• Title/Summary/Keyword: wood deterioration

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Physical and Mechanical Characteristics of Phellodendron amure Ruprecht (황벽나무의 물리·역학적 특성)

  • Kim, Hyun-Woo;Byeon, Hee-Seop;Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.5
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    • pp.519-524
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    • 2017
  • Physical, mechanical and deteriorating properties of Phellodendron amure were investigated. Air dried density located indoor was 0.41 but $0.43g/cm^3$ outdoor. In oven dry shrinkage, T/R ratio for located indoor was 1.40 but 1.32 outdoor. Hygroscopic property at $40^{\circ}C$ with 90% relative humidity was 16.30% for indoor and 15.80% for outdoor. Compressive strength for outdoor conditioned sample was 43.81 MPa but 40.33 MPa for indoor conditioned. Also bending strenght for outdoor conditioned was 84.63 MPa but 68.80 MPa for indoor conditioned. Impact strength was 3.43 and $4.00J/cm^2$ indoor and outdoor, respectively. Hardness at cross-section was 47.92 and 49.20 MPa indoor and outdoor, respectively. With one-year conditioning at indoor or outdoor, there was no significantly different in strength properties, which came from strong resistance for deterioration. Also Phellodendron amure wood showed dimensionally stable raw material based on low T/R ratio.

Properties of Particleboard Using Byproduct of Plywood Manufacture - Evaluation on the Elements of Surface Layer and Pre-treatment of Particles (합판 공장 부산물을 이용한 파티클보드의 물성에 관한 연구 - 표층 구성요소 및 파티클 전처리 여부에 따른 비교 -)

  • Hwang, Jung Taek;Pi, Duck Won;Kang, Seog Goo
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.1
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    • pp.33-41
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    • 2013
  • This study was performed to analyse cause of quality deterioration using byproduct of plywood and to determine physical and mechanical properties of particleboard used new bonding condition we found. The result of bending strength of Com-Ply board using EMDI is 57.7 $N/mm^2$ on linear direction and 25.1 $N/mm^2$ on vertical direction. EMDI has better water-resisting qualities than Urea formaldehyde adhesive according to result of thickness swelling and water absorption test. Pre-treatment soaked particle 72 hours in water caused increase of HCHO emission.

Evaluation of Modulus of Elasticity of Wood Exposed to Accelerated Weathering Test by Measuring Ultrasonic Transmission Time (촉진 열화 목재의 초음파 전달 시간 측정을 통한 탄성 계수의 평가)

  • Park, Chun-Young;Kim, Gwang-Chul
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.3
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    • pp.275-281
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    • 2014
  • In this study, accelerated weathering test was performed with wood, a major material for wooden cultural building. In order to evaluate the deterioration of wood, ultrasonic transmission times were measured to evaluate dynamic modulus of elasticity (MOE), which was verified by determining static MOE using three-point bending test. Ultrasonic transmission time was decreased with an increase in the weathering time levels (0, 500, 1000 hours) while it increased in 1500 and 2000 hours. Distribution of dynamic and static MOE was similar to that of the ultrasonic transmission time measurements. The results mean that the measurement of ultrasonic transmission time was very effective to evaluate MOE of wooden cultural buildings for their preservation and management. This method could be utilized to assess wooden cultural buildings as a way of preserving them in a scientific manner.

On-Site Conservation of the Underwater Objects Excavated (해저 발굴유물의 현장 보존처리)

  • Moon, Whan-Suk;Kim, Byung-Keun;Yang, Soon-Seok
    • 보존과학연구
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    • s.25
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    • pp.133-150
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    • 2004
  • Once the object has been excavated at underwater condition, it should be subjected to condition that may cause its deterioration. Therefore, it is important that the object immediately keeps stable environment. It means that the object was excavated at underwater and it exposed the deterioration condition, as soon as possible it was not dried on surface, especially metallic and organic material. Iron objects is particularly notorious for rapid disintegration that it kept wet or stored in a stable environment. Ceramics, glass and stone were handled carefully that it prevented physical damage by mishandling. Organic materials of wood, leather, rope, bone must not be allowed to dry out because the creaking, shrinking and warping are well known disintegration. Therefore objects is basis of keeping stable condition in on-site and then it will have to pass through a detailed conservation process in the laboratory.

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The Effect of Anti-UV Agents on UV Shielding and Photolytic Aging of Paper

  • Park Saung Bae;Hyun Byung Doo;Eom Tae Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.5 s.108
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    • pp.36-43
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    • 2004
  • The behaviors of deterioration in the mechanical and optical properties of paper during sunlight exposure are mainly attributed to UV irradiation. The effect of different additives (anti-UV agents) on paper properties during exposure was studied. The results showed negligible changes in the mechanical properties of samples prepared with two different ways, whereas the shielding ability was increased when the additives were applied to the surface of hand sheets. Also, the paper which is treated with anti UV agents can keep freshness more effectively of agricultural products from UV irradiation.

