Electromagnetic interference conductive fibers

Ethylene-vinyl acetate Fetterman [37] reinforced compounded ethylene-vinyl acetate (EVA) copolymer by using short hbers and found that silane coupling agents were effective at establishing improved hber-matrix adhesion. Das et al. [38] prepared carbon fiber-filled conductive composites based on EVA and studied the electromagnetic interference shielding effectiveness of the composites. 

FEL 06] Feller J.F., Roth S., Bourmaud A., Conductive polymer composites electrical, thermal, and rheological study of injected isotactic poly(propylene)/long stainless-steel fibers for electromagnetic interferences shielding . Journal of Applied Polymer Science, vol. 100, pp. 3280-3287,2006. 

The electrically conductive composites prepared by these methods are not sufficiently conductive for shielding of electromagnetic interference. Still more effective in producing conductive aramids is electroless plating. A high electrically conductive fiber is obtained. The fiber is impregnated with metal complexes using supercritical carbon dioxide. 

Antistatic additives are capable of modifying properties of plastics in such a way that they become antistatic, conductive, and/or improve electromagnetic interference shielding (EMI). Carbon fibers, conductive carbon powders, and other electrically conductive materials are used for this purpose. 

Electrical Conductivity. This quality is important to bleed off static charge and to avoid electromagnetic interference (EMI) (Sec. 5.9). It can be produced by adding carbon black, graphite, and especially metallic fillers (Table 5.23). This requires particle-to-particle contact, so flakes are more efficient than simple powders, and fibers are most efficient of all (Table 5.24). 

More recently, several novel conductive plastics have been introduced to provide shielding against electromagnetic interference (EMI). Filler and reinforcing materials contending for these applications include carbon fibers metallized mitrospheres aluminum fibers, flakes, and ribbon and aluminum-metallized glass fibers. 

EMS shields equipment that can produce electromagnetic interference (EMI) or that is affected by it (e.g., computers, television sets, telephones, etc.). Metal housings provide excellent shielding. However, conductive plastics offer lower part weight and greater facility of production. Very high conductivities have become achievable at low loading levels with some conductive metal fillers such as stainless steel fibers. 

Body temperature can be monitored by imbedding thermocouples or thermistors in conductive textile stmctures. Plastic optical fiber (POF) loops are temperature sensitive and used to detect body temperature in 0.3°C resolutions [19]. Optical sensors are immune to external electromagnetic interference and signal-to-noise ratio is very high compared with thermocouples and thermistors. The POF sensor is also easy to integrate into smart textile stmctures [20]. 

Thermoplastic Polymers. Thermoplastic polymers do not require a cure cycle but need only to be melted during processing (usually injection molding). The most common are nylon, polypropylene, and polyethylene which are usually molded with 10-25 vol.% discrete (chopped) carbon fibers. The addition of fibers substantially increases the modulus and, to a lesser degree, the strength. Electrical conductivity is also considerably increased and many applications of these composites are found in electromagnetic-interference (EMI) shielding. 

Carbon fibers are being considered for electromagnetic interference (EMI) shields. The fibers are sometimes coated with nickel by electroplating to increase the electrical conductivity, and molded in the form of sheets with a polymer such as polycarbonate.I ... 

Flakes and fibres are used as fillers in plastics to convert the inherent insulating polymeric material into electrically conductive composites. These composite materials have been studied and evaluated to create products to transmit electricity, to dissipate static charges built up by friction, or to provide electromagnetic interference (EMI) shielding. In this section, the focus is on recent developments in flake and fiber fillers that are used to provide EMI shielding for electronic devices that are found in homes, factories, offices, commercial establishments and transportation systems that ever increasingly rely on electronic broadcast systems for communications. 

Keywords aluminum, automotive applications, carbon, conducting fillers, copper, cost, electromagnetic interference (EMI), electronic devices, fibers, flakes, metal, nickel, polyethersulfone (PES), safety, health and environment, solder-like alloys. 

Initially, conductive fibers were mainly used in technical areas such as clean room garments, military apparel, medical application, and electronics manufacturing (Resistat, 2015). They can have a variety of functions, like antistatic apphcations (Sophitex, 2015), ElectroMagnetic Interference shielding (LessEMF, 2015), electronic apphcations, infrared absorption or protective clothing in explosive areas (Mcfarland etal., 1999). 

ETPs can be formulated to provide electromagnetic and radio frequency interference (EMI/RFI) attenuation in applications from electronics to material handling. The EMI/RFI shielding results from conductive fibers which form the conductive network. 

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