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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

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

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).

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.

This research aimed to evaluate the influence of storage time (0, 96 hours) ofPinus elliottiipieces and the tests to obtaining modulus of elasticity (static bending and transversal vibration) in glued laminated timber beams, produced with resorcinol based adhesive and 0.8 MPa compaction pressure. After pieces were properly prepared, part of them was used in immediate three manufacturing glulam beams, tested after adhesive cure, and part stored for 96 hours under a roof with a temperature of 25°C and relative humidity of 60% for subsequent manufacturing and testing three other glulam beams. Results of analysis of variance (ANOVA) revealed that the storage period was significant influence in modulus of elasticity obtained in static bending test (8% reduction from 0 to 96 hours). This not occurred with modulus of elasticity obtained by transversal vibration test (no significant influence). ANOVA results showed equivalence of means in both test procedures.

This research aimed to develop and evaluation the mechanical properties of a particleboard produced with bamboo particles and coconut fiber in three different experimental conditions. The panels were manufactured with castor oil based polyurethane bi-component resin in three different ratios of the adhesive components (pre-polymer and polyol). Mechanical characterization was conducted to determine modulus of elasticity (MOE) and modulus of rupture (MOR) in static bending. For the static bending test the better values were to the experimental condition 2, which relate de proportion of 1:1.5 of pre-polymer and polyol, respectively. This best solution is to reduce the amount of pre-polymer in the formulation of the adhesive, due to decreased of use of chemicals most polluting.

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

The objective of this article was to study the influence of the Pinus taeda wood moisture content to the production of EGP (Edge Glued Panel) in the bonding stage, using PVA adhesive. It was analyzed the joint resistances through shear-stress tests and rupture in the bondline. The wood moisture classes adopted to the panels were: “A” ( [8%, 9%[ ), “B” ( [9%, 10%[ ), “C” ( [10%, 11%[ ), “D” ( [11%, 12%[ ) e “E” ( [12%, 13%[ ). After the panel production, it was sawn the specimens for the resistance shear in the bondline tests by traction. The tests results show that it was statistically significant differences to the values of rupture tensions between A class and B, C, D and E classes. The wood medium rupture presented a tendency to reduce with the moisture increase, and the total rupture in the bondline presented a small tendency of a less number of occurrences with the rupture tension increases.

Made available in DSpace on 2015-03-18T15:56:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-01. Added 1 bitstream(s) on 2021-07-15T15:00:48Z : No. of bitstreams: 1 S1517-70762014000100002.pdf: 499334 bytes, checksum: 9e55165e2f358a739e8a678626cb0e2d (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This study evaluated the physical and mechanical characteristics of particleboards made of bamboo waste from the species Dendrocalamus giganteus bonded with two different types of adhesives: urea-formaldehyde (UF) and a castor oil based adhesive (M). Thus, eight types of particleboards were produced in the proportions of 6%, 8%, 10% and 12% for each adhesive. The results showed that particleboards produced with UF and M adhesives had acceptable behavior for physical tests according to the Brazilian standard NBR 14810. The results attained in mechanical tests (MOR and MOE), for all particleboards, were below the requirements for structural usage. This indicates that the residue of bamboo is a feasible raw material alternative for particleboards produced for non structural purposes, such as liners, partitions and other uses for internal seal. Regarding the adhesives, the particleboards produced with UF particleboards showed superior results for both physical and mechanical characteristics, when compared to M particleboards with the same percentage of adhesive. Univ Estadual Paulista Julio de Mesquita Filho UN, Fac Engn Bauru, Programa Posgrad Engn Prod, Sao Paulo, Brazil Univ Estadual Paulista Julio de Mesquita Filho UN, Fac Engn Ind Madeireira, Sao Paulo, Brazil Univ Estadual Paulista Julio de Mesquita Filho UN, Fac Engn Bauru, Programa Posgrad Engn Prod, Sao Paulo, Brazil Univ Estadual Paulista Julio de Mesquita Filho UN, Fac Engn Ind Madeireira, Sao Paulo, Brazil FAPESP: 07/59434-9

This study aimed to produce and determine physical and mechanical properties of three layers particleboards produced with Eucalyptus sp. particles, in outer layers, and Eucalyptus urograndis e Eucalyptus saligna bark, in internal layer. Recommendations of the Brazilian Code ABNT NBR 14810-3:2006 were adopted to fundament physical and mechanical tests. Properties considered were modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending; internal adhesion; thickness swelling; water absorption; moisture content and density of the panels. Four different panel compositions were studied, with 5, 10, 15 and 20% of bark (related to particle mass) the internal layer. Results were compared with the requirements of: Brazilian Code ABNT NBR 14810-2; European Code EN 312 and related literature. The produced panels were adequate to all the values stipulated the cited codes and also superior to similar studies found in the literature, for all compositions of bark in internal layer, except for the moisture content test, in which only the composition of 5 % hull met the normative specifications.

This research aimed to investigate, by means of the strength (MOR) and stiffness (MOE) properties in bending, the homogeneity in the manufacture of ply wood (Pinus sp wood and phenolic resin) produced by an industry located in the state of Parana (PR - Brazil). The factors and levels investigated in this study were the choice of panels (A, B, C and D), the extraction position of the specimens (Center; Side) and fiber orientation (Parallel, Perpendicular), providing a fu ll factorial design of 4 1 2 2 type, with 16 different treatments. On the panel, were extracted 20 specimens (500×75×18mm) for bending tests. ANOVA results showed that the choice of panel and fiber orientation was significant in the properties of strength and stiffness in bending, this is not occurring with the ext raction position of the specimens. The MOR and MOE of the specimens obtained in the parallel d irection were 87% and 141% h igher than the MOR and M OE of the specimens evaluated in the perpendicular direction, respectively, and with respect to non-equivalence found between the mechanical properties by the choice of the panel, for results with greater reliability it is necessary the development of new research with a significantly higher number o f ply wood.

The growing popularity of wooden panels renders this market segment increasingly competitive. MDF (Medium Density Fiberboard), in particular, is widely employed for a variety of applications, including civil construction, furniture, and packaging. This paper discusses a study of MDF produced from alternative raw materials, i.e., Eucalyptus fibers and castor-oil-based polyurethane resin. Physical and mechanical tests were performed to determine the MDF's modulus of elasticity and modulus of rupture in static bending tests, its swelling, water absorption, moisture and density. The results of the physical and mechanical characterization of this laboratory-produced MDF are discussed and compared with the Euro MDF Board standard. MDF produced with eucalyptus fiber and castor-oil-based polyurethane resin presents results very satisfactory.