• Journal of agriculture & life science
• /
• v.46 no.6
• /
• pp.75-86
• /
• 2012

In this study, eco-friendly hybrid composite boards were manufactured from green tea, 3 kinds of charcoals and wood fiber for developing interior materials to reinforce the strength performances and the functionalities in addition to performances of the hybrid composite boards composed of green tea and wood fiber. The effects for the kind and the component ratio of raw materials on dynamic MOE (modulus of elasticity) were investigated, and static bending strength performances were nondestructively estimated. Dynamic MOEs were highest in the hybrid composite boards composed of green tea, fine charcoal and wood fiber on the whole. However, the difference caused by the kind of charcoals was small. These values decreased with increasing component ratios of green tea and charcoals. The hybrid composite boards using $E_1$ grade urea resin had the higher values than those using $E_0$ grade urea resin, however the difference between them markedly decreased than that of hybrid composite board composed of green tea and wood fiber, and it was found that these values were markedly improved than those of the hybrid composite boards composed of green tea and wood fiber. There were mostly high correlations with significance at 1% level between dynamic MOEs and static bending strength performances, and this means that the static bending strength performances can be estimated from dynamic MOE.

• Journal of the Korean Wood Science and Technology
• /
• v.27 no.2
• /
• pp.31-37
• /
• 1999

This study was carried out to develop the Korean paper(Hanji) sludge-wood fiber composite boards utilizing the relinquished sludges occurring from the making process of Korean classic paper Hanji. The bark of paper mulberry(Broussonetia kazinoki Sieb.) has been used as a raw material since past hundreds and thousands years. Korean paper(Hanji) sludge was divided into two kinds, the one was the white sludge from the first stage and the other was the black sludge occurring from the final stage of Korean paper(Hanji) making. Four levels of the mixed ratio of each white or black sludge to wood fiber(10:90, 20:80, 30:70 and 40:60), three levels of the resin adhesives(PMDI, urea and phenol resin) and three levels of the density(0.60, 0.75 and 0.90) were designed to investigate the mechanical properties of Korean paper(Hanji) sludge-wood fiber composite boards. From the results and discussion, it could be concluded as follows : 1. In the white and black sludge-wood fiber composite boards, bending modulus of rupture showed the clear decreasing tendency according to the increase of sludge additive, but it was clearly increased with the increase of specific gravity. Modulus of elasticity showed the same tendency as in the modulus of rupture, and also tensile and internal bonding strength had the same tendencies as in these bending properties. 2. Among the resin adhesives, PMDI or urea resin showed great values in MOR of white sludge-wood fiber composite board, but urea resin was greater than PMDI in MOR and MOE of black sludge-wood fiber composite board. Tensile and internal bonding strength showed the same tendencies as in white sludge-wood fiber composite board. 3. It is suggested that the white sludge-wood fiber composite boards bonded with PMDI or black sludge-wood fiber composite boards bonded with urea resin were able to made similar boards to general fiberboard by the mixed ratio 20:80 of sludge to wood fiber.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2005.11a
• /
• pp.213-219
• /
• 2005

목재자원의 부족과 천연물 가공시 부산물의 재활용 등 다양한 이유로 적용되는 비목재 펄프류의 섬유 성상과 특성은 최종 제품의 품질과 그 가공 공정등에 지대한 영향을 끼치게 된다. 이를 위하여 본 연구에서는 화상분석을 통한 비목재 펄프의 섬유성상 분석 방법을 모색하였고, 실제 다양한 성상의 담배 부산물을 그 원료로 제조되는 종이형태의 재구성 담배인 판상엽 제품의 구성성분 분석에 적용하여 그 적용 가능성을 평가하였다.

