• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.156-167
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• 2015

The aim of this study was to determine the physical and mechanical properties of glued laminated timber (glulam) manufactured from small-diameter logs of three wood species, Acacia mangium (mangium), Maesopsis eminii (manii), and Falcataria moluccana (sengon), with densities of 533, 392, and $271kg/m^3$, respectively. Glulam measuring 5 cm by 7 cm by 160 cm in thickness, width, and length, respectively, was made with three to five lamina, or layers, and isocyanate adhesive. The glulams contained either the same wood species for all layers or a combination of mangium face and back layers with a core layer of manii or sengon. Solid wood samples of the same size for all three species were included as a basis for comparison. Physical-mechanical properties and delamination tests of glulam referred to JAS 234:2003. The results showed that the properties of same species glulam did not differ from those of solid wood, with the exception of the shear strength of glulam being lower than that of solid wood. Wood species affected glulam properties, but three- and five-layer glulams were not different except for the modulus of elasticity. All glulams were resistant to delamination by immersion in both cold and boiling water. The glulams that successfully met the JAS standard were three- and five-layer mangium, five-layer manii, and five-layer mangium-manii glulams.

• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.253-264
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• 2019

This study characterized the chemical compounds in tannin from mangium (Acacia mangium) bark extract and determined the physical-mechanical properties of glued laminated timber (glulam) made from sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), and mangium wood. The adhesives used to prepare the glulam were based on mangium tannin and phenol resorcinol formaldehyde resin. Five-layer glulam beams measuring $5cm{\times}6cm{\times}120cm$ in thickness, width, and length, respectively, were made with a glue spread of $280g/m^2$ for each glue line, cold pressing at $10.5kgf/cm^2$ for 4 h and clamping for 20 h. Condensed mangium tannin consisted of 49.08% phenolic compounds with an average molecular weight of 4745. The degree of crystallinity was 14.8%. The Stiasny number was 47.22%. The density and the moisture content of the glulams differed from those of the corresponding solid woods with mangium having the lowest moisture content (9.58%) and the highest density ($0.66g/cm^3$). The modulus of rupture for all glulam beams met the JAS 234-2003 standard but the modulus of elasticity and the shear strength values did not. Glulam beams made with tannin had high delamination under dry and wet conditions, but glulam made from sengon and jabon wood met the standard's requirements. All glulam beams had low formaldehyde emissions and were classified as $F^{****}$ for formaldehyde emissions according to the JAS 234 (2003) standard.

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.194-195
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• 1982

Recommendaton: These are the highlights of the findings of the Timber Consumption Survey carried out by the Project in 1966, and covering consumption for the period from 1961 to 1965. The survey was oriented towards consumption for structural, commercial and industrial purposes and existing estimates for local (village-level) consumption as fuel and the like were adopted. A full report on the survey was submitted to the Bureau of Forestry in 1966. Long-term Trends: After allowance for anticipated population increase, this ten year's increase in industrial wood consumption represents a gain of about 30% in per capita consumption (from 0.0913 cu.m. per capita to 0.118 cu.m. per capita). This is only about half the expected general economic growth of about 75% (7% per annum). It is therefore likely (a) that the 1975 estimate is conservative, (b) that the consumption demand beyond 1975 may be expected to build up at a greatly increased rate. Estimated income elasticity coefficients are high, and with expected ir,creases in prosperity and population, the consumption is expected to rise to 10 million cu. meters by the year 2,000. Consumption Pattern: The breakdown of industrial consumption (1965) is given in Table 4-2, showing sawnwood consumption as the most important in 1965. The upward trend in all sectors over the 1961-65 period is expected to continue. The general consumption pattern is expected to change through 1975 with a sharp increase in the relative importance of pulp products (to 30% of total consumption) offset by declining relative importance of sawlogs. The following recommendations follow from the study: (i) Industrial forests. - A programme of establishment of consolidated industrial forests should be initiated as a matter of urgency. (ii) Fuelwood forests - Properly sited, protected and managed fuelwood forest, worked on a 20-year rotation, should be established as a nation wide basis. (iii) Hardwood utilization - Detailed investigations are required into the use of indigenous hardwoods for the pulp, particle board and hardboard industries. (iv) Mining timber - Preservation treatment of all mining timber should be enforced by law. (v) Sawmills - Licencing restrictions should be enforced to reduce the number of small, inefficient sawmills. b. Extension work should be undertaken bv government to improve sawmilling practices.

