• 펄프종이기술
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• 제42권1호
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• pp.7-12
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• 2010

Morphological characteristics of hemp fiber were investigated using a light microscope in order to provide fundamental data for the use of hemp as a papermaking law material. Phloem of hemp is composed of cortical parenchyma cells and bast fiber with thick walls while xylem is composed of vessel, wood fiber and ray parenchyma cells. Also there are solitary pore and radial pore multiple which exist in diffuse porous pattern. Ray cells consist of uniseriate rays and thin walled ray parenchyma cells. Wood fibers are composed of three types: a large diameter fiber with longer length; a large diameter fiber with shorter length; a small diameter fiber with medium length. Vessel elements are composed of: a medium length one; a longer length one; the one whose both end walls have ligules or tails. Parenchyma cells in xylem and pit parenchyma cells have completely different size and shape. For bast fiber, the average length is about 4.4 mm and the width is about $30.5\;{\mu}m$; for vessel element, $600.0\;{\mu}m$ in length and $493.6\;{\mu}m$ in width; for wood fiber, $1000\;{\mu}m$ and $38.9\;{\mu}m$; for parenchyma cell, $50\;{\mu}m$ and $26.4\;{\mu}m$.

• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.406-417
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• 2012

이 연구에서는 선행연구에서 발표된 목재섬유에 녹차를 복합한 친환경 복합보드에 탈취성과 흡착성 등의 기능성을 보강한 건축내장재를 개발하기 위하여, 흑탄, 백탄, 활성탄 등 3종류의 숯을 혼합한 녹차-숯-목재섬유 복합보드를 제작하였고, 구성원료의 종류 및 배합비율이 복합보드의 치수안정성, 탈취성 및 포름알데히드 방산량에 미치는 영향을 조사하였다. 녹차-숯-목재섬유 복합보드의 흡수두께 팽창률은 녹차와 숯의 배합비율의 증가에 따라 증가하였으나, 활성탄 함유 복합보드를 제외하고, KS에 규정된 그 값보다 현저히 낮은 값을 나타내었다. 복합보드의 암모니아가스 감소율은 활성탄 10% 함유 복합보드에서 30분 경과시 96%의 높은 값을 나타내었고, 다른 모든 복합보드에서도 1시간 경과 후 거의 95%전후의 높은 암모니아가스 감소율을 나타내었다. 복합보드의 포름알데히드 방산량은 $E_1$급 요소수지를 사용했을 경우, $E_0$급에 가까운 방산량을, $E_0$급 요소수지를 사용했을 경우는 super $E_0$급의 낮은 포름알데히드 방산량을 나타내는 것이 확인되었다.

• 펄프종이기술
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• 제42권4호
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• pp.1-14
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• 2010

To investigate natural dyeing properties of bast fiber, properties of pre mordanting dyeing of sappan wood, gardenia and gallnut such as K/S values, developed color, and fastness were evaluated. Silk showed the most increased K/S values by pre mordanting treatment when Fe was uses as a mordant. The optimized amount of Fe was 3%. The colors of sappan wood was a series of YR. After pre mordanting treatment with Fe, the colors of bast fiber of mulberry and silk showed a series of RP, and the color of cotton showed a series of Y. The color of gallnut was a series of Y regardless of pre mordant treatment. Sappon wood (YR), gardenia (Y), and gallnut (Y) showed various colors such as YR, R, and RP, respectively. Sunlight fastness was not improved by pre mordanting treatment. The effect of pre mordanting treatment was not good. Especially the treatment with Al showed poor sunlight fastness.

• 폴리머
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• 제39권1호
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• pp.46-55
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• 2015

There is a limit for deforestation in order to keep the environmental cycle undisturbed. The heart of the paper is to replace the wood to a maximum extent to obtain a sustainable environment. This research aims at new natural composites in which treated hemp fiber used as reinforcement, synthetic cellulose used as particulate to improve the adhesion between matrix - fiber interface and Epoxy LY556 acted as matrix fabricated by hand layup technique. The density, water absorption, tensile properties, impact strength, hardness, flexural properties and compressive properties have been evaluated under ASTM standards and compare the results with existing materials such as wood, aluminium, etc., The composite hemp fiber reinforced polymer (HFRP) could be exploited as an effective replacement for wood and it would be suitable for automotive applications by comparing results.

• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.48-58
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• 2002

This study was carried out through scanning electron microscopy to elucidate the mechanism of thickness swelling in wood particle-polypropylene composite which is a typical way of using wood and plastic materials. For this purpose, control particleboards and nonwoven web composites from wood particle and polypropylene fiber formulations of 100:0, 70:30, 60:40, and 50:50 were manufactured at target density levels of 0.5, 0.6, 0.7, and 0.8 g/cm³. Their water absorption and thickness swelling were tested according to ASTMD 1037-93 (1995). To elucidate thickness swelling mechanism of composite through the observation of morphological change of internal structures, the specimens before and after thickness swelling test by 24-hour immersion in water were used in scanning electron microscopy. From the scanning electron microscopy, thickness swelling of composite was thought to be caused by the complicated factors of degree of built-up internal stresses by mat compression and/or amount of wood particles encapsulated with molten polypropylene fibers during hot pressing. In the composites with wood particle contents of 50 to 60% at target densities of 0.5 to 0.8 g/cm³ and with wood particle content of 70% at target densities of 0.5 to 0.7 g/cm³, thickness swellings seemed to be largely dependent upon the restricted water uptake by encapsulated wood particles with molten polypropylene fibers. Thickness swelling in the composite with wood particle content of 70% at target density of 0.8 g/cm³, however, was thought to be principally dependent upon the increased springback phenomenon by built-up internal stresses of compressed mat.

