• Title/Summary/Keyword: wood mold

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Effect of Neonicochid Type Wood Preservative on Adhesive Properties of Resorcinol Resin for Lminated Wood (네오니코치드계 목재보존제가 집성재 제조용 레조르시놀 수지의 접착력에 미치는 영향)

  • Lee, Dong Heub;Lee, Jong Shin
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.34-40
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    • 2014
  • The effect of neonicochid type wood preservatives on adhesive properties of resorcinol-formaldehyde resin for laminated wood manufacture was examined. By the previous studies, it was verified that the neonicochid type preservative has a high termite-proofing and anti-mold effectiveness. Commercial ACQ (ammoniacal copper quaternary compounds) and CUAZ (copper azol compounds) were used as comparison preservatives of effects on adhesive properties. The wood specimens used japanese red pine (Pinus densifrora) after application with preservatives and then bonded with resorcinol-formaldehyde resin. Adhesive properties were evaluated by shearing strength of adhesive bond and wood failure to dry condition or after accelerated aging test. Of all laminated woods, the wood specimens spread with ACQ or CUAZ showed the lowest shearing strength of adhesive bond. We estimated that the decrease of shearing strength was caused by copper in the ACQ or CUAZ preservatives. On the application of the neonicochid type preservatives, the wood specimens showed the highest shearing strength even after accelerated aging test. From these results, it is concluded that the copper-free neonicochid type preservative not affected the curing of resorcinol-formaldehyde resin.

Comparison of Hygrothermal Performance between Wood and Concrete Wall Structures using Simulation Program

  • Yu, Seulgi;Chang, Seong Jin;Kang, Yujin;Kim, Sumin
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.2
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    • pp.283-293
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    • 2016
  • Owing to an increase in the air tightness of recent buildings, the natural ventilation rate was significantly lowered and the removal of accumulated moisture became difficult in these buildings. The hygrothermal performance of these buildings should be carefully considered to provide comfortable indoor environment by removing the moisture condensation risk and the mold growth potential. In this study, hygrothermal performance of two selected wall structures was investigated based on WUFI simulation program. The results displayed that the indoor temperature had impact on the moisture accumulation in the insulation layer for both modeled walls, showing that lower indoor temperature resulted in higher moisture accumulation, especially in the wood frame structure. Also, the yearly moisture accumulation profile exhibited a downward shift throughout the year by adding a vapour retarder with a lower sd-value. In addition, both of the two walls have condensation risk in winter, due to low temperature level. The wood frame structure has a bigger fluctuation and higher condensation risk than the concrete structure.

Research Trend of The Heat-Treatment of Wood for Improvement of Dimensional Stability and Resistance to Biological Degradation (목재의 치수안정성과 내후성 개선을 위한 열처리 가공에 관한 연구 동향)

  • Kim, Yeong-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.3
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    • pp.457-476
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    • 2016
  • This was investigated on the major issues and research trends regarding the heat-treatment of woods through literature reviews. The principal heat-treatment technologies utilized for industrial purposes include the Plato-process (Netherlands), the Retification process (France), the OHT-process (Germany), and the Thermowood Process (Finland). Factors that mainly influence the heat-treatment process are the wood species, process temperature, processing time, and the heating medium (air, steam, vacuum, N2, oil, etc.). Researches on investigating the optimal conditions with these process conditions being the variables stand as the mainstream. Heat-treated woods present dimensional stability improvement, but mass loss and strength reduction, a wide variations for decaying inhibition, and insufficient resistance against mold, wood borer, and termites. For further improvement in respects of durability or resistance to biological degradation, necessity to search for more suitable heat treatment process and processing conditions fit for each wood species has been suggested. Exploiting new ways to utilize heat-treated wood and extending its range of use have been considered to be important matters that need more effort put into for the sustainable and sound environment as well as saving the wood resources.

