WOOD RESEARCH Volume 67, Number 5, 2022
Matheus Viana De Souza, Pedro Henrique Da Silva Cazella, Sérgio Augusto Mello Da Silva, Felipe Reis Rodrigues, Marjorie Perosso Herradon, Fabíola Medeiros Da Costa, Márcia Regina De Moura Aouada, Fauze Ahmad Aouada, Herisson Ferreira dos Santos, Edna Moura Pinto, Victor Almeida De Araujo, André Luis Christoforo, and Roberto Vasconcelos Pinheiro

Comparative study of particleboards with Hevea brasiliensis waste from different production and moisture configurations

After the production cycle of latex, Hevea brasiliensis trees become residual living plants for this activity, although their woody trunks are still potentially subject to industrial utilization. Bio-composites derived from rubberwood particles were manufactured using two different configurations as a strategy to examine the potential of this species with respect to mechanical behavior. Homogeneous panels were developed from particles at the saturation condition, and heterogeneous panels were obtained from dry particles conditioned at 12% moisture content. Both examples were heat-pressed and glued with castor oil-based polyurethane resin. Density,short-term water absorption and thickness swelling, modulus of rupture and modulus of elasticity in the static bending and perpendicular tensile were evaluated. Panels derived from rubberwood particles proved to be viable according to the technical standards.

WOOD RESEARCH Volume 64, Number 2, 2019
Zhou Qiaofang, Chen Chuanfu, Zhao Xiangyu, Tu Dengyun, and Li Kaifu

The effect of thermal modification by hot pressing on the some physical and mechanical properties in rubberwood (Hevea brasiliensis)

Rubberwood (Hevea brasiliensis) was thermal modified by hot pressing in an open system at three different temperatures (170, 185, 200°C) and two different durations (1.5, 3 h), and the effect on the physical and mechanical properties was studied. Results show that the thermal modification increased the oven-dried density and decreased the EMC (equilibrium moisture content) by 7.93% and 37.15%, respectively, and the dimensions stability was improved. Hardness, bending strength, modulus of bending and compressive strength parallel to grain of modified samples basically decreased with increasing temperature and time, but they showed a meaningful increase compared to control samples. However, impacting bending and nail withdrawal resistance decreased after hot pressing and thermal treatment, and the failure of the compensation for the impairment was the rubberwood hot pressed and thermal treated in the presence of air, and the participation of oxygen provoked rapid degradation reactions during the treatment.

WOOD RESEARCH Volume 64, Number 1, 2019
Xiangyu Zhao, Dengyun Tu, Chuanfu Chen, and Qiangfang Zhou

Prediction of the mechanical properties of thermally-modified rubber wood on the basic of its surface characteristic

The goal of this research was to investigate the effect of thermal treatment on mechanical properties and surface characteristic of rubberwood (Hevea brasiliensis) and find the mathematical model to predict the mechanical properties used by its surface characteristic. Rubberwood specimens were treated by steaming at five different temperature levels of 170, 185, 200, 215, and 230°C for two different durations of 1.5 and 3 h. Based on the results, the values of bending strength, modulus of elasticity, compression strength and impact bending decreased, and the glossiness and chromatic aberration (∆E) increased with increasing temperature and enlarging duration further. This study revealed that chromaticity parameters b*, ∆E and the gloss of perpendicular to grain (GZT) could evaluate the mechanical properties of thermally-modified wood to achieve the mechanical properties detection without destruction.

WOOD RESEARCH Volume 66, Number 1, 2021
Zhipeng Zhu, Dengyun Tu, Ziwei Chen, Chuanfu Chen, and Qiangfang Zhou

Effect of hot pressing modification on surface properties of rubberwood (Hevea brasiliensis)

This research aims to investigate the effect of thermal modification by hot pressing on surface characteristics of rubberwood. For this purpose, rubberwood specimens were thermally modified by hot pressing in an open system at three different temperatures (170, 185, and 200°C) for two different durations (1.5 or 3 h). Based on the results, the values of chromatic aberration (ΔE), contact angle and glossiness increased, and roughness decreased with increasing temperature and enlarging duration further. Although the contact angle had increased, it was still less than 90°. This aesthetic surface of rubberwood could be retained by using transparent organic coatings. The thermally modified rubberwood with excellent performance could be used as a material for solid wood flooring, wallboard, and furniture applications.