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The need for more technological products increases with nanomaterials as a viable proposal, presenting good results in many different industrial sectors, especially in wood panels. Particleboards are composites of wood that have been extensively studied, mainly in relation to the adhesives used in their manufacture, which have an influence on particleboard properties. Thus, as a way of improving these adhesives, zinc oxide nanoparticles were added, giving new properties to the particleboard. Thereby, the present work aimed to produce particleboard with the wood of Eucalyptus Urophila x Grandis hybrid and urea-formaldehyde adhesive with ZnO nanoparticles addition. The physical tests performed were density, moisture content, and thickness swelling. The mechanical tests performed were the modulus of elasticity, modulus of rupture, and bonding tests. The results obtained were submitted to statistical analysis and compared with the requirements standards, as well as with works found in the literature. The addition of zinc oxide nanoparticles did not exercise influence on mechanical tests; however, the physical properties were improved, mainly decreasing the thickness swelling, which is usually a problem for wood products.

The computer simulation of wood-based products poses a challenge for professionals in the area, as it is a material with anisotropy, whose properties vary according to the species. Among the wood-based composites is CLT (Cross- laminated Timber), manufactured with lamellae arranged in crossed layers and generally used as an element of walls, slabs and floors. The aim of this work was to analyze the stress distribution in numerical models of CLT beams subjected to three-point bending. Three types of constitutive models were evaluated: the linear isotropic; linear orthotropic; and orthotropic with physical nonlinearities, which is obtained with bilinear curves by Hill’s yield criterion. The validation of the numerical models was performed from the experimental load-deflection curves of CLT beams made with Eucalyptus grandis and Toona ciliata (Australian Cedar) loaded until failure. For the simulations, the ANSYS software was used, and the constitutive values of the models were determined from the properties of each lamella. It was concluded that the orthotropic model with physical nonlinearity was closer to the experimental results due to the plastic deformation of the beam. The highest values of von Mises stresses were concentrated at the supports and at the point of application of the load for the Australian Cedar beam, while the stresses were higher in the inner layer of the Eucalyptus beam, due to the rolling shear effect. From the numerical simulation, it was possible to justify the failure modes obtained experimentally.

The development of new materials for the construction sector is a global trend, and products that use by-products in their composition and have also incorporated technology are commercially competitive. Microparticles have large surface areas and can modify the microstructure of materials, positively affecting their physical and mechanical properties. In this context, this study aims to investigate the effect of incorporating aluminium oxide (Al2O3) microparticles on the physical and mechanical properties of oriented strand boards (OSBs) made from reforested residual balsa and castor oil polyurethane resin and to evaluate their durability performance under accelerated aging conditions. The OSBs were produced on a laboratory scale with a density of 650 kg/m3, strand-type particles measuring 90 × 25 × 1 mm3, using castor oil-based polyurethane resin (13%) and Al2O3 microparticle content ranging from 1% to 3% of the resin mass. The physical and mechanical properties of the OSBs were determined following the EN-300:2002 recommendations. The results obtained indicated that the OSBs with 2% Al2O3 presented thickness swelling significantly lower (at the 5% significance level) after being subjected to accelerated aging and internal bonding of the particles higher than the values obtained for the references, evidencing the positive effect of including Al2O3 microparticles in balsa OSBs.

Tendo em vista o grande potencial do mercado de produtos derivados de madeira no Brasil, destacando-se o setor de painéis, estudos voltados para aplicação de novas tecnologias na fabricação dos mesmos são imprescindíveis. É preciso obter painéis mais resistentes a esforços, ao contato com água e agentes biodegradadores, porém sem aumentar os custos de produção. Sendo assim, considerando a tendência atual do estudo de materiais nanopartículados, este trabalho teve como objetivo apresentar um levantamento das principais pesquisas relacionadas a adição de nanopartículas em painéis de madeira. Verificando-se que, apesar das constantes melhoras em suas propriedades físico-mecânicas, ainda é preciso maior aprofundamento no tema.

