• Journal of the Korean Applied Science and Technology
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• v.21 no.4
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• pp.279-288
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• 2004

Liquid crystal (LC) system was introduced into W/O emulsion in order to enhance the stability and moisturizing effect. The LC system, composed of beeswax, surfactant, and water was formed on the surface of emulsion droplet, which was investigated through a polarized microscope. The phenomenon that the viscosity in W/O emulsion system is decreased with time, was reduced by the formation of LC with the addition of beeswax. Centrifugal separation test showed that the stability of emulsion system was increased with the addition of beeswax to 3%. The color change of vitamin C was delayed in LC emulsion systems, which indicates stabilization effect against the oxidation of vitamin C. Evaporation rate in W/O emulsion was retarded by LC, so that high moisturizing effect is expected in W/O LC system.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.70-78
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• 2012

The Annals of Joseon Dynasty, which recorded governmental affairs for 472 years (AD 1392-1863) during the Joseon dynasty is an representative paper cultural heritage in Korea. Being recognised their authenticity and values they were designated as the No 151 national treasure of Korea in 1973 and registered as 'The Memories of the World' by UNESCO in 1997. Unusually, some volumes of the Annals were treated by beeswax for the permanent preservation. However, the examinations on the deterioration of the beeswax-treated volumes had been exposed the serious damage than the untreated volumes. In particular, the larger amount of beeswax were worst in deterioration condition. In order to solve these problems, NRICH(National Research Institute of Cultural Heritage) of Korea launched the investigation study for the conservation of beeswax-treated volumes of the Annals. Now then, the five study areas have been set up; 1) to understand the damaged condition of the Annals; 2) to analyse the raw materials and production techniques; 3) to test the degradation degree using the duplication samples for understanding the aging factors and mechanism; 4) to develop the conservation techniques through dewaxing and thereafter strengthening the base paper of Hanji; 5) to develop the long-term storage technique using inert gases. On the basis of outcomes from this study, NRICH will plan to establish the systematic conservation and management plan for the beeswax-treated volumes of the Annals in future.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.10-16
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• 2013

This study aims to carry out the final evaluation on the deterioration stability of dewaxing and strengthening treatments devised to conserve and restore the beeswax-treated volumes of the Annals of the Joseon Dynasty. Thus, this study artificially deteriorated dewaxed Hanji, strengthened Hanji and beeswax-treated Hanji with optimized processing conditions applied, and comparatively analyzed the deterioration characteristics of each kind of Hanji. As a result of this study, it turned out that there was the loss of physical strength and the value of $L^*$ was increased and the values of $a^*$ and $b^*$ were decreased from removing beeswax after dewaxing by supercritical fluid extraction (SFE). Also deteriorated strength during dewaxing was reinforced by strengthening treatment with methylcellulose and it showed higher strength than beeswax-treated Hanji. From the evaluation on deterioration stability after dewaxing and strengthening, it turned out that deterioration stability of strengthened Hanji is the superior. Therefore, it is presumed that conservation of aged beeswax-treated Hanji can be improved and extended when dewaxing and strengthening are applied under optimum conditions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.46-52
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• 2010

The annals of Joseon Dynasty has been known as one of the UNESCO's Memory of the World Heritage. The annals of Joseon Dynasty composed with two kind of books, wax coated book and non coated book. Especially the waxed book have been severely damaged by various reason. For the safety preservation of the annals of Joseon Dynasty waxed book, the thermal ageing mechanism of beeswax coated Hanji paper has been evaluated. The weight loss of waxed Hanji were rapidly increased until 30 days in three temperatures(105, 120 & $150^{\circ}C$) and stabilized after 30 days. The acid value and relative intensity of carbonyl groups in beeswax were increased with strong conditions. This means that the deterioration of beeswax should be progressed with oxidizing reaction. The physical strength and the crystallinity of dewaxed Hanji were decreased with ageing time.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.3
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• pp.15-21
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• 2012

