Properties of multi-laminated plywood produced with hovenia dulcis thunb. and pinus elliottii wood under different pressing pressures/Propriedades de paineis compensados multilaminados produzidos com madeira de Hovenia dulcis Thunb. e Pinus elliottii, em diferentes pressoes de prensagem

• Published in: Acta scientiarum. Technology 2017-04, Vol.39 (2), p.185
• Main Authors: Bednarczuk, Ezaquel, Hillig, Everton, Dias, Andrea Nogueira, Machado, Joao Fabio, Mustefaga, Erick Chagas
• Format: Article
• Language: Spanish
• ISSN: 1806-2563
• DOI: 10.4025/actascitechnol.v39i2.29496

This study aimed at evaluating the effect of different pressing pressures and the influence of the wood features on the properties of plywood produced with sapwood and heartwood Hovenia dulcis combined with Pinus elliottii. To support the discussion, the anatomical and physical characterizations of the wood were carried out. The panels were produced by applying three different press pressures (0.88, 1.18 and 1.47 MPa) and with six combinations of wood veneers. Phenol-formaldehyde resin was employed, 160 g [m.sup.-2] in a simple line and 35% solid content. The anatomical analysis revealed that the sapwood is more permeable than the H. dulcis heartwood. The H. dulcis wood basic density it was higher than that of the P. elliottii. Increased press pressure raised the values of the apparent density, thickness swelling and thickness swelling plus recovery of the plywood and water absorption reduction. The panels produced with H. dulcis veneers presented higher apparent density, MOR, MOE and bonding line resistance, as well as lower water absorption and moisture content, than those produced with P. elliottii veneers. No difference was noticed regarding the plywood properties when the main effects were evaluated in relation to the use of H. dulcis heartwood and sapwood veneers. Keywords: wood panels, japanese raisin tree, wood veneers, phenol-formaldehyde resin. O estudo avaliou o efeito do uso de diferentes pressoes de prensagem e a influencia das caracteristicas da madeira nas propriedades dos paineis compensados produzidos com laminas de alburno e de cerne da madeira de Hovenia dulcis, e em combinacao com Pinus elliottii. Para subsidiar a discussao, foi realizada a caracterizacao anatomica e fisica da madeira. Os paineis foram produzidos sob tres pressoes (0,88, 1,18 e 1,47 MPa) e em seis combinacoes de laminas de madeira. Utilizou-se resina fenolformaldeido, na gramatura de 160 g [m.sup.-2] em linha simples e teor de solidos de 35%. A analise anatomica mostrou que a madeira de alburno de H. dulcis e mais permeavel que a de cerne e que a densidade basica de ambas foi maior que a de P. elliottii. O aumento da pressao de prensagem causou aumento da densidade aparente, do inchamento e do inchamento mais recuperacao em espessura e reducao da absorcao d'agua dos paineis. Os paineis produzidos com laminas de H. dulcis tiveram maior densidade aparente, MOR, MOE e resistencia da linha de cola, e menor absorcao d'agua e teor de umidade, do que os produzidos com P. ellio