O resíduo florestal é todo e qualquer material que resulta da colheita ou do processamento da madeira que possa permanecer sem utilização definida no processo. As cinzas advindas de queima de carvão têm sido amplamente utilizadas em pesquisas, no entanto, trabalhos com o uso de cinzas de biomassa ainda são recentes. O objetivo dessa pesquisa consistiu em verificar a viabilidade da inserção de cinzas no traço de um compósito cimento-madeira. Foram realizados testes físicos para a determinação das propriedades físicas, densidade, inchamento e absorção de água, sendo também avaliada a inibição do cimento com os materiais adicionais e a temperatura de hidratação da mistura. Para as cinzas foram realizados testes para a obtenção do seu teor, avaliação da composição química, análise da distribuição granulométrica e espectroscopia de infravermelho com a transformada de Fourier (FTIR). A mistura com a cinza apresentou resultado superior com relação a mistura sem a cinza nas propriedades de densidade e inchamento, dando indícios de que a utilização da cinza de biomassa é recomendada na fabricação de materiais cimentícios compósitos com resíduo de madeira, pois pode contribuir com menor degradação do material que será avaliado em testes de durabilidade na sequência deste estudo.

Made available in DSpace on 2022-04-29T08:40:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Biomass has great potential for energy production, due to its renewability and low cost. The use of biomass as an energy source has intensified in Brazil, especially the use of agro-industrial waste. For a more appropriate use and the valorization of these residues it is necessary the knowledge of the chemical composition, which directly influences the energetic levels of biofuels. The main characteristics are the volatile matter and the High Heating Value (HHV). The aim of this paper was to evaluate the energy potential of agro-industrial waste through volatile matter and its HHV. The residues were soybean hull, peanut hull, sugar cane bagasse, sweet sorghum bagasse and tomato processing residue, which were compared with sawdust from Pinus sp. and Eucalyptus saligna. The HHV tests and volatile matter were performed according to the ASTM E 711-87 (2004) and E 872-82 (2013) standards, respectively. Results showed that the value of HHV of the residues varies from 18,418 to 24,844 ° MJ ° kg-1, as for the immediate analysis, the found values in the test of volatile materials and the fixed carbon content were close to pine and eucalyptus wood. Among the studied agro-industrial residues, the tomato-processing residue stood out due to its higher HHV. However, all residues indicate technical feasibility of using it for energy production. Universidade Estadual Paulista Júlio de Mesquita Filho Campus Experimental de Itapeva, Itapeva-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Engenharia de Guaratinguetá Campus de Guaratinguetá, Guaratinguetá-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Tecnológicas Campus de Dracena, Dracena-SP Universidade Estadual Paulista Júlio de Mesquita Filho Campus Experimental de Itapeva, Itapeva-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Engenharia de Guaratinguetá Campus de Guaratinguetá, Guaratinguetá-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Tecnológicas Campus de Dracena, Dracena-SP

Os compósitos madeira-cimento são formados por uma mistura de cimento Portland, água e resíduos de madeira em fibras ou partículas, aplicando-se principalmente em painéis, obtendo-se um destino aos resíduos da indústria madeireira. Fatores como a espécie, tratamento e dimensão das partículas de madeira interferem no desempenho físico e mecânico dos compósitos e por isso são continuamente investigados na literatura. Dessa forma, nesse trabalho apresentou-se uma análise físico-mecânica experimental de compósitos madeira-cimento com resíduos de Pinus sp. e bambu da espécie Dendrocalamus giganteus tratados em água quente e analisou-se seus efeitos na densidade, o módulo de elasticidade e o módulo de ruptura obtidos através de ensaio de compressão. Avaliou-se, também, a aplicação de modelos micromecânicos (regras de mistura) na predição do módulo de elasticidade. Por fim, os resultados experimentais foram analisados estatisticamente e o módulo de elasticidade obtido pelos modelos micromecânicos foram comparados aos obtidos experimentalmente.

