• Journal of the Korean Wood Science and Technology
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• v.37 no.2
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• pp.141-147
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• 2009

The fluctuation of physical properties in wood or wood composites is an important subject when the materials in building and construction. Sorption and desorption occur in wood when exposed to the open air, and the temperature distribution in wood can fluctuate as a result of changes in environmental temperature, solar radiation, humidity, and wind velocity. In this study, the temperature difference and fluctuation caused by outdoor environment among different wood species were analyzed using a numerical method. The effect on the process of heat transfer in wood caused by environmental factors was investigated using 1-dimensional partial differential equation with real boundary and initial conditions. The experimental data have been used to check the accuracy of programming code. Through analysis, it was found out that density and moisture content have a negative effect on thermal diffusivity of wood.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.572-579
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• 2017

Determination of the wood content in wood plastic composite (WPC) is crucial to form reliable WPC market. WPC with simple formulation consisting of only two components (wood flour and polypropylene) was examined using thermogravimetric analysis (TGA) and accelerator mass spectrometry (AMS) for determining wood content in the WPC. TGA method using derivative peak temperature (DTp) of polypropylene under low heating rate ($5^{\circ}C/min$) showed more reliable calibration curve and lower error factor compared to method of using the percentage of weight loss of wood flour. In addition, AMS using bio-based carbon content showed greater reliability for the determination of wood content in the WPC in comparison with the TGA method.

• Journal of Korea Foresty Energy
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• v.24 no.1
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• pp.33-38
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• 2005

To find a new use of wood tar which is obtained from the manufacturing process of wood charcoal, a resol type of phenol adhesive using wood tar was made and some adhesion tests on plywood were examined. Phenol adhesive synthesized with pine tar was almost same as an original phenol adhesive in physical properties such as solid content and viscosity and tensile-shear adhesive strength of plywood made of phenol adhesive synthesized with pine tar was not much lower than the original one in non-waterproof and waterproof tests. Phenol adhesive synthesized with oak tar, however, was different from original phenol adhesive in physical properties. Adhesive strength of plywood made of oak tar was $50\%$ lower than the original one on waterproof tests. The amount of emitted formaldehyde increased as the amount of wood tar increased.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.828-841
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• 2016

Relatively little information is available regarding the correlation between wood and veneer quality, especially for Samama wood, an endemic wood species in eastern Indonesia. This study addresses the quality of 8 years old Samama wood and its effect on the veneer quality. Samama wood quality was determined by evaluating its specific gravity, moisture content, fiber dimensions, and microfibril angle from pith toward bark. Meanwhile, veneer quality was assessed by examining veneer thickness and lathe check characteristics. Geometry factor model was constructed to elaborate the quantities of lathe check from pith toward bark. Results show that fair variations of veneer thickness, ranging from 1.5 mm to 3.0 mm, could be obtained from Samama wood. The quantity, depth, and length of lathe check were noticeably decreasing toward bark. Further, in the same manufacturing process, geometry factor was determined as the dominant factor over other wood properties in affecting the frequency of lathe checks from pith towards bark. These facts should be put into consideration in producing veneer from Samama wood. Moreover, these results enlighten the potential of Samama wood as plywood and other excellent veneer-based products.

• Journal of Korea Foresty Energy
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• v.18 no.1
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• pp.37-45
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• 1999

The greenhouse effect becomes the most serious environmental problem due to excessive emission of carbon dioxide. This effect is aggravated with the deforestation, particularly cleaning of tropical forest for agricultural use. As trees sequester carbon dioxide from atmosphere, forest and forest products play an important role in the use and reduction of carbon dioxide. Wood and wood products require far less energy than the alternatives such as steel, aluminium and concrete for production. Considering high probability of increasing costs in the use of fossil fuel, the relatively low energy requirement for wood processing to very important. Also wood and wood products perform as a long-term storage of carbon. Wood is therefore an environmentally desirable resource. Recently, many alternatives have been introduced for industrial use. In selecting resources, many aspects should be taken into consideration. Wood and wood products have less harmful effects on the environment than the alternatives. We should utilize wood and wood products more efficiently, which should be provided based on the sustainable forest management.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.309-317
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• 2014

Harvested wood products (HWP) are known as products from the tree such as sawn wood, plywood, particle board, structural lumber, wooden interior material, wooden furniture, and paper products. Because carbon is locked up in the HWP until eventual end-use of HWP, HWP played a role as the carbon storage which has the effect of stabilizing the concentration of carbon dioxide in the atmosphere. For these reasons, the suggestion that it must admit the carbon storage effect of HWP has been constantly raised. In 2011, the 17th session of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC) which was held in Durban, South Africa, assigned "Production Approach" which targets only the HWP producted by using round wood of domestic forestry as a official method for carbon accounting. Therefore, it is necessary that each country has to determine the half-life of wood in order to correspond to the discussions and negotiations between countries in the future and to develop an inventory of product-specific domestic wood. In this study, some countries' examples of the methods and conditions for determining half-life of HWP were investigated, and it was tried to derive the factor and methodology to determine half-life span of domestic HWP appropriately.

