• Journal of Ceramic Processing Research
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• v.19 no.6
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• pp.472-478
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• 2018

In this study, the sintering mechanism of woodceramics (WCs) from cashew nut shell waste (CNSW) was studied by analyzing chemical reactions and structural changes during the sintering process of of CNSW powder, liquefied wood and green bodies of WCs at $900^{\circ}C$ for 60 minutes in the $CO_2$ atmosphere. The chemical and structural properties of the products were investigated by X-ray diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared (FTIR), and scanning electron microscope (SEM). The results showed that the decomposition reactions of liquefied wood and CNSW occurred simultaneously to form the hard carbon and the soft carbon at high temperature. The sintering mechanism of WCs has been presented.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.35-41
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• 2012

Nondestructive evaluation (NDE) technique method using a resonance frequency mode was carried out for woodceramics made by different carbonizing temperature (600, 800, 1000, $1200^{\circ}C$) for Broussonetia kazinoki Sieb. Dynamic modulus of elasticity increased with increasing carbonizing temperature. There was a close relationship of dynamic modulus of elasticity and static bending modulus of elasticity to MOR. Therefore, the dynamic modulus of elasticity using resonance frequency mode is useful as a nondestructive evaluation method for predicting the MOR of woodceramics made by different carbonizing temperature for B. kazinoki Sieb.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.38-44
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• 2005

This research investigated the variation of density, the weight loss, dimensional shrinkage and heat conduction by the heating rate and keeping time at maximum temperature of woodceramics, when sawdust boards made from thinned logs of Pinus densiflora, Larix kaemferi and Pinus koraiensis were impregnated with phenol-formaldehyde resin, and then were formed by heating rate ($2^{\circ}C/min{\sim}6^{\circ}C/min$) and keeping time at maximum temperature (1~5 h). As the heating rate increased, the density and thickness shrinkage decreased, but weight loss and linear shrinkage increased. The more the keeping time at maximum temperature, the greater the linear shrinkage and thickness shrinkage. The heating conduction was superior at the heating rate is $2^{\circ}C/min$ and the keeping time at maximum temperature of 2 hs.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.158-164
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• 2002

The properties of new porous carbon materials "Woodceramics" are affected by the characteristics of raw boards. To investigate of density profile and resin contents in impregnated boards, control board and 3 types of steam-injected boards were made by steam injection time, The wood species used for manufacturing boards was Sugi(Cryptomeria japonica). The results are as follows: 1) The density gradient of board after 10 minutes steam injection was the smallest and non-steamed board was largest. 2) The resin content and dimensional rise decreased with increase of board density, and were the largest in board after 10minutes steam injection but there was little difference between boards after 5 and 10 minutes steam injection.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.29-34
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• 2012

To examine possibilities to make use of woodceramics for the lower material of hot-floored ondol boards, woodceramics made from sawdust board with Pinus densiflora, put them in a wood frame and concrete block and heated them sending an electric current, and measured changes in surface temperature of a laminated floor board and a plywood floor board. As the sending an electric current to time passed, their surface temperature increased rapidly up to 20 minutes, and then gradually ascended. In terms of the surface temperature in the wood frame, the beginning temperature of a plywood floor board was higher than that of laminated floor one; however, as time passed, a laminated floor board's temperature rose, and after 60 minutes, it showed similar to the temperature of a floor board of lamination. On the other hand, the surface temperature in a concrete block showed that the laminated floor board was higher than the plywood floor board in both early and 60-minute later temperatures. With the lapse of time after switching off, the surface temperature of floor boards slowly dwindled up to 9 minutes, and from that time on, began to drop sharply. In terms of the descent speed of surface temperature, when woodceramics' surface temperature was adjusted at $70^{\circ}C$, the laminated floor board was the highest; when it was at $80^{\circ}C$, the plywood floor board was the highest, resulting in rapid descent speed of heat.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.73-79
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• 2004

Research investigated the variation of density, weight loss and dimensional decreasing rate, heat conduction rate by the resin impregnation rate and burning temperature of woodceramics, which were formed by impregnation rate of 40~80% and burning temperature of 600~1500℃ with sawdust board impregnated with phenolic resin made from thinned logs of pinus densiflora, Larix kaemferi and pinus koraiensis. As the resin impregnation rate and the burning temperature increased, the density increased, however, as the burning temperature increased to at 1200℃ or more, the density decreased. The more the resin impregnation rate increased, the more the decreasing rate of weight and size decreased; the more the burning temperature increased, the more the decreasing rate of weight and size increased. When the resin impregnation rate was high, the heat conduction (mm/sec) was superior.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.80-87
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• 2003

This research was carried out to examine physical and mechanical properties of clay-woodceramics which were carbonized for 3 hours in a special furnace from 3 layers-clay-woodparticleboard made from pallet waste wood, phenol formaldehyde resin(hereafter PF, Non volatile content 52%, resin content 30%) and clay(10%, 20% and 30%). Carbonization temperature was 400℃, 600℃ and 800℃. The results are summarized as follows: 1. The higher the carbonization temperature, the higher the dimensional shrinkage and the lower the carbonization yield ratio. But the higher the clay addition, the lower the dimensional shrinkage and the higher carbonization yield ratio. 2. The higher the carbonization temperature, the higher the water absorption and the density. The higher the clay content, the higher the density. 3. The higher the carbonization temperature, the higher the bending Modulus of Rupture and bending Modulus of Elasticity.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.178-184
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• 2010

This study was carried out to investigate the properties of woodceramics made from woody part of Broussonetia Kazinoki at different impregnation ratios of phenolic resin of 40, 50, 60, 70%. The physical and mechanical properties increased with increasing impregnation ratio. The highest mean values of density, bending strength, Brinell hardness and compressive strength were 0.66 g/$cm^3$, 53 kgf/$cm^2$, 187 kgf/$cm^2$, 126 kgf/$cm^2$, respectively. There were close correlations between density and bending strength, Brinell hardness and compressive strength, and between MOE and MOR.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.9-13
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• 2007

Using sawdust boards made of pine by differing the percentage of resin impregnation, wood-ceramics were manufactured by carbonizing temperature at $650^{\circ}C$. Their electrical properties and surface temperature were measured by sending an electric current. As electrical resistance of woodceramic was lower, its surface temperature, even in a low voltage, became higher. It seemed to be necessary to applying higher voltage to the woodceramic to raise the surface temperature by target temperature $70^{\circ}C$ or more in this study, according as resistance increased. When the voltage increased, woodceramics showed higher level all in electric current, electric power and surface temperature. Arrival time, electric current and electric power increased with increase of target temperature under constant voltage.

• Journal of the Korean Wood Science and Technology
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• v.32 no.3
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• pp.25-32
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• 2004

This research work explored physical and mechanical properties of impregnated sawdust boards from three softwood species (P, densifora, L. kaemferi, and P. koraiensis) with phenol-formaldehyde (PF) resin by various vacuum treatment methods of combining pressure, vacuum, and ultrasonic waves. Simultaneous vacuum and ultrasonic wave treatments with no pressure resulted in the greatest increase in resin content, density, dimensional changes (thickness and length), bending strength, and hardness of impregnated board. This result seemed to be attributed to the ultrasonic wave treatment.