• Journal of the Korea Furniture Society
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• v.10 no.1
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• pp.1-12
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• 1999

Of the vast number of plant taxa in the world, the wood is one of the most useful resources. It is important to identify the fibers of wood and pulp for the plant taxonomy and for the uses, but we do not have enough information on them, on them, especially for the computerizd data. The fiber identification is one of the difficult tasks. In addition to the plant taxonomy and the fiber-using industries, such identification is also important in many other fields, including education. document examiners, etc. For these purpose, the fibers should be exactly distinguished. The TISS system I have programed to identify various woods would also be useful in the identification of fibers by the genus and species in the features of unknown samples and in searching the features of a species based on its scientific name. Such searching programs are being developed in many other countries with a view to searching for the species name by using the features of the cells of the woody materials. With the survey of all the available literature, the features of the fibers of 124 species both of softwood and hardwood were examined under the electron and optical microscopies. Each species were coded and carded by the feature, and the databases were built. The microscopic were inputted into a personal computer program called and by a slide film scanner. The new computer program called TISS 2 was developed using C computer language. Korean language fonts were added to the TISS 2. The TISS 2 can be in adding and searching a image of fiber features both of a known fiber and an unknown fiber. The databases were corded for the DELTA system with was developed by Dallwitz and Paine in Australia, 1986.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.231-237
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• 2006

Grease barrier food containers are commonly used for packaging of fast food, cooked food, and food in general. Greaseproofing is also used for certificate paper and label paper etc. Different pulp raw materials, due to their different fiber morphology and chemical compositions, produce papers of varying characteristics. We used optical photomicroscopy and fiber analysis data to evaluate fiber morphology and traits under various beating conditions in order to understand which pulp raw materials produced superior greaseproofing property when a fluorinated greaseproofing agent was added internally. The experiment studied 9 species of pulps, including 2 softwood (northern pine and radiata pine) bleached kraft pulps which were beaten to 550 and 350 mL CSF, respectively; 3 hardwoods (eucalypts, acacia, mixed Indonesian hardwoods) bleached kraft pulps which were beaten to 450 and 250 mL CSF, respectively; and nonwood fibers of reed, bagasse, and abaca. A fluorinated greaseproofing chemical at 0.12% dosage with respect to dry pulp was added to each pulp preparation and formed handsheets. A total of 67 sets of handsheets were prepared, and their basis weights, thickness, bulks, opacities, wet opacities, air resistance, water absorption and degrees of greaseproofing were measured for an overall evaluation of pulp and freeness on greaseproofing papers. The experimental fiber length, coarseness and distribution characteristics and the greaseproofing results suggest that softwood pulps (radiate pine > northern pine) were superior to hardwood pulps (eucalypts > acacia > mixed Indonesian hardwoods). The unbeaten pulps gave papers with high porosities and nearly devoid of greaseproofing property. Greaseproofing is proportional to air resistance. Among the nonwood fibers, bagasse had the best greaseproofing property, followed by reed and abaca was the poorest. With regards to waterproofing property, hardwood pulps (mixed Indonesian hardwoods > acacia > eucalypts) were better than softwood pulps (northern pine > radiate pine). Among the Nonwood fibers, reed had the highest waterproofing property, and it was followed by abaca, while bagasse had the poorest waterproofing characteristic. In summary, bleached kraft northern pine, eucalypts and reed pulps were best suited for making greaseproofing papers, Freeness of the pulps should be kept at $200{\sim}280mL$ CSF for optimal performance.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.82-89
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• 2004

