• 한국산업융합학회 논문집
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• 제4권3호
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• pp.267-273
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• 2001

In this study, the survival rate of fiber is investigated by nozzle size difference in injection/mold sides. The survival rate of fiber is influenced about the nozzle size differ. Also, The mechanical properties of short carbon glass fiber reinforced polypropylene are experimentally measured as functions of fiber volume fraction and nozzle size difference. These mechanical properties are compared with the survival rate of fiber and fiber volume fraction using image analysis after pyrolytic decomposition. The survival rate of fiber as well as fiber volume fraction is influenced by injection processing condition, the used materials, mold conditions and nozzle sides difference, etc, In particular, the survival rate of fiber is great influenced when injection/mold nozzle sides are different more than that of the same. Consequently, the mechanical properties of short carbon/glass fiber reinforced polypropylene arc improved as the nozzle sides are the same in injection mold sides.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.68-71
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• 1996

In the study, the thermal and optical properties of SiO$_2$-PbO-K$_2$O-Al$_2$O$_3$ g1asses were investigated. According to Ga$_2$O$_3$ addictions, the properties of bulk glass, transition temperature and softening temperature were increased, whereas thermal expansion coefficient was decreased; In the optical properties, refractive index was increased, and IR cut-off wavelength was enlarged from 4.64$\mu\textrm{m}$ to 5.22$\mu\textrm{m}$. But, the optical loss of fiber was decreased.

• ETRI Journal
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• 제27권4호
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• pp.411-417
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• 2005

$Pr^{3+}-doped$ selenide glass optical fiber, which guarantees single-mode propagation of above at least 1310 nm, has been successfully fabricated using a Ge-Ga-Sb-Se glass system. Thermal properties such as glass transition temperature and viscosity of the glasses have been analyzed to find optimum conditions for fiber drawing. Attenuation loss incorporating the effects of an electronic band gap transition, Rayleigh scattering, and multiphonon absorption has also been theoretically estimated for the Ge-Ga-Sb-Se fiber. A conventional double crucible technique has been applied to fabricate the selenide fiber. The background loss of the fiber was estimated to be approximately 0.64 dB/m at 1650 nm, which can be considered fairly good. When excited at approximately 1470 nm, $Pr^{3+}-doped$ selenide fiber resulted in amplified spontaneous emission and saturation behavior with increasing pump power in a U-band wavelength range of 1625 to 1675 nm.

• 센서학회지
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• 제32권3호
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• pp.159-163
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• 2023

Salt cores have attracted considerable attention for their application to the casting process of electric vehicle parts as a solution to ecological issues. However, the salt core still has low mechanical strength for use in high-pressure die casting. In this study, we investigated the improvements in the bending strength of KCl-based salt cores resulting from the use of reinforcing materials. KCl and Na₂CO₃ powders were used as matrix materials, and glass fiber and carbon fiber were used as reinforcing materials. The effects of carbon fiber and glass fiber contents on the bending strength properties were investigated. Here, we obtained a new fiber-reinforced salt core composition with improved bending strength for high-pressure die casting by adding a relatively small amount of glass fiber (0.3 wt%). The reinforced salt core indicates the improved properties, including a bending strength of 49.3 Mpa, linear shrinkage of 1.5%, water solubility rate of 16.25 g/min·m² in distilled water, and hygroscopic rate of 0.058%.

• 폴리머
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• 제24권3호
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• pp.326-332
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• 2000

유리섬유/불포화 폴리에스터 복합재료에서 섬유에 처리된 사이징제가 복합재료의 최종 물성에 미치는 영향을 상온에서의 접촉각 측정을 통해 고찰하였다. 본 연구에서는 폴리비닐알코올, 폴리에스터, 그리고 에폭시계 사이징제를 사용하여 유리섬유의 표면을 처리하였으며 각각의 물성을 비교하였다. 유리섬유의 접촉각은 증류수와 diiodomethane을 젖음액으로 사용하여 Washburn식을 기본으로 한 wicking법으로 측정하였다. 결과적으로 접촉각 측정에 의해 구한 표면자유에너지는 에폭시계 사이징제로 치리된 유리섬유에서 최대값을 나타내었다. 복합재료의 층간 전단 강도 (ILSS)와 파괴 인성 ( $K_{IC}$ )의 측정 결과로부터 사이징제의 처리에 따라 계면 결합력이 증진되며 결과적으로 복합재료의 기계적 강도가 증가함을 알 수 있었다. 이것은 복합재료에서 유리섬유의 표면 자유에너지 증가에 기인한다고 사료된다.

• The Korean Journal of Ceramics
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• 제1권3호
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• pp.160-164
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• 1995

Mechanical and chemical tests were performed on $Zro_2 \cdot SiO_2$ glass fibers manufactured by the sol-gel method and E-glass fibers-reinforced cement composites in order to investigate the interactions between glass fibers and cement matrices. Chemical attack leads to corrosion of the glass fiber surfaces. In the corrosion reactions, the surface of $30ZrO_2 \cdot 70 SiO_2$ glass fibers developed a densified concentric layer, which consists of glass corrosion products with much higher Zr and lower Si than the fresh glass fiber. The layer of reaction product is regarded to stiffen the cement matrices and provide a useful improvement to the mechanical properties. The addition of $ZrO_2$ content increases the corrosion resistance of glass fibers in cement by forming a passivating layer on the surface of glass fibers.