Made available in DSpace on 2020-12-12T01:46:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The use of particleboards (PB) has increased quickly as an alternative engineered wood product mainly due to its having a better ratio of resistance to weight and more elimination of wood defects, such as the presence of knots. Although the panel industry has been constantly growing, innovations are still necessary to improve the final product. The use of metallic oxide nanoparticles on the wood-based panels has the potential to increase the heat transfer process and improve the physico-mechanical properties. The aim of this work was to evaluate the influence of the addition of zinc oxide (ZnO) nanoparticles in PB, correlating the physical and mechanical properties of the panel with the heat transfer process at 180 °C. The results were compared with the Brazilian standard ABNT NBR 14810-2 (2013) and the European standard EN 312 (2010), as well with works found in literature. The results showed a homogenous heat distribution during the pressing, which improved physical properties, decreasing the 24h swelling from 22.2% to 14.9% and the 24 h absorption from 30.29% to 21.0%. Besides that, MOR values was increased from 11.3 MPa to 14.5 MPa and the MOE from 1880 MPa to 2510 MPa. Department of Mechanical Engineering São Paulo State University (UNESP), Avenida Ariberto Pereira da Cunha Faculty of Engineering and Architecture FUMEC University Department of Civil Engineering Federal University of São Carlos (UFSCar) Department of Structures Engineering Engineering School of São Carlos University of São Paulo (EESC/USP) São Paulo State University (UNESP) Campus of Itapeva, Rua Geraldo Alckmin Department of Mechanical Engineering São Paulo State University (UNESP), Avenida Ariberto Pereira da Cunha São Paulo State University (UNESP) Campus of Itapeva, Rua Geraldo Alckmin

Wood-based panel applications recently have expanded and become increasingly competitive, especially within the furniture and civil construction industries. To remain competitive, such products must present physical properties that meet consumer needs. In this context, the incorporation of nanomaterials is gaining momentum, mainly as a means to improve the physical characteristics of panels, thereby expanding their applications. The aim of this study was to evaluate the physical properties of medium density particleboard (MDP) panels after adding various proportions of nanocellulose in place of water to the urea-formaldehyde (UF) adhesive in MDP panel production. The results showed that the addition of nanocellulose resulted in no significant statistical difference in the density and moisture content of the panels. When tested for thickness swelling, only the panel with 100% nanocellulose solution exhibited a significantly higher value. The panels were subjected to scanning electron microscopy (SEM) analysis, which showed that the addition of nanocellulose led to a more polished, less irregular surface. Such physical effects of nanocellulose can potentially make panels more suitable for coating applications. The feasibility of coatings on nanocellulose MDP panels can be verified through future tests to determine the surface roughness of the panels.

Cement-based composites with lignocellulosic residues (e.g. wheat straw, rice husk, and bagasse) as fillers have reduced density and cost. Pretreatments have been applied in these raw materials to improve their compatibility with cement. This work aimed to characterize composites made from cement and wheat straw particles that had been chemically treated (2% NaOH solution) at two different temperatures (30 °C and 60 °C). Values of bulk density (209 kg·m-3) and specific density (679 kg·m-3) were determined for wheat straw at 12% moisture content. Straw yield was 71.9% and the particle size distribution showed large concentrations of wheat straw particulate material between 5- to 10-mesh. Composites made with wheat straw particles, in comparison to the control treatment, showed half the density, i.e., from 1800 to 900 kg·m-3. Also, the stress x strain curve presented a higher deformation before failure. NaOH pretreatment did not affect the mechanical properties of wheat straw composites.

The use of wood-base panels in humid environments, in general, presents low durability due to contact with water. In order to increase durability and reduce the attack of fungi, studies had been developed using resin with zinc oxide (ZnO) nanoparticles. This work aimed to produce medium density fiberboard with urea-formaldehyde resin and melamine-formaldehyde adding 0.5% and 1.0% of ZnO nanoparticles for the physical properties evaluation. All treatments were classified as medium density according to ABNT NBR 15.316-2 (2015) with values ranging between 550 and 800 kg*m-³. No differences were found between the two commercial adhesives used. The addition of 1.0% of nanoparticles resulted in lower density panels, higher moisture contents, and, after immersion in water for 24 hours, higher values of swelling in thickness. These results are explained by the lower compaction of the boards due to rapid cure of the adhesive using higher percentages of ZnO nanoparticles. The best treatment of the panels was with melamine-formaldehyde resin and 0.5% of nanoparticles.

