• Composites Research
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• v.29 no.2
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• pp.79-84
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• 2016

An adhesive can be used to connect two different materials in structures. In comparing with other connecting methods, such as bolt, rivet, and hot melting, the adhesive does not need to use them. It leads to reduce the weight and decrease the stress concentration along the connecting line. This work studied the comparison of mechanical and interfacial properties of commonly-used two adhesives, acrylic type and bisphenol-A epoxy type. Tensile and flexural strength of neat adhesives were also compared. Lap shear test of two adhesives was deduced from the measurement of tensile and fatigue tests. After testing, the failure patterns of adhesive surfaces were observed by a microscope. Tensile strength and mechanical fatigue resistance at using bisphenol-A epoxy adhesive were better than acrylic adhesive. Also adding CNT reinforcement in epoxy adhesive can anticipate mechanical improvement.

• Journal of Conservation Science
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• v.11 no.1 s.14
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• pp.38-51
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• 2002

The first priority we face in the conservation of wall paintings, is the conservation of painting layer. The 'painting layer' is sometimes called the pigment layer, and refers to the painted surface. For the consolidation of this painting layer we use 'fixative'. Fixative is a common adhesive which has been used in various field and conservators have made up for the weak points in the consolidation of wall paintings. In my thesis, I will summarise the range of use, standards of selection, and results of research on the use of fixative in the conservation of European paintings. In addition, I will describe various kinds of our traditional fixatives. As synthetic resins have proved that it is not ideal as a fixative for wall painting, conservators have studied to find an alternative. Same as European conservators, Asian scientists has researched to find alternative fixative which is more suitable to the wall paintings in Asia based on their traditional techniques and materials. Therefore, 1 have studied to find an adequate fixative for our own wall paintings and I could conclude that we can consider traditional fixative which is made of 'seaweeds' as an alternative and it is very important to proceed research and experiment on this material.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.245-250
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• 2019

In recent years, new technologies such as additive manufacturing have been applied to casting industry, paving new ways to achieve what have traditionally been impossible. In the global market, numerous successful cases of producing cores using additive manufacturing technology have been reported, and new techniques and markets are being developed under governments' support. In Korea, however; cases of applying additive manufacturing to casting are hard to come by, not to mention domestic AM machines and related technologies. Under these circumstances, introduction of additive manufacturing technologies and customized application to domestic casting industry are required. Each chapter of this paper explores topics ranging from the development of AM machine using binder jetting technology among various AM techniques through producing industrial cores to the on-site applications in the foundries.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.200-211
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• 2022

The celadon stools with an openwork ring design which consist of four items as one collection were excavated from Gaeseong, Gyeonggi-do Province. The celadon stools were designated and managed as treasures due to their high arthistorical value in the form of demonstrating the excellence of celadon manufacturing techniques and the fanciful lifestyles during the Goryeo Dynasty. However, one of the items, which appeared to have been repaired and restored in the past, suffered a decline in aesthetic value due to the aging of the treatment materials and the lack of skill on the part of the conservator, raising the need for re-treatment as a result of structural instability. An examination of the conservation condition prior to conservation treatment found structural vulnerabilities because physical damage had been artificially inflicted throughout the area that was rendered defective at the time of manufacturing. The bonded surfaces for the cracked areas and detached fragments did not fit, and these areas and fragments had deteriorated because the adhesive trickled down onto the celadon surface or secondary contaminants, such as dust, were on the adhesive surface. The study identified the position, scope, and conditions of the bonded areas at the cracks UV rays and microscopy in order to investigate the condition of repair and restoration. By conducting Fourier-transform infrared spectroscopy(FT-IR) and portable x-ray fluorescence spectroscopy on the materials used for the former conservation treatment, the study confirmed the use of cellulose resins and epoxy resins as adhesives. Furthermore, the analysis revealed the addition of gypsum(CaSO₄·2H₂O) and bone meal(Ca₁₀ (PO₄)₆(OH)₂) to the adhesive to increase the bonding strength of some of the bonded areas that sustained force. Based on the results of the investigation, the conservation treatment for the artifact would focus on completely dismantling the existing bonded areas and then consolidating vulnerable areas through bonding and restoration. After removing and dismantling the prior adhesive used, the celadon stool was separated into 6 large fragments including the top and bottom, the curved legs, and some of the ring design. After dismantling, the remaining adhesive and contaminants were chemically and physically removed, and a steam cleaner was used to clean the fractured surfaces to increase the bonding efficacy of the re-bonding. The bonding of the artifact involved applying the adhesive differently depending on the bonding area and size. The cyanoacrylate resin Loctite 401 was used on the bonding area that held the positions of the fragments, while the acrylic resin Paraloid B-72 20%(in xylene) was treated on cross sections for reversibility in the areas that provided structural stability before bonding the fragments using the epoxy resin Epo-tek 301-2. For areas that would sustain force, as in the top and bottom, kaolin was added to Epo-tek 301-2 in order to reinforce the bonding strength. For the missing parts of the ring design where a continuous pattern could be assumed, a frame was made using SN-sheets, and the ring design was then modeled and restored by connecting the damaged cross section with Wood epos. Other restoration areas that occurred during bonding were treated by being filled with Wood epos for aesthetic and structural stabilization. Restored and filled areas were color-matched to avoid the feeling of disharmony from differences of texture in case of exhibitions in the future. The investigation and treatment process involving a variety of scientific technology was systematically documented so as to be utilized as basic data for the conservation and maintenance.