Two kinds of chemicals (RNF-3 and RNF-4) with high anti-mold effectiveness against stored fungi causing fungal discoloration was selected from among the six kinds of fluoride-based chemicals in the preceding study. In this study, the anti-mold test using 16 species fungi isolated from the softwood lumbers which were fungal discolored and field test in the sawmill was carried out to prove the feasibility for practical using of selected chemicals.For the isolated fungi, the RNF-3 consist of F and Cu showed high mycelial growth control in the PDA medium and fungicidal effectiveness in the japanese red pine (Pinus densiflora), korean pine (Pinus koraiensis) and radiata pine (Pinus radiata) when the concentration was 2% or more. However the RNF-4 consist of F only was not effective compared with RNF-3 because of mycelial growth in the PDA medium and wood treated with 2% or more chemical solution. The RNF-3 also showed a strong anti-mold effectiveness because there was no fungal discoloration for the radiata pine boards treated by 2% and 10 min. soaking in the field test. These results mean that RNF-3 can be used as domestic anti-stain chemicals for prevention of fungal discoloration of the softwood lumber

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.26-33
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• 1989

The acoustic absorption coefficient and acoustic impedance of 5 species of softwood(sonamoo, sam namoo, gusang namoo, hwaback, sitka spruce) and 5 species of hardwood (Mulgusul namoo, Italian popular, white meranti, red meranti, kalantas) were measured by the standing wave method. which is simple in the setup and gives more accurate result than does any other measuring method. The dependence of the absorption coefficient and complex acoustic impedance on the wood sections. thickness of the sample itself and the back air gap was investigated experimentally in the frequency range from 200Hz to 1800Hz, and the result are as follows: 1. The acoustic absorption coefficient of wood sections was higher on the cross section than radial and tangential sections. 2) The acoustic absorption coefficient were higher in the frequency range from 400Hz to 600Hz, but decreased in the frequency above 600Hz. 3. The genenal tendency of the variation of the normal acoustic impedance was increased according to the frequency. 4. The acoustic absortion coefficient was increased in the to 7mm-thick sample and decreased in 9mm-thick sample. 5. The higher acoustic absorption coefficient was shown in the case with the backing an gap than in the case without the gap.

• Journal of the Korea Furniture Society
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• v.21 no.2
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• pp.188-195
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• 2010

This study has been focused on the evaluation of domestic softwood timbers to replace imported timbers for woodcrafts and furniture-making. Figures on radial and tangential sections were observed with naked eyes. As the result of study on the figures appeared on the wood surface of 6 species of trees, flat grain and edge grain were clearly found from Taxus cuspidata. Juniperus chinensis and Ginkgo biloba had wavy grain figure and pigment figure, and blister figure was found in Pinus densiflora, Larix kaempferi showed pitch streak and irregular figures on its tangential section due to growth abnormalities. Wavy grain figure appeared weakly on near knot of Pinus koraiensis. The characteristic figures shown from each species of trees are expected to be used for crafts, sculptures, furniture, and interior decoration. They are also considered to have great potential to substitute imported timber sufficiently, which are currently used a lot for wood crafts and furniture-making.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.83-87
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• 1995

Impact-bouncing height of steel balls dropped from 1m height on various floor materials were measured to evaluate impact-bouncing characteristics depending on floor materials and the effect of these properties on walkability and fatigue of humanbody. Stone and tile finished concrete floor showed the highest bouncing height of around 70%, and soil showed the lowest bouncing height of around 3%. The second highest bouncing height was about 40% which corresponded to terazo finished concrete floor and about twice as high as the bouncing height on concrete floor without finishing. The impact-bouncing height could be lowered to 15~20% by using gum tile on concrete floor. Steel showed similar bouncing height to concrete floor, and wood-based materials showed the second lowest bouncing height next to soil. Among wood-based materials, hardwood species having higher specific gravities showed relatively high bouncing height of 8~24%, softwood species having low specific gravities showed relatively lower bouncing height of 5~18%, and wood composites showed bouncing height of 8~18%. Among all the materials used in this study, wood-based floor materials corresponded to the bouncing height of 10~15% which is considered to be best for humanbody. Surface painting on wood-based materials increased the bouncing height, and the number of bouncing of steel balls after dropping from 1m height increased as the bouncing height increased.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.7-17
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• 1991

