• Title/Summary/Keyword: thermoplastic fiber

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Linear viscoelastic behavior of acrylonitrile-butadiene-styrene(ABS) polymers in the melt: Interpretation of data with a linear viscoelastic model of matrix/core-shell modifier polymer blends

  • Park, Joong-Hwan;Ryu, Jong-Hoon;Kim, Sang-Yong
    • Korea-Australia Rheology Journal
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    • v.12 no.2
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    • pp.135-141
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    • 2000
  • The linear viscoelastic behavior of acrylonitrile-butadiene-styrene (ABS) polymers with different rubber content has been investigated in the frame of a linear viscoelastic model, which takes into account the inter-connectivity of the dispersed rubber particles. The model developed in our previous work has been shown to properly predict the low frequency plateau for the storage modulus, which is generally observed in polymer blends containing core-shell-type impact modifiers. In the present study, further experiments have been carried out on ABS polymers with different rubber content to verify the validity of our linear viscoelastic model. It has been found that our model describes quite properly the rheological behavior of ABS polymers with different rubber content, especially at low frequencies. The experimental data confirm that our model describes the rheological properties of rubber-modified thermoplastic polymers with strong adhesion at the particle/matrix interface more accurately than the Palierne model.

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Mechanical Properties of GMT-Sheet on Press joined Molding (프레스 접합성형 GMT-Sheet의 기계적 성질)

  • Kim, H.;Choi, Y.S.;Lee, C.H;Han, G.Y.;Lee, D.G
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.04a
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    • pp.157-163
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    • 2000
  • The application as the parts of an automobile, using the property of GMT-Sheet, is increasing. In order to exchange the parts of an automobile for GMT-Sheet, at first, the establishment and joining problem of exact joining strength must be determined. We have studied it using composites which is not same each other fiber oriented condition so as to determine joining strength and joining condition of GMT-Sheet. In this study, the result of experiment of forming condition concerned joining problem of GMT-Sheet is this ; joining efficiency of GMT-Sheet, increases as lap joint length L increases. Increase of compression ration cause decrease of joining efficiency after of GMT-Sheet, joining. In the viewpoint of recycling, randomly oriented composite of GMT-Sheet is desirable more than unidirectional oriented composite. We have better design the structure so as not occur to stress centralization on the joining part.

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A Study on Formation of Conductive Pattern on Polymer Using LDS (LDS를 이용한 폴리머상의 전도성 패턴 형성 연구)

  • Paik, Byoung-Man;Lee, Jae-Hoon;Shin, Dong-Sig;Lee, Kun-Sang
    • Laser Solutions
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    • v.12 no.4
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    • pp.6-11
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    • 2009
  • The LDS(Laser Direct Structuring) process uses thermoplastic polymers with a additive compound that serves as plating seed after the activation by laser. It can realize industry requirement such as miniaturization of electrical component, design flexibility and reduction of production steps. The purpose of this study is to introduce LDS, and to investigate the fundamental mechanism. Also the characteristics of conductive patterns were investigated with respect to laser fluence and intensity. We have used a pulsed fiber laser (wavelength : 1064nm) and copper electroless plating to fabricate conductive patterns. The result showed that laser induced metal-organic complex was caused metalization by electroless copper plating, the critical laser fluence was $1.41\;J/cm^2$ at a scan speed of 1 m/s.

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Carbon Composite Material Using Nickel Nano-Powder Impregnation Research on Electromagnetic Shielding Effect (니켈나노파우더 함침기법을 이용한 탄소복합소재의 전자파차폐 효과에 관한 연구)

  • Seo, Kwang-Su;Kwac, Lee-Ku
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.12
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    • pp.49-55
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    • 2020
  • In order to improve the electromagnetic shielding rate of Carbon Fiber (CF), it was produced using the nickel nano-powder impregnating method. Using two types of nickel powder having thicknesses of 50 ㎛ and 100 ㎛, and a thermoplastic elastomer resin, a compound containing 10-20% nickel content was mixed and then manufactured through an extruder. The CF coated with the compound was woven and manufactured using a 1-ply specimen. The final nickel content of the specimen was verified using TGA and the distribution of nickel powder on the CF surface was verified using SEM. The metal shows a high shielding rate in the low-frequency band, but the shielding rate decreases at higher-frequency bands. The CF improves at the higher frequency band, and metals reflect electromagnetic waves while carbon absorbs electromagnetic waves. The study of shielding materials, which are stronger and lighter than metal, by using CF lighter than metal and enabling the shielding rate from low-frequency band to high-frequency band, confirmed that the larger the area coated with nickel nano-powder, the better the electromagnetic shielding performance. In particular, CF coated with a thickness of 100 ㎛ has a shielding rate similar to that of copper and can also be used for EV/HEV automotive cables and other applications in the future.

