy. Ten clonal progenies of 12-year-old Hevea brasiliensis from an experimental planting in Selvíria municipality were evaluated. Three trees per clone were evaluated for in-dividual properties of Higher Heating Value, immediate chemical
{"title":"Wood quality of ten clonal progenies of rubber tree as raw material for bioenergy","authors":"E. P. Amorim, E. Longui, M. Freitas, F. Yamaji, Francides Gomes da Silva, Marcela Aparecida de Moraes Silvestre, J. Cambuim, Mario Luiz Teixeira de Moraes, P. Gonçalves","doi":"10.4067/s0718-221x2023000100428","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100428","url":null,"abstract":"The use of wood as a bioenergetic source requires knowledge of its technical properties. The rubber tree Hevea brasiliensis has an economic life cycle of 25 to 30 years in Brazil. It is used for extracting rubber and generating residual wood for fuel. Our goal was to characterize the wood quality of 10 clonal progenies as a source of raw material for bioenergy. Ten clonal progenies of 12-year-old Hevea brasiliensis from an experimental planting in Selvíria municipality were evaluated. Three trees per clone were evaluated for in-dividual properties of Higher Heating Value, immediate chemical","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88691889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100424
J. Welling, John Albert Bartolo-Cuba, José Carlos Sánchez-Blanco, Javier Luis Ahrens-Castillo, José Alfredo Ugarte-Oliva
In the Amazonian forests of Perú a large variety of native wood species can be found, of which only a few are commercially exploited. Exploitation is focused on high density durable hardwoods for flooring appli - cations. After selective logging of a few valuable trees the forests often are considered being “unproductive” because there is no market for most of the remaining trees. Having a long-term sustainable forest management and utilization plan in mind, a continuous extraction of more tree species is desirable. For opening out new markets for lesser-used species a concise knowledge of their physical and mechanical properties is essential. Fifteen lesser-used Peruvian wood species were investigated to characterize their wood/water relations. Density, shrinkage behavior, and sorption characteristics were determined. In addition, the functional relation between electrical resistance and moisture content was determined to provide a sound basis for non-destructive moisture content measurements.
{"title":"Wood/water relations of 15 South American lesser-used wood species","authors":"J. Welling, John Albert Bartolo-Cuba, José Carlos Sánchez-Blanco, Javier Luis Ahrens-Castillo, José Alfredo Ugarte-Oliva","doi":"10.4067/s0718-221x2023000100424","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100424","url":null,"abstract":"In the Amazonian forests of Perú a large variety of native wood species can be found, of which only a few are commercially exploited. Exploitation is focused on high density durable hardwoods for flooring appli - cations. After selective logging of a few valuable trees the forests often are considered being “unproductive” because there is no market for most of the remaining trees. Having a long-term sustainable forest management and utilization plan in mind, a continuous extraction of more tree species is desirable. For opening out new markets for lesser-used species a concise knowledge of their physical and mechanical properties is essential. Fifteen lesser-used Peruvian wood species were investigated to characterize their wood/water relations. Density, shrinkage behavior, and sorption characteristics were determined. In addition, the functional relation between electrical resistance and moisture content was determined to provide a sound basis for non-destructive moisture content measurements.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89127679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100420
I. L. Lima, Izabella Vicentin Moreira, Maurício Ranzini, E. Longui, J. Cambuim, M. D. Moraes, J. Garcia
Our goal was to determine physical properties and anatomical features in 33-year-old Hevea brasiliensis clones. We cut wood samples from clones LCB510, RRIM600, IAN873, IAN717 and GT1 planted in Selvíria, Mato Grosso do Sul, Brazil. We used standard techniques in wood studies. We found that clones differ in basic density, volumetric shrinkage and anatomical features, with the exception of ray width. Basic density, volumetric shrinkage, fiber length, fiber wall thickness, vessel element length and vessel diameter tended to in - crease from pith to bark, while vessel frequency propended to decrease. We conclude that wood of the studied clones has potential for industrial use.
