• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.381-389
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• 2011

The effect of organoclays on the mechanical properties of cured phenol formaldehyde resin and oriented strand lumber made from Mountain Pine Beetle killed pine strands was analyzed. Three organoclays were used: a natural montmorillonite, hydrophobic organically modified 10 A, and hydrophilic organically modified 30 B. The oriented strand lumber samples were less creep deformation as well as improved internal bonding strength by adding organoclays in the order of 10 A 2% > MMT 2% > 30 B 2% > control. Furthermore, time-temperature superposition (TTS) analysis was proved to be able to predict the long-term creep behavior of MPB-OSL samples.

• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.68-74
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• 1997

This research was studied dissolving pulp for rayon production, which is not KP, SP methods but steam explosion and oxygen alkali treatment. The variation of characterization in wood cellulose after steam explosion and oxygen alkali treatment this follows. In the oxygen alkali treatment of exploded pine wood, yield of dissolving pulp was lower than steam-exploded oak wood, and we have obtained dissolving pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 200. In the case of steam-exploded oak wood, degree of polymerization was higher than steam-exploded pine wood but purity of cellulose was lower than its.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.96-103
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• 2003

This study was conducted to evaluate the tensile properties of metal plate connector for the domestic major softwoods, such as Korean red pine, Korean white pine, and Japanese larch. The maximum tensile load of Korean red pine was 3,612kgf in AA type, it was 1.2 and 1.7 times higher load than that of Japanese larch and Korean white pine. In EA type, it was 2,704kgf, and 1.1 and 1.5 times higher than the loads of Japanese larch and Korean white pine. The failure modes of metal plate connector were metal plate withdrawal, plate tensile failure, and wood shear block failure. The failure mode of Korean red pine connector was tensile failure of plate, that is reason of the high tensile load resistance for metal plate connections in Korean red pine. The mechanical properties of metal plate connector could be predicted by the Foschi model parameter. In the initial stage, the Korean red pine connector was stiffer than the other species. The design values for metal plate connector per tooth was 25, 22, and 15kgf for Korean red pine, Japanese larch, and Korean white pine in AA type and 19, 17, and 13kgf in EA type.

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.324-335
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• 2019

Timber from plantation forests has inferior physical and mechanical properties compared to timber from natural forest because it is mostly from fast-growing tree species that are cut at a young age. Filling cell voids with methyl methacrylate (MMA) can improve the wood properties. The purpose of this study was to determine the physical and mechanical properties of MMA-impregnated wood from three fast-growing wood species, namely jabon (Anthocephalus cadamba (Roxb.) Miq.), mangium (Acacia mangium Willd) and pine (Pinus merkusii Jungh. & de Vriese). Wood samples were either immersed in MMA monomer or impregnated with it and then heated to induce the polymerization process. Jabon, which was the lowest density wood, had the highest polymer loading, followed by pine and mangium. The physical and mechanical properties of samples were affected by wood species and the presence of MMA, with higher-density wood having better properties than wood with a lower density. Physical and mechanical properties of MMA wood were enhanced compared to untreated wood. Furthermore, the impregnation process was better than immersion process resulting the physical and mechanical properties. Based on MOR values, the MMA woods were one strength class higher compared to untreated wood with regard to Strength Classification of Indonesian Wood.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.45-45
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• 1982

There are many important exotic species in Korea, such as white pine, pitch pine, jack pine, oak, ash, etc. Some of them are already being used for various construction purposes, in spite of their history imported to and cultivated in Korea being very young. No study was carried out on the various properties of these exotic species, which arc needed for their proper use at present.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.677-684
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• 2016

This study was carried out to confirm the effects of the knife-incising and longitudinal kerfing treatment on high-temperature drying characteristics of red pine square timber with dimensions of thickness 15 cm. The range of final moisture content was investigated 5.6% to 7.5% after drying. The differences did not exist in the moisture content and distribution according to the pretreatment condition. In the case of longitudinal kerfing treatment, the surface check occurrence was reduced than the control. In addition, the twist had a tendency to decrease due to the longitudinal kerfing treatment. The knife-incising and longitudinal kerfing treatment were investigated to be ineffective on internal checks and drying shrinkage.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.736-742
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• 2016

Wooden dowels are commonly used to join the wooden members together in many types of structures, But little information is available concerning their holding properties in domestic wood. This study was performed to determine the withdrawal loads and strengths on the effect of diameter of dowel and hole clearance. The test block was manufactured from 15 mm thick korean red pine and korean pine. The dowel was manufactured 6, 8 and 10 mm diameters from korean castanea, korean pine and tuliptree. Research reported here indicates that withdrawal loads increase, but withdrawal strengths decrease, in a linear fashion as the dowel diameter increases. This study also indicates that dowel withholding load and strength increase in a linear fashion as a hole clearance decreases.

• Journal of the Korean Wood Science and Technology
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• v.20 no.3
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• pp.11-20
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• 1992

Steam explosion is one of the most effective pretreatment for fractionating wood. This leads to the total utilization of wood basic components; cellulose, hemicellulose and lignin. The amount of sugar and lignin extracted with the hot water method was very low. The lignin content of residues after extraction with using a sodium hydroxide treatment, increased delignification of carbohydrate as the concentration of alkali was increased. Oak, pretreated with steam exploded at 25kg/$cm^2$ for 6 min. then 1% alkali for 2hrs. showed a delignification rate up to 95%. A sodium chlorite treatment of steam exploded pine and oak also afforded a high deligninfication effect. Pine, treated 10% sodium chlorite for 2hrs. showed high delignification. However, by using a sodium hydroxide treatment, a 2% retreatment for Ihr. after a 2% for 2hrs. afforded remarkable delignification effect on exploded wood at 30kg/$cm^2$ for 9min. and at 35kg/$cm^2$ for 3-6min. In oak, an initial 2hrs. treatment of 2% sodium chlorite was followed by a second 2hrs. treatment at 10%. This showed a delignification rate of 96%.

• Fire Science and Engineering
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• v.25 no.3
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• pp.119-124
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• 2011

In this study, we measured the smoke density characteristics to find the fire risk of Wood-Plastic composites (WPCs) which are one of spotlighting materials for landscape architecture and residential construction material with the cone calorimeter tester (by ISO 5660-2) and the smoke density tester (by ASTM E 662). In addition, the identical test was implemented to compare the smoke density characteristics between the red pine and the antiseptic wood. The result of cone calorimeter test showed that emissions of carbon monoxide, carbon dioxide and total smoke production rate of WPCs were higher than those of red pine and antiseptic wood. And the result of smoke density test showed that maximum specific optical smoke density(Dm) of WPCs was higher than that of red pine and antiseptic wood as well.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.141-148
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• 2013

The goal of this study was to find the optimum lamina size from red pine (Pinus densiflora) and Japanese cedar (Cryptomeria japonica) logs for the cross laminated timber (CLT) production. From visual inspection of the logs from two species, red pine log showed a larger knot and warp compared to the Japanese cedar. Different cross-sectional sizes of lamina ($110mm{\times}30mm$, $110mm{\times}40mm$, $110mm{\times}50mm$, $50mm{\times}30mm$, $30mm{\times}30mm$) from two species were analyzed for yield and grade. Regardless of the species, the optimized cross sectional size for maximizing the yield was $110mm{\times}30mm$. In grading for the different size laminas from Japanese cedar and red pine, a higher percentage of the first and second grade was found from the $110mm{\times}30mm$ lamina cut.