• Journal of the Korea Furniture Society
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• v.17 no.2
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• pp.49-56
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• 2006

This research was carried out to examine the FIR (far-infrared rays) emissivity and emission power of five types of flooring board by the mixing ratio of charcoal and loess, and the physical property of five types of injected flooring board by the amount of mixture. Type D was appeared the most high value of FIR emissivity and emission power. But there was a little difference among the five types of flooring board values. In physical properties, control type flooring board and injected flooring board showed a similar tendency. Among the domestic trees, all of hard wood seems to be used to surface wood for strong hardness flooring board. But a coniferous tree was not.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.625-628
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• 2006

It is known that cement production not only consumes large amount of energy but also contributes substantially to the green house gas emission. Therefore, there is a demand to develope a new technology to produce energy efficient and environmental conscious cements. The most recent, wood wool ceramic board is being applied in various building material field, for example thermal insulating and acoustic absorption material. This paper focused on improvement of alumino-silicate binder's physical properties for wood wool ceramic board. As the result of this experiment, what we could obtain best fitted alumino-silicate binder's properties such as initial setting time, flow and compressive strength of 3 days aged, was 58min, 110% and 66.0Mpa. This result can be applicable to commercial wood wool ceramic board.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.711-714
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• 2005

This paper focused on development of geopolymer for wood wool ceramic board. Geopolymer can substitude ordinary portland cement and its accelerator of wood wool cement board as inorganic polymer. In this study, what we would obtain geopolymer's properties such as initial setting time(KS L 5108), flow(KS L 5102) and compressive strength of 3days aged(KS L 5105), was less than 1 hour, more than $110\%$, more than 40Mpa. Geopolymer have three essential materials called filler, hardener and geopolymer liquor. So, We applied filler by quartz, hardener by blast furnace slag powder, metakaoline and fly ash, geopolymer liquor by NaOH, KOH and sodium silicate solution. As result of this experiment, what we could obtain best fitted geopolymer's properties such as initial setting time, flow and compressive strength of 3days aged, was 45min, $116\%$ and 43.6Mpa. This result can be applicable to commercial wood wool ceramic board.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.74-81
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• 1993

This experiment was carried out to investigate the reaction of hydration of paper sludge during the setting of portland cement in a paper sludge, wood-cement-water mixturte. The percentage of paper sludge per cement is 7.5%, 15%, 30% respectively. The result indicated that the sludge of 7.5% had the most effect on reaction of hydration, and the sludge of 15% had moderately inhibitory effect but there is still possibility to make sludge-cement board. Paper sludge of 30%, Pinus koraiensis Sieb. et Zucc and Populus euramericana Guinier were proved to have the worst inhibitory effect on cement hydration, so pretreatment will be needed before making board with paper sludge-cement mixture.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.14-22
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• 2023

Economical use of larix (larch) boards (grade 3) in industries is lower than that of imported hardwood; thus, studies have been conducted toward performance improvement of larix boards. Herein, flexural modulus of larix board samples laminated with wood adhesives polyurethane resins, poly (vinyl acetate) resins, phenol-resorcinol-formaldehyde resins, melamine-formaldehyde resins, and urea-formaldehyde resins was compared with that of the samples bonded with adhesives reinforced with mesh-type basalt fibers. Moreover, the flexural moduli of the laminated samples bonded by mesh-type basalt fibers were compared with those of reinforced samples. The results showed that boards laminated with polyurethane and urea-formaldehyde resin adhesives had higher flexural modulus than those without the lamination. In particular, the increase in the flexural modulus was relatively significant for the 2- and 3-ply board structures laminated with polyurethane adhesives compared to those with reinforcement. The 3-ply board structure without reinforcement had the highest flexural modulus when the urea-formaldehyde resin adhesive was used.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.138-144
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• 1998

To provide further information for reutilization of the bed-logs decayed by oak mushroom(Lentinus edodes), the properties of wood-based board prepared with mixed materials of normal wood and bed-logs were examined. Wood fibers in bed-logs showed different morphology from normal wood fibers, that is, shorter length and rough surface. Thickness swelling increased with increasing mixing ratio of bed-log. On the other hand, modulus of rupture(MOR) in bending strength decreased. In products, the visual surface of board prepared from higher mixing rate of bed-log chips was smooth. Consquently, it is considered that the optimum mixing rate of bed-log to normal wood is the range of 25-50% and the bed-log can be used for raw material of board instead of normal wood.

