Amós Magalhães de Souza

Influence of Proportion Polyol/Pre-Polymer Castor-Oil Resin Components in Static Bending Properties of Particleboards Produced with Pinus sp.

The aim of this research is to evaluate the influence of castor-oil based polyurethane resin formulation (particularly proportion pre-polymer/polyol) in static bending properties of particleboards produced with Pinus sp. wood specie. Results related to modulus of rupture (MOR) and modulus of elasticity were determined. Four proportions polyol/pre-polymer were evaluated: 0.75:1; 1:1; 1:1.25; 1:1.5. Results showed improvement in MOR and MOE with increase of pre-polymer component. Proportion 1:1.25 (poliol: pre-polymer) was considered the most interesting once employs the least amount of the petroleum-derived component.

Effect of Alternative Wood Species and First Thinning Wood on Oriented Strand Board Performance

This study aimed to evaluate the feasibility of using and influence of alternative wood species such as Cambara, Parica, Pinus, and wood from first thinning operations on oriented strand board (OSB) physical and mechanical properties. Besides that, an alternative resin, castor oil-based polyurethane, was used to bond the particles, due to the better environmental performance when compared to other resins commonly used worldwide in OSB production. Physical properties such as the moisture content, thickness swelling, and water absorption, both after 2 and 24 hours of water immersion, and mechanical properties such as the modulus of elasticity and resistance in static bending, in major and minor axes, and internal bonding were investigated. All tests were performed according to European code EN 300:2006. Results showed the influence of wood species on physical and mechanical properties. Panels made with higher density woods such as Cambara presented better physical performance, while those made with lower density woods such as Pinus presented better mechanical properties. Besides that, strand particle geometry was also influenced on all physical and mechanical properties investigated. Therefore, the feasibility of using alternative species and wood from first thinning and with castor oil-based polyurethane resin in OSB production was verified.

Production of Structural OSB with Cajueiro (Anacardium sp.) and Amescla (Trattinikia sp.) - A Preliminary Study

The purpose of this research is to demonstrate, in an original study, the potentiality of the use of Cajueiro (Anacardium sp.) and Amescla (Trattinikia sp.), two low density tropical wood species, for producing OSB (Oriented strand boards), structural panels that replace plywood for several building purposes. In those panels, wood strands can be disposed in a specific direction or in random distribution, in order to reach the desirable mechanical properties. In this case, the strands were oriented by a separator to generate layers in mass proportion 20:60:20 (outer, inner and outer layers). Then these pre-panels went to a pre-pressing to form the mattress. Finally, they were pressed at 100°C, by 10 minutes, under 4.5MPa pressure, using castor oil based bicomponent polyurethane resin as adhesive. They were produced eight panels (four with Cajueiro e four with Amescla), with nominal dimensions 350mm length, 350mm width and 10mm thickness. Results showed that these wood species can be used to produce OSB, mainly considering values obtained in mechanical tests, that are superior to OSB produced in Brazilian enterprises and can be classified as OSB/4, as recommended by European standard EN 300. Research should continue to be developed in order to reach more adequate performance in swelling and water absorption.