Influence of the treatment of Pinus sp. veeners with boron salts on plywoods properties
Name: AMANDA MOTA NUNES
Publication date: 16/02/2017
Advisor:
Name |
Role |
|---|---|
| DJEISON CESAR BATISTA | Advisor * |
| JUAREZ BENIGNO PAES | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| DJEISON CESAR BATISTA | Advisor * |
Summary: NUNES, A. M. Influence of the treatment of Pinus sp. veeners with boron salts on plywoods properties. 2017. Dissertation (Masters degree in Forest Science) - Universidade Federal do Espírito Santo, Jerônimo Monteiro - ES. Advisor: Prof. Dr. Djeison Cesar Batista. Co-advisor: Prof. Dr. Fabricio Gomes Gonçalves, Prof. Dr. Juarez Benigno Paes.
Studies about plywood preservation are relatively recent in Brazil and they are necessary because of the use of Pinus sp. on its production, which are recognized as low natural durability species. Studies about the use of boron salts on the preservation of wood products aim to potentiate the use of less harmful products to humans and the environment. The aim of this study was to evaluate the influence of the treatment of Pinus sp. veneers with different solutions and concentrations of boron salts on plywoods properties. It was developed in a factorial scheme 3 x 3 + 1, represented by three compounds (boric acid, borax and boric acid + borax) and three concentrations (1%, 3% and 5%), besides a control (untreated), in a completely randomized design. Plywood was produced with three veneers, except the ones for glueline shear strength test (produced with five veneers), previously treated with the different boron solutions by simple immersion for 15 minutes, bonded with urea-formaldehyde which plywood was intended for interior use. Plywood was tested against dry-wood termites (Cryptotermes brevis) and mold (Penicillium sp.). Physical (hygroscopicity, apparent density, water absorption and swelling in thickness) and mechanical (static bending parallel and perpendicular to the fiber and glueline shear strength) properties were assessed. All treatments were efficient against dry-wood termites and mold. Three percent of concentration was the best against dry-wood termites. In general, physical and mechanical properties were more influenced by the raw material, except glueline shear strength, which were negatively affected by the boron compounds. Acid boric (3%) is recommended for treating Pinus sp. veneers intended for good performance plywood (intern use) regarding durability, physical and mechanicals.
Keywords: plywood; boric acid; borax; immersion; xylophages; physical and mechanical properties.
