RESUMO Este trabalho teve como objetivo analisar o desempenho de juntas coladas de madeiras da espécie Pinus elliottii com a utilização de dois adesivos comerciais à base de poliacetato de vinila (PVAc), com diferentes características físicas e composição química, ambos testados nas formas diluída em água e não diluída. As superfícies dos corpos de prova de madeira foram usinadas em processo de fresamento discordante. Uma plaina desengrossadeira de madeira com cabeçote de quatro facas afiadas de aço carbono semi-rápido à base de Cr-Ni-V foi utilizada. Essa máquina foi preparada para atuar com velocidade de corte (Vc) de 30,18 m.s-1 e velocidade de avanço da madeira (Vf) de 11,75 m.min-1, resultando num avanço por dente (fz) de 0,56 mm. Os corpos de prova foram confeccionados para ensaios de resistência a ruptura na linha de cola por esforços solicitantes ao cisalhamento de acordo com a ABNT NBR 7190:1997. Para a confecção dos corpos de prova, as peças foram coladas de maneira aleatória em relação aos planos de formação dos anéis de crescimento da madeira. Os seguintes valores médios de resistência ao cisalhamento na linha de cola (fv0), na forma diluída e não diluída foram, respectivamente, PVAc-M: 6,52 e 6,49 MPa; PVAc-H: 5,86 e 5,15 MPa. Em relação à resistência ao cisalhamento na linha de cola, concluiu-se que ambos adesivos na forma diluída com 33,33 % de água resultaram em maior adesão em relação à formulação original, sendo que o adesivo diluído do tipo M proporcionou um aumento de 21,01% na resistência à ruptura em relação ao adesivo não diluido do tipo “H”.

ABSTRACT This study aimed to analyze the performance of bonded joints of the Pinus elliottii wood species with the use of two commercial adhesives based on vinyl polyacetate (PVAc) with different physical characteristics and chemical composition, both tested on water diluted and undiluted modes. The surfaces of wood specimens were machined in discordant milling process. A wood thickness planer with headstock of four semi-fast carbon steel sharpened knives based on Cr-Ni-V was used. This machine was prepared to operate with cutting speed (Vc) of 30.18 ms-1 and feed rate of wood (Vf) of 11.75 m.min-1, resulting in an feed rate per tooth (fz) of 0.56 mm. The specimens were prepared for tests of resistance to rupture in the glue line by the shear stress efforts according to the ABNT NBR 7190:1997 standard. In order to specimen preparation, the parts were randomly glued in relation to the formation plans of the wood growth rings. The following average values of shear strength in the glue line (fv0) obtained in diluted and undiluted forms were, respectively, PVAc -M: 6.52 and 6.49 MPa; PVAc -H: 5.86 and 5.15 MPa. In relation to the shear stress at the glue line, it was concluded that both adhesives in diluted form with 33.33% of water resulted in higher adhesion strength in comparison to the original formulation, whereas the diluted adhesive type M provided an increasing of 21.01% regarding the undiluted adhesive of type H.

Compósitos de matriz polimérica reciclada reforçados com farinha de madeira podem ser uma alternativa viável para a substituição da madeira e de polímeros virgens em materiais empregados em pisos, batentes de portas, janelas e revestimentos externos. O objetivo desta pesquisa foi determinar alguns parâmetros físicos e mecânicos de compósito com farinha de madeira de Pinus taeda e elliotti e polipropileno reciclado, sem o emprego de compatibilizantes ou aditivos. Os compósitos foram separados em quatro traços, sendo eles: 100% polipropileno, 90% polipropileno com 10% de farinha de madeira, 80% de polipropileno com 20% de farinha de madeira e 70% de polipropileno com 30% de farinha de madeira. Para caracterização do compósito foram utilizadas as normas ASTM D-638-10, ASTM D256-00, ASTM D570-98, ASTM D1238-10 e ASTM G-155-05 e também a análise de superfície por microscopia eletrônica de varredura. Os ensaios de estabilidade dimensional apresentaram resultados satisfatórios. Mesmo o compósito com maior porcentagem de farinha de madeira (30%) apresentou um melhor índice de fluidez de 10,0MFI, sendo considerado compatível com os índices para PP (polipropileno) virgem da norma ASTM D-1238-10. A inclusão de farinha de madeira (FM) proporcionou a obtenção de compósitos com boas características mecânicas que podem ser aplicados na fabricação de diferentes materiais, empregados especificamente em ambientes externos.