• Journal of the Korean Wood Science and Technology
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• 제43권4호
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• pp.421-428
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• 2015

본 연구는 5개 종자 산지(Carleton, Simcoe, Chatham, Bancroft, Unknown)의 루브라참나무(Quercus rubra)를 대상으로 해부학적 성질을 조사하여, 이들의 종자산지 간 및 생장속도와의 관계를 규명하였다. 루브라참나무는 환공재로서 공권부는 대형도관이 1~3열로 배열하다가 공권 외부는 소형도관이 방사상으로 배열하였다. 산지 간에는 조재부 목섬유 길이, 조재부 도관의 직경에서만 차이가 있었다. 생장속도와는 목섬유 길이 및 도관요소 직경에서 만재부는 상관관계가 없고, 조재부는 부의 상관이었다. 도관요소 길이는 생장속도와 조, 만재에서 관계가 없었다. 조, 만재부에서의 구성요소 비율은 목섬유, 방사조직은 만재부에서 높았고, 도관요소는 조재부에서 높았다. 방사조직 높이는 11~15개 범위였다.

• 한국가구학회지
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• 제17권2호
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• pp.9-23
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• 2006

Control particleboards were significantly higher in thickness swelling than wood particle-polypropylene fiber composites and their thickness swelling increased with the increase of target density. In the composites, thickness swelling did not vary significantly with the increase of target density but increased with the increase of wood particle content. And the composites with fine wood particles were significantly lower in thickness swelling than those with coarse wood particles irrespective of target density and formulation. In the scanning electron microscopy, significantly higher thickness swelling in the composites with coarse wood particles was thought to be the result of more interfacial separations by higher swelling stresses.

• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.336-343
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• 2019

Effects of a novel mold inhibitor specifically for bamboo, on the properties of composite products have been confirmed in this study. The mechanical and dimensional stability properties of bamboo fiber-based composites (BFBCs) from different bamboo species were also investigated. The results showed that Burmanica Gamble possessed the highest values of modulus of elasticity (MOE) of 33.2 GPa, modulus of rupture (MOR) of 286.9 MPa, compressive strength of 182.6 MPa and shear strength of 24.0 MPa. By contrast, Phyllostochys heterocycla among all of species showed the lowest MOE of 16.3 GPa, MOR of 170.3 MPa and compressive strength of 128.9 MPa were the lowest among all of species. Moreover, there is a remarkable variation in the swelling and water absorption between the samples with 4 h and 28 h water immersion treatment, especially Phyllostachys iridenscens. Overall, the results suggested that TCIT (Tebuconazole and 3(2H)-isothiazolone) had no significant effect on the mechanical properties compared with the control condition, and it would be utilized as an antimould of BFBCs manufacturing.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.685-695
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• 2020

The connection performance between cross-laminated timber (CLT) walls and support has the greatest effect on the horizontal shear strength. In this study, the horizontal shear performance of CLT walls with reinforced connection systems was evaluated. The reinforcements of metal bracket connections in the CLT connection system was made by attaching glass fiber-based reinforcement to the connection zone of a CLT core lamina. Three types of glass fiber-based reinforcement were used: glass fiber sheet (GS), glass fiber cloth (GT) and fiber cloth plastic (GTS). The horizontal shear strength of the fabricated wall specimens was compared and evaluated through monotonic and cyclic tests. The test results showed that the resistance performance of the reinforced CLT walls to a horizontal load based on a monotonic test did not improve significantly. The residual and yield strengths under the cyclic loading test were 38 and 18% higher, respectively, while the ductility ratio was 38% higher than that of the unreinforced CLT wall. The glass fiber-based reinforcement of the CLT connection showed the possibility of improving the horizontal shear strength performance under a cyclic load, and presented the research direction for the application of real-scale CLT walls.

• 펄프종이기술
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• 제41권3호
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• pp.35-41
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• 2009

The new way of utilization of Hanji need to develop for adding high value added. An watermarked Hanji was prepared with non-mulberry mixed fibers and the properties were investigated. The mechanical properties of non-mulberry fiber mixed Hanji were very similar to mulberry fiber Hanji. The non-mulberry fiber mixed Hanji was a little brighter than original Hanji. The air permeability and pore size of the hot pepper fiber mixed Hanji were decreased depending on the content of hot pepper fiber. The printing ability of watermarked Hanji made of non-mulberry mixed fibers was higher than that of original paper mulberry Hanji. The preservation properties of non-mulberry fiber mixed watermarked Hanji were almost same as those of the original Hanji.