• Journal of the Korean Wood Science and Technology
• /
• v.48 no.4
• /
• pp.417-430
• /
• 2020

The flame retardancy, such as carbonized length and area, of four plank type wood products by the spreading concentration and impregnation time of flame retardant were measured according to standard of the Nation Fire Agency in Republic of Korea. To measure the flame retardancy, Korean pine plywood, Japanese larch plywood, Japanese cypress planks, and perforated birch plywood boards were treated with self-development flame retardant by 300 and 500 g/㎡ spreading concentration and those were compared with control specimen. In general, the flame retardant performance of wood products improved as the spreading concentration of flame retardant increased. Except for Japanese larch plywood, there was no significant difference in the flame retardant performance by the spreading concentration. The flame retardant performance of perforated birch plywood board was positively correlated up to 60 minutes of impregnation time, but then gradually decreased. These results about the flame retardancy of wood products by spreading concentration and impregnation time were expected to be basic data for improving flame-retardant treated wood.

• Journal of Conservation Science
• /
• v.1 no.1 s.1
• /
• pp.3-11
• /
• 1992

Micromorphological changes in waterlogged archaeological woods excavated from Sweden and Germany were investigated. Especially bacterial attacks on those wood samples under near anaerobic conditions were examined by transmission electron microscopy(TEM). The major feature of micromorphological alterations in those wood samples was the preferential destruction of secondary wood cell wall. In contrast, the middle lamella was not extensively degraded. Three distinct degradation patterns by bacteria were observed : erosion, cavitation and tunnelling bacteria. Erosion and cavitation bacteria attacked primarily $S_2$ layer, whereas tunnelling bacteria made the tunnel-like degradation along the $S_1$ layer. Tunnelling bacteria, in some samples, were able to degrade tunnel in the lignin-rich areas, such as middle lamella, suggesting that these bacteria had the capacity to degrade the lignin. IR spectra indicate that hemicellulose and cellulose in the waterlogged woods were preferentially decomposed. Breakdown of the lignin, on the other hand, was much slower.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.6
• /
• pp.751-760
• /
• 2019

Cellulase is an eco-friendly biocatalyst, and its demand is growing in many industrial applications such as food, textile, paper, and bioenergy. Strains with a high cellulase activities are the starting point for the economic production of cellulase. In a previous study, Acanthophysium sp. KMF001 with high cellulase production ability was selected among 54 wood-rotting fungi. In this study, we evaluated the cellulase productivity of Acanthophysium sp. KMF001 quantitatively and analyzed its taxonomic location using a genetic method. Acanthophysium sp. KMF001 showed high cellulase productivity similar to that of Acanthophysium bisporum and was much better than A. bisporum in specific enzyme activity. The 28S rRNA sequence of Acanthophysium sp. KMF001 was similar to that of Acanthophysium lividocaeruleum MB1825, with 98.40% homology. Phylogenetic analysis suggested that Acanthophysium sp. KMF001 is a new strain. In this study, we propose a new strain with high cellulase productivity.

• Journal of Adhesion and Interface
• /
• v.4 no.4
• /
• pp.7-14
• /
• 2003

"Tack" is defined as "the property that enables an adhesive to form a bond with the surface of another material upon brief contact under light pressure". The tack depends on a number of experimental parameters. We can control various experimental factors (contact force, dwell time, pretest speed) using probe tack tester. We are here concerned with pretest speed of experimental factors using SIS-based hotmelt PSA and water-borne acrylic PSA.

• Journal of the Korea Furniture Society
• /
• v.27 no.4
• /
• pp.335-342
• /
• 2016

In previous study, volatile organic compounds (VOCs) emission characteristics were highly affected by coating materials for wood finishing. Natural based coating materials showed that about 15~46% lower TVOC emission than typical products. In this study, long-term changes of VOCs emission characteristics from pine panel with three types of coating treatments were determined. Non-treated pine panel emitted $604.7{\mu}g/m^2{\cdot}h$ of TVOC that contained 66% of NVOC ($399.7{\mu}g/m^2{\cdot}h$) at 0 month. After 10 month, TVOC reduced 88% and 93% reduction on NVOC was observed. Natural oil and waterborne stain treated pine panel showed 61% and 77% lower TVOC, respectively, than non-treated pine panel. However, TVOC from finished pine panels showed higher TVOC emission than non-treated pine panel. All samples satisfied the VOC emission regulation (below $4,000{\mu}g/m^2{\cdot}h$) by Korean Ministry of Environment. Toluene emission regulation (below $80{\mu}g/m^2{\cdot}h$) was passed on all sample without varnish treated pine panel at 0 month. According to HB qualification standard for construction materials by Korea Air Cleaning Association (KACA), wood is not qualified to get the best tag due to high TVOC emission. At the 10 months, only non-treated pine panel could get the best tag of HB from KACA.

• Journal of Adhesion and Interface
• /
• v.5 no.3
• /
• pp.23-28
• /
• 2004

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.2
• /
• pp.121-127
• /
• 2009

Acacia wood (Acacia mangium Willd.) is the most popular fast growing tree species planted in timber estate in Indonesia and is considered to be very valuable raw materials for structural composite products. The objective of the research was to evaluate the properties of OSB prepared from A. Mangium wood with or without immersing the strands to hot water at $80^{\circ}C$ for 2 hours. MDI adhesive was used in 3 levels i.e., 3%, 5%, and 7%. The moisture content of strand was 7%. The results indicated that immersing strands in hot water for 2 hours at $80^{\circ}C$ prior to manufacture OSB improved significantly the mechanical peoperties (i.e., MOR and MOE) of OSB. The higher the adhesive content resulted in the better the dimensional stabilisation (i.e., water absorption and thickness swelling) and the mechanical properties (i.e., MOR, MOE and IB) of OSB. OSB prepared from hot-water immersed strands with 5% adhesive content has met all parameters requirement on the JIS A 5908 (2003) standard.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.48 no.3
• /
• pp.73-79
• /
• 2016

Hexeneuronic acid in soda-anthraquinone(AQ) pulps from Moso bamboo(Phyllostachys pubescebs), Timber bamboo(Phyllostachys bambusoides) and Henon bamboo(Phyllostachys nigra var. henonis) was investigated with mercuric chloride hydrolysis and UV spectroscopic quantification. Concentration of hexeneuronic acid in bamboo pulps was $36.6-45.4{\mu}mol/g$, which contributed to 3.1-3.9 value increase of kappa number. Lower concentration of 4-O-methylglucuronic acid in bamboo xylan contributed to lower hexeneruonic acid content in bamboo pulps than those of hardwood(yellow poplar or eucalyptus) but higher than softwood(red pine).

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.5 s.133
• /
• pp.45-49
• /
• 2005

The sound absorption coefficients of three types commercial fiberboard were experimentally measured under a relatively low frequency range of 50 to 1600 Hz by the two microphone transfer function method. The sound absorption coefficient of 30 mm thick fiberboard was higher than that of 18 mm thick fiberboard at the frequency range of 50 to 1.2 KHz. The sound absorption coefficient of medium density fiberboard was a little higher than that of low density fiberboard.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.41 no.3
• /
• pp.71-75
• /
• 2009

Cotton waste is usually used for cultivating agaric mushroom after outdoor fermentation for a few months. Electron beam was used to break down the polymer chaims of cotton waste for increasing low molecular weight soluble sugars, which may enhance the agaric mushroom cultivation. By increasing electron beam radiation, alpha cellulose content of the cotton waste was decreased while beta cellulose content and hot water solubles were increased. Electron beam radiation over 240 kGy on cotton waste caused significant increase of mushroom yield without lowering mushroom quality.