• Title/Summary/Keyword: glass fiber

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Mechanical Properties of Steel Fiber Reinforced Concrete Using Waste Glass (폐유리를 혼입한 강섬유보강 콘크리트의 역학적 특성)

  • 박승범;이봉춘
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.1032-1039
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    • 2002
  • Since recycling waste glass as a material for concrete has a great advantage environmentally and economically, the US, Japan and other countries have started recycling waste glass widely and accumulating the technology of manufacturing equipment and its construction. However, there is no practical data on the mechanical property of concrete using waste glass. In this study, the mechanical property of the steel fiber reinforced concrete using waste glass was analyzed in terms of waste glass content(20vo1. %, 40vo1. % as a part of fine aggregate) and steel fiber content(0.5~ 1.5vol.%). The results of this study are as follows : The workability of the concrete including steel fiber and waste glass decreases, as the inclusion rate of waste glass and steel fiber increases. The tensile strength, flexural strength and flexural toughness of the concrete including waste glass increase considerably, as the inclusion rate of steel fiber increases. From the results, the appropriate inclusion rate of steel fiber and waste glass is thought to be 1.0vol. % and 20vo1. %, respectively.

Precise Drilling characteristics of glass fiber epoxy composite material (유리섬유 에폭시 복합재료의 정밀드릴가공 특성)

  • 김홍배
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.4
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    • pp.117-122
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    • 1998
  • Glass fiber epoxy composite material is widely used in the structures of aircrafts, robots and other machines because of their high specific strength, high specific stiffness and high damping. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joint must be provided, which require precise machining. In this paper, the machinability of the glass fiber epoxy composite material was experimentally investigated. The results can be summarized as follows : 1. The entrance of hole is very good manufacturing existing, but exit come to occur sever surface exfoliation. 2. The cutting force in drilling of the glass fiber epoxy composite material is decreased as the drilling speed increased. 3. If the glass fiber epoxy composite material is drilling by the standard twist drill, then the hole recommand cutting condition is spindle speed 400∼600rpm, feed 40∼50mm/min.

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Drilling Characteristics of Glass Fiber Reinforced Polyester (유리섬유 강화 폴리에스터의 드릴가공 특성)

  • 김성일
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.3
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    • pp.90-95
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    • 2000
  • Today fiber composite materials are routinely used in such wide applications as ships automobiles aircraft space vehi-cles containers sporting goods and appliances. The current knowledge of machining glass fiber reinforced polyester com-posites unfortunately is inadequate for its optimum utilization in many applications. Therefore This paper deals with drilling characteristic of glass fiber reinforced polyester composites. In the drilling of glass fiber reinforced polyester the quality of the cut surfaces is strongly dependent on the drilling parameters. drilling tests were carried out on glass fiber reinforced polyester using standard HSS tools. The material containing random chopped strand fibers and woven roving was fabricated by hand lay-up The entrance and exit surface of the holes was examined. The cutting force was also mea-sured to analyze the drilling characteristics,.

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A study of warpage caused by glass fiber orientation in Injection Molding to Upper Frame of Magnetic Contactor in 85 AF (Magnetic Contactor Upper Frame 사출성형시 유리섬유 배향에 따른 뒤틀림 변형에 관한 연구)

  • Park, Jin-Young;Cho, Hae-Yong;Kim, Kil-Su;Hwang, Han-Seong
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.766-771
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    • 2000
  • As using of insulating material of plastic to industrial electric field, thermoset has been gradually substituted for thermoplastic. But changing the material with crystalline has some problem, which is strength or warpage, Especially getting a strength to endure inner pressure is necessary when arc is occurred. So we use the material that is composed of glass fiber to compensate strength. By the way as the reinforced glass-fiber material is used in injection molding, unstableness of dimension is appeared frequently and it is difficult to know warpage pattern. So this paper will be contributed to know warpage pattern of mold product that is upper frame of magnetic contactor caused by glass-fiber orientation with fixed gate-system, when glass-fiber reinforced material with classification of poly-amide is used in injection molding.