The feasibility of treating three softwood(Japanese larch pitch pine, and Korean pine) thinned logs by double-diffusion treatment processes was investigated. Some posts were incised before immersion, and others were imersed in hot copper sulfate solution. Comparison among species indicated that. in general, pitch pine was most treatable and Japanese larch least treatable. For all three species, almost all treatment schedules gave consistently good penetration and high net retention, but very steep gradient of preservative distribution. As expected, the treatability was increased by the extension of immersion time, increased concentration of treating solution, incising. and heating of the first solution. Of the variables tested, it appears that heating of the first solution is the most important. From the data in this paper, it may be concluded that, if the first solution is not heated, the best schedule is #3. If the first solution is healed. it appears the best schedules are #10 or #11. Since heating of the first solution improves the treatability. schedules # 10 or :#11 are recommended if the cost of heating might be justified. The data presented in this paper indicate that double-diffusion treatment processes seem to offer a promise as a comparatively effective and easy-operating method of treating thinned logs for the small-scale production of treated stock.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.46-54
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• 2007

The purpose of this study was to examines the burning rate of fire retardant treated wood in the cone heater with a one-dimensional integral model. The wood samples used in this study were four species. The species of woods are Redwood, White oak, Douglas fir and Maple. Each sample was nominally 50mm thick and 100mm square. Samples were exposed to a range of incident heat fluxes 10 to $35kW/m^2$ using the cone heater. A one-dimension integral model has been used to predict burning rate, heat of gasification, flame heat fluxes, charring rate and char depth of samples. As a result measurement of mass loss rate, softwoods(Redwood and Douglas fir) has relatively low value than those for hardwoods(White oak and Maple). Average charring rate of woods in case of fire retardant treatment showed reduction effect of 41.29%, 50.00%, 48.18% and 60.82% for Redwood, Douglas fir, White fir and Maple, respectively. Almost all the predictions from integral model showed faster charring than those measured. Average difference between predictions and experimental data was 16%, 9.5% and 11.8% for N, F1 and F2 respectively. Water-soluble fire retardant used in this study find out more effect in hardwood than softwood from the result of measurement of mass loss rate and average charring rate.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.317-321
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• 2006

The investigation of the formation of organic sulfur compounds (i.e., odor species), mainly methyl mercaptan and demethyl suifide, during kraft pulping has been conducted, in which both hardwood and softwood species were used. It was discovered that there is an organic sulfur compounds formation phase transition point with respect to delignification extent. The transition point occurs at a kappa number of approximately 35 and 20 for softwoods and hardwoods, respectively. The results also showed that both low sulfidity and anthraquinone (AQ) addition are helpful to control the formation of theses organic sulfur compounds during kraft pulping. Whereas Hexenuronic acid (HexA) has contribution to Kappa number, the extended delignification not only lead to low pulp yield, but also be adverse to odor control. A significant in-digester odor reduction can be achieved if the pulping is to be terminated before phase transition point and combined with AQ addition.

• Journal of the Korea Furniture Society
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• v.10 no.1
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• pp.23-32
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• 1999

The ultrastructural characteristics of shear fracture surfaces of laminated wood prepared from major four Korea wood specimens were examined. Commercial urea and urethan resin were used as adhesives for laminated woods of both homospecies and heterospecies. The morphology of fracture surface was observed using an optical microscopy and scanning electron microscopy. Three anatomical failure types were recognized : intercell failure, intrawall failure and transwall failure. In dry specimen, failure occurred mainly in woods. Laminated woods of softwoods showed mostly intrawall failure and transwall failure of tracheids, and them of hardwoods indicated mainly intrawall failure and interwall failure. Laminated woods prepared with urethan resin showed coarse fracture surface, on the other hand, those prepared with an urea formaldehyde resin had clean surface. In wet specimen, failure occurred dominantly in glue line. Intrawall failure and flags were characterized in laminated wood prepared with urethan resin. In heterospecies laminated woods, failure was occurred mainly in softwood. Consequently, fracture morphology of laminated wood may be influenced by adhesives, moisture content, species and anatomical characteristics.