• 한국환경복원기술학회지
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• 제16권2호
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• pp.127-135
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• 2013

This study was carried out to verify the suitability of GRS(Glass-fiber Reinforced Slag) as natural type landscape stone according to the material property and structural safety performance standards. The structural safety performance of the GRS panel showed 12.4MPa and 16.2MPa each in flexural strength at 2 and 3% content of glass fiber while the flexural strength at 4 and 5% of glass fiber content showed 26.9MPa, and 30.2MPa, respectively, all satisfying the standards. In addition, air-dried gravity was found to be 1.82~1.89 in measuring range at 2~5% level of glass fiber content, satisfy the existing standards 1.8~2.3. In structural safety performance, the range of flexural strength consequent on glass fiber content was surveyed to be 12.8~30.2MPa, all satisfying the performance standards, while 10MPa and more while the compressive strength range was found to be 41.5~53.3MPa, all satisfying the performance standards, 40~60MPa. This study judged the suitability of only the items for a property of matter of landscape stone GRS by applying the natural-form landscape stone GFRC material standard, but in case an installation constructed with GRS material comes into existence later, there should be comprehensive performance guidelines through the research on durability, landscape performance and environmental and ecological performance.

• 대한치과기공학회지
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• 제42권2호
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• pp.91-98
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• 2020

Purpose: This study is to compare the flexural strength and modulus by inserting a mesh and stick type fiberglass reinforcement into resin specimens. Methods: Wax specimens (length 64 mm, width 39 mm, thickness 5 mm) are prepared according to ISO 20795-1:2013. Mesh type and stick type glass fiber reinforcements were prepared. The prepared wax specimens were used plaster and flask for investment. The flask was separated and the wax was removed. The heat curing resin was injected into the flask, and then a mesh type and stick type fiberglass reinforcement were inserted. The prepared resin specimen was cut into three equal parts (length 64 mm, width 10 mm, thickness 3.3 mm). The mesh type glass fiber reinforcement (MT group) and the stick type glass fiber reinforcement (ST group) were classified into two groups. The prepared specimen was measured using a universal testing machine (UTM). The data were analyzed by Mann-Whitney U test, and the significance level was set to 0.05. Results: In the flexural strength, the ST group was higher than the MT group, and there was a significant difference between the two groups (p<0.05). In the flexural modulus, the ST group was higher than the MT group, and there was a significant difference between the two groups (p<0.05). Conclusion: The stick-type glass fiber inreased the flexural strength than the mesh-type glass fiber reinforcement.

• Composites Research
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• 제29권6호
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• pp.336-341
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• 2016

본 논문에서는 복합재 풍력 블레이드를 위한 CNT 코팅 유리섬유의 전자기적/기계적 적용성에 대한 연구를 수행하였다. MW급 이상의 대형 복합재 블레이드는 민수용/군수용 레이더와의 신호간섭 문제로 인한 발전단지 위치선정 제약과 무게 증가에 따른 발전효율 저해, 구조적 건전성 부족에 따른 수리비용 증가의 당면과제를 안고 있다. 이에 본 연구에서는 이러한 문제를 극복하기 위한 방안으로 CNT 코팅 유리섬유를 제안하였다. 먼저 제안된 CNT 코팅 공정을 통해 유리섬유 표면에 CNT를 강력히 코팅하고, Va-RTM을 통해 CNT 코팅/유리섬유 에폭시 복합재를 제작하여 전자기적/기계적 물성을 평가하였다. 또한 전자파 흡수체 설계/제작 및 시험/평가를 통해 X-band의 8.3~12.1 GHZ에서 90% 이상 전자파 흡수성능을 가짐을 검증하였다. 이와 더불어 기계적 물성 시험/평가를 통해서 인장, 압축, 면내전단 강도/강성의 모든 기계적 물성이 향상됨을 확인하였다.

• 대한치과보철학회지
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• 제43권4호
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• pp.415-425
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• 2005

Statement of problem : Fracture of composite resin core will be occulted by progress of crack. Bonding interface of different materials has large possibility of starting point of crack line. Therefore, the bond strength of glass fiber post to composite resin core is important for prevention of fracture. Purpose: This in vitro study tried to find out how to get the higher strength of glass fiber post to composite resin core through surveying the maximum load that fractures the post and cote complex. Materials and methods: 40 specimens made with glass fiber Posts(Style $post^{(R)}$, Metalor, Swiss) and composite resin core ($Z-100^{(R)}$, 3M, USA) were prepared and loaded to failure with push-out type shear-bond strength test in a universal test machine. The maximum fracture load and fracture mode were investigated in the specimens that were restored with four different surface treatments. With the data. ANOVA test was used to validate the significance between the test groups, and Bonferroni method was used to check if there is any significant statistical difference between each test group. Evely analysis was approved with 95% reliance. Results: On measuring the maximum fracture load of specimens, both the treatments of sandblasted and acid-etched one statistically showed the strength increase rather than the control group (p<0.005). The scanning electric microscope revealed that sand blasting made more micro-retention form not only on the resin matrix but on the glass fiber, and acid-etching contributed to increase in surface retention form, eliminated the inorganic particles in resin matrix. Specimen fracture modes investigation represented that sand blasted groups showed lower bonding failure than no-sand blasted groups. Conclusion: Referring to the values of maximum fracture load of specimens, the bonding strength was increased by sand blasting and acid-etching.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.30-34
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• 2012