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Fabrication and characterization of boron free E-glass fiber compositions (붕소를 함유하지 않는 E-glass fiber의 제조 및 특성에 대한 연구)

  • Lee, Ji-Sun;Lim, Tae-Young;Lee, Yo-Sep;Lee, Mi-Jai;Hwang, Jonghee;Kim, Jin-Ho;Hyun, Soong-Keun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.1
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    • pp.44-50
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    • 2013
  • E-glass fiber is the most widely used glass fiber for reinforced composite materials of aircrafts, automobiles and leisure equipments. But recently researches are being progressed to reduce boric oxide from 8 % to 0 (zero), as is called 'Boron free E-glass', because of increasing material cost, environmental problem, and improving chemical resistance and mechanical properties of E-glass fiber. In this study, we fabricated the bulk glass and fiber glass of 'Boron free E-glass (BF) compositions', and characterized thermal properties and optical properties. 'Boron free E-glass (BF)' was obtained by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different $Al_2O_3$ compositions 5~10 %. We obtained transparent clear glass with high visible light transmittance value of 81~86 %, and low thermal expansion coefficient of $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$ and softening point of $907{\sim}928^{\circ}C$. For the chemical resistance test of 'BF' fiber samples, we identified that the higher alumina contents gives the better corrosion resistance of glass fiber.

Processability and Mechanical Characteristics of Glass Fiber and Carbon Fiber Reinforced PA6 for Reinforcement Content

  • Lee, S.B.;Cho, H.S.;Lyu, M.-Y.
    • Elastomers and Composites
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    • v.50 no.3
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    • pp.184-188
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    • 2015
  • There is a need for light weight and high stiffness characteristics in the building structure as well as aircraft and cars. So fiber reinforced plastic with the addition of reinforcing agent such as glass fiber, carbon fiber, aramid fiber is utilized in this regard. In this study, mechanical strength, flow property and part shrinkage of glass fiber and carbon fiber reinforced PA6 were examined according to reinforcement content such as 10%, 20%, and 30%, and reinforcement type. The mechanical property was measured by a tensile test with specimen fabricated by injection molding and the flow property was measured by spiral test. In addition, we measured the part shrinkage of fiber reinforced PA6 that affects part quality. As glass fiber content increases, mechanical property increased by 75.4 to 182%, and flow property decreased by 18.9 to 39.5%. And part shrinkage decreased by 52.9 to 60.8% in the flow direction, and decreased by 48.2 to 58.1% in the perpendicular to the flow direction. As carbon fiber content increases, mechanical property increased by 180 to 276%, flow property decreased by 26.8 to 42.8%, and part shrinkage decreased by 65.0 to 71.8% and 69.5 to 72.7% in the flow direction and the direction perpendicular to the flow respectively.

Computational Thermo-Fluid Analysis for the Effects of Helium Injection Methods on Glass Fiber Cooling Process in an Optical Fiber Manufacturing System (광섬유 냉각장치의 헬륨 주입기 설계를 위한 전산열유동해석)

  • Park, Shin;Kim, Kyoungjin;Kim, Dongjoo;Park, Junyoung;Kwak, Ho Sang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.2
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    • pp.124-130
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    • 2014
  • In a mass manufacturing system of optical fibers, the sufficient cooling of glass fibers freshly drawn from a draw furnace is essential, asinadequately cooled glass fibers can lead to poor resin coating on the fiber surface and possibly fiber breakage during the process. In order to improve fiber cooling at a high drawing speed, it is common to use a helium injection into a glass fiber cooling unit in spite of the high cost of the helium supply. The present numerical analysis carried out three-dimensional thermo-fluid computations of the cooling gas flow and heat transfer on moving glass fiber to determine the cooling performance of glass fiber cooling depending on the method of helium injection. The results showed that afront injection of helium is most effective compared to a uniform or rear injection for reducing air entrainment into the unit and thus cooling the glass fibers at a high fiber drawing speed. However, above a certain amount of injected helium, there was no more increase of the cooling effect regardless of the helium injection method.