O uso de nanopartículas tem ganhado espaço no mercado, principalmente pela capacidade de atribuir novos comportamentos e novas propriedades a diferentes produtos. Assim, o uso de nanopartículas em painéis particulados revela a possibilidade de aprimoramento do desempenho desses, com novas alternativas para suas aplicações. Com isso, este trabalho avaliou a adição de 0,5% de nanopartículas de Al2O3 e CuO em painéis MDP produzidos com ureia-formaldeído e prensados a 150 ºC, verificando a interferência do material adicionado e analisando suas propriedades físicas. Os ensaios físicos analisados foram, inchamento, absorção, densidade e teor de umidade. Os resultados obtidos foram comparados com as normas NBR 14810-2:2018, EN 312:2003 e ANSI 208-1:2009, bem como com trabalhos da literatura, mostrando que a adição das nanopartículas proporciona um pequeno aumento da densidade dos painéis, sem interferência no teor de umidade, indicando também que o desempenho em contato com a água sofre influência da interação adesivo-madeira.

Made available in DSpace on 2021-07-14T10:49:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-13. Added 1 bitstream(s) on 2021-07-14T11:39:10Z : No. of bitstreams: 1 S1678-86212021000100023.pdf: 748403 bytes, checksum: 7b3f33e40d372cbdfc5c907755ba1fc1 (MD5) Coordenação de Aperfeiçoamento de Pessoal do Ensino Superior Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Painéis OSSB (Oriented Structural Straw Board) são compósitos produzidos com palha proveniente de resíduos agrícolas e utilizando de adesivo sem formaldeído, cuja principal aplicação se volta para a construção civil como material de fechamento e forros. Este trabalho teve como objetivo avaliar o efeito do teor de poliuretano no adesivo sobre propriedades físicas e mecânicas do OSSB produzido com SbS (palha de soja) localmente disponível. Quatro composições de poliuretano à base de óleo de mamona (6%, 9%, 12% e 15%, em relação à massa de palha) foram testadas. Painéis OSSB foram avaliados de acordo com os padrões europeus para compósitos à base de madeira; também, uma caracterização física e química da SbS foi realizada. A SbS possui formato irregular, o que reduziu o desempenho mecânico do OSSB devido à baixa densificação do compósito e ao desenvolvimento de trincas transversais na SbS após o processo de fabricação do compósito. O desempenho em testes de flexão estática e inchamento de espessura do OSSB não foi melhorado pelo aumento do teor de adesivo de poliuretano. A SbS apresentou baixo teor de cinzas (menos que 4.3%) e pH neutro, isto indica que estas propriedades químicas provavelmente não afetaram na cura do adesivo. Oriented Structural Straw Board (OSSB) panels are composites made from straw originally from agricultural residues and non-formaldehyde based adhesive, whose main application is for construction as a closing and ceiling material. The objective of this study was to evaluate the effect of the polyurethane adhesive content on physical and mechanical properties of OSSB produced with locally available SbS (soybean straw). Four castor oil based polyurethane ratios (6%, 9%, 12% and 15%, by mass of the SbS) were tested. OSSB was evaluated according to European standards for wood-based composites; also, a physical and chemical characterization of the SbS was performed. SbS has an irregular shape, which reduced the OSSB mechanical performance due to the low densification of the composite and the development of transversal cracks on the SbS after the OSSB manufacturing process. The static bending and thickness swelling performance of SbS OSSB was not improved by the increase of polyurethane adhesive content. SbS low ash content and neutral pH extractives indicates that probably its chemical properties should not affect the setting of the adhesive. Universidade Estadual Paulista Universidade de São Paulo Universidade Federal de São Carlos Universidade Estadual Paulista Coordenação de Aperfeiçoamento de Pessoal do Ensino Superior: 001; #131765/2018-3; #2018/00801-7 CNPq: 001; #131765/2018-3; #2018/00801-7 FAPESP: 001; #131765/2018-3; #2018/00801-7

