• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.23-26
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• 2002

The generation of wastewood is currently about 40% level of the amount of domestic wood use. When the rate of wood self-supply is considered, the recycling of wastewood in wood panel products industry should be encouraged. This study was evaluated the performance of particleboard (PB) made from wastewood. PBs were manufactured with the synthesized urea-formaldehyde resin at 5 minutes hot-press time, and at 162℃ press temperature with 6 percent resin solids level on an ovendry wastewood particle weight basis. The PBs were tested by the procedure of ASTM D 1037. Test results exceeded the minimum strength requirement according to KS F 3104 Particleboard type 8.0. The PB's performance showed that wastewood is suitable raw material for PB.

• Journal of Korean Association for Spatial Structures
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• v.9 no.3
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• pp.93-100
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• 2009

As interest in latest cultural heritance is increased, an importance about conservation of dilapidated cultural building asset is risen. Most of cultural building asset used wood by main material and conservation repair about corrosion and damage by deterioration of these cultural building asset considers cultural value of member and the basis principle is the archetype maintenance. Accordingly, conservation processing method that use synthetic is embossed. This paper experimented with reinforcement sectional area ratio, direction of section, length, strength of synthetic resins as variable and manufactures total 14 specimens as experimental study about compression reinforcement performance of circular section wood that strengthen by synthetic resins. The result of this paper has shown that adequate strengthen is more efficient than new member and the most important authenticity in strengthen and repair of cultural heritance can be ensured.

• Journal of Conservation Science
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• v.37 no.6
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• pp.801-806
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• 2021

In order to improve the usability of glue, a traditional adhesive material, and the gelation process of seaweed extract carrageenan, a liquid adhesive for wood preservation was prepared by mixing the two materials. The prepared wood adhesive was mixed with a 15 wt% aqueous solution of glue, λ-carrageenan, an antibacterial agent, an antifoaming agent, and the maximum adhesive strength of 1.80 Mpa was confirmed. As a result of comparison, the adhesive strength was superior to that of 5 different types of traditional natural adhesive ingredients (aqueous solution) and 1 type of polyvinyl acetate-based adhesive.

• Journal of the Korean Wood Science and Technology
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• v.11 no.3
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• pp.3-13
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• 1983

Fiber mats were made at five density levels, using fibers from kraft pulp screening rejects, rice straw and a 50/50 mixture of the two. They were soaked in the sulfur compounds. Specimens cut from the composite panels were tested in flexure at time intervals for one year to study the effect of aging. Modulus of elasticity (MOE) and modulus of rupture (MOR) were determined. Under optimum conditions of fiber mat preparation and saturation with molten sulfur and modified sulfur, composites were produced which exhibited mechanical properties comparable to conventional fiberglass in some properties and superior to conventional wood-based composition boards, For example. the moduli of elasticity of the reinforced composites made from pulp screening rejects, with a density of 0.35 gm/$cm^3$, were greater than 1,000,000 psi as compared 800.000 psi for high-density hardboard (1.28 gm/$cm^3$). Modulus of rupture of the best reinforced composites was about 7,000 psi, comparable to 6,000 psi of high-density hardboard.

• Journal of the Korean Wood Science and Technology
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• v.14 no.2
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• pp.21-28
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• 1986

A quartz type gasification reactor was designed and used for pyrolysis and gasification of sawdust, ricestraw and ricehusk. The initial reaction temperature was 350$^{\circ}C$, and up to 550$^{\circ}C$ to complete pyrolysis and gasification reaction. In order to examine the effect of catalyst on reaction temperature, $K_2CO_3$ and $Na_2CO_3$ as catalyst were also used. The product gas mixtures are identified to be CO, $CO_2$, $CH_4$ and $CH_3CHO$ etc. by Gas Chromatography and Mass Spectrometer. The highest gas volume of the gasified sawdust at 550$^{\circ}C$ amounts to 1800ml/g of sawdust, even though the yield and composition of this product gas are depending on the reaction temperature of the reactor and catalyst used.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.391-395
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• 2009

For the conversion of domestic waste-wood into energy, a fixed bed gasifier ($0.9 m{\times}2.4 m$) having the capacity of 2 ton/day was designed and constructed. The dual knife valve was used to feed waste-wood of which size was 3~5 cm and a rotary stoker system was installed in the bottom of gasifier. The pilot gasification system consisted of feeding system, fixed bed gasifier, gravity fine particle collector, heat exchanger for syngas cooling, ID fan, and cooling tower. The operation temperatures of gasifier were $700{\sim}1000^{\circ}C$ and the concentrations of syngas were CO: 25~40 vol%, $H_2$: 7~12 vol%, $CH_4$: 2~4 vol%, $CO_2$: 12~24 vol%. The calorific value of syngas was $1100{\sim}1500kcal/Nm^3$ and was enough to be applied in the industrial combustor. Also the gas engine was operated by using syngas from biomass gasifier and produced 1~4 kW of power.

