Abstract
This study aimed to reduce the loss of mechanical strength in heat-treated rubberwood by rapid cooling. Heat-treated rubberwood specimens were prepared by controlling their cooling rate during the cooling phase of the heat treatment. The effects of cooling rate on the physical properties, chemical composition, and mechanical properties of heat-treated rubberwood were evaluated. Results indicated that cooling rate significantly influenced mass loss (ML). ML in heat-treated rubberwood cooled at 6 °C min−1 decreased by 23% relative to that in heat-treated rubberwood subjected to natural cooling. Compared with the heat-treated rubberwood subjected to natural cooling, the heat-treated rubberwood that was cooled at 4.5 °C min−1 increased in modulus of rupture (MOR), surface hardness, and screw withdrawal strength (tangential section) by 26, 8, and 16%, respectively. The cool rates exerted less effects on the dimensional stability, surface color, modulus of elasticity (MOE), compressive strength parallel to grain (CS), and screw withdrawal strength (radial section) of the heat-treated rubberwood. The application of rapid cooling to wood heat treatment could efficiently shortened the heat treatment period, thus increasing productivity.
Award Identifier / Grant number: 2017A050501030
Funding source: National Natural Science Foundation of China
Award Identifier / Grant number: 31770601
Funding source: South China Agricultural University
Acknowledgments
The authors acknowledge the technical support from the South China Agricultural University and its laboratory. We thank all participants who contributed to this research.
Research funding: The authors acknowledge the financial support from the Science and Technology Plan Project of Guangdong Province of China (grant no. 2017A050501030) and the National Natural Science Foundation of China (grant no. 31770601).
Conflicts of interest: None.
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