• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.748-755
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• 2018

Timber from fast-growing tree species is susceptible to by biodeterioration attack, particularly subterranean termites. Impregnation with methyl methacrylate (MMA) potentially increases wood resistance to subterranean termite attack. Four wood species, namely sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii), were impregnated with MMA, and samples of untreated and imidacloprid-preserved wood were prepared for comparison purposes. Small stakes, sized 0.8 cm by 2 cm in cross section by 20 cm in the longitudinal direction, were inserted into the ground for 3 months, and the weight loss of each specimen was determined at the end of the test period. A factorial $4{\times}3$ completely randomized design was used for data analysis; the first factor was wood species, and the second factor was treatment. The results showed that MMA polymer loadings were 27.88%, 24.91%, 14.14%, and 17.81% for sengon, jabon, mangium, and pine, respectively, and amounts of imidacloprid retention were $7.56kg/m^3$, $5.98kg/m^3$, $5.34kg/m^3$, and $9.53kg/m^3$, respectively. According to an analysis of variance, wood species, treatment, and interaction of both factors significantly affected the weight loss of wood specimens. Mangium had the smallest weight loss, followed by pine, sengon, and jabon. MMA impregnation into the wood increased the resistance of wood samples to subterranean termite attack during in-ground testing, but the resistance level was lower than that of imidacloprid-preserved wood. Except for mangium wood, the MMA treatment did not significantly affect resistance.

• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.18-25
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• 2002

Research to discuss the fire performance of materials requires tools for measuring their burning characteristics and validated fire growth models to predict fire behavior of the materials under specific tire scenarios using the measured properties as input for the models. In this study, burning characteristics such as time to ignition, weight loss rate, flame spread, heat release rate, total heat evolved, and effective heat of combustion for four types of wood-based materials were evaluated using the cone calorimeter and inclined panel tests. Time to ignition was affected by not only surface condition and specific gravity of the tested materials but also the type and magnitude of heat source. Results of weight loss rate, measured by inclined panel tests, indicated that heat transfer from the contacted flame used as the heat source into the inner part of the specimen was inversely proportional to specific gravity of material. Flame spread was closely related with ignition time at the near part of burning zone. Under constant and severe external heat flux, there was little difference in weight loss rate and total heat evolved between four types of wood-based panels. More applied heat flux caused by longer ignition time induced a higher first peak value of heat release rate. Burning characteristics data measured in this study can be used effectively as input for fire growth models to predict the fire behavior of materials under specific fire scenarios.

• Journal of the Korean Wood Science and Technology
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• 제40권4호
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• pp.237-243
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• 2012

유기용매 전처리에 의한 목재 횡단면의 흡음성능과 구조적 특징의 변화를 관찰하고자 낙엽송과 백합나무로부터 원반형 시험편을 채취하였다. 탈 섬유소처리를 한 후 처리목재의 구조적 특징 변화를 관찰하고, 전달함수법을 이용하여 섬유방향 흡음율을 측정하여 이를 무처리 시의 결과와 비교하였다. 측정주파수범위(50~6,400 Hz)에서 유기용매 전처리 시험편이 무처리 시험편보다 높은 흡음율을 나타내었으며, 특히 2~4 kHz의 주파수영역에서는 90% 정도 높은 흡음율을 나타내었다. $70{\sim}120^{\circ}C$에서 유기용매 전처리한 목재는 무처리 목재와 비교하여 1.0% 미만의 중량 감소율을 보였고, 현미경에 의해 해부학적 구조 변화를 관찰할 수 있었다. 측정주파수영역에서의 흡음율 증가는 유기용매 전처리에 의한 목재의 구조적 변화에 의한 것으로 판단되었다.

• Journal of the Korean Wood Science and Technology
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• 제43권1호
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• pp.112-121
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• 2015

국내에서 사용되고 있는 가압주입 처리용 구리 붕소 아졸화합물계의 목재 방부제 Copper Azole (CuAz)의 목재내 주입량별 부후 특성을 조사하였다. 여러 가지 주입량으로 CuAz-2 방부제를 가압주입한 시편을 이용하여 갈색부후균인 부후개떡버섯에 의한 방부효력시험을 실시한 후 질량감소율을 측정하였다. 또한, CuAz-2 처리 시편을 부후개떡 버섯으로 부후시킨 후 광학현미경과 전자현미경으로 부후 특성을 관찰하였다. 그 결과, 부후개떡버섯에 의한 무처리재는 40% 이상의 질량감소율을 보여주었고 실내 부후에 의한 CuAz-2 약제의 방부효력을 나타내는 값은 $1.79{\sim}3.32kg/m^3$이었다. CuAz-2의 주입량에 따라 횡단면, 방사단면, 접선단면에서의 목재조직은 무처리 시편과 비교하여 부후 정도가 다르게 나타났다. 횡단면에서는 조재와 만재부분에서 수직수지구, 방사조직의 부후가 많이 관찰되었고, 방사단면에서는 방사가도관, 방사유세포, 벽공 부분이 부후되어 파괴되었고, 접선단면에서는 방사조직, 수평수지구가 심하게 부후되었다. 따라서 본 연구에서 주입량에 따른 부후 현상이 크게 차이가 난 점 등을 고려하여, 현재의 CuAz-2 주입량에 대한 적정성 검토가 국내 환경에 대해서 이루어져야 할 것으로 생각된다.