• 제목/요약/키워드: glass fiber composite

검색결과 730건 처리시간 0.03초

Development of a cavity pressure measuring device and estimation of viscosity functions of various polymer composites (사출성형 금형 캐비티 내압 측정장치 개발 및 이를 이용한 새로운 복합재료의 점도 측정)

  • Kim, Yong-Hyeon;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제16권1호
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    • pp.877-887
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    • 2015
  • We have proposed a new method for estimating the viscosity of the composite. In this paper, we have developed a device for measuring the injection mold cavity pressure. This makes it possible to verify the accuracy of the viscosity in CAE D/B in real time by measuring the melt pressure in the mold, and comparing this with the simulated pressure from the CAE analysis. Materials used in this study is a PP(Polypropylene), PP/LGF30%(Polypropylene/long glass fiber 50% composite) and PA66/LGF50%(Polyamide 6,6/long glass fiber 50% composite). The viscosity data for PP and PP long fiber composite have already been built, but the one for PA66 long-fiber composite does not exist because it is a newly developed material. Thus we obtained the viscosity curve of PA66/LGF50% by this system. Then, the viscosity curves from conventional viscometer were also compared with the viscosity obtained by the our method. And, we proved the accuracy of the CAE data of PP. In case of PP/LGF50% which is highly viscous and complex material, we improved the existing CAE data.because there was a difference between the measuring data and the CAE data.

A Viscoelastic Study of Glass Transition and Degradation Processes of Phenolic Resin/Carbon Fiber Composites (페놀수지/탄소섬유 열경화성 복합재료의 유리전이와 고온 분해과정에서 관찰되는 점탄성 특성 연구)

  • ;J. C. Seferis
    • The Korean Journal of Rheology
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    • 제11권1호
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    • pp.9-17
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    • 1999
  • Viscoelastic characteristics of cured phenolic resin/carbon fiber composite materials were investigated through glass transition and degradation reaction processes in the high temperature region up to $400^{\circ}C$. A typical glass transition of the cross-linked thermoset polymer was followed by irreversible degradation reactions, which were exhibited by the increasing storage modulus and loss modulus peak. A degradation master curve was constructed by using the vertical and horizontal shift factors, both of which complied well with the Arrhenius equation in light of the kinetic expression of degradation rate constants. Using an analogy to the Havriliak-Negami equation in dielectric relaxation phenomena, a viscoelastic modeling methodology was developed to characterize the frequency- and temperature-dependent complex moduli of the degrading thermoset polymer composite systems. The temperature-dependent relaxation time of the degrading composites was determined in a continuous fashion and showed a minimum relaxation time between the glass transition and degradation reaction regions. The capability of the developed modeling methodology was demonstrated by describing the complex behavior of the viscoelastic complex moduli of reacting phenolic resin composite systems.

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Binary Mixture Rule for Predicting the Dielectric Properties of Unidirectional E-glass/Epoxy Composite Materials (일방향 유리섬유/에폭시 복합재료의 유전성질 예측을 위한 혼합법칙)

  • Chin Woo Seok;Lee Dai Gil
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 한국복합재료학회 2004년도 추계학술발표대회 논문집
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    • pp.175-179
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    • 2004
  • Since the electromagnetic properties of fiber reinforced polymeric composites can be tailored effectively by adding small amount of electromagnetic powders to the matrix of composites, they are plausible materials for fabricating the radar absorbing structures (RAS) of desired performance. In order to design the effective electromagnetic wave (EM) absorber with the fiber reinforced polymeric composites, the electromagnetic characteristics with respect to the constituents of the composite should be available in the target frequency band. In order to describe the dielectric behavior of low loss unidirectional fiber reinforced composite, theoretical models and mixture equations for estimating its dielectric constant were proposed with respect to the fiber, matrix volume fractions and fiber orientations, and verified by the experiments. From the investigation, it was found that the suggested binary mixture rules agreed well with the experimental results.

