Textiles aramid fibres

The aramid fibres (Kevlar and Nomex are the trade names for two of the most common) are especially desirable for their strength-to-weight ratios being superior to metals. They are most often used in composites having polymer matrices (generally epoxies and polyesters). Since the fibres are relatively flexible and somewhat ductile, they may be processed by most common textile operations. 

There are two types of aramid (fully aromatic polyamide) fibre those with high thermal stability and flame resistant properties but mechanical properties similar to those of standard textile fibres such as polyester, sometimes referred to as meta-aramid fibres because the main commercial products are of this chemical structure the others with additionally exceptionally high tensile strength and modulus, sometimes referred to as para-aramid fibres on similar grounds. The former type is not widely used in composite structures, but some of the most important uses of the latter lie in this area. 

On an industrial scale, the SFE-FTIR couple has been successfully used to determine aramid, polyamide and polyurethane-based fibres, which require a different finish for textile processing [127], By using CO, at 350 atm, 75°C and a flow-rate of 1.2 ml/min, the polyurethane finish [poly(dimethylsiloxane) oil] was thoroughly extracted within the first 10 min by contrast, less than 35% of sorbitol derivatives present in the aramid finish could be separated after 20 min. The separation efficiency for polyamide finish components varied between 74 and 100%, with relative standard deviations for the most extractable finishes — which were recovered by more than 98% — ranging from 5.7 to 21%. 

Apart from the normally accepted textile products, heat and fire resistant textiles find use in engine insulation (e.g. ceramic stractures around combustion chambers), fuselage acoustic iusulatiou (e.g. glass fibre-based battiugs iu FR polymeric film containers), reinforcements for composites (e.g. carbon fibre reinforcements for major stmctural elanents), aramid honeycomb reinforcanent for wall and floor stractures. 

Many of the first electronic textiles used Indian metal silk organzas (Buechley, 2007). These organzas are made from silk wound with thin gold strips to form a heUx (Post, 1996), again in a method used by the ancients. Another approach is to add a metallized coating directly to a core yam. In the conunercial products, a number of base fibres are used. These range from cotton, silk, polyester and nylon to polybenzoxazole (PBO Zylon ), aromatic polyesters (Vectran ) and aramids (Kevlar ). 

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