• The Korean Journal of Mycology
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• v.44 no.4
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• pp.300-306
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• 2016

Recently, the incidence of oak wilt disease has been increasing in Korea, resulting in an increasing number of dead trees. In this study, we performed sawdust bag cultivation of shiitake (Lentinula edodes) using oak wilt-diseased logs and measured the antioxidant activities of the resulting mushrooms. For sawdust media, 4 types of logs (healthy, infected, dead, and fumigated ones) were used. As inocula, three strains of L. edodes (NIFoS 764, Sanjo 701ho, and Sanmaru 2ho) were used. The productivity of L. edodes from dead logs was similar to that from healthy logs. Except for the Sanmaru 2ho strain, fumigated logs and infected logs yielded a lower productivity of L. edodes compared to healthy logs. In terms of antioxidant activity, L. edodes grown on sawdust from fumigated logs showed higher values than those from other logs.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.315-327
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• 2021

Purpose of this study is reviewing the use method for the sawdust (sawmilling by-product) and rice husk (Agriculture by-product) by adding charcoal, an eco-friendly material. Mixed composite boards were manufactured with those materials with each density and mixing ratio, and bending performance was investigated. When the addition ratio of sawdust, rice husk and charcoal is 50:20:20 and the resin addition ratio is 10%, as the density of the prepared mixed board ranges from 0.5 g/cm³ to 0.7 g/cm³, the bending strength was 0.42~3.24 N/mm², dynamic modulus of elasticity was 94.5~888.4 N/mm², and the static modulus of elasticity was in the range of 31.4~220.7 N/mm². As the density increased, the bending performance increased, indicating that the density had a significant effect on the bending performance. In a board prepared by setting the density of 0.6 g/cm³, the addition ratio of sawdust to 50%, and the addition ratio of rice husk and charcoal at different ratios, the bending performance showed a tendency to decrease as the addition ratio of charcoal increased. The relationship between the addition ratio of rice husk and charcoal, bending strength, resonance frequency, and dynamic and static bending modulus showed a rather low correlation with the values of the coefficient of determination (R²) of 0.4562, 0.4310, 0.4589, and 0.5847, respectively. Thus, we found that the effect of the addition ratio on the bending performance was small.

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.98-108
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• 2023

In this study, the boards were manufactured according to the mandarin peels addition rate using sawdust and mandarin orange peel. After that, the mechanical properties and density profile of ceramics prepared by conditions through resin impregnation process and carbonization process were investigated. The bending and compression strengths of ceramics tended to increase as the resin impregnation rate increased. When the resin impregnation rate was 70%, the highest values were 8.58 MPa and 14.77 MPa, respectively. Also, the mechanical properties of ceramics according to carbonization temperature showed the highest values at 1,200℃ for bending strength of 11.09 MPa and compression strength of 17.20 MPa. The bending strength and compression strength according to the mandarin peels addition rate showed the highest values at 8.62 MPa and 14.16 MPa, respectively, when the mandarin orange peel addition rate was 5%. The mechanical properties tended to decrease when the addition rate of mandarin orange was increased. The density profile of ceramics showed a similar tendency to the mechanical properties. It can be seen that the density distribution from the surface layer to the center layer is more uniform as the resin impregnation rate and carbonization temperature increase and the mandarin peels addition rate decreases.

• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.55-59
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• 2012

We designed a new rapid detection method for volatilized formaldehyde from wood. The process was installed with volatilizing and collecting parts in an incubator. For rapid sampling of formaldehyde from wood, we pulverized the wood to sawdust, and used 0.15-2.0 mm particles for the tests. The highest sampling rate (94.8%) was obtained at 40 mL/min flow rate and $100^{\circ}C$. Under the optimized condition, we could collect the volatilized formaldehyde with good recovery rate. The developed method was applied to the monitoring of the formaldehyde from wood, and the measured concentrations were 0.7-4.6 ${\mu}g/g$ from natural wood, 5.9-12.3 ${\mu}g/g$ from preserved wood, and 5.9-211.5 ${\mu}g/g$ from chemical adhesive processed wood. From the results, we identified natural wood sawdust and chemically processed wood (medium density fiberboard, high density fiberboard, particle board) by the formaldehyde contents except preserved wood.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.258-267
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• 2017

