Carbon Fiber Manufacturing and Applications as a Benchmark for Nanotube Superfiber Development

Comparative study of ultrasonic techniques for reconstructing the multilayer structure of composites

“…This also contributes to worse performance of the 50 MHz and the 15 MHz signals in the experiments. Another potential problem of using high-frequency ultrasound is that it could be sensitive to fiber tows inside the plies [67]. There is an obvious difficulty in reconstructing the positions of the interplies because the echoes from the fiber tows could be mistaken as the echoes from the interplies.…”

Impact of Spinning Conditions on the Structure and Tensile Properties of Mesophase Pitch Carbon Fibers

“…Figure 4. 6 Estimated extensional stress as a function of drawn down ratio from fiber extrusion measurements at different spinning temperatures. Figure 4.7 X-ray diffraction subtracted baseline gaussian fit for pitch filaments from 2, 9 and for central domain experiments.…”

“…This data has been reproduced from Holmes (5) and is presented in Table 1.1. Recent researches do not suggest a change in this trend (6). Coal tar had been produced as a by-product of metallurgic cokes.…”

“…For these reasons, the fiber spinning experiment is not a true rheometer, but gives an apparent uniaxial extensional viscosity of the material (54). Table 4.5 shows the averaged apparent extensional viscosity of the steady state process (calculated as equation [3][4][5][6][7][8][9][10][11] and total extension rate (as in equation [3][4][5][6][7][8][9][10][11][12]. Apparent extensional viscosities found on experiments ranged from 8.65 × 10 5 to 2.29 × 10 7 Pa.s.…”

“…(a) 327 • C, 331 • C and 337 • C (b) 343 • C and 347 • C Figure 4.3 Viscosity as a function of shear rate at 331, 337 and 343 • C.Figure 4.4 First normal stress difference as a function of shear rate at 331, 337 and 343 • C.Figure 4.5Extensional viscosity based on fiber spinning measurements. Figure4 6. Estimated extensional stress as a function of drawn down ratio from fiber extrusion measurements at different spinning temperatures.…”