• Journal of the Korean Wood Science and Technology
• /
• v.28 no.2
• /
• pp.10-18
• /
• 2000

Nondestructive testing(NDT) by using ultrasonic sound is widely applied to wood for grading, moisture and defect detecting, estimating degree of decay, etc. Before practicing such application, basic relationships between ultrasonic transmission and wood properties shall be studied first. In this study, ultrasonic NDT was applied to larch and red pine to investigate the effects of moisture content and slope of grain on ultrasonic transmission speed. Specimens for testing about moisture content were prepared to have moisture content of green state, 30%, 20%, 10% and oven-dry state. Specimens for testing about slope of grain were prepared to have grain angle of 0, 15, 30, 45, 60, 75 and 90 degree in the tangential direction. Ultrasonic transmission speed was inversely proportional to moisture content in low range of moisture content under around 30% that was considered to be close to fiber saturation point. In high moisture content range above 30%, the ultrasonic transmission speed was almost constant. The same trend was observed in the relationships between compressive strength and moisture content. Slope of grain also had inversely proportional relationship with ultrasonic transmission speed and compressive strength. The relationship between compressive strength and ultrasonic transmission speed could be expressed by a linear equation.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.6
• /
• pp.861-867
• /
• 2015

The Compact Tension (CT) type test was performed in order to evaluate the fracture toughness performance of glass fiber-reinforced laminated timber. Glass fiber textile and sheet Glass fiber reinforced plastic were used as reinforcement. The reinforced laminated timber was formed by inserting and laminating the reinforcement between laminated woods. Compact tension samples are produced under ASTM D5045. The sample length was determined by taking account of the end distance of 7D, and bolt holes (12 mm, 16 mm, 20 mm) had been made at the end of artificial notches in advance. The fracture toughness load of sheet fiberglass reinforced plastic reinforced laminated timber was increased 33 % in comparison to unreinforced laminated timber while the glass fiber textile reinforced laminated timber was increased 152 %. According to Double Cantilever Beam theory, the stress intensity factor was 1.08~1.38 for sheet glass fiber reinforced plastic reinforced laminated timber and 1.38~1.86 for glass fiber textile reinforced laminated timber, respectively. That was because, for the glass fiber textile reinforced laminated timber, the fiber array direction of glass fiber and laminated wood orthogonal to each other suppressed the split propagation in the wood.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2011.03a
• /
• pp.101-101
• /
• 2011

재생 셀룰로스 섬유의 원료로 사용되는 셀룰로스는 면, 마, 목재 등 고등식물의 주성분으로 매년 수십억톤이 광합성에 의하여 생산되어지고 있다. 따라서 석유류와 같은 화석연료의 가격 변동에 영향을 받지 않고 안정적으로 수입되고 있다. 또한, 셀룰로스에는 면이나 마류 등과 같이 간단한 정제 처리에 의해 의류용 섬유로서 사용될 수 있는 것과 목재 섬유와 같이 펄프화하여 종이, 인견섬유, 필름 등으로 사용되어지는 것이 있으며, 셀룰로스 유도체도 제조할 수 있다. 현재까지 개발된 섬유들 중 대표적인 셀룰로스계 재생섬유인 비스코스 레이온(Viscose rayon)은 그 제조 방법이 환경적으로 치명적인 문제를 안고 있으나 고유의 우수한 드레이프성, 흡습성, 독특한 광택, 시원한 촉감 등을 가지고 있어 그 소비는 꾸준한 상황이다. 이러한 Viscose rayon을 대체하기 위하여 친환경적인 공법을 이용하여 개발된 Lyocell 제품이 각광을 받고 있다. 면 셀룰로스 재생섬유는 기존의 Lyocell섬유에 비해 신도는 높고 모듈러스가 낮아 Modal과 같은 촉감을 가지고, 피브릴 발생이 없어 방사공정에서 가교반응이 필요치 않는 것으로 기대된다. 친환경 공법인 Lyocell 공법으로 개발된 면 린터 원료를 이용하여 면 린터 셀룰로스 재생섬유 제조기술을 개발하고자 한다. 따라서 본 연구에서는 면 린터 셀룰로스 재생섬유의 기술적인 신뢰성을 검증하기 위해 면 린터 셀룰로스 재생섬유소재 피브릴화 정도의 표준화 시험법을 연구하고자 한다. 사용원단으로 Tencel A-100, Tencel standard, Modal, Lyocell LF, 면 린터 섬유를 사용하였으며, 세탁, 염색, 알칼리조건 처리에 따른 물성 변화를 알아보았다. 물성 변화는 전자현미경으로 측정하였다.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.6
• /
• pp.406-417
• /
• 2012