Decay Resistance of Borate-Modified Oriented Strandboard: A Comparison of Zinc and Calcium Borate

  • Lee, Sun-Young;WU, Qinglin
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.5
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    • pp.1-10
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    • 2008
  • Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified oriented strandboard (OSB) from southern mixed hardwood and southern yellow pine was investigated in this study. Brown rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolar were used to examine the decay resistance of the OSB. The OSB test specimens were colonized by brown and white rot fungal mycelium in both the brown and white-rot culture bottles after 8 and 12 weeks, respectively. The wood species and fungus type had the significant effects on the decay resistance. Brown rot decay was evident for all untreated southern pine and mixed hardwood controls. The white-rot decay, however, did not show significant weight loss at both species control samples. The incorporation of ZB and CB composites provides suitable protection against brown-and white-rot fungi. No significant weight loss was observed from the borate treated OSB.

Development of Environment-friendly Cushioning Materials by Pulping of Waste Residual Woods (폐잔재의 펄프화를 통한 환경친화적 완충소재의 개발)

  • Lee, Young-Min;Kim, Chul-Hwan;Kim, Jae-Ok;Kim, Gyeong-Yun;Shin, Tae-Gi;Song, Dae-Bin;Park, Chong-Yawl
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.2 s.115
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    • pp.61-71
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    • 2006
  • Environment-friendly shock-absorbing (cushioning) materials were made using a vacuum forming method from waste wood collected from local mountains in Korea. The waste wood was pulped by thermomechanical pulping. The TMP cushions showed superior shock-absorbing properties with lower elastic moduli compared to EPS(Expanded Polystyrene) and pulp mold. Even though the TMP cushions made using at different suction times had many free voids in their inner fiber structures, their apparent densities were a little higher than EPS and much lower than pulp mold. The addition of cationic starch improved elastic modulus of the TMP cushions without increasing the apparent density, which was different from surface sizing with starch. The porosity of the TMP cushions was a little greater than EPS and much less than pulp mold. Finally, the TMP cushions have great potential to endure external impacts occurring during goods distribution.

Antifungal Activity of the Quercus Mongolica Extracts Against Botrytis cinerea (신갈나무로부터 유래된 추출물의 Botrytis cinerea 균주에 대한 항균활성)

  • Yeo, Hee Dong;Lee, Hyung Chul;Lim, Bu Kug;Kim, Hee Kyu;Choi, Myung Suk;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.1
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    • pp.88-101
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    • 2008
  • The aim of this study was to attempt the efficacy of antifungal activity of the wood extracts against Botrytis grey mold. Wood chip derived from Quercus mongolica was obtain from steam explosion process and extracted by hot water and methanol and ethanol. The conidial germination was maximum growth with the application temperature for 20 and $25^{\circ}C$. In pH test, we observed the maximum growth in pH 5.0 and 7.0. Antifungal activity was the best in the hot water extractives against Botrytis cinerea. The separation of the antifungal substances was performed using a silica-gel column (n-hexane : chloroform : ethyl acetate : formic acid = 12 : 17 : 8 : 0.2, v/v/v/v), TLC and UV-Spectrophotometer, and isolated 6 fraction group. The result of antifungal activity in 6 fraction group, fraction group I and fraction group II were the highest antifungal activity against grey mold with the present study. Three peaks in fraction group I and II were detected by HPLC and this compounds were suppose to effective of antifungal activity.

Effect of Wood Charcoal and Pyroligneous Acid on Soil Microbiology and Growth of Red Pepper (탄화물이 토양미생물 및 고추 생육에 미치는 영향)