Field Application of an Ultrasonic Testing for Reconstructing CT Images of Wooden Columns

  • Lee, Sang-Joon;Park, Chun-Young;Kim, Kwang-Mo;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.2
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    • pp.148-154
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    • 2009
  • This research examined the applicability of using an ultrasonic test to reconstruct CT images of an ancient wooden building. Most of the columns in the building are severely deteriorated due to termite attacks or the effect of weathering. Ultrasonic CT images of the columns were used to create highly accurate digital reconstructions, despite a lack of the data caused by parts of the building walls being buried. Another semi-NDE technique, a drilling test based on resistography, was applied in order to verify the ultrasonic test results. The discrepancy in detection between two methods is believed to be due to the fundamental differences between two methods. The performance of the ultrasonic test was hindered by poor surface conditions and this technique tended to over-estimate the size of cavities produced by termites or other insects. Nevertheless, the deterioration detected was in many ways congruent with the drilling test results

A Study on the Flexural Capacity of Rectangular Section Wood Using Synthetic Resins (합성수지를 이용한 사각단면 목재의 휨 보강 성능에 관한 연구)

  • Park, Kwang-Seob;Kang, Pyeong-Doo;Ha, Jong-Han;Park, Sung-Moo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.6 s.58
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    • pp.106-114
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    • 2009
  • The basis principle of conservation about deterioration and corrosion of cultural assets building is the archetype maintenance, and should not make a factitious damage mistake by repair. Accordingly, conservation processing method using synthetic resins is embossed. The purpose of this paper is about flexural capacity of rectangular section wood using synthetic resins, the 11 specimens are manufactured and made an experiment about reinforcement length, ratio, material strength, direction of synthetic resins as variable. The results of this paper has shown that flexural reinforcement of wood by synthetic resins are efficient and found the possibility of using.

Evolution of the Hanji-making Technology, from Ancient Times to the Present

  • Oh-Kyu LEE;Seokju KIM;Hyung Won LEE
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.6
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    • pp.509-525
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    • 2023
  • This study has delved into the evolution of Hanji-manufacturing molds and techniques from ancient times to the present, aiming to uncover the current state of traditional Hanji-making techniques. In the absence of records on Hanji-making, various ancient documents, rare books, and documents during the Japanese occupation period, among other artifacts and relics, were analyzed in this study. It was discovered that a sudden significant transformation occurred in the Hanji field during the Japanese occupation period. Soda ash and caustic soda were commonly used for the pretreatment of White bark. Furthermore, a chemical bleaching powder was introduced for the pretreated White bark. Additionally, manual beating of the bark was replaced by mechanical beating methods. While these changes brought convenience to papermakers, they also resulted in a deterioration of Hanji quality. Furthermore, it was revealed that the term "Hanji" has been in use since at least 1908. Furthermore, this study clarified that Heulimtteugi is not the only traditional Hanji-making method in Korea. Instead, there existed Korea's own traditional Gadoomtteugi method, at least up to the 1930s, before the Japanese-style Gadoomtteugi became common in Korea. Additionally, for the first time, this study raises the possibility of the adoption of mold-hanging techniques into Korea's Heulimtteugi method from foreign sources.

Predicting Influence of Changes in Indoor Air Temperature and Humidity of Wooden Cultural Heritages by Door Opening on Their Conservation Environment (개방에 따른 실내 온습도 변화가 목조문화재 보존환경에 미치는 영향 예측)

  • Kim, Min-Ji;Shin, Hyun-Kyeong;Choi, Yong-Seok;Kim, Gwang-Chul;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.6
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    • pp.798-803
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    • 2015
  • This study was conducted to predict the effect of door opening in wooden cultural heritages (WCHs) on their conservation environment. For this prediction, measured relative humidity (RH) and surface wood moisture content (MC) of inner part of wood columns in open wooden building and neighboring closed wooden building were compared with minimum RH, including the duration of minimum RH, and MC required for spore germination and resultant growth of wood-degrading fungi reported in some literatures. Moisture conditions, namely RH of inside wooden building and MC of wood was unsuitable for decay and sap-stain fungi all the year round; however, moisture conditions during summer season was suitable for spore germination and resultant growth of surface mold fungi, regardless of door opening. When compared, the duration of minimum (75%) or higher RH and the number of wood columns with MC level greater than the minimum MC (15%) during summer season, the surface mold related to the conservation environment of inside wooden building was somewhat better in open building than in closed building. Rather, doors should be opened in closed building for reducing indoor RH as a necessary measure during summer season when outdoor RH is high.

Effects of Color Pigments on the Hanji Deterioration (체색용 안료가 한지의 열화에 미치는 영향)

  • Nam, Hyun-Ju;Cho, Kyoung-Sil;Choi, Tae-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.70-79
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    • 2015
  • This study was carried out to analyze deterioration characteristics of color-pigments painted Hanji to preserve and restore the cultural properties. On the traditional painting technique, glue was used with pigments in various ways for painting, but it eventually caused the deterioration of paintings. Thus, five colors were selected and analyzed for this study for investigating their characteristics of deteriration. Three kinds of glues (Wugyo, Nokgyo, and Togyo) and two kinds of pigments (Chinese and Gilsang) were painted on the Hanji for the accelerated aging test. And then color fastness of pigments and tensile strength of painted Hanji were measured for the estimation of deterioration degree. The results of SEM-EDS showed that Chinese pigments including blue, yellow, green, and red were composed of inorganic substances but the brown was organic substance. Gilsang pigments were composed mainly of Si and Ti ions. Color fastness of the Gilsang pigment blue, yellow, green, and brown were better than those of Chinese. Chinese pigment brown with organic substance showed the worst color fastness. Generally, Chinese pigments painted Hanji showed higher tensile strength than Gilsang in the accelerated aging test. Hanji treated with Chinese pigment and Nokgyo (antler glue) blends and Gilsang pigment and Togyo (rabbit pelt glue) blends showed higher tensile strength than the others. And Andong Hanji showed the highest tensile strength.