• Journal of the Korean Wood Science and Technology
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• 제47권5호
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• pp.547-556
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• 2019

Thinned, small larch logs have small diameters and no value-added final use, except as wood chips, pallets, or fuel wood, which are products with very low economic value; however, their mechanical strength is suitable for structural applications. In this study, small larch logs were sawed, dried, and cut into square timbers (with a $90mm{\times}90mm$ cross section) that were laterally glued to form core panels used to manufacture cross-laminated timber (CLT) wall panels. The surface and back of these core panels were covered with 12-mm-thick structural plywood panels, used as cross bands to obtain three-ply CLT wall panels. This attachment procedure was conducted in two different ways: gluing and pressing (CGCLT) or gluing and nailing (NGCLT). The size of the as-manufactured CLT panels was $1,220mm{\times}2,440mm$, the same as that of the plywood panels. The final wall panels were tested under lateral shear force in accordance with KS F 2154. As the lateral load resistance test required $2,440mm{\times}2,440mm$ specimens, two CLT wall panels had to be attached in parallel. In addition, the final CLT panels had tongued and grooved edges to allow parallel joints between adjacent pieces. For comparison, conventional light-frame timber shear walls and midply wall systems were also tested under the same conditions. Shear walls with edge nail spacing of 150 mm and 100 mm, the midply wall system, and the fabricated CGCLT and NGCLT wall panels exhibited maximum lateral resistances of 6.1 kN/m (100%), 9.7 kN/m (158%), 16.9 kN/m (274%), 29.6 kN/m (482%), and 35.8 kN/m (582%), respectively.

• 한국산림과학회지
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• 제71권1호
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• pp.1-8
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• 1985

본(本) 연구(硏究)는 국내재(國內材) 유통시장(流通市場)을 파악(把握)하고 유통개선방법(流通改善方法) 제시(提示)하고자 지역별(地域別) 유통주체자별(流通主體者別)로 가격형성과정(價格形成過程)을 조사(調査)하였다. 그 결과(結果) 국내재(國內材) 유통경로(流通經路)는 타농산물(他農産物)에 비(比)하여 비교적(比較的) 단순(單純)하였으며 벌채산주(伐採山主)외 대부분(大部分)이 유통정보(流通情報)에 어두워 산지시장(山地市場)은 벌출상(伐出商)이 주도권(主導權)을 갖고 있었다. 그러나 벌출상(伐出商)외 대부분(大部分)은 사업량(事業量)이 작고, 본인자본율(本人資本率)이 낮아 영세성(零細性)을 탈피하지 못하므로 자금력(資金力)을 갖춘 수집상(蒐集商)에게 중간유통시장(中間流通市場)외 주도권(主導權)을 넘겨주고 있었다. 이와 함께 목재(木材) 유통시장(流通市場)의 거래검척방법(去來檢尺方法)이 다양함은 유통시장(流通市場)을 더욱 혼란(混亂)시키는 원인(原因)이 되고 있다. 따라서 다음과 같이 제안(提案)하였다. 1) 산주(山主)에 대(對)한 유통시장정보(流通市場情報)의 적극적인 홍보(弘報), 2) 벌출상(伐出商)의 양성화(陽性化), 3) 벌출상(伐出商)을 집단화(集團化)한 계통출하(系統出荷), 4) 생산재질(生産材質)의 우량화(優良化).

• 펄프종이기술
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• 제48권3호
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• pp.73-79
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• 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
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• 제39권6호
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• pp.521-530
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• 2011

구조용 집성재의 시장 수요가 확대되고 다양화되면서 교량이나 파고라와 같이 외기에 노출되는 조건에서 사용하기 위한 고 내구성 구조용 집성재에 대한 시장 요구가 증가할 것으로 예견된다. 따라서 본 연구는 국산 침엽수재로 제조되는 구조용 집성재에 적합한 방부처리 기술 및 기준을 개발하기 위한 목적으로 진행되었다. 본 연구에서는 방부처리된 국산 리기다소나무 제재목을 이용하여 구조용 집성재를 제조하고 제조 단계별 생산수율과 KS 품질기준 충족여부를 평가하였다. 방부집성재의 제조수율은 일반 집성재와 큰 차이를 나타내지 않았으며, 목재자원의 효율적인 활용을 위해서는 집성재 제조수율 향상방안과 함께 부산물에 대한 효율적 활용방안도 함께 검토되어야 한다. 리기다소나무 방부처리재의 경우 불균일한 방부약제 흡수량으로 인하여 구조용 집성재 제조용으로 적합하지 않은 것으로 확인되었으며, 집성재 제조 후에 유용성 방부제를 처리하는 방안에 대한 추가적인 검토가 요구되었다.