{"title":"Physical and anatomical properties of Hevea brasiliensis clones","authors":"I. L. Lima, Izabella Vicentin Moreira, Maurício Ranzini, E. Longui, J. Cambuim, M. D. Moraes, J. Garcia","doi":"10.4067/s0718-221x2023000100420","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100420","url":null,"abstract":"Our goal was to determine physical properties and anatomical features in 33-year-old Hevea brasiliensis clones. We cut wood samples from clones LCB510, RRIM600, IAN873, IAN717 and GT1 planted in Selvíria, Mato Grosso do Sul, Brazil. We used standard techniques in wood studies. We found that clones differ in basic density, volumetric shrinkage and anatomical features, with the exception of ray width. Basic density, volumetric shrinkage, fiber length, fiber wall thickness, vessel element length and vessel diameter tended to in - crease from pith to bark, while vessel frequency propended to decrease. We conclude that wood of the studied clones has potential for industrial use.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78215317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100422
M. Oncel, O. E. Ozkan
Plywood is used for insulation systems in liquid natural gas cargo ships because of its good thermal properties. However, there are only a few research investigating the mechanical properties of plywood exposed to ultra-low temperatures. This study aims to determine how plywood reacts when exposed to ultra-low temperatures, such as - 196 °C. To achieve this purpose, the present study investigated the bending strength, modulus of elasticity, and tensile-shear strength of painted and film-coated plywood under ultra-low temperatures. The mechanical properties of plywood were discovered to be significantly impacted by the ultra-low temperature as a result of this research. Moreover, not only the bending strength of the painted and film-coated plywood in - creased with decreasing temperature, but also the modules of elasticity of the painted and film-coated plywood increased. At decreasing temperature, the tensile shear strength of the painted and film-coated oven-dried plywood increased, but the ensile-shear strength of painted and film-coated air-dried plywood decreased. The tensile shear strength of air-dried plywood was determined to be more sensitive to the temperature change. Therefore, attention should be paid to plywood used in liquefied natural gas cargo ships with high humidity.
{"title":"Effect of ultra-low temperature on some mechanical properties of painted and film-coated plywood","authors":"M. Oncel, O. E. Ozkan","doi":"10.4067/s0718-221x2023000100422","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100422","url":null,"abstract":"Plywood is used for insulation systems in liquid natural gas cargo ships because of its good thermal properties. However, there are only a few research investigating the mechanical properties of plywood exposed to ultra-low temperatures. This study aims to determine how plywood reacts when exposed to ultra-low temperatures, such as - 196 °C. To achieve this purpose, the present study investigated the bending strength, modulus of elasticity, and tensile-shear strength of painted and film-coated plywood under ultra-low temperatures. The mechanical properties of plywood were discovered to be significantly impacted by the ultra-low temperature as a result of this research. Moreover, not only the bending strength of the painted and film-coated plywood in - creased with decreasing temperature, but also the modules of elasticity of the painted and film-coated plywood increased. At decreasing temperature, the tensile shear strength of the painted and film-coated oven-dried plywood increased, but the ensile-shear strength of painted and film-coated air-dried plywood decreased. The tensile shear strength of air-dried plywood was determined to be more sensitive to the temperature change. Therefore, attention should be paid to plywood used in liquefied natural gas cargo ships with high humidity.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86211125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.4067/s0718-221x2023000100429
S. Şahin, B. Esteves, A. Can, H. Sivrikaya, I. Domingos, J. Ferreira, Ü. Ayata
Radiata pine boards were coated with two different methods A and B both beginning with a hydro primer and finishing with a mat oil but method A using an acrylic high gloss coating and method B three layers of an acrylic sealer in between. The samples were subjected to aging processes for 144 h, 288 h, and 432 h by using UV-A 340 nm lamps. The CIE L * a * b * and CIE L * C * H * coordinates were determined ( L *, a *, b *, C *, h o *, Δ E *), gloss (perpendicular ( ) and parallel (//) to the grain at 20°, 60°, and 85° angles) and surface adhesion strength via the pull-off method were tested before and after weathering. Results have shown that lightness ( L *), decreases with weathering for both varnish applications with a higher decrease for the B coating sys - tem. Redness increased for both applications with no significant differences. At the same time there was a yellowing of the samples along the weathering period. Parallel and perpendicular gloss decreased for 20º and 60º angles while it increased for 85º angle. The adhesion strength of method A was higher and its decrease with weathering was smaller than for method B. Both varnish applications have proven to confer some protection against wood discoloration, but method A showed the best results and is therefore the best method to be used by radiata pine.