The optimum dewaxing ratio in dewaxing treatment by the heat and pressure method was investigated by considering aging stability of dewaxed Hanji. Commercial Hanji was coated with beeswax and thermally aged at $150^{\circ}C$ for 24 hours. Then it was dewaxed using the laboratory sheet press equipped with hot plates on both top and bottom sides. Dewaxing ratio was controlled by pressing temperature and time. Four type of dewaxed Hanji samples with different dewaxing ratio were prepared and thermally aged at $150^{\circ}C$. Then the aging stability of dewaxed Hanji samples was evaluated in terms of optical and strength properties. It was found that the aging stability of dewaxed Hanji was superior with higher dewaxing ratio. The result concluded that, in the aspect of aging stability, the coated beeswax in beeswax-treated Hanji shall be completely removed if the coated wax would be dewaxed.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.98-105
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• 2011

Patterns and levels of aging vary between the book volume and sheets, even though both are made from the same paper materials. In case of book format, the outside is more easily affected than inner side by environmental factors such as temperature, humidity and air. In this study, the change in optical properties after dry heating accelerated aging was comparatively analyzed to understand the difference of the optical aging characteristics between outside and inner side of the duplicated beeswax-treated volume. It is found that the cover pages of the beeswax-treated volumes were more optically deteriorated than their middle pages. This indicates that outer sides of aging book volume directly exposed to the air is more vulnerable to serious deterioration than inner sides. Also, aromatic compounds such as benzoic acid and cinnamic acid were observed in the investigation of UV/VIS absorbance of the beeswax in each aged sample.

• 보존과학연구
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• s.30
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• pp.149-155
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• 2009

Annals of the Joseon Dynasty were composed of 1,229 volumes, and the 475 copies of total annals were wax-treated. Compared to non-wax treated copies, waxed volume of annals were seriously damaged such as crack, stick, discoloration to brown or black, and partially degradation. It is believed that the purpose of wax treatment for some volumes in the annals of the Joseon Dynasty is to prevent paper to deteriorate and to keep for the long time. But, beeswax could be deteriorated itself more rapidly. As a result, the waxed volume was much more damaged than non-waxed volume. Therefore, the investigation of decomposition and deterioration mechanism of beeswax-treated paper which might be used in waxed volume of the annals of the Joseon Dynasty must be done in order to prevent further decomposition and to restore the degraded wax-treated copies of the annals. For basis data of this purpose, physical properties of beeswax-treated paper be analyzed by coating methods. In result, sample products was manufactured reproducibility in lab scale. Specially, beeswax-treated method improved a orientation of papers. And the brushing method was stronger than the dipping method.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2009.10a
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• pp.13-17
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• 2009

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.56-62
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• 2014

This study aims to investigate the applicability of supercritical fluid extraction as a dewaxing technique to restore the beeswax-treated volume of the Annals of the Joseon Dynasty in various deterioration and damage conditions. Thus, this study analyzed the dewaxing efficiency and changes in physical and morphological properties before and after dewaxing, by applying the optimal supercritical fluid extraction dewaxing condition ($70^{\circ}C$, 40 MPa, $CO_2$, Co-solvent 20% DCM, 2 hour) to 3 kinds of beeswax-treated paper with different deterioration rates (dry artificial aging of 10, 20 and 30 days at $120^{\circ}C$). After dry artificial aging at $120^{\circ}C$ for 30 days, the average molecular weight of the beeswax-treated specimen was $1.856{\times}10^5g/mol$, showing deterioration about 80% of the beeswax-treated paper before dewaxing. It was a similar level to the molecular weight of the bees-waxed volume of the Annals of the Joseon Dynasty that has a higher degree of damage. As a result of analyzing the dewaxing efficiency through FT-IR analysis, this study discovered that it was possible to effectively dewax beeswax-treated paper in the range of deterioration 20 to 80% with this supercritical fluid extraction dewaxing technique applied. As a result of analyzing changes in the physical and morphological properties before and after dewaxing, the viscosity tended to decrease to a slight degree, and since no morphological deformation or damage of stencil fibers was found, it was concluded possible to conduct stable dewaxing through this supercritical fluid extraction technique.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.66-72
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• 2011

The annals of Joseon Dynasty is one of UNESCO's Memory of the World Register. For the safety preservation of the waxed annals of Joseon Dynasty, the acidic and alkaline aging mechanism of beeswax and beeswaxed Hanji has been investigated. The weight loss of beeswaxed Hanji by the acidic aging was higher than those of alkaline beeswax. The acid value and relative intensity of carbonyl groups in beeswax were slowly increased with aging time. The strength of dewaxed Hanji was decreased with aging time. The significant changes of crystallinity of dewaxed Hanji by acidic and alkaline aging were not observed.