• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.433-440
• /
• 2006

A fiber processing method, which might be an alternative for conventional refining process, was introduced. The method consists of repetitive, gentle, mechanical impacts on fiber, and ensued fiber uncurling process. This method was very effective for OCC and BCTMP for increasing WRVs (water retention value) while keeping fiber lengths from shortening. For OCC and BCTMP, gentle mechanical impacts on fibers using Hobart mixer increased breaking lengths and tear strengths simultaneously at fast drainage level, and straightening fibers using kady mill increased those strength properties further. For SwBKP and HwBKP, only mechanical impacts using the mixer were effective on increasing tensile and tear strength at fast drainage, but not kady mill treatment. The strength increases of BCTMP by this alternative fiber processing method were exceptionally high. An extensive engineering development should be followed to actualize this fiber processing mechanism in an energy-effect way.

• Computers and Concrete
• /
• v.4 no.1
• /
• pp.19-32
• /
• 2007

This paper is concentrated on the behaviors of five different types of fiber reinforced concrete (FRC) in uniaxial tension and flexural impact. The complete stress-strain responses in tension were acquired through a systematic experimental program. It was found that the tensile peak strains of concrete with micro polyethylene (PEF) fiber are about 18-31% higher than that of matrix concrete, those for composite with macro polypropylene fiber is 40-83% higher than that of steel fiber reinforced concrete (SFRC). The fracture energy of composites with micro-fiber is 23-67% higher than that of matrix concrete; this for macro polypropylene fiber and steel fiber FRCs are about 150-210% and 270-320% larger than that of plain concrete respectively. Micro-fiber is more effective than macro-fiber for initial crack impact resistance; however, the failure impact resistance of macro-fiber is significantly larger than that of microfiber, especially macro-polypropylene-fiber.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.4
• /
• pp.59-66
• /
• 2011

This study was carried out to develop the automation bark peeling process of paper mulberry for making Hanji. Nowadays, almost raw material has been imported from south-east asia for making Hanji. Raw material dependence is very high for Hanji-making by low productivity in korea. This study is focused on the resolution for problem of bark peeling automation. Water and sand jet of compressed air was possible bark peeling for black bast fiber. The effect of removing black bast fiber increased the longer the steaming time. Also using drum of bark peeling showed that results under temperature $80^{\circ}C$ and Rpm 50/min were best bark peeling and separating bast fiber from stem. The contents of holocellulose, lignin, ethanol-benzene extractives, and ash were 91.63~95.55%, 1.4~2.0%, 1.12~1.65%, and 1.4~4.3%, respectively. Chemical characteristics are similar between imported raw-material with drum bark.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.45 no.4
• /
• pp.16-20
• /
• 2013

Yellow poplar grown in Korea and imported eucalyptus were compared their kraft pulping characteristics and evaluated the replacing possibility of eucalyptus by yellow poplar. Difference between yellow poplar and eucalyptus were investigated in chemical composition and fiber morphology. Yellow poplar kraft pulp resulted in the higher yield, longer fiber length and thicker fiber, and higher pulp strength than that of eucalyptus. More xylan survived in eucalyptus than yellow poplar during kraft pulping, which led to similar pulp yield even though polysaccharides in Eucalyptus was 4.5% less than in yellow poplar. Longer and thicker yellow poplar pulp fiber resulted in better beating response and pulp strength properties.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.207.2-207.2
• /
• 2015

