• Composites Research
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• 제26권3호
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• pp.155-159
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• 2013

연속 섬유의 펼침에 대한 기술 현황 및 이의 적용에 대해 본 연구에서 정리되었다. 이론적 접근을 통해 연속 섬유 펼침의 효과를 소개하였고, 섬유 펼침 수단과 섬유 펼침 장치의 공정 상 위치를 기준으로 연속 섬유의 펼침에 대한 기술을 분류 정리하였다. 또한, 각 기술의 일반적인 섬유 펼침 원리, 기술적용 및 기술의 장 단점에 대해 소개하였으며, 향후 연속 섬유의 펼침에 대한 기술 연구 방향에 대해서도 고려되었다.

• Composites Research
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• 제33권6호
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• pp.390-394
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• 2020

탄소섬유 스프레드 토우를 제조하는 과정에서 섬유 손상이 발생하며, 이는 스프레딩 과정에서 장비와 섬유 사이 혹은 섬유 간의 마찰로 발생한다. 이로 인해, 재료 및 장비조건에 따라 프로세스 성능에 차이가 발생하고, 제품 물성이 하락한다. 섬유 손상을 최소화하는 것은 스프레드 토우를 제조하는 공정에서 반드시 고려되어야 한다. 본 연구에서는 공기를 이용한 탄소섬유 스프레딩 공정에서 탄소섬유의 필라멘트 수와 사이징 함량, 탄소섬유토우 스프레딩 장비의 공정 변수(초기섬유장력, 열풍온도, 진공압력)를 달리하여 스프레드 토우의 공정성능 변화를 관찰하였다. 탄소섬유 품종에 따른 조건 별 최적조건에서 제조된 샘플을 이용해 인장강도를 평가하여, 탄소섬유의 손상에 따른 기계적 물성 감소를 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제33권4호통권132호
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• pp.60-65
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• 2005

어저귀 한지의 발묵특성을 장 단섬유의 혼합비율에 따라 비교 검토하여 화선지로써의 적용 가능성을 검토하고자 하였다. 제조한 한지의 발묵특성을 검토한 결과, 인피펄프 단독으로 초지한 한지는 발묵상태가 매우 불량하여 화선지용으로는 적합하지 않은 것으로 나타났으며, 목질부 단독으로 초지한 한지의 발묵상태가 시판 화선지류보다도 훨씬 우수한 경향을 나타냈다. 강도적인 측면을 고려한다면 설포메틸 펄프화법으로 처리한 단섬유인 목질부 펄프를 60% 혼합한 어저귀 한지가 화선지용으로 적합하다고 사료된다. 펄프화 방법에 있어서도 설포메틸 펄프화법으로 초지한 한지의 발묵상태가 우수하였다. 이렇듯 한지의 발묵상태는 장섬유와 단섬유의 혼합량 및 지합과 밀접한 관련이 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.363-363
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• 2010

The high capillarity of a plastic fiber network having superhydrophilic Si-DLC coating is studied. Although the superhydrophilic surface maximize wetting ability on the flat surface, there remains a requirement for the more wettable surface for various applications such as air-filters or liquid-filters. In this research, the PET non-woven fabric surface was realized by superhydrophilic coating. PTE non-woven fabric network was chosen due to its micro-pore structure, cheap price, and productivity. Superhydrophobic fiber network was prepared with a coating of oxgyen plasma treated Si-DLC films using plasma-enhanced chemical vapor deposition (PECVD). We first fabricated superhydrophilic fabric structure by using a polyethylene terephthalate (PET) non-woven fabric (NWF) coated with a nanostructured films of the Si-incorporated diamond-like carbon (Si-DLC) followed by the plasma dry etching with oxygen. The Si-DLC with oxygen plasma etching becomes a superhydrophilic and the Si-DLC coating have several advantages of easy coating procedure at room temperature, strong mechanical performance, and long-lasting property in superhydrophilicity. It was found that the superhydrophobic fiber network shows better wicking ability through micro-pores and enables water to have much faster spreading speed than merely superhydrophilic surface. Here, capillarity on superhydrophilic fabric structure is investigated from the spreading pattern of water flowing on the vertical surface in a gravitational field. As water flows on vertical flat solid surface always fall down in gravitational direction (i.e. gravity dominant flow), while water flows on vertical superhydrophilic fabric surface showed the capillary dominant spreading.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.245-248
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• 2002

Research on the high performance and strength thermoplastic/continuous fiber composites was performed. New concept of impregnating die for developing continuous strand and prepreg tape of engineering plastic/glass fiber was introduced and estimated. Fully impregnated prepreg strand and tape was successfully manufactured through the new pin structure of impregnating die and control of spreading variable. Also design variables for stability of increasing processing speed were shown. And tensile strength of prepreg tape manufactured in this study was much higher than composites made by other competition company.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.1-7
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• 2005