• Journal of the Korean Wood Science and Technology
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• v.52 no.3
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• pp.243-261
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• 2024

In this study, samples were collected from various ancient wooden shipwrecks, including the Shinan shipwreck and Jindo shipwreck that used iron nails, the Yeongheungdo shipwreck carrying iron artifacts, as well as the Sibidongpado shipwreck and Wando shipwreck where degradation products were not observed, all of which were salvaged by the National Research Institute of Maritime Heritage. The aim was to analyze the characteristics of degradation products generated by iron (Fe) within the salvaged wooden shipwreck materials and establish fundamental data on degradation products in waterlogged archaeological wood. The analysis revealed that sulfur (S) is generally accumulated in wood obtained from marine environments. It was observed that the content of inorganic substances such as iron and sulfur was significantly higher in the Shinan shipwreck, Jindo shipwreck, and Yeongheungdo shipwreck compared to Sibidongpado shipwreck and Wando shipwreck, which used wooden nails. This indicates that the presence of iron affects the accumulation of degradation products and suggests that iron is a factor in the corrosion of wood. Furthermore, crystallin compounds were observed within the cell walls, and higher concentrations of iron and sulfur were found in the resin ducts, rays, and radial tissues. This suggests that during desalination and consolidation treatments, warm water or polyethylene glycol (PEG) may move degradation factors into resincanals, rays, radial tissues, etc.

• Journal of the Korean Wood Science and Technology
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• v.51 no.6
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• pp.542-554
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• 2023

This study is a continuation of our previous work, which focused on the resistance of jabon wood to termites after impregnation with wood vinegar (WV) and animal-based adhesive (kak). This paper presents the physicomechanical properties of fast-growing jabon wood impregnated with kak at two concentrations (8% and 10%) in wood vinegar or water as a solvent with and without 4% borax. The physical properties of the impregnation solution, that is, viscosity, density, pH, and solid content, were evaluated according to SNI 06-4567-1998. Some physical parameters, such as weight percent gain (WPG), density, water uptake, anti-swelling efficiency (ASE), crystallinity, and mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS), of the impregnated wood were determined. Based on these results, wood impregnated using a mixture of kak in WV presented better physical (increased WPG, density, dimensional stability, and crystallinity) and mechanical (increased MOE/MOR and compression strength) properties than wood impregnated with a water solvent or untreated wood. The wood impregnated using WV and water solvent improved the physical and mechanical properties. The density of the wood increased by 44%-58% and 32%-47%, ASE radial-tangential increased by 38%-45%; 15%-28% after 24 h of water immersion, crystallinity increased by 59%-74%; 36%, MOE increased by 46%-57%; 28%-31%, MOR increased by 29%-34%; 14%-27%, and compression strength increased by 40%-76%; 38%-72% values to untreated wood.

• Journal of the Korea Furniture Society
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• v.23 no.2
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• pp.110-121
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• 2012

With people's recent increasing interest in good design products, wood and metal products have gained great popularity. However, it was believed that it would be necessary to have a transformation to the manufacturing method based on digital data and equipments from existing analog-based manufacturing method, in order to meet consumers' demand. This study was aimed to seek for the possibility of mass-producing wood and metal products through the research on the type, usage and development conditions of digital data and the methods of utilizing digital equipments. As for research methods, the study analyzed the concepts and types of digital data through various internet and literature reviews and suggested perpetual calendar products as the final outcome of design development using computer data. Through this, the study summarized and organized actual design development processes by stage to provide basic data that could become the foundation of research on the design of wood and metal products using digital data. Through the outcome of this project, the following effects could be expected by developing wood and metal products through digital data. First, its accurate and precise process would help mass-produce complex forms of products and reduce their defective rate. Second, the compatible production of various types of digital equipments would lead to a cost reduction. Third, the diversity of design could be pursued by overcoming technical limitations. In order to satisfy the above expectation effects, such as realization of developing and producing various wood and metal products, there should be designers' creative experimental spirits, their active information exchange and cooperation with the companies concerned.

• Journal of the Korean Wood Science and Technology
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• v.2 no.1
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• pp.3-18
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• 1974

The exports of plywood are increasing annually and it has ranked first in the world market because of the high quality product and manufactured using mordern techniques. However, it is known that the exports of the other wood products, except plywood, is inactive because of their low quality. Accordingly, to increase the exports of various wood products investigations were carried out on kiln drying techniques to improve the quality of the wood. Wet wood should be kiln dried before use to prevent various drying defects such as distortion, shrinkage etc., which would develop after processing,:and also wet wood is not suitable for cutting, gluing and finishing. Therefore, the kiln drying properties of lumber from such species as oak, ramin and meranti which are used in large quantity for manufacturing exporting wood products have been studied. The results of the research are summarized as follows. (1) The end checks and the time for drying from initial moisture content of about 40 percent to 5 percent moisture content in ovendry were investigated as follows: (2) The kiln dried results, for 30mm stock, which are presented by using kiln schedule table 3 are as follows: (3) The kiln schedules for ramin, meranti and oak are given respectively as follows: Ramin kiln schedule: Table 17 and Table 18. Meranti schedule : Table 12. Oak schedule : Table 15.