• Journal of the Korean Wood Science and Technology
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• 제25권1호
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• pp.8-14
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• 1997

Stress wave velocity, wave impedance, and stress wave elasticity of small, clear bending specimens of five domestic softwoods (Pinus densiflora, Pinus koraiensis, Chamaecyparis obtusa, Cryptomeria japonica, and Larix leptolepis) and four tropical hardwoods(Kempas, Malas, Taun, and Terminalia) were correlated with static bending modulus of elasticity(MOE) and modulus of rupture(MOR). The degree of correlation between stress wave parameters and static bending properties was dependent on wood species tested. Stress wave elasticity and wave impedance were better predictors for static bending properties than stress wave velocity for each species individually and for softwood or hardwood species taken as a group, even though elasticity and impedance were nearly equally correlated with static bending properties apparently. Based upon the correlation coefficient between stress wave parameters and static properties, stress wave elasticity and wave impedance were found as stress wave parameters which can be used for the purpose of the reliable and successful prediction of bending properties. The degree of correlation between static MOE and MOR was also different according to wood species tested. Static MOE was nearly as well correlated with MOR as was stress wave elasticity. The results of this research are encouraging and can be considered as a basis for further work using full-size lumber. From the results of this study, it was concluded that stress wave measurements could provide useful predictions of static bending properties and was a feasible method for machine stress grading of domestic softwoods and tropical hardwoods tested in this study.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2000년도 춘계학술발표논문집
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• pp.39-46
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• 2000

In pulp and papermaking process, enzymatic treatment of pulp fibres has been a topic of increasing interest in last decade. Lots of patents, papers and research reports were published on the application of enzymes in the fields of enzymatic bleaching, deinking, slime control, pitch control, waste water treatment and fibre modification. Cellulase and hemicellulase are the principal enzymes used for the modification of fibre property. This study was carried out for determinating the behaviors of enzyme to pulp fibres. A commercial enzyme, Denimax BT which is consisted with cellulase and hemicellulase, was treated to the kraft pulp produced from domestic hardwood mixtures. Results were mainly concentrated on the behaviors of freeness, drainability and fines content of fibres, and physical properties of paper with enzyme treatment. The freeness levels and dewatering ability were developed, and the fines contents were decreased. The creation of fines were controlled by the method of pre-enzyme treatment prior to fibre beating. The mechanical strength of paper, like tensile, burst, tear strength and folding endurance, were remarkably improved by the pre-enzyme treatment.

• Journal of the Korean Wood Science and Technology
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• 제14권1호
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• pp.55-60
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• 1986

Discoloration sensitivities of woods grown in this country haven't reported yet. Therefore we examined discoloration sensitivities of domestic wood specimens to iron (0.1 %, $FeCl_3.6H_2O$), alkali (pH 12.0, NaOH). acid (pH 1.0, $C_2H_2O_4$) and exposing to sunlight (40 hrs), Thirty-six hardwood species were collected and examined. All specimens were prepared from heartwoods of the collected species. But the specimens of 4 Betula species were divided into sapwoods and heartwoods. By iron stain, the color differences (${\Delta}E$) of 21 wood specimens including one Betula sapwood showed above 12.0, which means strong discoloration sensitivities, and of 3 specimens including one Betula sapwood showed below 2.5, which means weak discolorations. The most strong iron discoloration species was Jungkukgulpi-namu (Pterocarya stenoptera). By alkali stain, the color differences (${\Delta}E$) of 3 wood specimens showed above 9.0, which means strong discoloration sensitivities, and of 18 wood specimens including 4 Berula sapwoods showed below 2.5, which means weak discolorations. By acid stain, the color differences (${\Delta}E$) of 6 wood specimens showed above 10.0 which means strong discoloration sensitivities, and of 12 wood specimens including one Betula sapwoods showed below 2.5, which means weak discolorations. By exposing to sunlight, the color differences (${\Delta}E$) of 31 wood specimens including one Betula sapwoods showed below 6.5, which means, strong discoloration sensitivities, and of only one specimens showed below 2.5, which means weak discoloration. The most strong discoloration species by exposing to sunlight was Guirung-namu (Prunus padus). In general, it was shown that hardwoods grown in Korea were most subject to change of color by exposing to sunlight and next were by iron stain. Domestic hardwoods showed some differences in discoloration sensitivities from domestic softwoods previously reported.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.608-617
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• 2020