The objective of this work was to investigate the effect of spreading behavior of the sizing agents (AKD or dialkyl ketone) on the sizing development of AKD-sized paper. There was a direct relationship between the spreading behavior of the sizing agents and their melting points. Both AKD and dialkyl ketone showed no substantial spreading until the temperature reaches to their melting points. Consequently, dialkyl ketone did not provide sizing development when the paper was heat-treated below $75^{\circ}C$, while AKD provided sizing effect even the paper heated at $50^{\circ}C$. The ketone, however, provided rather higher sizing effect than that of AKD, when the paper was heat-treated over $100^{\circ}C$. This result means that the ketone also gives sizing development to paper, moreover the ketone could give higher sizing effect to paper than AKD when it was melted and well spreaded on the fiber surface. While the ketone introduced to papers from hydrolyzed AKD emulsion could not contribute to sizing development.

• Journal of the Optical Society of Korea
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• 제7권3호
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• pp.180-187
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• 2003

A theoretical presentation by using a three-dimensional finite difference beam propagating method (3-D FD-BPM) for the evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with a perfect conductor (PEC) on one side. The coupling and propagation of light are found to depend on both the relationship between the refractive index values of two structures and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of a PWGCC is presented with the distribution of electric fields in xy - plane and the absolute amplitude of electric fields along the x and y axis. The power of the light propagation in a fiber decreases exponentially along the fiber axis as it is transferred to the PWGCC, where it is carried away.

• Composites Research
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• 제28권5호
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• pp.249-253
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• 2015

본 연구는 탄소섬유 펼침 기술을 이용한 적층 복합재료의 특성을 평가하였다. 섬유 펼침 기술이 적용되어 기존 12 K 탄소섬유 토우의 폭이 7 mm에서 20 mm로 늘어나면서 두께가 더 얇아졌다. 폴리프로필렌 필름을 spread tow에 함침시켜 프리프레그를 만들고 이를 적층 후 열압축 성형을 통해 시편을 제조하였으며 이들의 기공함유량 및 인장, 굴곡 시험을 통해 물리적, 기계적 물성을 평가하였다. 그 결과, 탄소섬유 펼침 기술이 적용된 적층 복합재료의 기공함유량이 기존의 섬유 토우를 사용한 것보다 작게 나타났고, 섬유함유량이 낮았음에도 불구하고 기계적 물성이 향상됨을 알 수 있었다.

• Journal of the Optical Society of Korea
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• 제7권1호
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• pp.20-27
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• 2003

A theoretical presentation of evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with the perfect conductor (PEC) on one side. The behavior of the distributed couple. is examined using a coupled mode model, which takes account of the two dimensions of the waveguide configuration. The coupling and propagation of light were found to depend on both the relationship between the refractive index values of each structure and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of the PWGCC is described in terms of a simple geometrical interpretation of the synchronization condition that is in agreement with a previous investigation of the problem based on the coupled-mode theory (CMT). The power of the light propagation in the fiber decreased exponentially along the fiber axis as it was transferred to the PWGCC, where it was carried away.

• 한국재료학회지
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• 제20권7호
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• pp.392-400
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• 2010

The electrospinning process was established as a promising method to fabricate nano and micro-textured scaffolds for tissue engineering applications. A BCP-loaded PCL micro-textured scaffold thus can be a viable option. The biocompatibility as well as the mechanical properties of such scaffold materials should be optimized for this purpose. In this study, a composite scaffold of poly ($\varepsilon$-caprolactone) (PCL)-biphase calcium phosphate (BCP) was successfully fabricated by electrospinning. EDS and XRD data show successful loading of BCP nano particles in the PCL fibers. Morphological characterization of fibers shows that with a higher loaded BCP content the fiber surface was rougher and the diameter was approximately 1 to 7 ${\mu}m$. Tensile modulus and ultimate tensile stress reached their highest values in the PCL- 10 wt% BCP composite. When content of nano ceramic particles was low, they were dispersed in the fibers as reinforcements for the polymer matrix. However, at a high content of ceramic particles, the particles tend to agglomerate and lead to decreasing tensile modulus and ultimate stress of the PCL-BCP composite mats. Therefore, the use of nano BCP content for distribution in fiber polymer using BCP for reinforcement is limited. Tensile strain decreased with increasing content of BCP loading. From in vitro study using MG-63 osteoblast cells and L-929 fibroblast like cells, it was confirmed that electrospun PCL-BCP composite mats were biocompatible and that spreading behavior was good. As BCP content increased, the area of cell spreading on the surface of the mats also increased. Cells showed the best adherence on the surface of composite mats at 50 wt% BCP for both L-929 fibroblast-like cells and MG-63 osteoblast cell. PCL- BCP composites are a promising material for application in bone scaffolds.