Made available in DSpace on 2021-06-25T10:27:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This research aims to investigate, with the aid of the Brazilian standard NBR 7190, analysis of variance (ANOVA—5% significance) and the regrouping bootstrap technique, the influence of the provenance regions Bonfim, Mucajaí and Claudia on the physical and mechanical properties (twenty properties and 720 determinations) of Angelim-pedra (Hymenolobium petraeum Ducke.) and to assess the possibility of estimating, via regression models (152 in all), the physical and mechanical properties investigated as a function of apparent density (ρ12) and compressive strength parallel to the grain (fc0). The results indicated equivalence in most of the physical and mechanical properties, evidencing the small influence of the tree harvest regions. From the regression models, some were considered significant by ANOVA (at the 5% level of significance), which implies that variations in ρ12 and fc0 explain variations in the values of the other estimated properties; however, the low precision indicates that it is not feasible to estimate the variables just based on the ρ12 or fc0. Department of Civil Engineering Federal University of São Carlos Araguaia Engineering Institute Federal University of Southern and Southeastern Pará Department of Mechanical Engineering Federal University of São João del-Rei Department of Production Engineering Federal University of São Carlos College of Industrial Timber Engineering São Paulo State University (UNESP) Department of Civil Engineering São Paulo State University (UNESP) Department of Structural Engineering University of São Paulo College of Industrial Timber Engineering São Paulo State University (UNESP) Department of Civil Engineering São Paulo State University (UNESP)

Made available in DSpace on 2020-12-12T01:31:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Accurate estimation of average modulus of elasticity in compression parallel to the grain (Ec0) is of paramount importance for rational sizing of timber structures, given the use of this property in the estimation of stability of compressed parts (ultimate limit state, ULS) and in calculation of excessive strains (serviceability limit state, SLS). In Brazil, if values cannot be experimentally determined, ABNT NBR 7190 (1997) allows for estimation of Ec0 through relations to average modulus of elasticity both in tension parallel to the grain (Et0) (Ec0 = Et0) and in bending (EM) (Ec0 = EM/0.90). This research aimed to access the efficiency of these relations by testing 30 tropical wood species. The analysis of variance results showed that Ec0 and Et0 were statistically equal. However, Ec0 and EM/0.90 were not statistically equal, and the method of least squares resulted in a coefficient of 0.98, which was 8.89% higher than the one suggested by ABNT NBR 7190 (1997) and close to 1, thus, validating the results of ANOVA, which pointed on the equivalence between Ec0 and EM (Ec0 = EM). As an alternative to simplified equations of the standard, two-parameter regression models were used. The geometric model with R = 91.67% proved to be the model of best fit, which demonstrated that Ec0 could be calculated as a function of EM. Department of Civil Engineering Federal University of São Carlos (UFSCar) Institute of Engineering of Araguaia Federal University of Southern and Southeastern Pará (UNIFESSPA) Federal Institute of Santa Catarina (IFSC) São Paulo State University (UNESP) Federal University of Minas Gerais (UFMG) Department of Structural Engineering University of São Carlos (EESC/USP) São Paulo State University (UNESP)

Plywood can be used in the furniture industry and in civil construction due to its structural strength. However, for long useful life in construction, especially in tropical countries, it needs to undergo treatments against xylophagous organisms. The most common preservative treatment is the chemical chromated copper arsenate (CCA); there are alternatives, such as heat treatment, that do not use chemicals. The objective of this work was to evaluate the mechanical resistance of CCA and heat-treated plywood prepared at three different temperatures (160 °C, 180 °C, and 200 °C). Pinus taeda plywood with seven veneers and phenol-formaldehyde adhesive was produced and subjected to the preservative treatments. The results showed that the CCA treatment reduced the mechanical strength of the panels, while the heat treatment did not. Heat treatment also decreased panel hygroscopicity, indicating a better dimensional stability.