• Korean Journal of Heritage: History & Science
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• v.54 no.4
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• pp.78-89
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• 2021

Organic residues analysis is an analysis method that reveals the types of organic material samples by using the characteristic that main components constituting substances are different depending on the species of animals and plants. In this study, scientific analysis of the organic residues attached to wood coffins in the Joseon Dynasty Hoemyo excavated from the site of Singok-dong, Uijeongbu was used to identify the types of remnants and to use them as information to restore the uses of organic materials and the way they lived in the past. As a result of FT-IR analysis of the residue attached to the inside of the wood, it was estimated to be a natural plant resin material. In addition, as a result of analysis by GC-MS to confirm the characteristic factors of natural resins, diterpenoids (abietane) and pimaran (pimarane), such as dehydroabietic acid and pimaric acid (diterpenoid) compounds, and saturated and unsaturated fatty acid components were detected together. Diterpenoid compounds are components mainly found in Pinaceae resins. It is confirmed in the literature that rosin, a representative material of Pinaceae resin, was used as an adhesive material. Considering the situation where an organic material remained at the joint of the wood, the organic material attached to the wood is judged to be an adhesive material made of Pinaceae resin. In addition, the fatty acid component detected together is a component derived from plant oil, and it is presumed to be made by mixing rosin and oil as recorded in previous studies. This study confirms that organic residues remain in the burial environment without losing their characteristics. It is expected that scientific analysis of organic residues will be conducted in the future to accumulate information necessary for the interpretation of past living culture.

• Journal of Conservation Science
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• v.30 no.1
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• pp.33-38
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• 2014

The adhesive material was found for joining pottery fragments from Duurlig Nars, Mongolia estimated in AD 1C. In this study, analysis of natural substance for joining fragments of pottery was performed using gas chromatograph and mass spectrometer. As a result, it was identified triterpenoid substances, such as lupeol and betulin which were known to constituents of birch bark tar. It was suggested that Mongolian used adhesives made by birch bark tar for joining pottery fragments. Therefore if organic materials of ancient objects are systematically researched, it can provide significant evidence related to the way of life of ancient people.

• Conservation Science in Museum
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• v.7
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• pp.3-10
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• 2006

The bronze bowl with lid excavated from Eunnyeongchong Tumulus in Gyeongju had been united in the past and then damaged. We removed deteriorated adhesive and other impurities from it and reunited it. Some fragments of the artifact has been lost; in particular, only half of the whole main body remains. Therefore, it needed restoration treatment for exhibition and conservation. The lid, relatively much part of which remains, was treated with the method that could easily detach the restored part; the main body with much restored part was united using epoxy resin so that the restored part could well bear the weight of the artifact.

• Journal of Conservation Science
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• v.35 no.5
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• pp.453-469
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• 2019

The celadon jar with inscription of 'the Fourth Sunhwa Year' is an important chronology that shows the conditions of production of the early celadon due to the inscription on the bottom including its purpose, application, and the producer. This celadon jar has been restored several times in the past. However, concerns over the structural stability, such as the separation and level differences in the joined cracks, have risen because of the aging of the repair materials, which were subjected to various environmental changes over a long time. By examining the conditions of preservation, the major damage was identified as the '入' shaped crack on the front, the 'V' shaped restored part and the crack on its left side, and the 'J' shaped crack on the back side. In the past, the cracks were found to be joined using a refined lacquer containing camphor, drying oil, rosin, etc. mixed with soil powder. The joint line was repainted with the refined lacquer and covered with gold powder. The missing parts were restored with gypsum and colored with acrylic color. After that, the repair materials were aged and emergency treatment was performed at the National Museum of Korea in 1981. At that time, Cemedine C or Cemedine C mixed with microballoons was used for reinforcing the cracks. Conservation treatment focused on removing the past repair materials and reinforcing the physically fragile parts by joining and restoring them based on the examination of the preservation condition. in addition, the area around the restored part was colored for future exhibition.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.51-61
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• 2022

Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.