선박용 부품에 적용할 수 있는 고분자 소재를 개발하기 위한 연구의 일환으로, 폴리에스테르 수지의 인장강도에 미치는 실리카와 절단 유리섬유의 영향을 조사하였다. 실리카와 절단 유리섬유의 첨가량 및 표면 개질에 사용된 커플링제의 농도를 변화시키면서 실험을 수행하였다. 표면 개질을 수행하지 않은 경우, 유리섬유의 첨가량이 증가하면 인장강도가 증가하였으나, 실리카는 첨가량이 증가할수록 인장강도가 감소하였다. 커플링제를 사용하여 첨가제의 표면을 개질하면 인장강도에 긍정적인 효과를 나타내었으며, 개질된 실리카와 절단 유리섬유를 혼합 첨가하면 인장강도의 증가에 상승효과를 나타내는 것을 알 수 있었다.

• 대한치과기공학회지
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• 제40권4호
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• pp.201-207
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• 2018

Purpose: The purpose of this study is to evaluate the fitness of lower jaw compete denture with glass fiber. Methods: Lower jaw edentulous model was selected as the master model. Ten study models were produced using Type IV stone(n=10). Lower jaw trial dentures were produced by the wax denture base and artificial teeth. Conventional complete denture (CD) group was fabricated by excluding glass fiber reinforcement (n=5). Glass fiber complete denture (GD) group was fabricated with glass fiber reinforcement (n=5). The lower jaw trial complete denture was invested using a plaster. PMMA resin was injected and curing was performed. The CD and GD groups measured the fit using silicone replica technology. The measured data was verified by t-test. Results: The anterior area of the CD group showed the smallest value. There was a statistically significant difference in the anterior area of the CD group and the GD group (p<0.05), but there was no statistically significant difference in the posterior area (p>0.05). Conclusion : Complete denture with glass fiber showed low fitness and further study is needed to apply it clinically.

• 한국화재소방학회논문지
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• 제16권4호
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• pp.65-71
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• 2002

무기계 난연제로 널리 사용되고 있는 aluminum trihydrate와 antimony trioxide의 첨가에 의한 열화거동과 난연효과를 열분석 및 화염특성시험(LOI test, flammabilty을 45 degree test)을 통하여 알아보았다. 일반 구조용 glass fiber/unsaturated polyester 복합재료 제조 시 난연 조성에 따른 난연 효과와 기계적 특성(경도, 인장강도, 탄성률) 변화를 조사하였다. 항공우주용 구조에 사용되는 난연 처리된 glass fiber/epoxy prepreg 복합재료 제조 시 공정조건에 따른 난연 특성을 비교 분석하였다. 실험결과를 이용하여 난연제의 난연 기구 및 기계적 물성을 고려한 최적 난연 조성은 ATH의 경우 10∼20 phr이였으며, autoclave 공정압력이 증가할수록 높은 LOI 값을 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.216-219
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• 1995

One of the principal problems encountered in the use of glass fiber reinforced Plastic composites(GFRP) is to establish an active fiber surface to achieve maximum adhesion between resin and fiber surface. In order to develope new process to overcome the disadvantage of chemical agent, we have studied the effect of reactive plasma glass surface treatment on the electrical and mechanical properties of glass fiber reinforced epoxy composites. It is found that the electrical and mechanical characteristics of the composites treated with plasma is improved especially in the dielectric strength by 20% and tensile strength by 15%, whereas the tan $\delta$ is decreased significantly.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.785-792
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• 2000

Repair and retrofit system of concrete structures has been developed from conventional reinforced concrete overlaying, steel plate bonding and recently to fiber composite systems. Research and study on carbon, aramid, and glass fiber composite system has been actively carried out from all over the world Glass fiber composite is proved to be competitive technically and enconomically, among fiber composite system. CAF system is a system developed locally using all domestic materal, glass fabric and epoxy, and improved in shear bonding property by utilizing silica fume mixed with epoxy. All the tests on material properties, structural behavior, constructiveness at site and quality control procedure proved to be most appropriate system so far developed. Futher research work is and will be under progress for utilization of this system which will be applied to more adverse situation.

• 유변학
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• 제10권2호
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• pp.57-64
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• 1998

A pultrusion resin impregnation (PRI) die, which has been developed recently in our laboratory, was used to pre-pare various composite system. The continuous fiber reinforced composites of glass fiber/polypropylene(GFPP) and glass fiber/polyamide 6 (GFPA) were first manufactured by means of the PRI die and then cut into chopped pellets of predet-ermined length. These pellets and either virgin or modified thermoplastic resin were melt-mixed by a twin screw extruder to prepare GF/PA/PP and GF/PA/PPMA system. The mechanical properties of these blends were investigated and discussed in terms of their morphological observations. These preliminary results revealed that this new impregnation die could be suc-cessfully applied to produce prepregs suitavle for the final shaping process.