In vitro study of microleakage of endodontically treated teeth restored with different adhesive systems and fiber-reinforced posts (다양한 접착시스템을 이용하여 섬유 강화형 포스트로 수복한 치아에서의 미세누출에 관한 연구)

  • Park, Joon-Ho;Choi, Yu-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.52 no.2
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    • pp.74-81
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    • 2014
  • Purpose: While studies have examined microleakage in endodontically treated teeth restored with posts, microleakage among post and adhesive systems remains a concern. This study compared the sealing properties of 3 adhesively luted post systems. Materials and methods: Thirty-six endodontically treated permanent maxillary central incisors were divided into 3 groups: Zirconia-glass fiber, Quartz-glass fiber, Polyethylene fiber posts. Post space was prepared and each post was adhesively luted with 3 systems. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The root portion of tooth were horizontally sectioned into three pieces (apical, middle, and coronal portions). An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. Results: No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). There were significant differences between the apical and coronal sections of each post type, and between apical versus middle sections of quarze-glass fiber and polyethylene fiber posts (P<.05). Conclusion: No significant differences were found among post types. The 3-stage adhesive produced significant differences in microleakage between the following post pairs.

The Reliability of Optical Fiber Assembly Using Glass Solder

  • Lee, Jong-Jing;Kang, Hyun-Seo;Koh, Jai-Sang
    • Proceedings of the Korean Reliability Society Conference
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    • 2004.07a
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    • pp.147-151
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    • 2004
  • In this study, an optical fiber assembly directly coupled with a laser diode or a photo diode is designed to confirm high reliable optical coupling efficiency of optical transmitter(Tx) and receiver(Rx). The optical fiber assembly is fabricated by soldering an optical fiber and a Kovar ferrule using a glass solder after inserting an optical fiber through a Kovar ferrule. The Kovar which has good welding characteristics is applied to introduce laser welding technique. The glass solder has excellent thermal characteristics such as thermal shift delamination compared with PbSn, AuSn solder previously used usually. Furthermore, the glass solder doesn't need fiber metalization and this enables low cost fabrication. However, the glass soldering is high temperature process over 35$0^{\circ}C$ and the convex shape after solidification due to surface tension causes the stress concentration on optical fiber. The stress concentration on the optical fiber increases the optical insertion loss and possibility of crack formation. The shape of glass solder was designed referring to 2-D Axi-symmetric FEM simulation. To test the mechanical reliability, mechanical vibration test and shock test were done according to Telcorida GR-468-Core protocol. After each test, the optical loss of the stress distributed fiber assembly didn't exceed 0.5 dB, which passes the test.

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Surface Fracture Behaviors of Unidirectional and Cross Ply Glass Fiber/Epoxy Lamina-Coated Glass Plates under a Small-Diameter Steel Ball Impact (일방향 및 직교형 유리섬유/에폭시 복합재로 피막된 판유리의 미소강구 충격에 의한 표면파괴거동)

  • Chang, Jae-Young;Choi, Nak-Sam
    • Composites Research
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    • v.22 no.4
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    • pp.33-40
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    • 2009
  • Fiber orientation effects on the impact surface fracture of the glass plates coated with the glass fiber/epoxy lamina layer were investigated using a small-diameter steel-ball impact experiment. Four kinds of materials were used: soda-lime glass plates, unidirectional glass fiber/epoxy layer(one ply, two plies)-coated, crossed glass tiber/epoxy layer (two plies)-coated glass plates. The maximum stress and absorbed fracture energy were measured on the back surface of glass plates during the impact. With increasing impact velocity, various surface cracks such as ring, cone, radial and lateral cracks appeared near the impacted site of glass plates. Cracks in the plate drastically diminished by glass fiber coating. The tiber orientation guided the directions of delamination and plastic deformation zones between the tiber layer and the glass plate. Impact surface-fracture indices expressed in terms of the maximum stress and absorbed energy could be used as an effective evaluation parameter of the surface resistance.