The Recovery of Carbon Fiber from Carbon Fiber Reinforced Epoxy Composites Applied to Railway Vehicles (철도차량용 폐 복합소재로부터 탄소섬유 회수)

  • Lee, Suk-Ho;Kim, Jung-Seok;Lee, Cheul-Kyu;Kim, Yong-Ki;Ju, Chang-Sik
    • Journal of the Korean Society for Railway
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    • v.12 no.6
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    • pp.1059-1066
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    • 2009
  • Recently, the amount of thermosetting plastic wastes has increased with the production of reinforced plastic composites and causes serious environmental problems. The epoxy resins, one of the versatile thermosetting plastics with excellent properties, cannot be melted down and remolded as what is done in the thermoplastic industry. In this research, a series of experiments that decompose epoxy resin and recover carbon fibers from carbon fiber reinforced epoxy composites applied to railway vehicles was performed. We experimentally examined various decomposition processes and compared their decomposition efficiencies and mechanical property of recovered carbon fibers. For the prevention of tangle of recovered carbon fibers, each composites specimen was fixed with a Teflon supporter and no mechanical mixing was applied. Decomposition products were analyzed by scanning electron microscope (SEM), gas chromatography mass spectrometer (GC-MS), and universal testing machine (UTM). Carbon fibers could be completely recovered from decomposition process using nitric acid aqueous solution, liquid-phase thermal cracking and pyrolysis. The tensile strength losses of the recovered carbon fibers were less than 4%.

Property improvement of natural fiber-reinforced green composites by water treatment

  • Cho, Dong-Hwan;Seo, Jeong-Min;Lee, Hyun-Seok;Cho, Chae-Wook;Han, Seong-Ok;Park, Won-Ho
    • Advanced Composite Materials
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    • v.16 no.4
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    • pp.299-314
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    • 2007
  • In the present study, natural fibers (jute, kenaf and henequen) reinforced thermoplastic (poly(lactic acid) and polypropylene) and thermosetting (unsaturated polyester) matrix composites were well fabricated by a compression molding technique using all chopped natural fibers of about 10 mm long, respectively. Prior to green composite fabrication, natural fiber bundles were surface-treated with tap water by static soaking and dynamic ultrasonication methods, respectively. The interfacial shear strength, flexural properties, and dynamic mechanical properties of each green composite system were investigated by means of single fiber microbonding test, 3-point flexural test, and dynamic mechanical analysis, respectively. The result indicated that the properties of the polymeric resins were significantly improved by incorporating the natural fibers into the resin matrix and also the properties of untreated green composites were further improved by the water treatment done to the natural fibers used. Also, the property improvement of natural fiber-reinforced green composites strongly depended on the treatment method. The interfacial and mechanical results agreed with each other.

Synchrotron SAXS Study on the Micro-Phase Separation Kinetics of Segmented Block Copolymer

  • Lee, Han-Sup;Yoo, So-Ra;Seo, Seung-Won
    • Fibers and Polymers
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    • v.2 no.2
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    • pp.98-107
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    • 2001
  • The phase transition behavior isothermal micro-phase separation kinetics of polyester-based thermoplastic elastomer were studied using the synchrotron X-ray scattering(SAXS) method. The structural changes occurring during heating period were investigated by determining the changes of the one-dimensional correlation function, interfacial thickness and Porod constant. Based on the abrupt increases of the domain spacing and interfacial thickness, a major structural change occurring well below the melting transition temperature is suggested. Those changes are explained in terms of melting of the thermodynamically unstable hard domains or/and the interdiffusion of the hard and soft segments in the interfacial regions. SAXS profile changes during the micro-phase separation process were also clearly observed at various temperatures and the separation rate was found to be sensitively affected by the temperature. The peak position of maximum scattering intensity stayed constant during the entire course of the phase separation process. The scattering data during the isothermal phase separation process was interpreted with the Cahn-Hilliard diffusion equation. The experimental data obtained during the early stage of the phase separation seems to satisfy the Cahn-Hilliard spinodal mechanism. The transition temperature obtained from the extrapolation of the diffusion coefficient to zero value turned out to be about 147$\pm$$2^{\circ}$, which is close to the order-disorder transition temperature obtained from the Porod analysis. The transition temperature was also estimated from the inveriant growth rate. By extrapolating the inveriant growth rate to zero, a transition temperature of about 145$\pm$$\pm$$2^{\circ}$ was obtained.