차세대 디스플레이 소자로서 TAOS TFT (transparent amorphous oxide semiconductor Thin Film Transistor)가 주목 받고 있다. 또한, 최근에는 값 비싼 전자 제품을 저렴하고 간단히 처분 할 수 있는 시스템으로 대신 하는 연구가 진행되고 있다. 그중, cellulose-fiber에 전기적 시스템을 포함시키는 e-paper에 대한 관심이 활발하다. cellulose fiber는 가볍고 깨지지 않으며 휘는 성질을 가지고 있다. 가격도 저렴하고 가공이여 용이하여 차세대 기판의 재료로서 주목받고 있다. 하지만, cellulose-fiber 위에는 고온의 열처리공정과 고품질 박막 성장이 어려워서 TFT 제작에 어려움을 겪고 있다. 이러한 문제를 해결하기 위해서 산화물 반도체를 이용하여 TFT를 제작한 사례가 보고되고 있다. 또한, 채널 물질 뿐만 아니라 cellulose fiber에도 다른 물질을 첨가하거나 증착하여 전기적 화학적 특성을 개선시킨 사례도 많이 보고되고 있다. 본 연구에서는 가장 저품질의 용지로 알려진 신문지와 A4용지를 gate dielectric을 이용하여서 a-IGZO TFT를 제작하였다. 하지만, cellulose fiber로 만들어진 TFT의 경우에는 고온의 열처리가 불가능 하다. 따라서 저온에서 높을 효율은 보이는 microwave energy를 이용하여 열처리를 진행하였다. 추가적으로 저품질의 종이의 특성을 개선시키기 위해서 high-k metal-oxide solution precursor를 첨가 하여 TFT의 특성을 개선시켰다. 결과적으로 cellulose fiber에 metal-oxide solution precursor을 첨가하는 공정과 micro wave를 조사하는 방법을 사용하여 100도 이하에서 cellulose fiber를 저렴하고 우수한 성능의 TFT를 제작에 성공하였다.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.5
• /
• pp.617-632
• /
• 2019

This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian's method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1993.10a
• /
• pp.23-28
• /
• 1993

Shearing properties of soil reinforced with discrete randomly oriented inclusions depend on soil density, particle size, grading, fiber length, tensile strength and stiffness of fiber, mixing ration of fiber, confining stress, etc.. In this paper the effects of those various factors on shear strength of the fiber-reinforced soil was evaluated through triaxial tests and uniaxial tests. Tests were performed on two sandy soils and one silty soil with inclusions in varing lengths, contents and tensile strengths and tested at different confining stresses in triaxial test. From the experimental results, it was investigated if there is an optimal range of fiber lengths and fiber contents for the tested soils.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.478-481
• /
• 1995

This paper presents the system demonstrator for an optical fiber sensor system developed as a technological evaluator suitable for generic sensric sensing applications. The new type of fiber-optic sensor employed a diaphragm displacement transforms pressure into optical intensity. Form this sensing technique, we can know the variation of source intensity, the loss of a optical fiber, and the reflectivity of the diaphragm surface. Experimental results are applied to the low-pressure transducer suitable for measuring miniature pressure.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.5
• /
• pp.72-79
• /
• 2003

Nalita wood (Trema orientalis), one of the fastest growing woods in the world, is characterized anatomical, morphological and chemical properties at annual growth ring level in order to investigate as papermaking raw material. The proportion of fibers and vessel was increased with an increase of growth ring (from pith to bark). The fiber length of Nalita was increased with increasing growth ring, and an average fiber length was about 817 um. The average basic density of Nalita was about 0.38 g/cc. The total lignin & holocellulose in Nalita were increased and ash & alcohol-benzene extract decreased from pith to bark. These values were about 23.5 - 24.4 ％, 78.1 - 80.1 ％, 1.04 - 0.92 ％ and 2.1 - 1.8 ％, respectively. The xylan was the predominant sugar in the hemicellulose of Nalita.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.9
• /
• pp.1180-1185
• /
• 2014

This paper describes the effects on SUS tube of power optical fiber composite cable on underground transmission lines. The effects on grounding, air gap between SUS tube and metal sheath, contact resistance between outer semi-conducting layer and metal sheath and grounding of SUS tube application or not are variously analysed using EMTP in normal operating condition as well as single line to ground fault. From these results, in this paper, the scheme for protecting the electrically abnormal phenomena will be established on power-optical fiber composite cable of underground transmission lines. This paper can contribute to specification of grounding reference of SUS tube of optical fiber composite power cable system.