For efficient use and expansion of domestic small- and medium-diameter woods, cross-laminated wood panels composed of tropical hardwoods and domestic temperate woods were fabricated, and the bending creep behavior under long-term loading was investigated. The bending creep curve of the cross-laminated wood panels showed an exponential function graph with a sharp increase at the top right side. The wood panel composed of a teak top layer and larch core and bottom layers recorded the highest initial deformation, and that composed of a merbau top layer and tulip core and bottom layers showed the lowest initial deformation. Creep deformation of the cross-laminated wood panels showed the highest value in that composed of a teak top layer and larch core and bottom layers and showed the lowest value in that composed of a merbau top layer and tulip core and bottom layers. The obtained creep deformation is 3.1-4.3 times that of merbau, however, it is remarkably lower than that of tulip and larch. The highest relative creep was recorded by the wood panel composed of merbau top layer and larch core and bottom layers, whereas that composed of the teak top layer and tulip core and bottom layers showed the lowest relative creep.

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.10-15
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• 2003

본 연구는 주요 국산 활엽수재 원반에서 채취한 원주상(圓周狀)슬라이스를 오-븐에서 급속건조하면서 각 원반내 함수율의 방사방향 분포추이를 조사하기 위하여 수행하였다. 느티나무의 경우 변재부 또는 심변재경계부가 이미 섬유포화점 이하의 함수율에 도달하였으나, 최내측슬라이스는 아직도 약 40% 정도의 높은 함수율을 나타내었다. 벚나무의 경우 최내측 슬라이스와 바로 인접한 슬라이스간의 수분경사가 건조시간이 경과하면서 더욱 심해지는 경향을 보였다. 음나무 원반에서는 생재상태에서는 심재부의 함수율이 변재부보다 약 23% 정도 더 높은 분포를 보였으며, 이러한 분포유형이 평균함수율 약 15%일 때까지도 지속되었다. 참중나무의 경우 전(全)건조기간에 걸쳐 외주측의 심변재혼합 슬라이스들과 최내측 슬라이스의 함수율이 나머지 부위의 함수율보다 낮은 값을 나타내었다.

• 한국산림과학회지
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• 제81권4호
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• pp.383-392
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• 1992

우리나라의 산림자원관리정책(山林資源管理政策)의 두가지 흐름 즉, 목재생산의 경제성을 제고하기 위한 임도개설을 비롯한 임업경영기반의 확대전략과 산림(山林)의 공익적(公益的) 기능(機能)을 제고하기 위한 공익(公益) 환경림(環境林)의 확대전략이 어떻게 국내재의 장기공급 가능성에 영향하는가를 평가하는 데 이 연구의 목적(目的)이 있다. 이러한 목적을 달성하기 위하여 국내재공급함수(國內材供給函數)를 추정하고 각각의 정책대안(政策代案)에 준하는 자원관리시나리오를 작성하여 미래의 국내재공급 가능성을 예측 비교하였다. 국내재(國內材)의 공급(供給)은 수종에 따라서 그 행태가 다르게 나타났는데, 활엽수재(闊葉樹材)의 공급은 가격에 대해서 탄력적이었으나 침엽수재(針葉樹材)의 경우는 비탄력적이었다. 임업경영기반조성사업(林業經營基盤造成事業)으로 최근에 확대되고 있는 임도개설(林道開設)은 아직까지는 국내재공급에 큰 영향을 끼치지 못하는 것으로 평가되었다. 최근에 국민대중의 환경보전(環境保全)에 대한 인식의 확산에 호응하는 공익(公益) 환경림(環境林)의 확대전략은 한편으로는 장래의 국내재공급 가능성을 크게 제약할 것으로 평가되었다.

