2007 Fiscal Year Final Research Report Summary
Study on Recovery of the Shrinkage and Deformation of Excavated Waterlogged Wooden Objects Treated by PEG method
| Project/Area Number |
16500641
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cultural property science
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| Research Institution | Gangoji Research Institute of Archaeology, Cultural Anthropology, and Conservation Science |
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Principal Investigator |
INOUE Michiko Gangoji Research Institute of Archaeology, Cultural Anthropology, and Conservation Science, 研究部, Engineer (70223279)
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| Co-Investigator(Kenkyū-buntansha) |
ITOU Kenji Gangoji Institute for Research of Cultural Property, 研究部, Researcher (00176330)
UEDA Naomi Gangoji Institute for Research of Cultural Property, 研究部, Researcher (10193806)
HUJITA Hiroaki Gangoji Institute for Research of Cultural Property, 研究部, Engineer (50344403)
山田 卓司 財団法人元興寺文化財研究所, 研究部, 研究員 (30435903)
ITOU Kenji Gangoji Institute for Research of Cultural Property, Researcher (00176330)
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| Project Period (FY) |
2004 – 2007
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| Keywords | Polyethylene glycol / Shrinkage / Deformation / Recavery method / Excavated Water-logged Wooden objects / Sodium hydroxide / Water content / Chestnut tree |
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| Research Abstract |
The impregnation treatment using PEG (Polyethyleneglycol #4000) is well known to be effective for the conservation of excavated waterlogged wooden objects. However, in many cases, this treatment induces serious problems, shrink and deformation of the wooden subjects. Therefore, in this research, the recovery for the shrinkage and deformation of those wooden objects treated by PEG to their original shape are studied in detail.
Through the soaking experiments using many solutions, we found that soaking of the deformed test samples for Oak, Chestnut, Japanese Chestnut and camphor tree in a 0.5% NaOH solution was useful to recover the original shape from the PEG-impregnated ones.
It is said that when the concentration of NaOH solution is over 9%, natural cellulose changes to Na-cellulose. Also, the sodium hydroxide is known to be easily removed with water, Na-cellulose returns easily to natural cellulose, as reported by Uda (1968). However, we have expected that NaOH solution only swell the natural-cellulose when we applied a 0.5% NaOH solution. Therefore, we have to examine whether NaOH not only swell cellulose, but also not form Na-cellulose, as we expected.
As a result of weight and dimension measurements and diffraction X-ray analysis of the PEG-treated wooden specimens, it was found that the weight and the tangential length slightly decreased after 10 days from starting day of soaking in water..In order to ensure the above recovery method we have to realize whether the NaOH residue is in the wood after recovery or not. It is also important to study the effects of the agent against the other agents used for re-treatment after recovering.
As another problem the 0.5% NaOH solution became black during soaking of test pieces, probably due to the degraded ingredients of wood. In order to prevent this phenomenon, we further need to analyze what they are and modify the appearance of the final PEG-impregnated specimens for excavated waterlogged wooden objects.
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Research Products
(10 results)
