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Characteristics of the Radio-Frequency/Vacuum Drying of Heavy Timbers for Post and Beam of Korean Style Housings Part I : For Japanese larch round logs with 150 mm and 210 mm in diameter and 2,500 mm in length

  • Lee, Nam-Ho (Department of Wood Science and Technology, Chonbuk National University) ;
  • Zhao, Xue-Feng (Department of Wood Engineering, Beihua University) ;
  • Shin, Ik-Hyun (Department of Wood Science and Technology, Chonbuk National University) ;
  • Park, Moon-Jae (Division of Wood Engineering, Korea Forest Research Institute) ;
  • Park, Jung-Hwan (Division of Wood Engineering, Korea Forest Research Institute) ;
  • Park, Joo-Saeng (Division of Wood Engineering, Korea Forest Research Institute)
  • 투고 : 2010.10.14
  • 심사 : 2010.12.09
  • 발행 : 2011.03.25

초록

The characteristics of radio-frequency/vacuum drying Japanese larch boxed heart round logs with 150 mm and 210 mm in diameter and 2,500 mm in length, subjected to compressive loading, after the pretreatment of kerf were investigated. The results of this study were as the follows: The drying time of about 120 hours~130 hours was needed from green to about 15 percent of moisture content. The gradient of final moisture content for all specimens was very gentle in both longitudinal and transverse directions owing to dielectric heating. The surface checks seriously occurred although the occurrence extent of surface check for the kerfed specimens was slight compared with that for the control specimens because drying stress was relieved by kerf. The occurrence of surface checks for the L-specimen was more serious than that for the S-specimen.

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참고문헌

  1. Avramidis, S., F. Liu, and B. J. Neilson. 1994. Radio-frequency/vacuum drying of softwood: drying of thick western red cedar with constant electrode voltage. Forest Products Journal 44(1): 41-47.
  2. Harris, R. A. and M. A. Taras. 1984. Comparison of moisture content distribution, stress distribution and shrinkage of red oak lumber dried by a radio- frequency/vacuum drying process and a conventional kiln. Forest Products Journal 34(1): 44-54.
  3. Helsing, G. and R. D. Graham. 1976. Saw kerfs reduce checking and prevent interal decay in pressure-treated Douglas-fir poles. Holzforschung 30(6): 184-186. https://doi.org/10.1515/hfsg.1976.30.6.184
  4. Kanagawa, Y. 1989. Resin distribution in lumber dried by vacuum drying combined with radiofrequency. Proc. of the IUFRO International Wood Drying Symposium. Seatle, Washington, USA: 158-163.
  5. Lee, N. H., K. Hayashi, and H. S. Jung. 1998. Effect of radio-frequency/vacuum drying and mechanical press-drying on shrinkage and checking of walnut log cross sections. Forest Products Journal 48(5): 73-79.
  6. Lee, N. H. and J. Y. Luo. 2002. Effect of steam explosion treatments on drying rates and moisture distributions during radio-frequency/vacuum drying of larch pillar combined with a longitudinal kerf. Journal of Wood Science 48: 270-276. https://doi.org/10.1007/BF00831346
  7. Yoshida, T., T. Hashizume, and N. Fujimoto. 2000. High-temperature drying characteristics on boxedheart square timber of karamatsu and sugi Influences of high temperature conditions with lowhumidity on drying properties. Mokuzai Kogyo 55(8): 357-362 (in Japanese).