In this study, eco-friendly hybrid composite boards were manufactured from green tea, three kinds of charcoals and wood fiber for developing interior materials to reinforce the functionalities such as the deodorization and the absorbability on the green tea-wood fiber hybrid boards in the previous researches. The effects of kind of raw materials and the component ratio of raw materials on dimensional stability, deodorization and emission of formaldehyde were investigated. Thickness swelling of the hybrid composite boards increased with increasing of component ratio of green tea and charcoals, but the values were markedly lower than that of Korean standard (KS) for commercial medium density fiber board (MDF), except for hybrid composite boards composed of greed tea, activated charcoal and wood fiber. Reduction rate of ammonia gas for the hybrid composite boards composed of green tea, activated charcoal and wood fiber showed a high value of 96% after 30 minute from the beginning of the test, and the other hybrid boards also showed a high value of about 95% after one hour. Emission amount of formaldehyde was similar to that of $E_0$ grade in case of using $E_1$ grade urea resin, and was similar to that of super $E_0$ grade in case of using $E_0$ grade urea resin.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.2
• /
• pp.26-32
• /
• 2004

Chemical compositions and chemical structure of lignin and alkali cooking condition and fiber length of red pepper were investigated and compared to those of woods. The chemical compositions of red pepper were higher component of extraction than that of wood. The contents of carbon and hydrogen of Klason lignin in red pepper were similar to that of pine and birch wood. On the other hand, the contents of oxygen and nitrogen of Klason lignin in the red pepper were higher than that of wood. The result of nitrobenzene oxidation shows that Klason lignin of red pepper was similar to lignin of softwood. The best alkali cooking condition of red pepper was 0.2%-anthraquinone, active alkali of 20% and liquor ratio of 1:7. The fiber length of red pepper was about 0.47 mm. Therefore, the red pepper fiber will be able to use special purpose of short fiber.

• Journal of the Korean Wood Science and Technology
• /
• v.17 no.4
• /
• pp.83-88
• /
• 1989

목재의 섬유방향에 경사진 균열의 모-드I과 모-드II의 혼합모-드파괴시의 파괴거동을 조사하기 위하여 라왕(Shorea Spp.)의 LA시스템에 있어서 서로 다른 경사각도를 가진 SEN시험편(Single edge notch specimen)에 대하여 휨 시험을 행하였다. 얻이진 결과는 혼합모-드파괴시, 모-드I응력확대계수$K_I$과 모-드II응력확대계수$K_II$간에 일정한 상호작용이 존재한다는 것을 나타내었다. 또한, 모-드I과 모-드II의 임계응력확대계수(Critical stress intensity factor) $K_{IC}$와 $K_{IIC}$ 이용하여 혼합모-드파괴시의 $K_I$과 $K_II$간의 상호관계를 규정할 수 있었으며, 이미 보고된 여러 실험식과 본 실험결과를 비교하여 가장 적합한 관계로서 아래와 같은 관계를 얻을 수 있었다.

• Journal of the Korean Wood Science and Technology
• /
• v.30 no.2
• /
• pp.144-150
• /
• 2002

Indian mallow is characterized by the rapid growth and high harvest of the fibrous materials. This study was carried out to investigate the sheet properties of Hanji using Indian mallow, made by different pulping methods, such as alkali and sulfomethylated pulpings and different stock compositions, various mixing ratios of bast fiber, woody core and whole stalk fibers. The results from this study were summarized as follows. The length and width of the bast fibers were 1.40-430 mm(av. 235 mm), and 9.2-26.4 ㎛(av.18.3 ㎛), respectively. The cell wall thickness was 4.0-115 ㎛(av. 7.7 ㎛). Runkel ratio, flexibility coefficient and fiber length/fiber width ratio were 1.38, 0.42 and 128 respectively. Bast fiber and whole stalk were cooked by alkali and sulfomethylated methods. Sulfomethylated pulping resulted in superior pulp in terms of yield and quality as compared with those of alkali pulping. The pulp yields of bast fiber was higher than those of whole stalk