Nos últimos anos o setor florestal vem se destacando por inovações tecnológicas e criações de novos materiais e produtos. Com isso, a geração de resíduos referente ao processamento da madeira ainda é um grande problema para o segmento, pois embora as novas tecnologias apresentem maquinários mais modernos, o volume gerado ainda é bastante significativo. Com a expressiva geração de resíduos nas indústrias de base florestal, surge à necessidade de utilizar tais resíduos de modo a agregar valor aos mesmos e minimizar o impacto ambiental proporcionado. Neste segmento de novos materiais à base de madeira a partir de resíduos como fonte de matéria-prima pode-se destacar os painéis, principalmente, particulados (MDP) e de fibras (MDF). O MDP faz parte da nova geração de Painéis de Partículas de Média Densidade, onde suas características são superiores e totalmente distintas dos painéis de madeira aglomerada de antigamente. A partir desta disposição do mercado madeireiro definiu-se o objetivo do presente estudo, que consistiu em produzir o painel de madeira a partir de resíduos de Eucaliptus. sp. e avaliar o comportamento da resistência mecânica frente à variação da porcentagem granulométrica das partículas da camada interna do painel, produzidos a partir de resíduos. A caracterização mecânica foi embasada no documento normativo da Associação Brasileira de Normas Técnicas ABNT-NBR 14810-2/2013. Os resultados obtidos foram analisados estatisticamente e, em seguida comparados com a norma brasileira bem como, trabalhos encontrados na literatura.

Made available in DSpace on 2020-12-10T19:49:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01. Added 1 bitstream(s) on 2021-07-15T15:06:47Z : No. of bitstreams: 1 S1516-14392019000700278.pdf: 828426 bytes, checksum: 6f781343cc2246d1e6445db1f8e67105 (MD5) research group Biomass and Bioenergy of UFSCar -Sorocaba campus Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Eucalyptus bark is a waste generated in large volume and has been used as a source of energy. This study tries to use the Eucalyptus sp. bark as a source of raw material for the charcoal production and to study the influence of pyrolysis temperatures on charcoal properties. Charcoal was produced at different temperatures: 300, 400 and 500 degrees C, and their properties were determined by proximate analysis, higher heating value and thermogravimetric analysis. It was observed that higher pyrolysis temperature resulted in increase of the fixed carbon content and higher heating value. In the thermogravimetry and derivative thermogravimetry curves it was possible to determine the differences in the thermal stability of charcoal produced. It can be concluded that the eucalyptus bark charcoal is an alternative for the energy reutilization of this waste and also can be used as charcoal for heating. Univ Estadual Paulista Juleo de Mesquita Filho, Dept Engn Mecan, Av Ariberto Pereira da Cunha 333, BR-12516410 Guaratingueta, SP, Brazil Univ Fed Sao Carlos, Dept Ciencias Ambientais, BR-18052780 Sorocaba, SP, Brazil Inst Fed Educ Ciencia & Tecnol Sao Paulo, BR-18202000 Itapetininga, SP, Brazil Univ Estadual Paulista, Dept Engn Eletr, BR-12516410 Guaratingueta, SP, Brazil Univ Estadual Paulista, Campus Itapeva, BR-18409010 Itapeva, SP, Brazil Univ Estadual Paulista Juleo de Mesquita Filho, Dept Engn Mecan, Av Ariberto Pereira da Cunha 333, BR-12516410 Guaratingueta, SP, Brazil Univ Estadual Paulista, Dept Engn Eletr, BR-12516410 Guaratingueta, SP, Brazil Univ Estadual Paulista, Campus Itapeva, BR-18409010 Itapeva, SP, Brazil CAPES: 001