• Journal of the Korean Wood Science and Technology
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• 제50권1호
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• pp.1-11
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• 2022

To evaluate the bearing strength of red pine cross-laminated timber (CLT) with self-tapping screw (STS), which is widely used as a fastener for connection in CLT building, the bearing test was conducted. Accoring to the STS's diameters (8, 10, 12 mm), the bearing test specimens with half hole were manufactured. Bearing strength was compared and reviewed in consideration of the configuration in STS and the loading direction to the grain of red pine. As a result of the bearing test on the STS's diameter, the yield bearing load increases as the larger diameter of the STS in all directions of the red pine. The bearing strength of the thread part (thread + tip) was higher than the shank part (shank + shank cutter). In compared with the directions to the grain of red pine, the bearing strength of the cross section parallel to the loading direction was the highest, and the tangent section was the lowest bearing strength. The average bearing strength of the loading direction in parallel to the grain was 23.43 MPa, which was about 45% higher than the average 16.16 MPa in perpendicular to the grain. The predicted bearing strength calculated by Eurocode (EN) and Korean Building Code (KBC)'s equation was lower than the experimental value. It is nessesary to propose the new equations of bearing strength reflected the configuration information of STS.

• 한국산림과학회지
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• 제97권4호
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• pp.408-416
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• 2008

본 연구는 비농산물시장접근분야 의장이 제안한 세부원칙에 따른 목재류의 품목별 관세 감축 변화를 분석하여 금후 우리나라의 WTO/DDA협상 전략 수립의 기초 자료로 활용하는 데에 목적을 두었다. 2007년초에 재개된 WTO/DDA협상에 대비하여 지금까지 진행되어온 협상의 주요 핵심의제를 중심으로 2006년 이후 협상 주요 논의 동향, 주요 핵심쟁점 사항을 정리, 분석하였다. 우리나라는 비농산물시장접근분야 의장안 세부원칙에 의한 관세 감축 변화 분석 결과, 제재목과 단판의 경우 선진국 지위시에는 2007년 실행세율과의 차이가 크지 않으나 개도국 지위시에는 2007년 실행세율보다 오히려 관세감축 후의 세율이 더 높아지는 것으로 나타났다. 그러나 미양허품목인 합판, MDF 등 목질패널류의 경우 선진국 지위시에는 관세감축을 2007년 실행세율의 절반 이하로 감축해야 하는 것으로 나타나 관세감축 변화에 따른 영향이 클 것으로 판단된다. 반면에 개도국 지위시에는 2007년 실행세율 보다 높아 협상 타결에 의한 관세 감축 변화는 없는 것으로 분석되었다.

• 한국산림과학회지
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• 제106권2호
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• pp.219-229
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• 2017

임도는 산림자원의 조성과 관리, 그리고 목재와 단기소득 임산물 생산 운반 등 산림경영을 위한 필수적인 기반시설이다. 최근에는 산림 병해충 방제, 산불예방 및 진화뿐만 아니라 산림휴양과 산림스포츠 등에도 적극 활용되고 있다. 임도를 건설하면 산림 내에서 경제적 기능이 활성화되어 생산 및 부가가치 유발은 물론 고용창출의 파급효과를 가져올 수 있다. 따라서 본 연구의 목적은 임도를 건설함에 따라 경제 전반으로 발생하는 파급효과를 분석하는 것이다. 분석을 위해 산업 간의 상호연관관계를 수량적으로 분석하는 산업연관분석 방법을 적용하였다. 자료는 2014년 한국은행의 투입산출표를 사용하였다. 임도를 건설하면 임도 건설에 따른 경제적 효과도 발생하지만, 임도 건설 후 임산물 생산 증대로 인한 경제적 효과도 발생하게 된다. 따라서 두 가지 효과에 대한 경제적 파급효과를 분석할 것이다. 몇 가지 가정을 통해 임산물 재배의 경제적 효과인 임산물 생산액 예측치를 계산하고 경제적 파급효과를 분석하였다. 임도 건설부문은 농림수산토목 부문으로 정의하였고, 임산물 부문은 원목, 식용임산물, 기타임산물의 합으로 정의하였다. 임도건설과 임업임산물로 정의한 2개 부문을 제외하고 나머지 부문은 기존 한국은행 30개 통합대분류의 분류체계에 맞게 통합하여 총 32개 부문으로 분류하였다. 분석결과 임도건설에 대한 생산유발계수는 2.767로 분석되었고 임업임산물에 대한 생산유발계수는 1.565로 분석되었다. 이는 임도를 건설하면 임도건설에 따라 그 투자수요의 2.767배 만큼의 생산이 전체 산업에서 유발됨을 나타내고 임업임산물 생산 증대에 따라 전체 산업에서 임업임산물 생산액의 1.562배 만큼의 생산이 유발되는 것을 의미한다. 임도건설에 대한 부가가치유발계수는 0.977로 분석되었고 임업임산물에 대한 부가가치유발계수는 0.985로 분석되었다. 임도시설은 임업발전의 필수적인 기반시설로서 산림경영, 산림휴양, 산림스포츠, 마을연결 등의 기능과 함께 목재생산과 단기임산물 생산의 필수적인 요소이므로 지속적인 투자가 이루어져야 할 것이다.