In this study, pitch pine (Pinus rigida, PIR) and Mongolian oak (Quercus mongolica, QUM) pellets were fabricated with bark or/and drying waste liquor (DWL) of larch (Larix kaempferi, LAK) as an additive. Based on the results of fuel characteristics of the pellets, optimal conditions for producing the high-quality pellets were provided. In the analysis of chemical composition, bark contained holocelluose and lignin of 90% and over. DWL had 0.1% solid assumed to sugars which are generated from the oven-drying of LAK logs. QUM showed high ash content (2.2%) by containing of bark in the sawdust. Bark and DWL of LAK had high ash content of 4% and over. Calorific values of all specimens and additives were higher than that of the $1^{st}$-grade standard of wood pellets designated by NIFOS (18.0 MJ/kg). PIR and QUM pellets were fabricated with additive of 2 wt% based on the solid weight of oven-dried sawdust using a piston-type flat-die pelletizer, and thus ash content and calorific value of the pellets did not affect by the use of additive. Durability of the pellets increased with the use of additive. Durabilties of pellets, which were fabricated with bark as an additive and DWL as a controller of moisture content for sawdust, did not differ from those of pellets without additives and were lower than those of pellets either with bark or DWL. However, use of both bark and DWL for the production of wood pellets might be favorable because it can make a profit from the collection process of DWL. Based on the results of fuel characteristics of the pellets, QUM and PIR pellets were produced by a flat-die pelletizer. Moisture content (MC), bulk density and durability of the pellets improved with the use of additive. Particularly, sawdust MC of 10% and the addition of bark or DWL for PIR as well as sawdust MC of 12% and the addition of bark for QUM might be optimal conditions for the production of high-quality pellets. Except for the ash content of QUM pellets, other properties of PIR and QUM pellets exceeded the $1^{st}$-grade wood pellets standards of NIFOS.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.33-37
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• 1976

This experiment was carried out to study the effects affecting to particle board quality by the mixed use of sawdust abandoning as the sawmill residues. The obtained results at this study are summarized as follows: 1) There was no significance in bending strength between 5% sawdust addition and non mixed particleboard. 2) The water absorption was increased as accordance with adding more sawdust. When the boards were mixed with sawdust until 20% the differences were shown among the test boards. 3) There was no differences between the moisture contents and also specific gravities between the comparated boards. There was no difference between the boards mixed with 5% sawdust and non mixed boards.

• Journal of the Korean Wood Science and Technology
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• v.11 no.3
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• pp.31-38
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• 1983

This experiment was carried out to improve the physical and mechanical properties of sawdust-board by combining with reinforce material, that is, plastic wire screen and steel wire screen. In experiment results, the density of sawdust-board reinforced with three steel wire screens was highest and its bending strength was also highest. Wastepaper-5% mixed sawdust-board showed as high bending strength as other boards, and therefore the possibility of using wastepaper as raw materials for boards. The sawdust-board with steel wire screen was not ruptured immediatedly after having been deformed by static loading. However, plywood showed higher bending strength than the reinforced sawdust-boards.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.419-424
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• 2004

In order to increase the efficiency of the sawdust machine, the helical type drums with an oblique cutting condition (3D) were developed. The preexisting drums have an orthogonal cutting condition (2D) considering of a saw cutter and a wood cutting pattern. Unfortunately, the disadvantages of this type drum are the big cutting resistance, the high cost of a cutting power and the extreme occurrence of a vibration. To improve this shortcoming, the helical type drum with an oblique cutting condition was developed. Therefore, this type drum decreased the vibration and the cutting resistance of the sawdust machine, and also improved the productivity of 30% or more and the porosity of the sawdust.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.88-92
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• 2004

We developed a helical type drum with an oblique cutting condition for sawdust machine. The existing drum has an orthogonal cutting(2D) condition considering of saw cutter and wood cutting pattern. Additional disadvantage of this type include big cutting resistance, high cost of cutting power and extreme occurrence of vibrations. To improve this shortcoming, we developed a helical type drum with an oblique cutting(3D) condition, therefore, this type drum decreased the vibration and cutting resistance of sawdust machine, and also improved productivity and sawdust porosity.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.30-37
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• 2005

This study aimed at offering basic data to develop a new use of sawdust and rice husk. Research investigated the variation of density, weight loss and dimensional decreasing rate by the percentage of resin impregnation and carbonization temperature of ceramics, which were formed by the percentage of resin impregnation of 40~80% and carbonization of $600{\sim}1200^{\circ}C$ with board impregnated with phenolic resin made from sawdust and rice husk. The results of this study were as follows:1) As the percentage of resin impregnation increased, the thickness shrinkage and weight loss were decreased; on the other hand, density and modulus of rupture increased. Meanwhile, the carbonization temperature at $1200^{\circ}C$ showed the highest values, as the density was $0.81g/cm^3$ and the bending strength was $77.9kgf/cm^2$ in the percentage of resin impregnation at 70%. 2) As the carbonization temperature grew higher the linear shrinkage, thickness shrinkage and weight loss increased while the density increased until the carbonization temperature of $1000^{\circ}C$; but then decreased slightly at $1200^{\circ}C$.