Particleboards were made using particles from sugarcane bagasse and eucalyptus residues of the pulp industry. The particleboard properties were evaluated according to ABNT NBR 14810-1 (2013), ABNT NBR 14810-2 (2013), and ANSI A208.1 (1999) standards, which compared the efficiency of castor oil-based polyurethane resin (PU-Castor) and urea-formaldehyde resin (UF). The particleboards were composed of 60% wood particles and 40% bagasse, with a 10% adhesive dose based on the dry mass of particles. The following parameters were evaluated: apparent density, moisture content (MC), thickness swelling after 24 h, modulus of rupture (MOR), modulus of elasticity to static bending (MOE), and internal bond strength of panels (IB). The results obtained demonstrated the potential use of eucalyptus and sugarcane bagasse residues in the production of high-density particleboards. The panels produced with PU-Castor showed greater efficiency, and their physical and mechanical properties were compatible with the requirements of the Brazilian standard for P4 panels (structural panels for use in dry conditions) and the American standard for H-3 panels (high industrial density).

Made available in DSpace on 2018-11-12T17:27:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01. Added 1 bitstream(s) on 2021-07-14T17:51:21Z : No. of bitstreams: 1 S1678-86212018000300227.pdf: 888905 bytes, checksum: 22fd990606591d5846a362f4864d3623 (MD5) Resumo Esta pesquisa objetivou avaliar a influência do período de exposição ao intemperismo (0, 1, 2, 3 e 4 meses), do tipo de agente preservante (CCA ou CCB) e do tipo de revestimento superficial (resina à base de óleo de mamona ou à base de água com filtro solar) nos valores da rugosidade (Ra) de painéis de partículas fabricados com madeira de Pinus sp. e resina poliuretana à base de mamona, assim como, investigar a possibilidade da estimativa da rugosidade em função dos valores dos parâmetros colorimétricos (L*, a* e b*). Os valores de rugosidade (entre 0,07 e 2,82 µm) foram inferiores a 12,5 µm, o que categoriza os painéis produzidos na classe N10 da norma ABNT NBR 8404 (1984), evidenciando assim, a potencialidade dos compósitos fabricados. O uso do revestimento com resina poliuretana forneceu os menores valores da rugosidade, além disso, as rugosidades dos painéis envelhecidos durante os quatro meses foram estatisticamente equivalentes, o que demonstra o bom desempenho dos materiais fabricados quanto às intempéries, e a boa qualidade obtida dos modelos de regressão multivariáveis (R2 = 77,02%) evidenciam a possibilidade da estimativa da rugosidade por meio de parâmetros colorimétricos. Abstract The aim of this research was to evaluate the influence of the period of exposure (0, 1, 2, 3 and 4 months), the type of preservative agent (CCA and CCB) and the surface coating type (castor oil based polyurethane resin; water-based open pore coating with sunscreen) in the roughness values (Ra) of particleboards manufactured with wood Pinus sp.and castor oil based polyurethane resin, as well as to investigate the possibility of roughness estimation as a function of the measurements of colorimetric parameters (L*, a* and b*). The results of the roughness values (between 0.07 µm and 2.82 µm) were lower than 12.5 µm, which categorizes the panels produced in the N10 class of ABNT NBR 8404 (1984) standard, thus showing the potentiality of the composites manufactured. The use of the castor oil based polyurethane resin coating gave the lowest values of roughness and the roughness values of the aged panels during the four months were statistically equivalent, evidencing the good performance of the fabricated materials. The good quality obtained from the multivariable regression models (R2 = 77.02%) show the possibility of estimating the roughness by colorimetric parameters. Universidade de São Paulo Universidade Federal de São Carlos Universidade Estadual Paulista Júlio de Mesquita Filho Universidade Estadual Paulista Júlio de Mesquita Filho

