Characteristics of radio-frequency/vacuum combined with mechanical press drying of heavy softwood timbers with longitudinal kerf
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Xuefeng Zhao
Abstract
The aim of this study was to evaluate the characteristics of radio-frequency/vacuum combined with mechanical press (RF/VP) drying on three softwood timbers (Douglas fir, Hemlock, and Radiata pine) with longitudinal kerfs. The results were as follows: Due to the dielectric permittivity of wood, RF/VP drying at a fixed frequency of 13.56 MHz significantly influenced the moisture content (MC) distribution, the number of surface checks, shrinkage, and warp. These observations were attributed to the formation of a temperature gradient along the charge plate during the drying. The presence or absence of pith, more affected an occurrence of surface checks than that of the stresses within the wood during drying. The longitudinal kerf reduced the number of surface checks, but did not affect the MC distribution or the twist after drying.
Funding source: Business for Cooperative R&D between Industry, Academy, and Research Institute Korea Small and Medium Business Administration
Award Identifier / Grant number: C0103823
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: This work was supported by Business for Cooperative R&D between Industry, Academy, and Research Institute Korea Small and Medium Business Administration (no. C0103823).
Employment or leadership: None declared.
Honorarium: None declared.
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
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© 2020 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
- Original articles
- Xylan deposition and lignification in differentiating tension wood fibers in Mallotus japonicus (Euphorbiaceae) with multi-layered structure
- Water sorption hysteresis in wood near 100 °C
- Investigation of the material resistance and moisture performance of pubescent oak (Quercus pubescens)
- Fatigue behavior of beech and pine wood modified with low molecular weight phenol-formaldehyde resin
- Characteristics of radio-frequency/vacuum combined with mechanical press drying of heavy softwood timbers with longitudinal kerf
- Surface properties of thermally treated European beech wood studied by PeakForce Tapping atomic force microscopy and Fourier-transform infrared spectroscopy
- Wettability of welded wood-joints investigated by the Wilhelmy method: part 1. Determination of apparent contact angles, swelling, and water sorption
- Wettability of welded wood-joints investigated by the Wilhelmy method: part 2. Effect of wollastonite additive
- Chemical improvement of surfaces. Part 6: enhanced flame retardancy of Scots pine sapwood by covalent modification with phosphorus and boron functionalized benzoates
- Properties of a formaldehyde-free tannin adhesive and mechanical strength of oriented bamboo scrimber board bonded with it
- Annual reviewer acknowledgement
- Reviewer acknowledgement Holzforschung volume 74 (2020)
Articles in the same Issue
- Frontmatter
- Original articles
- Xylan deposition and lignification in differentiating tension wood fibers in Mallotus japonicus (Euphorbiaceae) with multi-layered structure
- Water sorption hysteresis in wood near 100 °C
- Investigation of the material resistance and moisture performance of pubescent oak (Quercus pubescens)
- Fatigue behavior of beech and pine wood modified with low molecular weight phenol-formaldehyde resin
- Characteristics of radio-frequency/vacuum combined with mechanical press drying of heavy softwood timbers with longitudinal kerf
- Surface properties of thermally treated European beech wood studied by PeakForce Tapping atomic force microscopy and Fourier-transform infrared spectroscopy
- Wettability of welded wood-joints investigated by the Wilhelmy method: part 1. Determination of apparent contact angles, swelling, and water sorption
- Wettability of welded wood-joints investigated by the Wilhelmy method: part 2. Effect of wollastonite additive
- Chemical improvement of surfaces. Part 6: enhanced flame retardancy of Scots pine sapwood by covalent modification with phosphorus and boron functionalized benzoates
- Properties of a formaldehyde-free tannin adhesive and mechanical strength of oriented bamboo scrimber board bonded with it
- Annual reviewer acknowledgement
- Reviewer acknowledgement Holzforschung volume 74 (2020)
