• Journal of the Korean Wood Science and Technology
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• 제51권5호
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• pp.419-430
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• 2023

In this study, the floor impact sound insulation performance of Korean domestic Cross-Laminated Timber (CLT) slabs was evaluated according to their joint types, species and thicknesses in laboratory experiments. The sound insulation performance of the CLT has not been investigated before, thus, this study was conducted to quantify basic data on floor impact sound insulation performance of CLT slabs. 5-ply and 150 mm thick CLT panels made of 2 species, Larix kaempferi and Pinus densiflora, were used for the study. The CLT panels were assembled by 3 types of inter-panel joints to form floor slabs: spline, butt and half-lap. And the 150 mm thick Larix CLT slabs were stacked to the thicknesses of 300 mm and 450 mm. The heavy-weight floor impact sound insulation performance of the 150 mm CLT slabs were evaluated to be 70 dB for the Larix slabs and 71.6 dB for the Pinus slabs, and the light-weight floor impact sound insulation performance, 78.3 dB and 79.6 dB, respectively. No significant difference in the sound insulation performance was found between the slabs of the 2 species or among the 3 types of joints. The reduction of 1 dB in the heavy-weight floor impact sound and 1.6 dB in the light-weight floor impact sound per 30 mm increase in thickness were confirmed through the experiments. This study can be viewed as the basic research for the evaluation of floor impact sound insulation performance of CLT.

• 한국가구학회지
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• 제21권5호
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• pp.354-366
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• 2010

The modern unique woodworking furniture has been made in earnest from 50 years ago. Some oil from nut such as soybean, walnut and perilla, which is usually used in our common life, has been used as finishing material for the unique woodworking furniture. Recently, woodworking studio business among the whole furniture industry has grown gradually and many woodworkers uses various kinds of imported wood finishing oil. Many woodworkers use the imported finishing oil in the old ways instead of understanding the characters of the various kind of oil and It causes some serious problems in furniture finishing process. Therefore, this study aims at taking theoretical approach in wood finishing oil and presenting correct usage in understanding the types and characters of oil. Resultingly the new method of oil finishing for wood is suggested and this suggestion is to guide woodworkers into the right usage of wood finishing oil.

• 한국의류산업학회지
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• 제6권2호
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• pp.239-244
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• 2004

On the whole the various medium colors were developed by repeat dyeing with different colorants after dyeing with one colorant in case of natural dyeing. In this study, in order to obtain various colors on wool fabrics with Gardenia and Sappan wood colorants, pre-mordanting and combination dyeing were carried out. Gardenia and Sappan wood used as natural colorants for combination dyeing showed good miscibility in dye bath, Metal compounds containing alum, copper and iron were used for pre-mordants. The various medium colors such as yellow-red were obtained according to various metal compounds for pre-mordants and various mixing portion of these natural colorants. The surface reflactance spectra and color characteristics of wool fabrics by mordanting and combination dyeing were investigated.

• 한국의류산업학회지
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• 제5권1호
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• pp.82-88
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• 2003

This study was carried out to investigate combination dyeing of the cationized cotton with natural colorants extracted from Gardenia and Sappan wood extract using methanol. To improve dyeing properties of cotton with natural dye, cotton fabric was preheated with cationizing agent containing chlorohydrine group in aqueous solution of sodium hydroxide. On the whole the various medium colors were developed by repeat dyeing with different colorants after dyeing with one colorant in case of natural dyeing, In this study, however in order to obtain various colors on cationized cotton fabrics with natural dyes, pre-mordanting and combination dyeing were carried out. The various colors were obtained according to various metal compounds for pre-mordants and various mixing portion of Gardenia and Sappan wood. Metal compounds containing alum, copper and iron were used for pre-mordants.

• Journal of the Korean Wood Science and Technology
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• 제28권4호
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• pp.83-93
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• 2000

This study was carried out to improve the physico-mechanical properties of board products by applying the technique of high frequency heating, and find out the optimum conditions of high frequency heating, compared with the technique of hot platen heating. The possibility of isocyanate resin application to board production was also considered to solve the problem of free formaldehyde emission from urea resin which is generally used in wood industry. For this study, 30 mm thick MDP (medium density fiberboard) with isocyanate resin were manufactured by the techniques of hot platen heating, high frequency heating and the combination techniques of both heating methods, and compared in several point of views.

• Journal of the Korean Wood Science and Technology
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• 제49권4호
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• pp.328-335
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• 2021

Considerable differences exist in the characteristics of size reduction and classification because of biomass species. Miscanthus sacchariflorus (M. sacchariflorus) Goedae-Uksae 1 is not used efficiently because of the imperfections of the processing technology for this biomass. Therefore, for the best use of specific biomass, improvement in the feedstock preparation of the biomass for processing, such as pellet manufacturing, is necessary. In this study, a laboratory-scale cone grinder and air classifier were designed and combined to investigate the performance of the combination system for M. sacchariflorus. The average equivalent spherical diameter of particles showed a close relationship with air velocity for air classification. The air velocity range to classify proper particles for pelletization was determined to be 6.0-6.8 m/s. The mass ratios of the collected particles to feed mass for four lengths of chopped M. sacchariflorus were 45.1%:46.1%, 39.1%:46.6%, and 44.1%:52.8% at the first, second, and third steps in simulating the multistep combination system, respectively.

