• Journal of the Korean Wood Science and Technology
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• 제45권1호
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• pp.12-19
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• 2017

황장목(黃腸木)은 적황색을 띠는 심재부의 비율이 높고 연륜폭이 매우 조밀하며 최소 수령이 100년 이상 되는 귀중한 소나무 자원이다. 조선시대에는 황장목을 궁궐, 사찰 등 중요 건축물에 사용하였다. 하지만 황장목의 재질특성에 관한 연구는 매우 부족한 실정이다. 본 연구에서는 황장목의 천연내구성을 검토하기 위하여 부후균 및 흰개미 저항성을 조사하였다. 공시균은 갈색부후균(Fomitopsis palustris)과 백색부후균(Trametes versicolor) 균주를 사용하였고, 공시 흰개미는 일본흰개미(Reticulitermes speratus)를 사용하였다. 그 결과, 갈색 및 백색부후균에 의한 중량감소율은 심재부에서 3.7~5.6%, 변재부에서는 16.1~26.3%로 나타났다. 또한, 흰개미 사충률은 심재부에서 약 47%로 매우 높게 나타났다. 이러한 결과를 통하여 황장목의 심재부는 부후균 및 흰개미에 대한 저항력이 뛰어난 것을 알 수 있었다.

• 대한수의학회지
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• 제55권1호
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• pp.13-20
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• 2015

This study was performed to investigate the antibacterial, antioxidant, and termite repellent effects of citronella oil (CiO) and lemongrass oil (LO). When the antibacterial activity against Staphylococcus (S.) aureus with various levels of antibacterial resistance were tested, a 0.05% concentration of CiO and LO completely inhibited the growth of all tested S. aureus strains. Evaluation of the antioxidant effect demonstrated that the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of CiO was 2~3 times greater than that of LO. Among trial products made with various combinations of CiO and LO, a CiO : LO ratio of 6 : 4 had the most potent termite repellent effects. Assessment of acute toxicity of the trial product showed that the $LD_{50}$ was more than 2,000 mg/kg. Based on the above results, CiO and LO have antibacterial, antioxidant, and termite repellent activities. Therefore, both compounds could be potential termites repellent reagents.

• Journal of the Korean Wood Science and Technology
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• 제52권1호
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• pp.70-86
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• 2024

Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.155-165
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• 2018

The objective of the research was to evaluate the effect of particle pre-treatment on physical, mechanical, and durability of jatropha fruit hulls (JFH) particleboard. The pre-treatments included were immersing in cold water, hot water, and acetic acid solution. After each treatment, the particles were dried up to 3% moisture content. Urea-formaldehyde (UF) resin was used to fabricate particleboards with board size, thickness and density target of 25 cm by 25 cm, 0.80 cm, and $0.70g/cm^3$, respectively. Board pressed at $130^{\circ}C$ for 10 minutes, and $25kg/cm^2$ pressure. The evaluation of particleboard followed the JIS A 5908-2003. Whilist their resistance to subterranean termite test (mass loss, mortality, antifeedant value and feeding rate) refers to the Indonesian standard (SNI 01.7207-2006). The physical and mechanical properties of particleboards showed that all pre-treatments decreased the pH of particles. Overall, all particle immersing treatments resulted of better physical and mechanical properties of particleboard than those of untreated ones. The acetic acid treatment resulted the best physical and mechanical properties of particleboard. Based on the mass loss of JFH particleboard, hot water and acetic acid treated particleboards were classified into weak resistance to subterranean attack. The other two treatments were classified into very weak resistance. Hot water treated particleboard provided the highest mortality and antifeedant as much as 87.40% and 34.20%, respectively. Based on antifeedant classification, hot water treated particleboards were classified into moderately strong resistance, while other treatments were categorized into weak resistance. The lowest feeding rate value ($45.30{\mu}g/termite/day$) was attained by hot water treatment.