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Impact of nanocomposite material to counter injury in physical sport in the tennis racket

  • Hao Jin;Bo Zhang;Xiaojing Duan
    • Advances in nano research
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    • v.14 no.5
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    • pp.435-442
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    • 2023
  • Sports activities, including playing tennis, are popular with many people. As this industry has become more professionalized, investors and those involved in sports are sure to pay attention to any tool that improves athletes' performance Tennis requires perfect coordination between hands, eyes, and the whole body. Consequently, to perform long-term sports, athletes must have enough muscle strength, flexibility, and endurance. Tennis rackets with new frames were manufactured because tennis players' performance depends on their rackets. These rackets are distinguished by their lighter weight. Composite rackets are available in many types, most of which are made from the latest composite materials. During physical exercise with a tennis racket, nanocomposite materials have a significant effect on reducing injuries. Materials as strong as graphite and thermoplastic can be used to produce these composites that include both fiber and filament. Polyamide is a thermoplastic typically used in composites as a matrix. In today's manufacturing process, materials are made more flexible, structurally more vital, and lighter. This paper discusses the production, testing, and structural analysis of a new polyamide/Multi-walled carbon nanotube nanocomposite. This polyamide can be a suitable substitute for other composite materials in the tennis racket frame. By compression polymerization, polyamide was synthesized. The functionalization of Multi-walled carbon nanotube (MWCNT) was achieved using sulfuric acid and nitric acid, followed by ultrasonic preparation of nanocomposite materials with weight percentages of 5, 10, and 15. Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) confirmed a synthesized nanocomposite structure. Nanocomposites were tested for thermal resistance using the simultaneous thermal analysis (DTA-TG) method. scanning electron microscopy (SEM) analysis was used to determine pores' size, structure, and surface area. An X-ray diffraction analysis (XRD) analysis was used to determine their amorphous nature.

Development of Thermoplastic Carbon Composite Hybrid Bipolar Plate for Vanadium Redox Flow Batteries (VRFB) (바나듐 레독스 흐름전지용 열가소성 탄소 복합재료 하이브리드 분리판 개발)

  • Jun Woo Lim
    • Composites Research
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    • v.36 no.6
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    • pp.422-428
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    • 2023
  • The electrical contact resistance between the bipolar plate (BP) and the carbon felt electrode (CFE), which are in contact by the stack clamping pressure, has a great impact on the stack efficiency because of the relatively low clamping pressure of the vanadium redox flow battery (VRFB) stack. In this study, a polyethylene (PE) composite-CFE hybrid bipolar plate structure is developed through a local heat welding process to reduce such contact resistance and improve cell performance. The PE matrix of the carbon fiber composite BP is locally melted to create a direct contact structure between the carbon fibers of CFE and the carbon fibers of BP, thereby reducing the electrical contact resistance. Area specific resistance (ASR) and gas permeability are measured to evaluate the performance of the PE composite-CFE hybrid bipolar plate. In addition, an acid aging test is performed to measure stack reliability. Finally, a VFRB unit cell charge/discharge test is performed to compare and analyze the performance of the developed PE composite-CFE hybrid BP and the conventional BP.

Thermoforming Technology of Textile Composite Tubes

  • OZAKI Jun-ichi;MANABE Ken-ichi
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.04a
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    • pp.63-66
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    • 2003
  • Thermoforming of fiber reinforced thermoplastic (FRTP) braided tubes was studied as a new forming technique. FRTP braided tubes with four plies are fabricated by the pressure bonding method are used in thermoforming. Bulge forming, bending process, pipe fittings and FE analysis are carried out in this study. In bulge forming the composite tube can be expanded up to about two times initial diameter. The suggested bending process can be obtained bent products with various bending radii. In pipe fitting it is possible to fabricate T-shape fitting, cross fitting and two-branch fitting. These results exhibit developed forming processes become useful processes for textile composite tubes.

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