Woven carbon fibers

Other reinforcements that may be used in the substrate layers of decorative laminates and throughout the stmcture of industrial laminates are woven fabrics of glass or canvas and nonwoven fabrics of various polymeric monofilaments such as polyester, nylon, or carbon fibers. Woven and nonwoven fabrics tend to be much stronger than paper and have much more uniform strength throughout the x—y plane. They greatly enhance properties of laminates such as impact and tear strength. 

The compaction behavior of the preform differs a lot depending on the preforming method and the type of reinforcement that has been used. A typical compaction curve for a carbon-fiber-woven fabric is shown in Figure 12.4. The three curves correspond to... 

Heating elements can be anything that conducts current and can be heated through Joule heating. This includes nichrome wire, carbon fiber, woven graphite fabric, and stainless steel foil. Implant materials should be compatible with the epoxy adhesive and the intended application, since they will remain in the bond line for the life of the product. 

Adsorption of aniline on minerals, such as kaolinite, montmorillonite and vermiculite as well as on a-alumina and iron powders, has been studied in order to better understand the interaction of the adsorbate with natural adsorbents154-157. However, the results, similarly to those obtained on a smooth polycrystalline platinum electrode158, are not useful for the removal of aniline from waste water. The commonly used activated charcoal is also deficient owing to slow kinetics of the removal of dissolved pollutants. In this situation, activated carbon fibers, woven as a C-cloth, seem to be the ideal adsorbents for removal of aniline from waste streams. The reports of Niu and Conway159,160 explained the adsorptive and electrosorptive behavior of aniline on C-cloth electrodes and suggested a methodology for clean-up of industrial waste waters. 

As of mid-2008, spider silk birllet-proof vests and rtano-based armors are being developed for potential market release. Both the British and American militaries have erqrressed interest in a carbon fiber woven from carbon nanotubes that was... 

Eurocarbon BV, Sittard, Netherlands—manufacture carbon fiber woven tapes, fabrics and braided reinforcements. 

For nosetip materials 3-directional-reinforced (3D) carbon preforms are formed using small cell sizes for uniform ablation and small pore size. Figure 5 shows typical unit cell dimensions for two of the most common 3D nosetip materials. Carbon-carbon woven preforms have been made with a variety of cell dimensions for different appHcations (27—33). Fibers common to these composites include rayon, polyacrylonitrile, and pitch precursor carbon fibers. Strength of these fibers ranges from 1 to 5 GPa (145,000—725,000 psi) and modulus ranges from 300 to 800 GPa. 

Carbon-Carbon. Carbon-carbon composites consist of a carbon fiber substrate, either in the form of woven fabric or random felt, and a carbon matrix. The matrix is produced by the pyrolysis of a polymer,... 

Figure 9.2 Fiber and foam structures, (a) Knitted silica fibers catalyst. (Reprinted from [7].) (b) Woven active carbon fiber catalyst. (Reprinted from [8].) (c) Aluminum foam. (Reprinted from [9].)...

CNF is an industrially produced derivative of carbon formed by the decomposition and graphitization of rich organic carbon polymers (Fig. 14.3). The most common precursor is polyacrylonitrile (PAN), as it yields high tensile and compressive strength fibers that have high resistance to corrosion, creep and fatigue. For these reasons, the fibers are widely used in the automotive and aerospace industries [1], Carbon fiber is an important ingredient of carbon composite materials, which are used in fuel cell construction, particularly in gas-diffusion layers where the fibers are woven to form a type of carbon cloth. 

As discussed previously, a number of different materials have been considered as potential candidates to be used as diffusion layers in PEMFCs and direct liquid fuel cells (DLFCs). The two materials used the most so far in fuel cell research and products are carbon fiber papers and carbon cloths, also known as carbon woven fabrics. Both materials are made from carbon fibers. Although these materials have been quite popular for fuel cells, they have a number of drawbacks—particularly with respect to their design and model complexity—that have led to the study of other possible materials. The following sections discuss in detail the main materials that have been used as diffusion layers, providing an insight into how these materials are fabricated and how they affect fuel cell performance. 

Aumo, J., Oksanen, S., Mikkola, J. P., Salmi, T. and Murzin, D. Yu., Novel Woven Active Carbon Fiber Catalyst in the Hydrogenation of Citral, Cat Today 102-103 (2005), 128-132... 

Figure 12.4 Compaction behavior of a woven carbon fiber fabric. The solid curve shows the behavior at room temperature the other two lines show the behavior at 100 C and 110°C. The fabric was factory treated with an epoxy preform binder...

Engineering thermoplastics have also been used in preimpregnated constructions. The thermoplastic is thoroughly dispersed as a continuous phase in glass, other resins, carbon fibers (qv), or other reinforcement. Articles can be produced from these constructions using thermoforming techniques. For example, the aerospace industry uses polyetheretherketone (PEEK) in woven carbon-fiber tapes (26). Experimental uses of other composite constructions have been reported (27) (see also COMPOSITE MATERIALS, POLYMER-MATRIX). 

Carbon-fiber based porous materials, namely non-woven carbon paper and woven carbon cloth, shown in Fig. 5, have received wide acceptance as materials of choice for the PEFC GDL owing to high porosity ( 70% or higher) and good electrical/thermal conductivity. Mathias et al.32 provided a comprehensive overview of the GDL structure and functions. In this work, the reconstruction of non-woven carbon paper GDL is presented. 

Catalyst bodies can also be made of knitted threads or woven in fabrics, felts, etc. (5-7) (Figure 5). A wide variety of materials have been considered for such catalysfs, buf mosf affenfion has been given to glass, sintered metal, and carbon fibers. 

FIGURE 5 Fiber structures left, knitted silicon fibers catalyst (6) right, woven carbon fibers (7). 

Microstructure of non-woven mats of (a) glass and (b) carbon fibers. 

The orthogonal 3D woven laminate used in this work was elaborated and produced by the 3TEX Inc (USA). These laminates consist of unidirectional in-plane layers orientated in the 0 and 90° directions, The transverse reinforcing components are yarns orientated perpendicularly to the midplane, These yarns bind the material and hold the in-plane fibers together. This is achieved without interweaving the in-plane fibers, and hence the reduction in the in-plane stiffness caused by the fiber waviness is avoided. The amount of transverse yarns is about 3 percent of total fiber volume. The longitudinal modulus E of beams were 17.9 GPa and 56,3 GPa for glass and carbon fiber specimens respectively (measured in simple tension) The mechanical properties of the materials are described in detail in [5],... 

Defibrillation lead employing electrodes fabricated from woven carbon fibers 5..3,36,2.54 1994 Brennen. Williams. Gabler... 

Carbon fibers are commercially available us endless fiber-hanks with 1000 to 160 000 individual filaments. Carbon fibers are flexible and can be treated as textile fibers, due to the small fiber diameter of the individual fibers (ca. 8 pm). Therefore two-dimensional woven articles, knitted articles and felts are available in addition to yarn and thread. Staple fibers are formed by cutting or grinding endless fibers and are available in different lengths (0.5 to 50 mm). 

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