Recycled polymer matrix composites reinforced with wood flour can be a viable alternative for the replace-ment of wood and virgin polymers in materials used in floors, door frames, windows and external cladding. The objective of this research was to determine some physical and mechanical parameters of composite made with Pinus taeda and elliottii wood flour (WF) and recycled polypropylene (PP), without the use of compatibilizers or additives. The composites were separated into four traits, namely 100% PP, 90% PP with 10%, WF 80% PP with 20% WF and 70 % PP with 30% WF. The characterization of the composite followed the standards ASTM D-638-10, ASTM D256-00, ASTM D570 -98, ASTM D1238 -10 and ASTM G 155-05, it was also employed the surface analysis by scanning electron microscopy. The dimensional stability tests showed satisfactory results. Even the composite with a higher percentage of wood flour (30%) had a flow index of 10 MFI, considered compatible with that observed for PP (polypropylene) virgin by standard ASTM D 1238-10. The inclusion of wood flour (FM) afforded composites with good mechanical characteristics which can be applied in manufacture of different materials, specifically employed outdoors.

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.

The objective of this study was to evaluate the density, density profile, water swelling and absorption, modulus of elasticity and rupture from static bending, and tensile strength of experimental medium-density fiberboards manufactured using Dendrocalamus giganteus (Munro bamboo). The fiber production was carried out through the chemo-thermo-mechanical pulping process with four different conditions. The panels were made with 10% urea formaldehyde resin based on dry weight of the fibers, 2.5% of a catalyzer (ammonium sulfate) and 2% paraffin. The results indicate that treatments with the highest alkali (NaOH) percentage, time and splinter heating temperature improved the physical properties of the panels. The root-fiber interface was evaluated through scanning electron microscopy in fracture zones, which revealed fibers with thick, inflexible walls. The panels' mechanical properties were affected due to the fiber wall characteristics and interaction with resin. Giant bamboo fiber has potential for MDF production, but other studies should be carried out.

ABSTRACT The design and production process of the workshop shed made of bamboo presented in this paper is the result of almost two years of cooperation between “Viverde” Farmers Association, “Universidade Estadual Paulista” and “Unisol”. The system consists of rounded aroeira pillars, a roof structure formed by in natura bamboo frames and metal connections. The development of the parts and connections detailing, through the technical drawing of each component, enabled the development of standardized precision fittings aiming at optimizing the execution and saving time, energy and raw material on the assembly line. In this process, the creation and improvement of templates was necessary in order to facilitate the assembly of parts. The component assembly phases were recorded at the Experimental Laboratory for Bamboo and Wood Processing - UNESP/FEB. The results showed the good performance of the pre-fabrication process of bamboo components.

RESUMO O projeto e o processo de produção do galpão oficina em Bambu apresentado neste trabalho é fruto de quase dois anos de cooperação junto à Associação de Agricultores Viverde, Universidade Estadual Paulista e Unisol. O sistema é composto de pilares de aroeira roliça, estrutura de cobertura formada por pórticos em bambu in natura e conexões metálicas. O desenvolvimento do detalhamento das peças e ligações, por meio de desenhos técnicos de cada componente, permitiu a elaboração de encaixes com precisão e padronização com vistas à otimização da execução, economia de tempo, de matéria-prima e de energia na linha de montagem. Nesse processo, fez-se necessário a criação e o aprimoramento de gabaritos para facilitar a montagem das peças. Foram registradas as etapas de montagem dos componentes junto ao Laboratório Experimental de Bambu e Processamento de Madeiras da UNESP/FEB. Os resultados obtidos permitem concluir o bom desempenho do processo de pré-fabricação de componentes de Bambu.

The compaction rate, the relation between the density of the wood panel and the density of the wood used for producing the particles, is an indicator of the product's densification. Among the various types of wood panels, particleboards are widely employed in the lumber industry, mainly for the furniture production. This paper presents a study of the relation between the compaction rate and the properties of tensile strength perpendicular to surface, Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) obtained from a static bending test, thickness swelling and water absorption (2 and 24 hours). These properties were calculated according to the Brazilian ABNT, NBR 14810 standard. Particleboards were produced using the species Pinus elliotti and adhesive ureaformaldehyde. The relation was established by a multiple linear regression, and the most appropriate statistical models were determined. The estimated models indicate statistically significant effects of water absorption in 2 hours and MOR in the particleboards' compaction rate.