Metallic fibre fabrication

Textile reinforcement is not defined in an unambiguous way, but it is usually admitted that all non-metallic fibres, fabrics and mats are considered as such. The general classification of textile fibres is shown in Figure 5.8 and some of them are used for cement-based materials. Several kinds of textile fibres, short chopped or long continuous ones, are described in more detail in other chapters and only their common features are considered here. 

Catalyst-assisted CVD processes can also be used to fabricate delicate microcomponents. Coiled fibres of carbon and refractory carbides are examples of such components which may be used in functional applications such as microsprings, microsensors and fillers of electromagnetic shielding materials. The microstructure of some coiled fibres is shown in Figure 3.39a. The device for the production of coiled fibre fabrication is shown in Figure 3.39b. A graphite plate substrate is placed at the central part of a horizontal CVD reaction chamber, and a metal... 

The traditional TPS for launcher fairings and re-entry capsules consists of an external ablative insulation, fixed or bonded onto a metallic primary structure. Ablative materials are based on thermosets (phenolic and epoxy resins) or elastomers (ethylene-propylene and silicone rubbers) usually filled and reinforced with cork, cotton, glass, silica, quartz, carbon, silicon carbide, nylon and aramid in the form of powders, fibres, fabrics and felt (Table 2). 

Filtration can be used to distinguish between dissolved and dispersed components in a colloidal dispersion. Membrane filtration involves passing a suspension through a thin, porous membrane, which is usually polymer or ceramic in nature, but could also be woven fabric or metal fibres. Filtration is also a common method... 

Ziaja J., Koprowska J., Janukiewicz J., (2008a). Using of plasma metallization for fabrication of fabric screens against electromagnetic field, FIBRES TEXTILES in Eastern Europe 5, s. 70-72... 

A. R. Boccaccini, J. Ovenstone and P. A. Trasty, Fabrication of woven metal fibre reinforced glass matrix composites, Applied Composite Materials 4, 145-155 (1997). 

MEDIA STUCTURE Woven (mono-/multi-filament) Non-woven Cartridge Metal/solid fabrication Loose fibres/particles FILTRATION PROPERTIES Particle retention Flow resistanoe Dirt holding oapaoity Tendenoy to biind Cake discharge characteristics Cleanabiiity ... 

Work on metallic additives has been particularly to the fore in Japan. A process to produce very fine metal fibres has been developed at the Nippon Institute of Technology (NIT), Saitama, Japan, and has been commercialized in a joint venture with NV Bekaert, Belgium, under the name Bekinit KK. Described as coil shaving, it is faster and more versatile than traditional methods. Fibres of 20-100 pm in diameter can be produced from titanium, aluminium, nickel, copper, and stainless steel, which offer improved conductivity in plastics compounds. Filter media, heat-resistant fabrics, and motorcycle silencers are among other potential applications. 

A rather broad definition proposed by the ACI 549.2R-04 for ferrocement is A type of thin wall reinforced concrete constructed of hydraulic cement mortar reinforced with closely spaced layers of continuous and relatively small wire diameter mesh. The mesh may be made of metallic or other suitable materials. In this definition all kinds of non-metallic meshes are included, as well as fabrics and mats made with non-metallic fibres that are treated as textile reinforcement. 

Because different materials are joined in composites, there are a large number of possible combinations. Metal, ceramic, or polymer matrix composites can be strengthened with different kinds of particles or fibres. Composites may be classified either by the geometry of the strengthening particles (fibres, fabrics, etc.) or by the matrix material used. 

Various types of fibres could be used in making filter fabrics they include glass fibres, synthehc fibres, ceUulosic fibres (eg, natural wood pulp fibres, viscose fibres, and Lyo-ceU fibres), wool fibres, metal fibres, ceramic fibres, high-performance polymer fibres (eg, inherenfly fire-resistant fibres, chemical resistance fibres, high-strength, and high-modulus fibres), microfibers, and nanofibers. 

These materials are fabricated using conducting carbon black, graphite whiskers or metallic fibres as filler. 

Quite often, NBR adhesives are used to bond various kinds of gasketing (cork, fibre, foam, rubber, metal) to rigid superstructures, such as aircraft. Films cast from solution are often used to fabricate honeycomb structures for aircraft. 

Many other opportunities exist due to the enormous flexibility of the preparative method, and the ability to incorporate many different species. Very recently, a great deal of work has been published concerning methods of producing these materials with specific physical forms, such as spheres, discs and fibres. Such possibilities will pave the way to new application areas such as molecular wires, where the silica fibre acts as an insulator, and the inside of the pore is filled with a metal or indeed a conducting polymer, such that nanoscale wires and electronic devices can be fabricated. Initial work on the production of highly porous electrodes has already been successfully carried out, and the extension to uni-directional bundles of wires will no doubt soon follow. 

The current (2003) edition of PD 5500 covers vessels fabricated in carbon and alloy steels, and aluminium. The design of vessels constructed from reinforced plastics is covered by BS 4994. The ASME code covers steels, non-ferrous metals, and fibre-reinforced plastics. 

Each type of pressure leaf filter features a pressure vessel in which are located one or more filter elements or leaves of circular or rectangular construction. The filter media may be in the form of a synthetic fibre or other fabrics, or metallic mesh. Supports and intermediate drainage members are in coarse mesh with all components held together by edge binding. Leaf outlets are connected individually to an outlet manifold which passes through the wall of the pressure vessel. 

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