• 대한조선학회논문집
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• 제59권4호
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• pp.207-213
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• 2022

LNG CCS which is a special type of cargo hold operated at -163℃ for transporting liquefied LNG is composed of a primary barrier, plywood, insulation panel, secondary barrier, and mastic. Currently, glass fiber is used to reinforce polyurethane foam. In this paper, we evaluated the possibility of replacing glass fiber-reinforced polyurethane foam with basalt fiber-reinforced polyurethane foam. We conducted a thermal conductivity test to confirm thermal performance at room temperature. To evaluate the mechanical properties between basalt and glass-fiber-reinforced polyurethane foam which is fiber content of 5 wt% and 10 wt%, tensile and an impact test was performed repeatedly. All of the tests were performed at room temperature and cryogenic temperature(-163℃) in consideration of the temperature gradient in the LNG CCS. As a result of the thermal conductivity test, the insulating performance of glass fiber reinforced polyurethane foam and basalt fiber reinforced polyurethane foam presented similar results. The tensile test results represent that the strength of basalt fiber-reinforced polyurethane foam is superior to glass fiber at room temperature, and there is a clear difference. However, the strength is similar to each other at cryogenic temperatures. In the impact test, the strength of PUR-B5 is the highest, but in common, the strength decreases as the weight ratio of the two fibers increases. In conclusion, basalt fiber-reinforced polyurethane foam has sufficient potential to replace glass fiber-reinforced polyurethane foam.

• 한국결정성장학회지
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• 제25권6호
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• pp.263-271
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• 2015

기존의 내알칼리 유리섬유는 복합재료의 보강섬유로 가장 널리 사용되고 있는 일반적인 E-glass fiber보다 우수한 내화학 특성을 갖고 있으나 용융유리의 점도가 너무 높아 섬유화가 어려운 문제점을 가지고 있다. 본 연구에서는 지르코니아 함량이 상용 제품에 비해 낮은 범위에서 지르코니아 함량별로 내알칼리유리섬유를 제조하고 이들의 특성을 E-glass 섬유와 비교하였다. 지르코니아의 함량을 0.5~16 wt%까지 변화시키면서 제조한 각각의 배치원료를 $1600^{\circ}C$에서 2시간 용융하여 투명하고 맑은 유리를 얻을 수 있었다. 이들 유리는 약 90 %의 높은 가시광 투과율을 나타내었고, 열적특성에서 $703{\sim}887^{\circ}C$의 연화점을 나타내었으며, 지르코니아의 함량이 증가함에 따라 연화점이 상승하는 경향을 나타내었다. 지르코니아 함량이 4 wt%인 조성을 E-glass 조성과 비교한 결과, 연화점에서는 $-94^{\circ}C$의 차이를, 고온점도에 있어서는 log3 온도가 $+68^{\circ}C$, log5 온도가 $-13^{\circ}C$의 차이를 나타내었다. 내알칼리 유리섬유를 알칼리용액에 48시간 및 72시간 침적 후 SEM을 통해 섬유의 내침식성이 양호함을 확인할 수 있었고, 인장강도도 일반 E-glass 섬유에 비해 48시간에서 1.7배와 72시간에서 2.2배의 높은 값을 나타냄을 알 수 있었다. 결론적으로 이러한 내알칼리 유리섬유는 쉬운 제조조건과 낮은 지르코니아 함량에도 불구하고 좋은 특성 때문에 일반적인 내알칼리 유리섬유로서 널리 사용될 수 있을 것으로 판단되었다.

• 한국해양공학회지
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• 제14권4호
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• pp.49-55
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• 2000

This study has been investigated to apply fiber reinforced composites instead of asbestos as a friction material. the reinforced used was E-glass fiber and binder resin was phenol having good mechanical properties and heat resistance. And it has been also investigated the effect of molding conditions and some additives such and carbon black, alumina and rubber powder in E-glass fiber/phenol resin composite on the friction on the friction and wear characteristics. As a result, it was found that the molding conditions of E-glass fiber/phenol resin composites for friction materials had to be different from those of phenol resin and was found that the wear rate of E-glass fiber/phenol resin composites added alumina powder was higher than of composites added carbon black in the same wear distance. And it was found that friction coefficient of E-glass/phenol resin composites added carbon black was decreased and that of the composites added the powder of natural rubber and ABS rubber were increased compared to the composites.

• Composites Research
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• 제35권2호
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• pp.75-79
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• 2022

본 연구에서는 충격에 의해 파손된 열가소성 유리 섬유 강화 복합재료의 재성형을 통한 물성변화를 조사하였다. 복합재료 시편은 유리섬유 부직포와 폴리프로필렌 필름을 이용하여 핫 프레스 압축 성형 공정을 통해 제작하였다. 총 3번의 낙하 충격 테스트를 진행하였으며, 시편의 물성을 확인하기 위하여 인장시험, 굽힘시험, 낙하충격시험, 시차주사열량계, 주사전자현미경 측정을 진행하였다. 그 결과, 재활용 단계가 반복될수록 결정화도, 인장강도, 탄성계수, 굴곡강도는 증가하였으나 충격특성은 크게 감소하였다.