RESUMO O compensado é um painel de madeira que pode ser utilizado tanto na indústria moveleira quanto na construção civil, devido ao seu uso estrutural. Entretanto, para ser utilizado na construção civil, o compensado necessita ser resistente aos agentes xilófagos e à umidade, sem comprometer suas propriedades mecânicas. Nesse aspecto, a termorretificação surge como uma alternativa de tratamento, que aumenta a resistência da madeira ao ataque de fungos e a sua estabilidade dimensional. Desse modo, o objetivo deste trabalho foi avaliar o efeito da termorretificação na qualidade de colagem de lâminas de madeira para a produção de compensado. Para isso, foram realizados os testes de molhabilidade utilizando o goniômetro digital, para lâminas tratadas nas três temperaturas e na amostra de controle. Além disso, foi realizado, o ensaio de cisalhamento na linha de cola, para testar a qualidade da colagem segundo a ABNT NBR ISO 12466-1 (2006). Com os resultados obtidos pode-se perceber que a superfície da madeira tratada se tornou mais hidrofóbica com o aumento da temperatura, e isso resultou também na diminuição da resistência ao cisalhamento na linha de cola, pois o adesivo utilizado (fenol-formaldeído) é à base de água, contudo, os requisitos normativos foram atendidos. ABSTRACT Plywood is a wood panel that can be used both in the furniture industry and in construction due to its structural use. However, to be used in construction, it needs to be resistant against wood decay agents and water, without compromising its mechanical properties. The heat treatment is an alternative treatment which improves the wood resistance to fungi and improves its dimensional stability. Thus, the objective of this study is to evaluate the influence of the heat treatment with three different temperatures, 160, 180 and 200°C in the wettability of wood veneers and the shear strength in the bond line of the plywood produced with them. To do so, it was carried out the wettability testing using digital goniometer in the treated veneers at three temperatures and for the control specimen. Besides, it was carried out the shear strength in the bond line test, for testing the quality of bonding according to ABNT NBR ISO 12466-1 (2006). Because of the results obtained, it could be seen that the surface of the treated wood became more hydrophobic with increasing temperature, and this also resulted in a decrease in shear strength in the bond line, once the adhesive used (phenol-formaldehyde) is water based, however, the regulatory requirements have been met.

Studies that estimate technological properties of tropical wood species (especially those from the Amazon Rainforest) for their use in building construction, mainly structures, are very desirable. This paper aimed to investigate, aided by ABNT NBR 7190 (1997) recommendations, by Kruskal-Wallis analysis of variance (ANOVA), and regrouping bootstrap simulation technique, the influence of procurement sites (Caracarai and Bonfim do Sul, State of Roraima, Brazil) and Claudia (State of Mato Grosso, Brazil) on physical and mechanical properties of a Cupiuba wood species (Goupia glabra Aubl.). It was intended to assess the possibility of estimating (by linear, exponential, geometric, and logarithmic mathematical models) the physical and mechanical properties investigated as a function of density at 12% of moisture content. The results of ANOVA indicated equivalence in 94% of the properties of the Caracarai and Claudia sites, and no equivalence in 50% of the properties in the Bonfim site; even after extrapolation by the bootstrap simulation technique, the non-equivalence was still 44%. Results obtained from the regression models implied a possibility of an estimate of the physical and mechanical properties of Cupiuba wood species using density as the estimator.

This research aimed to produce and determine physical and mechanical properties of three-layered particleboard produced with Pinussp. wood particlesand three different times of press, i.e., 3, 5 and 7 minutes. Recommendations of the Brazilian standard ABNT NBR 14810 [1] were adopted to fundament physical and mechanical tests. The properties evaluated were the modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending; internal bond; thickness swelling; water absorption; moisture content and apparent density.The mean values showed, for the physical properties, that all the panels manufactured achievedthe requirements of theBrazilian standard, and for mechanical properties, only the panelsmanufacturedwith 7minutesofpressing timemet therequirements. From the Tukey test results, timesof the pressingcycleinfluencedsignificantlyin allinvestigatedphysical and mechanicalproperties, showed better results the panels madewithseven minutesof the pressingcycle, implyingthat the time ofseven minutesof the pressingcycle is thebest among theinvestigatedperiodsin the manufactureofparticleboard.