• 보존과학연구
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• s.7
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• pp.56-86
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• 1986

The aim of this study is to scientifical conservation for the Sin An Ship. The test object is Pinus massoniana and Cunninghamia lanceolata of Sin An Ship's timber .Comtrast object is water soaked fresh wood of Pinus densiflora and Cryptomeria japonica The results were as follows.1. M. C is 280.9% in high degraded Planking board,237.5% in low degraded Planking board,158.6% in fresh wood of Pinus densiflora,222.6% in Bulkhead167.3% in fresh wood of Cryptomeria japonica2. Absorption rate of P.E.G is good at heating condition ($55∼60^{\circ}C$), especially in highdegraded wood.3. The dimensional change of wood during air drying is somewhat shrinked That's 7.22% in low degraded Planking board9.8% in high degraded Planking board and 4.11% in water soaked Pinus densiflora.4. The dimensional change of wood during P.E.G treatment is mostly swollen of wery small quantity.5. Salinity in desalinization tank showed below 50 p.p.m. It's indicate the end of desalinization treatment.6. Filtration with filter paper was possible up to 40% concentration only. Key words :M.c ; Moisture Content, Absorption rate, Dimension change, Salinity, Filtration.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.239-248
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• 2019

This research presents an improvement of the physical and mechanical properties of composite board (com-ply) made of Oriented Strand Board (OSB) coated with wood veneer of Pine (Pinus merkusii), Avocado (Persea Americana) and Mahogany (Swietenia mahogany). 1.5 mm thick veneers of those three wood types were adhered to the surface of OSB using two adhesive types: epoxy and isocyanate. The adhesive with the glue spread of $250g\;m^{-2}$ applied using single glue line was spread and then cold pressed with the pressure of $15kg\;cm^{-2}$ for 3 hours. The research result showed an improving dimension stability of com-ply, but not found on all parameters of physical property test. The moisture content seemed to be influenced by the com-ply type, yet not related to its thickness swelling, water absorption and linear expansion. The exception took place in the parallel linear expansion when immersed for 2 hours. The highest to the lowest increases of MOE and MOR were consecutively found on OSB coated with wood veneer of Pine, Mahogany and Avocado. However, the increases were statistically insignificant. The highest increasing screw hold power was found at the com-ply type AE (avocado veneer and epoxy adhesive) that was by 28%.

• Journal of the Korean Wood Science and Technology
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• v.21 no.2
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• pp.57-65
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• 1993

The aim of this research was to manufacture sludge-particle board using paper sludge with wood particle and to investigate physical and mechanical properties of various sludge-particle boards, fabricated with ratios of sludge to particle of 10 to 90, 20 to 80, 30 to 70, 40 to 60 and 50 to 50(oven dry weight based). Sludge-particle boards were manufactured by urea-formaldehyde resin, 0.8 target specific gravity, and 10mm thickness. It was possible to manufacture sludge-particle board as the same processing in the present particleboard manufacturing system. This sludge-particle board have different properties as composition ratios of sludge and particle. And sludge-particle board made from 10 percent to 20 percent of sludge mixing ratio have similar mechanical properties compared with control particleboard. Especially, the sludge-particle board made from 10 percent to 40 percent mixing ratios of sludge have superior to control particleboard in internal bond, screw withdrawal holding strength and modulus of elasticity. In the case of dimensional stability, water absorption was increased and thickness swelling was decreased as increased with sludge mixing proportion. The sludge-particle board made of different mixing ratios of our laboratory design was able to concluded that there is possibility of partial substitution of wood particle materials.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.245-252
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• 2020

This study was performed to analyze the mechanical properties of tropical hybrid cross-laminated timber (CLT) with bamboo laminated board as the core layer in order to evaluate the possibility of its use as a CLT material. Bamboo board was used as the core layer and the tropical species Acacia mangium willd., from Indonesia, was used as the lamination in the outer layer. The modulus of elasticity (MOE), modulus of rupture (MOR), and shear strength of the hybrid CLT were measured according to APA PRG 320-2018 Standard for Performance-Rated Cross-Laminated Timber. The results show that the bending MOE of the hybrid CLT was found to be 2.76 times higher than SPF (Spruce Pine Fir) CLT. The reason why the high MOE value was shown in bamboo board and hybrid CLT applied bamboo board is because of high elasticity of bamboo fiber. However, the shear strength of the hybrid CLT was 0.8 times lower than shear strength of SPF CLT.