• Journal of Conservation Science
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• v.35 no.6
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• pp.681-688
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• 2019

In this study, the characteristics of natural and synthetic adhesives used in woodcraft were evaluated. The pattern of deterioration of wood and adhesives according to changes in temperature and humidity were compared. For materials, one type of anlmal glue, three kinds of polyvinyl acetate adhesives, one type of epoxy adhesive and one type of zelkova wood were selected. Characteristics of physical and chemical characteristics, weather resistance and drying speed assessment were carried out. The adhesion characteristic evaluation showed that the adhesion strength of anlmal glue and one type of polyvinyl acetate adhesive were 6.54 N/㎟ and 7.01 N/㎟, pH meter of anlmal glue and polyvinyl acetate adhesives was pH 7.03 and pH 3.32-3.59 which were range of available as an adhesive. According to the test results of weather resistance, epoxy adhesives had the highest decreasing value in adhesion strength after deterioration. In the reversible test of the adhesive, it was found to be highly reversible in NaOH, a soluble solvent excluding epoxy, but attention is required when using the wood since it may show discoloration during processing.

• Analytical Science and Technology
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• v.5 no.1
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• pp.25-31
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• 1992

A benzene synthesizer was manufactured and has been used for the treatment of the various samples such as wood, charcoal, shell and soil for radiocarbon dating using liquid scintillation counter. The experimental conditions were optimized in each successive step of the synthesis of carbon dioxide, acetylene and the final product of benzene. Fifteen hours operation of the benzene synthesizer leads to product yields consistently in excess of 85% based on the content of calcium carbonate for the organic samples. Purity of the synthesized benzene was measured to be more than 99.9% by GC/MS.

• Fire Science and Engineering
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• v.34 no.1
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• pp.1-10
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• 2020

In this study, boron/silicon sol compounds were applied to wood for construction and durable materials, and fire risks were investigated in terms of smoke performance index (SPI), smoke growth index (SGI), and smoke intensity (SI). The compound was synthesized by reacting tetraethoxyorthosilicate with boric acid and boronic acid derivatives. Smoke characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment for cypress wood. The fire intensity fixed the external heat flux at 50 kW/㎡. The smoke performance index measured after the combustion reaction increased between 13.4% and 126.7% compared with cypress wood. The fire risk due to the smoke performance index decreased in the order of cypress, phenylboronic acid/silicon sol (PBA/Si), (2-methylpropyl) boronic acid/silicon sol (IBBA/Si), boric acid/silicon sol (BA/Si). The smoke growth index decreased between 12.0% and 57.5% compared to the base specimen. The risk of fire caused by the smoke growth index decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si. The fire risk due to smoke intensity decreased between 3.2% and 57.8%, and in the order of cypress, PBA/Si, IBBA/Si, BA/Si. CO_peak concentrations ranged between 85 and 93 ppm, and decreased between 37% and 43% compared to the base specimen. A comprehensive assessment of the fire risk on smoke hazards decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.82-89
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• 2004

Two kinds of chemicals (RNF-3 and RNF-4) with high anti-mold effectiveness against stored fungi causing fungal discoloration was selected from among the six kinds of fluoride-based chemicals in the preceding study. In this study, the anti-mold test using 16 species fungi isolated from the softwood lumbers which were fungal discolored and field test in the sawmill was carried out to prove the feasibility for practical using of selected chemicals.For the isolated fungi, the RNF-3 consist of F and Cu showed high mycelial growth control in the PDA medium and fungicidal effectiveness in the japanese red pine (Pinus densiflora), korean pine (Pinus koraiensis) and radiata pine (Pinus radiata) when the concentration was 2% or more. However the RNF-4 consist of F only was not effective compared with RNF-3 because of mycelial growth in the PDA medium and wood treated with 2% or more chemical solution. The RNF-3 also showed a strong anti-mold effectiveness because there was no fungal discoloration for the radiata pine boards treated by 2% and 10 min. soaking in the field test. These results mean that RNF-3 can be used as domestic anti-stain chemicals for prevention of fungal discoloration of the softwood lumber