Radiata松木板采用两种不同的方法A和B进行涂覆，一开始使用水力底漆，最后使用垫油，但方法A使用丙烯酸高光泽涂层，方法B在两者之间使用三层丙烯酸密封剂。在UV-A 340 nm灯下分别进行144 h、288 h和432 h的老化处理。确定了CIE L * a * b *和CIE L * C * H *坐标(L *， a *， b *， C *， H o *， Δ E *)，光泽度(与晶粒垂直()和平行(//)在20°，60°和85°角)，并通过拉脱法测试了风化前后的表面附着力。结果表明，两种清漆的光度(L *)随老化而降低，其中B涂层的光度降低幅度较大。两种应用的发红度都增加了，但没有显著差异。同时，随着风化时间的推移，样品呈黄化趋势。平行和垂直光泽度在20º和60º角度时下降，而在85º角度时增加。与方法b相比，方法A的附着力更高，其随风化的下降幅度更小。两种清漆的应用都证明了对木材变色有一定的保护作用，但方法A显示出最好的效果，因此是辐射松使用的最佳方法。
{"title":"Effects of artificial weathering on the surface properties of coated radiata pine","authors":"S. Şahin, B. Esteves, A. Can, H. Sivrikaya, I. Domingos, J. Ferreira, Ü. Ayata","doi":"10.4067/s0718-221x2023000100429","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100429","url":null,"abstract":"Radiata pine boards were coated with two different methods A and B both beginning with a hydro primer and finishing with a mat oil but method A using an acrylic high gloss coating and method B three layers of an acrylic sealer in between. The samples were subjected to aging processes for 144 h, 288 h, and 432 h by using UV-A 340 nm lamps. The CIE L * a * b * and CIE L * C * H * coordinates were determined ( L *, a *, b *, C *, h o *, Δ E *), gloss (perpendicular ( ) and parallel (//) to the grain at 20°, 60°, and 85° angles) and surface adhesion strength via the pull-off method were tested before and after weathering. Results have shown that lightness ( L *), decreases with weathering for both varnish applications with a higher decrease for the B coating sys - tem. Redness increased for both applications with no significant differences. At the same time there was a yellowing of the samples along the weathering period. Parallel and perpendicular gloss decreased for 20º and 60º angles while it increased for 85º angle. The adhesion strength of method A was higher and its decrease with weathering was smaller than for method B. Both varnish applications have proven to confer some protection against wood discoloration, but method A showed the best results and is therefore the best method to be used by radiata pine.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86058497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-01DOI: 10.4067/s0718-221x2023000100412
F. Henríquez, D. Hernández, Felipe Varas-Concha, Camila Gutierrez, Héctor Quinteros-Lama, J. O. Morales-Ferreiro
Pollutant residential emissions from wood stoves have significant impacts both on the environment and people’s health. The above makes it essential to know the types of volatile organic compounds emitted during combustion and explore their relationship with particulate matter and greenhouse gas emissions. This paper studies and analyzes these emissions using Eucalyptus globulus as fuel varying its moisture levels. Emissions were determined using an adapted commercial stove. The concentration levels of volatile organic compounds and particulate matter increase with the moisture of wood. When analyzing volatile organic compounds, particulate matter, and O 2 with the combustion stages of wood, it is found that their concentrations were higher in the ignition and the reload stage. The concentrations of CO 2 and NO x were higher in the reload stage. Other chemical compounds, such as toluene, xylene, and benzene, were also found within the volatile organic compounds listing, which increased their concentration in the ignition and stable reload stages. However, in the quenching stage, they are not present. Finally, the dispersion of these molecules in the environment is evaluated, obtaining that if the atmospheric conditions are adverse, these molecules remain in the environment in direct contact with the people living in those places.
{"title":"VOCs and PM listing of Eucalyptus globulus combustion in residential wood stoves","authors":"F. Henríquez, D. Hernández, Felipe Varas-Concha, Camila Gutierrez, Héctor Quinteros-Lama, J. O. Morales-Ferreiro","doi":"10.4067/s0718-221x2023000100412","DOIUrl":"https://doi.org/10.4067/s0718-221x2023000100412","url":null,"abstract":"Pollutant residential emissions from wood stoves have significant impacts both on the environment and people’s health. The above makes it essential to know the types of volatile organic compounds emitted during combustion and explore their relationship with particulate matter and greenhouse gas emissions. This paper studies and analyzes these emissions using Eucalyptus globulus as fuel varying its moisture levels. Emissions were determined using an adapted commercial stove. The concentration levels of volatile organic compounds and particulate matter increase with the moisture of wood. When analyzing volatile organic compounds, particulate matter, and O 2 with the combustion stages of wood, it is found that their concentrations were higher in the ignition and the reload stage. The concentrations of CO 2 and NO x were higher in the reload stage. Other chemical compounds, such as toluene, xylene, and benzene, were also found within the volatile organic compounds listing, which increased their concentration in the ignition and stable reload stages. However, in the quenching stage, they are not present. Finally, the dispersion of these molecules in the environment is evaluated, obtaining that if the atmospheric conditions are adverse, these molecules remain in the environment in direct contact with the people living in those places.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90554636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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