• 제목/요약/키워드: 임산공학

검색결과 68건 처리시간 0.022초

Effects of Polyethylene Glycol Treatment for Improvement of Preservative Penetration and Prevention of Drying Check of Preservative Treated Round Post (방부처리 원주가공재의 방부제 침윤도 향상 및 건조 할렬 방지를 위한 폴리에틸렌 글리콜 처리 효과)

  • Lee, Jong-Shin;Yoon, Sun-Mi
    • Journal of the Korean Wood Science and Technology
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    • 제30권4호
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    • pp.27-32
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    • 2002
  • We investigated the effect of polyethylene glycol(PEG) treatment of preservative treated green japanese cedar(Cryptomeria japonica) round posts on their preservative penetration and check formation during the air drying. The round rods were dip-treated in 10% preservative solution of Basilit CFK for 1 day, followed by application(3, 5, and 10 times) with 50% PEG-400 solution, and then dried for 30 days under natural conditions. The rate of preservative penetration into sapwood was a low by 23.2% without PEG treatment, whereas that was a high by about 51.2~64.5% with PEG treatment. From these results, it was assumed that PEG played an affirmative role in the penetration of preservative components loaded onto the surface of round rods by dipping. During the air drying, the formation of drying checks decreased significantly with increasing application times of PEG. Even though some drying checks in PEG treated rods were developed, the number and size of checks was reduced remarkably by PEG treatment. After 2 months of outdoor exposure, PEG treatment failed to reduce checking in preservative-treated rods whereas finishing of polyurethane resin lacquer after PEG treatment was significantly effective in preventing check development.

Application of Korean Rhus Lacquer Containing Tung Oil For Exterior Coatings (동유를 함유하는 목조주택 외장용 옻칠도료의 적용)

  • Song, Byong-Min;Lee, Byoung-Hoo;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • 제31권4호
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    • pp.81-90
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    • 2003
  • In this study, we investigated the weathering properties of Korean Rhus lacquers containing tung oil and their potential use as exterior coatings. The finished lacquers were prepared with a raw Korean Rhus lacquer or refined Korean Rhus lacquer content of 10, 20, 30 and 40 wt.% (corresponding to ratios of 10/90, 20/80, 30/70 and 40/60 by weight of Korean Rhus lacquer/tung oil, respectively). The curing temperature of the prepared lacquer increased with increasing the content of the raw Korean Rhus lacquer. This increased curing temperature is related to higher proportion of hydroxyl groups in the prepared lacquer, due to the content of the raw Korean Rhus lacquer. In accelerated weathering testing, the changes in the gloss and contact angle of the prepared lacquers showed a similar trend to that of traditional exterior oil stain. In addition, the prepared lacquers containing tung oil showed greater discoloration than traditional exterior oil stain. However, the discoloration of the prepared lacquer with a raw Korean Rhus lacquer content of 40 wt.%, and that of the prepared lacquer with refined Korean Rhus lacquer contents of 30 wt.% and 40 wt.%, showed a similar trend to that of traditional exterior oil stain. Consequentially, these prepared lacquers showed a potential for being used as exterior coatings.

Manufacturing of Korean Paper(Hanji) with Indian Mallow (Abutilon avicennae Gaertner) as the Alternative Fiber Resources(I) - Productivity and Pulping Characteristics of Indian Mallow - (대용섬유자원으로써 어저귀를 이용한 한지제조(제1보) - 어저귀의 건물 생산량 및 펄프화 특성 -)

  • Jeong, Seon-Hwa;Cho, Nam-Seok;Choi, Tae-Ho
    • Journal of the Korean Wood Science and Technology
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    • 제30권2호
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    • pp.144-150
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    • 2002
  • Indian mallow is characterized by the rapid growth and high harvest of the fibrous materials. This study was carried out to investigate the sheet properties of Hanji using Indian mallow, made by different pulping methods, such as alkali and sulfomethylated pulpings and different stock compositions, various mixing ratios of bast fiber, woody core and whole stalk fibers. The results from this study were summarized as follows. The length and width of the bast fibers were 1.40-430 mm(av. 235 mm), and 9.2-26.4 ㎛(av.18.3 ㎛), respectively. The cell wall thickness was 4.0-115 ㎛(av. 7.7 ㎛). Runkel ratio, flexibility coefficient and fiber length/fiber width ratio were 1.38, 0.42 and 128 respectively. Bast fiber and whole stalk were cooked by alkali and sulfomethylated methods. Sulfomethylated pulping resulted in superior pulp in terms of yield and quality as compared with those of alkali pulping. The pulp yields of bast fiber was higher than those of whole stalk

Evaluation of Bending Property on Principal Domestic Speciees (주요 국산수종의 휨가공성 평가)

  • Jung, In-Suk;Lee, Weon-Hee;Chang, Jun-Pok;Bae, Hyun-Mi
    • Journal of the Korean Wood Science and Technology
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    • 제30권2호
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    • pp.87-94
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    • 2002
  • This study was carried out to evaluate bending property on principal domestic species such as sargent cherry(Prunus sargentii), bitter wood(Picrasma quassioides), horn beam(Carpinus laxiflora), cork oak(Quercus variabilis), birch(Betula schmidtii), painted maple(Acer mono), basswood(Tilia amurensis), red pine(Pinus densiflora), pitch pine(Pinus rigtda), royal pawlonia(Paulownia tomentosa) by microwave heating. In this study, radius of curvature(ROC) for bending process was classified by radius of curvature(ROC) of bending plate such as 4 cm, 6 cm, and 10 cm, and thickness of metal-strap(TMS) was 0.6 mm and 0.8 mm. Bending process was successfully operated for 100 percent in bitter wood, horn beam, birch and painted maple. On the other hand, there was a success rate of 58 percent in sargent cherry and 83 percent in cork oak and 29 percent in basswood and 8 percent in royal pawlonia which is the worst bending property. All specimens of basswood and royal pawlonia were broken at 4 cm of ROC. Success rate of bending property was shown 44 percent in red pine and 56 percent in pitch pine. TMS has an effect on only drying speed in drying process than difficulty and facility of bending property. It was considered that the thinner TMS in drying process is the faster in drying speed of bent wood.

Classification of Insects Collected in Historical Wooden Building (목조 고건축물에서 채집된 곤충의 분류)

  • Jeong, In-Soo;Lee, Yang-Soo;Lee, Hee-Kwon
    • Journal of the Korean Wood Science and Technology
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    • 제31권2호
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    • pp.52-57
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    • 2003
  • This research is to collect, classify and identify the insects boring tunnels into wood or damaging wooden frame structure. Intensive insect collections have been carried at the historical local schools annexed to the confucian shrine from March to September 2001. Ten species of Coleoptera, 15 species of Hymenoptera, 6 species of Hemiptera, 4 species of Ditera and 1 species of Demaptera were recorded. Most species of Coleoptera and Hymenoptera have the manducatory apparatus in the mouth-part that cause severe damage in wood, and showed the highest population among the genera recorded. Further research should be considered on the identification of wood demage insects at the species level among present collection and their mechanism of wood demage in the wood.