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GLASS FIBER REINFORCED STRIP CROWN IN PRIMARY TEETH (강화형 strip crown의 사용)

  • Kim, Dae-Eop
    • Journal of the korean academy of Pediatric Dentistry
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    • 제32권1호
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    • pp.132-135
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    • 2005
  • The purpose of this study was to propose the modified strip crown technique for esthetic restoration of primary anterior teeth using glass fibers. Celluloid crown form(3M, USA), Z100(P shade, 3M, USA). Aeliteflo(Bisco Inc., USA), and Clearfil SE Bond(Kuraray Medical Inc., Japan) were used for this technique. Mesh type of glass fiber(TESCERA Fiber Mesh, Bisco Inc, USA) was used for reinforcing material. After trimming the celluloid crown form, resin adhesive and flowable resin were applied on the pre-shaped glass fiber mesh. That mesh was placed on the lingual surface of inside of celluloid crown form and followed by light activation. Composite resin was filled into the celluloid crown form and put it on a prepared tooth and then light activated and finished the margin. The new modified strip crown technique can provide esthetics and increased durability for restoration of primary anterior teeth.

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Flexural and Interfacial Bond Properties of Hybrid Steel/Glass Fiber Reinforced Polymer Composites Panel Gate with Steel Gate Surface Deformation for Improved Movable Weir (개량형 가동보에 적용하기 위한 하이브리드 강판/GFRP 패널 게이트의 강판게이트 표면형상에 따른 휨 및 계면 부착 특성 평가)

  • Kim, Ki Won;Kwon, Hyung Joong;Kim, Phil Sik;Park, Chan Gi
    • Journal of The Korean Society of Agricultural Engineers
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    • 제57권2호
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    • pp.57-66
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    • 2015
  • The purpose of this study was to improved the durability of a improved movable weir by replacing the improved movable weir's metal gate with a hybrid steel/glass fiber reinforced polymer composites panel gate. Because the metal gate of a improved movable weir is always in contact with water, its service life is shortened by corrosion. This study made four type of hybrid steel/glass fiber reinforced polymer composites panel gate with different steel gate surface deformation (control, sand blast, scratch and hole), flexural. Fracture properties tests were performed depending on the steel gate surface deformation. According to the test results, the flexural behavior, flexural strength and fracture properties of hybrid steel/glass fiber reinforced polymer composites panel gate was affected by the steel panel gate surface deformation. Also, the sand blast type hybrid steel/glass fiber reinforced polymer composites panel gate shows vastly superior flexural and fracture performance compared to other types.

Prediction of Deterioration Rate for Composite Material by Moisture Absorption

  • Kim, Yun-Hae;An, Seung-Jun;Jo, Young-Dae;Bae, Chang-Won;Moon, Kyung-Man
    • Journal of Advanced Marine Engineering and Technology
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    • 제34권2호
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    • pp.296-302
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    • 2010
  • If the fiber reinforced plastic is exposed to the moisture for a long period of time, most of moisture absorption occurs on the resin place, thus dropping cohesiveness between the molecules as the water molecules permeated between high molecular chains grant high molecular mobility and flexibility. Also as the micro crack occurs due to the permeation of moisture on the interface of glass fiber and epoxy resin, it is developed to the overall damage of interface place. Hence, the study on absorption is essential as the mechanical and physical properties of fiber reinforced composites are reduced. However, the study on absorption has the inconvenience needing to expose composite materials to fresh water or seawater for 1 month or up to 1 year. Therefore, this study has exposed fiber reinforced composites to fresh water and has developed a model with an accuracy of 98% after comparing the analysis value obtained by using ANSYS while basing on the experimental value of property decline by absorption and the basic properties of glass fiber and epoxy resin used in the experiment.

Comparison of Machining Defects by Cutting Condition in Hybird FRP Drilling (유리탄소섬유 하이브리드 복합재의 절삭 조건에 따른 가공 결함 비교)

  • Baek, Jong-Hyun;Kim, Su-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제21권9호
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    • pp.12-20
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    • 2022
  • Delamination and burr defects are important problems in drilling fiber reinforced plastics. A method for measuring FRP drilling defects has been studied. Delamination and burr factors were defined as the relative length or area. Using these factors, the effects of tool shape and drilling conditions on delamination and burr were studied. In this study, the defects that occur when drilling a glass-carbon fiber hybrid composite were compared in terms of three factors. In the glass-carbon fiber hybrid composite, the effects of the feed rate and tool point angle on the delamination and burr factors were similar to those in previous studies. The diameter of the tool did not affect the defect factor. A circular burr was generated in a drill tool with a point angle of 184°, and a relatively small deburring factor was observed compared with a tool with a point angle of 140°.