  • 안병준;조성택;조태수;이성재;이윤수
    • Journal of Korea Foresty Energy
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    • v.22 no.3
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    • pp.49-56
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    • 2003
  • As a part of agricultural utilization of charcoal and pyroligneous acid, the effect of wood carbonization products on the growth of red pepper and soil microorganisms was investigated. The treatment of charcoal and pyroligneous acid provided good growth conditions to microorganisms through neutralizing soil acidity and improving the physicochemical properties of soil. Therefore the density of useful microorganism in the soil has been increased. In the growth of red pepper, the length, diameter, and the fruit numbers of red pepper have been increased by treating with wood carbonization products. It was especially shown that yield has increased about 50% in the fruit number, by treating charcoal 1kg, 1000 time-diluted solution of pyroligneous acid and bacteria, compared with the control. It was estimated that increasing the length of seedling and the diameter of red pepper stem contributed to the resistance against the prerequisites of various environmental changes in open field. Therefore, the final yield would be increased. In the antagonism experiment of red pepper mold (Colletotrichum gloeosporioides), the mold became extinct in the 2- and 10-time diluted solution of pyroligneous acid, compared with the control. On the other hand, their growth speed was delayed in the 100- and 1000 time-diluted solution.

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The Study on the perilla oil for the conservation of wooden cultural properties (목조문화재 보존 및 단청에 이용하는 들기름에 관한 연구)

  • Kim, Soon-Kwan;Hong, Jung-Ki
    • 보존과학연구
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    • s.21
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    • pp.273-291
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    • 2000
  • The perilla oil is painted to the wooden cultural properties of protection of wood and pigment. But that is happened to discolor and gather mold because of the long drying time. So we were put to the test for the improvement of this matter. The result is follows;1. The perilla oil, do not parched domestic Perilla japonica, add to the Japanese acid clay, later passing through the filter paper that the pore size is less than $7\mum$ 2. If the perilla oil add to the antiseptic of Thiazole origin, the mold is suppressed.3. In the painting of perilla oil, the existing Dan-chung paints one time (Luster generation in the more than two times) and the non-existing Dan-Chung paints two times.

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Sensitive Product Design of Ultra High Performance Concrete (UHPC) (감성 콘크리트 블루투스 스피커 (콩스) 제품 디자인)

  • Kim, Kyuong-Hwan;Kim, Byoung-Il
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.197-198
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    • 2020
  • A study was conducted on UHPC production using the silicone mold method. UHPC (Ultra-High-Performance Concrete) has the advantage of being able to shape the product in a free-form shape on concrete, but when mass-producing products in one design, such as electronic products, rather than one-time products such as buildings and decorations Demolition is difficult with wood and mold. This study uses silicone molds, UHPC mix to ensure fluidity, self-integrating performance and mechanical performance Prototyping was done proportionally.

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Sapstain and Mold Control on Radiata Pine Lumber: Laboratory and Field Tests of Selected Fungicides

  • Kim, Jae-Jin;Ra, Jong-Bum;Kim, Hyung-Jun;Kim, Gyu-Hyeok
    • Mycobiology
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    • v.30 no.1
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    • pp.37-40
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    • 2002
  • The susceptibility of radiata pine sapwood to fungal attack and the ability of selected fungicides to control colonization of sapstain and mold fungi on green radiata pine sapwood were evaluated. Radiata pine sapwood was highly susceptible to fungal staining, suggesting that prompt application of fungicides after sawing is essential for preventing fungal colonization. The ability of commercial fungicides to prevent fungal discoloration on radiata pine sapwood was assessed using an accelerated 6-week test on small samples in the laboratory, and in field tests using bulk-piled boards exposed outdoors for 6 weeks during summer rainy season. In laboratory tests, Hylite extra provided excellent protection against fungal discoloration even at the lowest concentrations. Hylite clear, Britewood S, and NP-1 Plus provided good short-term protection(2 to 4 weeks), but higher chemical loadings were, required for long-term protection(6 weeks). Woodguard produced little or no protection over the test periods. In field tests, Kathon 893 provided markedly superior protection at the concentration of 0.5 percent or higher. NP-1 Plus provided relatively good protection at all concentrations evaluated. Hylite extra was effective only for short-term protection(2 to 4 weeks) at all concentrations tested, but higher solution strengths were needed for longterm protection.