Effect of conditioning history on the characterization of hardness of thermo-mechanical densified and heat treated poplar wood
-
Tao Li
,
Jia-bin Cai
Abstract
Poplar wood was modified by a combination of thermo-mechanical densification (TMD) and heat treatment (HT) process at five temperatures ranging from 170 to 210°C. A new two-step conditioning method (CM) is suggested, in the course of which the modified wood is submitted to 50°C/99% RH→25°C/65% RH, where RH means relative humidity in the climate chamber. The traditional one-step CM (25°C/65% RH) served as reference. The effects of conditioning history on hardness were observed and analyzed along with the change of dimensional stability. The hardness of the modified wood was lower in the case of the proposed CM due to more set-recovery release, but the extent of that decreased with the HT temperature. For a good hardness, HT200°C should be selected with the proposed CM, which is different from the optimization output of 180°C obtained from the traditional CM. In conclusion, a specific assessment method for the performance characterization of this type of modified wood would be beneficial for the combined TMD and HT processes.
Acknowledgments
The authors are grateful for the support from Doctorate Fellowship Foundation of Nanjing Forestry University, Jiangsu Natural Science Foundation (BK20140974), Swedish Research Council Formas (2014–172), Jiangsu Government Scholarship for Overseas Studies, and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
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Articles in the same Issue
- Frontmatter
- Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin
- 2D NMR characterization of wheat straw residual lignin after dilute acid pretreatment with different severities
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- Fatigue behavior of Japanese cypress (Chamaecyparis obtusa) under repeated compression loading tests perpendicular to the grain
- Influence of strain rate, temperature and fatigue on the radial compression behaviour of Norway spruce
- Effect of conditioning history on the characterization of hardness of thermo-mechanical densified and heat treated poplar wood
- An innovative composite plywood for the acoustic improvement of small closed spaces
- Antioxidant activity of Scots pine heartwood and knot extractives and implications for resistance to brown rot
- Quantitative observation of the foraging tunnels in Sitka spruce and Japanese cypress caused by the drywood termite Incisitermes minor (Hagen) by 2D and 3D X-ray computer tomography (CT)
Articles in the same Issue
- Frontmatter
- Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin
- 2D NMR characterization of wheat straw residual lignin after dilute acid pretreatment with different severities
- Determination of inorganic element distribution in the freeze-fixed stem of Al2(SO4)3-treated Hydrangea macrophylla by TOF-SIMS and ICP-AES
- NMR determination of sorption isotherms in earlywood and latewood of Douglas fir. Identification of bound water components related to their local environment
- The combined effects of initial microfibrillar angle and moisture contents on the tensile mechanical properties and angle alteration of wood foils during tension
- Fatigue behavior of Japanese cypress (Chamaecyparis obtusa) under repeated compression loading tests perpendicular to the grain
- Influence of strain rate, temperature and fatigue on the radial compression behaviour of Norway spruce
- Effect of conditioning history on the characterization of hardness of thermo-mechanical densified and heat treated poplar wood
- An innovative composite plywood for the acoustic improvement of small closed spaces
- Antioxidant activity of Scots pine heartwood and knot extractives and implications for resistance to brown rot
- Quantitative observation of the foraging tunnels in Sitka spruce and Japanese cypress caused by the drywood termite Incisitermes minor (Hagen) by 2D and 3D X-ray computer tomography (CT)