The Influence of Mechanical Properties with the Number of Recycling of Fiber-reinforced Thermoplastic Composites Damaged by Impact (충격에 의해 손상된 섬유강화 열가소성 수지 복합재료의 재활용 횟수에 따른 물성의 변화)

  • Bae, Kwak Jin;Lee, Joon Seok
    • Composites Research
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    • 제35권2호
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    • pp.75-79
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    • 2022
  • In this study, the effect of mechanical and chemical properties of glass fiber reinforced thermoplastic (GFRTPs) according to the number of recycling was confirmed. The composite materials were manufactured through a hot press compression molding process using an E-glass chopped strand mat and a polypropylene film. Four specimens were named according to the number of recycled test repeat: First manufacture, 1st Recycle, 2nd Recycle, and 3rd Recycle. To investigate the mechanical properties of the prepared specimen, tensile test, flexural test, drop-weight impact test, differential scanning calorimetry (DSC), and field emission electron gun-scanning electron microscope (FE-SEM) was performed. As a result, as the number of recycling steps repeat, the degree of crystallization, tensile strength, elastic modulus, and flexural strength were increased, but the impact properties were greatly reduced.

The Characteristics of Acoustic Emission Signal under Composite Destruction on GFRP Gas Cylinder (유리섬유강화 복합재료 가스실린더의 복합재료 파괴시 발생하는 음향방출 특성)

  • Jee, Hyun-Sup;Lee, Jong-O;Ju, No-Hoe;So, Cheal Ho;Lee, Jong-Kyu
    • Journal of the Korean Society for Nondestructive Testing
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    • 제33권5호
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    • pp.430-435
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    • 2013
  • This study is investigation of the characteristics for acoustic emission signal generated by destruction on glass fiber bundles and specimen that was machined composite materials surrounding the outside of GFRP cylinder. The Amplitude of acoustic emission signal gets bigger as the cutting angle of knife increases. Accordingly, the number of hits in destruction of composite materials specimen have more in longitudinal direction (longitudinal direction to the glass fiber) than in hoop direction (horizontal direction to the glass fiber) while the amplitude of signals were bigger in hoop direction than longitudinal direction. It was found out that the amplitude of the glass fiber breakage is more than 40 dB and that the amplitude of signal for matrix crack was less than 40 dB because matrix crack signal was not observed when threshold value is 40 dB and matrix crack signal suddenly appered when threshold value is 32 dB. The slope of the amplitude is related to the acoustic emission source and the slope of the amplitude of the horizontal and vertical directions are 0.16 and 0.08. In particular, The slope of the amplitude of longitudinal direction breakage appear similar to the glass fiber breakage and therefore Acoustic emission source of longitudinal direction breakage is estimated the glass fiber breakage.

Electromagnetic-wave Shielding by Nano Particles-contained Glass Fiber Reinforced Composite Materials (나노입자 첨가 유리섬유강화 복합재료의 전자기파 차폐특성)

  • 정우균;안성훈;원명식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1331-1334
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    • 2004
  • The research on electromagnetic shielding has been advanced for military applications as well as for commercial products. Utilizing the reflective properties and absorptive properties of shielding material, the replied signal measured at the rear surface or at the signal source can be minimized. The shielding effect was obtained from materials having special absorptive properties or from structural characteristics such as stacking sequence. Recently researchers studied the electromagnetic properties of nano size particles. In this research {glass fiber}/{epoxy}/{nano particle} composites(GFR-Nano composites), was fabricated using various nano particles, and their properties in electromagnetic shielding were compared. For the visual observation of the nano composite materials, SEM(Scanning Electron Microscope) and TEM(Transmission Electron Microscope) were used. For the measurement of electromagnetic shielding, HP8719ES S-parameter Vector Network Analyser System was used on the frequency range of 8 GHz~12GHz. Among the nano particles, carbon black and Multi-Walled Carbon Nano-Tube (MWCNT) revealed outstanding electromagnetic shielding. Although silver nano particles (flake and powder) were expected to have effective electromagnetic shielding due to their excellent electric conductivities, test showed little shielding effect.

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