• 한국화재소방학회논문지
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• 제29권3호
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• pp.1-5
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• 2015

산업의 발달과 소득의 증가로 인해 목재와 같은 다공성 물질의 수요 및 생산은 지속적으로 증가하고 있다. 축산 농가를 비롯한 가공 산업 분야에서 목분의 활용이 증대됨에 따라 화재 위험도 높아지고 있다. 화재 발생시 목분은 깊이 방향으로 연소의 전이가 발생하며 내부 산화제의 소멸에 따라 화염이 없는 훈소로 진행되기도 한다. 훈소로 진행되는 경우는 화원의 위치 파악 곤란으로 초동진화에 실패하여 2차 피해를 키우는 직접적 원인으로 작용한다. 본 연구에서는 국 내외적으로 수요가 높은 뉴질랜드산 목분을 대상으로 자연대류 상태의 하향식 심부화재를 모사하였다. 본 실험에서는 실험용기 내의 목분의 체적 밀도(3%, 5%, 10%, 15%)를 변화시켜 깊이방향으로 전파되는 심부의 온도를 측정하여, 화원의 전이 속도를 실험적으로 규명하였다. 본 실험의 결과로 목분의 체적 밀도가 증가함에 따라 내부 온도는 감소하는 경향을 확인하였다. 그러나 목분 밀도체적 $0.2140g/cm^3$ (5%) 이상의 조건에서는 온도의 감소가 발생하지 않음을 실험적으로 규명하였으며 본 실험을 통하여 뉴질랜드산 소나무 목분의 온도 전이속도는 평균 0.249 mm/min의 속도 값을 가짐을 밝혔다.

• Journal of the Korean Wood Science and Technology
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• 제12권1호
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• pp.11-30
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• 1984

본(本) 연구(硏究)는 한국산(韓國産) 단판수종(單板樹種)의 목재특성(木材特性)을 조사(調査)하여 합판공업(合板工業)에 필요(必要)한 기초자료(基礎資料)를 제공하기 위해 실시(實施)하였다. 최근(最近) 목재자원(木材資源)이 점차 고갈(枯渴)되어 외재(外材)의 도입사정(導入事情)이 악화(惡化)됨에 따라 합판공업(合板工業)에 한국재(韓國材)의 활용(活用)을 증진(增進)시키고 그 가공기술(加工技術)을 발전(發展)시킴에 있어서 단판수종(單板樹種)의 목재특성(木材特性)에 관(關)한 연구(硏究)는 우선적으로 취급되어야 할 것이다. 본(本) 연구(硏究)에서 이들 취급(取扱)된 단판수종(單板樹種)은 우리 나라에 생장(生長)하고 있는 33개(個)의 속(屬)으로부터 50개(個)의 경제수종(經濟樹種)을 선정(選定)하였으며 이들 수종(樹種)에 대하여 주로 육안적(肉眼的) 목재특성(木材特性)을 조사(調査)하여 수종별(樹種別)로 기재(記載)하였고 이를 바탕으로 하여 침엽수재(針葉樹材) 및 활엽수재별로 목재식별(木材識別) 검소표(儉素表)를 간략(簡略)하게 작성(作成)하여 보고(報告)한다. 본(本) 연구(硏究)에서 육안적(肉眼的) 특성(特性)에 따른 식별(識別) 원표(圓表)를 작성(作成)하고 이를 바탕으로 하여 우리나라산(産) 단판수종(單板樹種)의 육안적(肉眼的) 식별(識別) 검소표(儉素表)를 나타내면 다음과 같다.

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.168-179
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• 1982

The first step to utilize the growing resources of Italian poplar (Populus euramericana I-476) for pulp-Woods, its characteristics and adaptabilities to the pulp industry must be investigated completely. The plantation methods are important for its fast growing in stock, and no less important is the cutting age for its utilization as pulpwood. In this paper, the stone groundwood pulping, refiner groundwood pulping and chemi-groundwood pulping characteristics by the age of tree, along with their physical and chemical characterstics were tested, and relationships between the age groups were analyzed to find out the optimum felling age. The results obtained are as follows: 1. The coefficient of pliability was a little higher in the case of younger trees. 2. The water retention value of each pulp was directly proportional to its physical strength, but this tendency was not detected between the age groups of sample woods. 3. Generally, the physical strength of younger wood pulp was lower regardless of the pulping process. But in the case of pretreatment with NaOH, Asphund and CGP pulp from 5 year old sample wood were stronger in physical strengths than those of GP and Asplund pulp with no pretreatment from 10 years old sample wood. 4. The tear factor of Asplund pulp with alkali pretreatment was higher than that of CGP pulp but the breaking length and the burst factor was similar in all processes. Considering the pulp yield and its brightness, CGP process seems to be advantageous. 5. The dissimilarity of physical strength between 7 and 10 years old wood pulp was not very large in all pulping processes but the physical strength of 5 year old wood pulp was very weak. In the of groundwood pulping from Italian poplar woods, 5 year old wood pulp should be mixed with other long fiber pulp for making a good paper.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.