Maria Fátima do Nascimento

Sugarcane bagasse and castor oil polyurethane adhesive-based particulate composite

This paper discusses the potential use of sugarcane bagasse in two different fiber lengths (5 mm and 8 mm) of the same density as a raw material for the production of particleboards, using castor oil-based two-component polyurethane adhesive. The quality of the product that can be manufactured industrially was evaluated based on density, thickness swell (TS), absorption (WA), modulus of elasticity (MOE), modulus of rupture (MOR) in static bending and internal bond (IB), according to the Brazilian NBR 14.810:2006 standard. The results revealed a significant difference between the particleboards made with 5-mm-long fibers and those made with 8-mm-long fibers. An analysis by scanning electron microscopy (SEM) indicates that the interparticle spaces are filled with castor oil-based two-component polyurethane adhesive, contributing to improve the physicomechanical properties of the particleboards. A durability assessment based on accelerated aging tests shows that waterproofed particleboards can be used in moist environments.

Accelerated artificial aging of particleboards from residues of CCB treated Pinus sp. and castor oil resin

Tests simulating exposure to severe weather conditions have been relevant in seeking new applications for particleboard. This study aimed to produce particleboards with residues of CCB (chromium-copper-boron oxides) impregnated Pinus sp. and castor oil-based polyurethane resin, and to evaluate their performance before and after artificial accelerated aging. Panels were produced with different particle mass, resin content and pressing time, resulting eight treatments. Particles moisture and size distribution were determined, beyond panel physical and mechanical properties, according to NBR14810-3: 2006. After characterization, treatments B and G (small adhesive consumption and better mechanical performance, respectively) were chosen to artificial aging tests. Statistical results analysis showed best performances were achieved for waterproof aged samples, of both B and G treatments. As example, in treatment B, MOR and MOE values were 23 MPa and 2,297 MPa, samples before exposure; 26 MPa and 3,185 MPa, 32 MPa and 3,982 MPa for samples after exposure (non-sealed and sealed), respectively.

Oat hulls as addition to high density panels production

Wood panels manufacture show advantages of possibility to use alternative raw materials, as agro-industrial waste. Such products have increasing their importance, representativeness and use around the world, including Brazil, stimulated by the economic and environmental benefits of natural and renewable raw materials.Considering wood-based panels from reconstituted wood, particleboard can be highlighted because it is the most consumed and produced worldwide (Brazilian Association of Wood Panels Industry – ABIPA)

Viabilidade técnica de produção e propriedades de painéis de partículas de casca de amendoim

In this study, the potential use of residues of peanut husks was verified, in order to add value to these materials through the manufacture of panels of particleboards. For this procedure, it was used urea- formaldehyde resin and the panels were mechanical pressed at a temperature of 100 oC. The quality of the panels was evaluated based on the prescriptions of the normative document ASTM D 1037:2006, through physical and mechanical tests of characteristics, such as: density, swelling in thickness, water absorption and static bending. The panels evaluated showed bulk density varying between 0,69 a 0,83 g cm -3 , MOR and MOE between 4,37 - 5,34 MPa and 590 - 700 MPa respectively, for panels with and without preservative treatment. It is possible said to claim, based in the normative document ANSI A208.1:1993, that the material presents a potential for use in internal areas as superficial covering of residential buildings, agricultural buildings, furniture and decorative sectors. Intervention in the board production process is recommended, in order to improve the mechanical properties of the material and enable its structural use.

Painéis de partículas provenientes de rejeitos de Pinus sp. tratado com preservante cca e resina derivada de biomassa

RESUMO – A utilizacao do preservante CCA (sais de cromo, cobre e arsenio) tem sido questionada devido ao impacto relacionado a dispersao, principalmente, do cobre e do arsenio para o ambiente, antes de sua completa fixacao na madeira. Outra questao se relaciona a disposicao indevida dos residuos provenientes da madeira tratada, viabilizando a lixiviacao devido a maior area passivel desses rejeitos sujeita a tal fenomeno. Este trabalho teve como objetivo a producao de paineis de particulas, avaliando o efeito da adicao de residuos de Pinus sp. tratado com sais de cromo, cobre e arsenio (CCA), em associacao com material da mesma especie sem preservantes, alem de alteracoes no teor de adesivo poliuretano a base de mamona empregado na producao. As propriedades dos paineis produzidos foram determinadas conforme recomendacoes da NBR 14810-3: 2006. Por meio de analise estatistica, observou-se que a adicao da madeira tratada proporcionou desempenho superior no inchamento em espessura (2 h), ao passo que esse insumo utilizado na mesma proporcao que a madeira sem preservantes foi significante, obtendo os melhores resultados na adesao interna. Os modulos de ruptura e de elasticidade na flexao nao sofreram influencia das variacoes nos insumos utilizados nos paineis. Os paineis, em grande parte, apresentaram-se em conformidade com os principais requisitos nesse âmbito, mostrando a possibilidade da utilizacao dos referidos insumos na producao, alem da obtencao de um produto com consideravel apelo ambiental. Palavras-chave: Pinus sp.; Paineis aglomerados; Tratamento CCA. PARTICLEBOARDS USING WASTES FROM CCA-TREATED Pinus sp. AND RESIN FROM BIOMASS

Evaluación de Propiedades Físicas y Mecánicas de Tableros OSB Utilizando Técnica de Ensayo No Destructiva

The efficiency of ultrasound techniques to estimate physical and mechanical parameters of commercial Oriented Strand Board (OSB) panels manufactured in Brazil, has been investigated. Among engineered wood products, the OSB is the one that has been increasingly used in building subsystems, all around the world. Also, nondestructive methods are frequently preferred to be applied to wood based materials. Structural OSB/3 panels were tested, being one 15mm thick and the other 25mm thick. The mean velocity values obtained in panels OSB in longitudinal and transversal directions, as well as the significant linear correlation between some physical and mechanical properties, the velocity and dynamic constants suggest the possibility of using ultrasound techniques in OSB quality control.

Painéis OSB fabricados com madeiras da caatinga do nordeste do Brasil

Este trabalho objetivou avaliar a viabilidade da producao de paineis OSB feitos com especies de madeira da caatinga do nordeste do Brasil – marmeleiro (Croton sonderianus Muell. Arg.), jurema-branca (Piptadenia stipulacea (Benth.) Ducke) e catanduva (Piptadenia moniliformis Benth.) – e resina poliuretana bicomponente derivada de mamona. As propriedades investigadas foram: densidade aparente; inchamento em espessura e absorcao de agua, ambos em 2 h e 24 h; modulo de elasticidade e resistencia na flexao, na direcao paralela e na direcao perpendicular ao painel; adesao interna e arrancamento de parafuso em relacao a face, conforme as normas europeias EN. Os resultados das propriedades fisicas e mecânicas obtidas evidenciaram a possibilidade da producao em laboratorio de paineis OSB com as tres especies analisadas, conforme valores medios e variabilidade de propriedades equivalentes as chapas fabricadas em escala industrial, alem de comparados aos requisitos da norma EN 300 (EUROPEAN..., 2006) para paineis dos tipos OSB/3 e OSB/4. Pela analise de variância, os paineis OSB fabricados com strands de madeiras de catanduva apresentaram os melhores resultados para as propriedades mecânicas; para as fisicas, os melhores desempenhos foram provenientes dos paineis feitos com madeira de marmeleiro e jurema-branca.