• Journal of the Korean Wood Science and Technology
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• 제46권5호
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• pp.497-510
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• 2018

본 연구에서는 과열증기를 이용하여 열처리한 낙엽송재의 야외 내후성 시험을 통해 부후균과 해충에 대한 저항성을 평가하였다. 12개월간 진행된 야외 내후성 시험 결과, 무처리재는 흰개미에 의한 피해가 두드러지게 나타났지만 방부목재와 과열증기 열처리재에서는 육안으로 관찰되는 피해는 발견되지 않았다. 무처리재와 방부목재는 약 5%의 질량 감소를 보였으며, 과열증기 열처리재는 약 1%의 질량 감소를 보였다. 야외 내후성 시험이 진행된 후 방부목재에 남아있는 방부약제의 함량이 야외 내후성 시험 전보다 감소한 것으로 보아 야외 내후성 시험이 진행되는 동안 방부약제가 일부 용출된 것으로 보이며, 이에 따라 방부목재의 질량 감소가 무처리재와 유사한 수준으로 나타난 것으로 생각되었다. 과열증기를 이용한 열처리는 방부약제 주입과 같은 화학적인 처리 없이 친환경적으로 목재의 부후균과 해충에 대한 저항성을 개선시킬 수 있는 가능성이 확인되었으며, 이를 위하여 장기적인 관찰이 추가적으로 필요할 것이라 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제51권1호
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• pp.49-57
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• 2023

This research aimed to evaluate the durability of Samama (Anthocephalus macrophyllus) wood treated with boron preservatives, citric acid (CA), and heating against termites. Wood samples were impregnated firstly with 5% boron solutions, such as boric acid, borax and boric acid + borax combination at 1:1 (w/w). The second impregnation used 5% CA. The impregnations were conducted in a pressure tank at 7 kg/cm² for 4 hours. After impregnation, the samples were heat treated at 80℃ or 160℃. All the treated and control samples were exposed to decay fungi, drywood termites and subterranean termites based on SNI 7207:2014 standard. The results showed that boron preservatives reduced fungal attacks on Samama wood. The combination treatment of boric acid, CA and heat treatment at 160℃ was also effective to increase the resistance of Samama wood against white- and brown rot fungi, and drywood termites. Heat treatment consistently improved the resistance of Samama wood from decay fungi.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.907-916
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• 2020

This research was conducted to investigate the linear expansion and resistance properties of a composite board (com-ply). This board was made of medium-density fiberboard (MDF) laminated using avocado (Persea americana), mahogany (Swietenia mahogani), and pine (Pinus merkusii) veneers. These three types of veneers were laminated on both surfaces of the MDF using adhesives, namely, epoxy and isocyanate. Glue (250 g·m^-2) was spread on the surface, followed by cold press for 3 h with an applied pressure of 15 kg·cm^-2. The research result revealed that com-ply exhibited an increased dimensional stability compared with MDF, indicated by reduction in water absorption, thickness swelling, and linear expansion. The com-ply made of the pine veneer and isocyanate adhesive exhibited high density, water absorption, thickness swelling, and screw withdrawal load. The com-ply that exhibited the strongest resistance to drywood termite attacks was the one made of the mahogany veneer and isocyanate adhesive. Moreover, the com-ply that exhibited the biggest weight loss (3.6 %) was made of the pine veneer and epoxy adhesive. The results of this research may facilitate in manufacturing com-ply using the selected veneer and adhesive without the application of hot press.

• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.55-64
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• 2023

Properties of a lesser-used wood species were investigated to determine its potential for structural utilization. Trees of Delonix regia were felled and sampled at the base, middle and top and then sectioned to inner wood, middle wood, and outer wood for variation across the axial and radial directions. Hence, selected physical and mechanical properties as well as natural durability of D. regia along the radial and axial directions were examined. Obtained data were analyzed using analysis of variance (ANOVA) at α_0.05. There was no significant difference in the Moisture content (MC) of the wood but specific gravity (SG) decreased from base to top ranging from 0.35-0.44. Water absorption, volumetric swelling, and volumetric shrinkage range from 46.18-51.86%, 2.57-4.02%, and 2.26-3.96% respectively along the axial plane. The weight loss for graveyard exposure and accelerated laboratory decay test ranged from 25.14-48.00% and 32.02-44.45% respectively. Modulus of Rupture and Modulus of Elasticity values range from 29.42-72.68 Nmm² and 3,834.54-8,830.37 Nmm² respectively. The SG values has confirmed the species as a medium density wood and values of other properties tested showed that the wood is dimensional stable and moderately resistance to fungi and termite. Hence, it could be used for light construction purposes such as furniture and other interior woodwork.