• 한국산림과학회지
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• 제97권1호
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• pp.45-52
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• 2008

본 연구의 목적은 MDF산업의 지속적이고 안정적인 육성을 위해 MDF 생산장기전망에 의한 침엽수 원목공급방안을 제시하고자 하는 것이다. 이를 위해 고전적최소자승법(Ordinary Least Squares Method, OLS)을 이용하여 장기공급함수모델을 개발하였다. 그 결과 MDF의 국내 생산량이 2005년 1,653천$m^3$에서 2050년 2,041천$m^3$으로 증가하는 것으로 전망되었다. 국산 침엽수원목의 MDF 원자재 공급량은 2050년에 2,041천$m^3$의 MDF를 생산하는데 약 1,355천$m^3$이 소비되는 것으로 나타났다. 현재 MDF원자재로 사용되고 있는 리기다소나무의 경우 2050년도에 국산재 원목공급에 필요한 벌채면적은 10,828ha인 것으로 추정되었다. 낙엽송은 9,160ha의 벌채면적이 필요한 것으로 추정되었다. MDF생산의 국산원목사용량의 구성비 시나리오를 35%, 45%, 55%의 3가지로 나누어서 2050년에 침엽수 수종별 예상 연간 벌채량과 총 조림면적을 구하였다. 벌채면적을 기준할 경우 낙엽송을 식재하는 것이 유리하지만 각 수종별 용도 및 생육적 특성이 있으므로 MDF원자재를 공급하려고 하면 어느 정도 이러한 점을 고려한 조림정책이 이루어져야 할 것이다. 그리고 리기다소나무 벌채 후 활엽수 조림정책을 실시하더라도 현재의 MDF 보드산업의 안정적인 육성을 위해서는 MDF의 원자재 공급에 필요한 침엽수종의 일정 면적이 유지 및 관리되는 것이 필요하다.

• 한국산림과학회지
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• 제96권2호
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• pp.197-202
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• 2007

This study is conducted to investigate the factors affecting lumber conversion rate of sawmill industry in South Korea. Data were obtained from the survey of 38 sawmills in all geographic regions of South Korea. The variables examined in this study were region, softwood/hardwood log, domestic/imported/both log, the number of power-driven carriages (PDC) installed, the year when and country where PDCs was manufactured, the horse power of PDC, the number of labors required to operate each PDC, the sawing capacity of mill (mill size), and the types of major product and by-products. The lumber recovery factor (LRF) of sawmills were significantly influenced by the origin of logs, level of PDC automation, sawmill size, and size of logs (measured in diameter and length) while not by the location of the mill, types of major product and by-product, log species, and characteristics of PDC. Although these results provide useful information for understanding the technological characteristics of the Korean sawmill industry, further investigation with larger sample is necessary to reveal the more reliable characteristics of sawmill industry in South Korea.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.622-628
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• 2017

본 연구에서는 국산 참나무류의 고부가가치재 이용기술 개발을 위해 굴참나무와 신갈나무를 대상으로 입목으로부터 마루판재까지의 가공수율을 조사하였다. 또한 참나무류 건조시간 단축을 위한 건조스케줄의 개선 및 물성평가를 수행하였다. 건조시간은 총 173시간이 소요되었으며, 최종함수율은 굴참나무 5.39%, 신갈나무 4.17%로 측정되었다. 건조에 따른 굴참나무와 신갈나무의 재색변화는 ${\Delta}E$ 값이 7~11으로 현저한 변화를 보였다. 건조에 따른 수축률은 굴참나무의 경우, 접선방향 8.1%, 방사방향 5.0%이었으며, 신갈나무의 경우, 접선방향 8.5%, 방사방향 6.2%로 평가되었다. 제재수율은 30~40%, 최종제품수율은 8~15%로 평가되었다. 본 연구에서 조사된 참나무류의 가공특성은 아직까지 저이용되고 있는 국산 활엽수의 효율적인 생산계획을 수립하는데 기여할 수 있을 것으로 기대된다.

• 한국유기농업학회지
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• 제20권3호
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• pp.297-311
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• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted during the process in order to select carbon basic units for agricultural production system compliant in domestic situation instead of relying on overseas data and apply life cycle assessment of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.0088kg-$CO_2$ for charcoal, 0.1319kg-$CO_2$ for grass liquid, and 0.2804kg-$CO_2$ for microbial agent.