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Polyamide fibres, characteristics

A study was carried out to prepare antibacterial polyamide fibres by the modification of standard monofilament yam with nitrofuiylo, to examine the liberation of biocides into water and to verify the antibacterial effects of the modified fibres by in vitro testing using Gram-positive and Gram-negative bacterial strains characteristic of hospital conditions. 22 refs. [Pg.93]

Inherently FR polyamide fibres. Nylon or polyamide 6.6 has a higher melting point and superior tensile properties to polyamide 6 and so has the better characteristics to offer technical textiles. However, and in spite of the considerable research over the last 40 years, at the present time only one flame retardant polyamide 6.6 appears to available, which is Nexylon FR, EMS-GRILTECH of unknown composition, announced in September 2012. This fusible fibre is currently being aimed at the protective clothing and workwear markets but such applications will require flame retardancy as their primary property rather than heat protection. [Pg.253]

A characteristic feature of acid dyes for protein and polyamide fibres is the presence of one or more sulfonate (-SO3 ) groups, usually present as the sodium (Na ) salt. These groups have a dual role. Firstly, they provide solubility in water, the medium from which the dyes are applied to the fibre. Secondly, they ensure that the dyes carry a negative charge [i.e., they are anionic). When acid conditions are used in the dyeing process, the protein molecules acquire a positive charge. This is due mainly to the fact that, under acidic conditions. [Pg.173]

Figure 6.8 plots the reinforcement ratios for short glass fibre reinforced polyamide (PA-GF) versus neat polyamide for six important characteristics calculated versus density and material cost. These characteristics are tensile strength, tensile and flexural modulus, impact strength, HDT A and B. [Pg.788]

The use of glass fibre reinforced polyamide or BMC for engine covers the two techniques are industrialized. One is predominant in the USA, the other in Europe and Japan. The main characteristics are roughly similar, as shown in Table 7.3. [Pg.842]

The hollow fibre is the most crucial part of the microdialysis probe. It acts as a membrane, and its characteristics affect performance in the sampling step as well as the probe s suitability for the selected application. Hollow fibres are commercially available in different materials, the most common being polycarbonate (PC), regenerated cellulose (Cuprophan, CU), cellulose acetate (CA), polyacrylonitrile (PAN), polyethersulphone (PES), polysulphone (PE), and polyamide (PA). Generally, the fibres have an outer diameter between 200... [Pg.225]

Commonly used natural fibres are cotton and silk, but also included are the regenerated cellulosic fibres (viscose rayon) these are widely used in non-implantable materials and healthcare/hygiene products. A wide variety of products and specific applications utilise the unique characteristics that synthetic fibres exhibit. Commonly used synthetic materials include polyester, polyamide, polytetrafluoroethylene (PTFE), polypropylene, carbon, glass, and so on. [Pg.136]

Each fabric has its own particular characteristic vtiiich can be used to advantage in the filtration process. Thus the smooth-surfaced mono- and multifilament (high-twist) cloths are particularly suited to the liquid environment, in the separation of sticky, clogging substances such as sludges or colloids. Retention of such small material depends on a rapidly formed surfece layer of particulates in the reported use of monofilament polyamides for effluent treatment plants [Grove Daveloose, 1982]. Apparently in this application, change firom q>un fibre to woven cloth increased the cloth lifetime from 3 months to 2.5 years The adhesive nature of such solids may be modified by treatment with polyelectrolytes. Quite opposite results can also be experienced, however, where the three-dimensional capture characteristics of staple fibre material is the best option. [Pg.128]

Polyamide monofilament sutures show smooth surhices wifti a circular cross-section before implantation (see Fig. lb). No fibrous tissue cqisule was observed on the suture surface or around the knot post implantation. This is contributed to its smooth surface characteristic. However a closer examination of the opened knot shows flattening of the knot region (see Fig. 7). This is attributed to the ductile structure of polyamide sutures. It shows permanent deformation due to lateral forces exerted during loading. The rupture of the melt-spun synthetic fibres like polyamide is dominated by yield. Plastic yield of material causes the crack to open into a V-notch, vduch propagates steadily into the specimeiL This typical ductile fixture was seen at the broken ends, alter tmisile tests, both before and er implantation (see Fig. 8). [Pg.435]

Polymer Blends.—In addition to the work on polyester—polyamide blends reported in Section 2, several other papers describe the characteristics of various polymer formulations with polyamides. Biconstituent fibres have been formed from nylon-6 and poly(ethylene terephthalate). The same polyamide and nylon-12 have been blended with acrylonitrile-butadiene-styrene copolymer and the temperature and the concentration dependence of the dynamic modulus evaluated. The rheological properties of acrylonitrile-styrene copolymer/nylon-6 mixture have also been reported. Fourier transform infrared studies of nylon-6 and PVC have indicated the presence of specific interactions between the two polymers in both the molten and solid states. Finally X-r y studies carried out on injection-moulded blends of nylon-6, -12, and -66, have revealed that the addition of small amounts of the second component initiates formation of the y-crystalline phase within the nylon-6 polymer matrix. ... [Pg.65]

Several workers have proposed new combinations of materials in an attempt to overcome wear. Studies involving polyimides, polyamide-imides, and poly-tetrafluoroethylene-filled polyoxymethylene demonstrated that although wear characteristics were good in dry conditions, the presence of lubricants (blood plasma, water) decreased the wear resistance. Results obtained with reinforcing materials such as carbon fibre and with an aluminium oxide ceramic ball used in conjunction with a polyethylene socket have been presented, Examples of other types of reconstructive surgery involving hard tissue replacement are the use of poly(methyl methacrylate) in chest wall reconstruction and repair of depressed skull fractures, the repair of major crano-orbital defects with the aid of a polyurethane-coated poly(ethylene terephthalate) mesh, and the use of silicone rubber in total finger joint and carpal bone replacement. [Pg.420]

Polyamide 66 is manufactured by polymerisation of the nylon salt monomer in solution. Different grades of polymer can be produced, with characteristics which depend on the further processing required downstream (spiiming, compounding, etc.), and on the specific application of the end-product, within the product groups in which polyamide 66 is involved (textiles, carpets, industrial fibres, engineering resins, etc.). [Pg.142]

Hermann Staudinger, there has been an increasing development of these materials for numerous apphcations, including textiles. Polyamide 6.6 fibre (nylon), developed by Du Pont de Nemours in 1938, was a revolution in clothing and mihtary uses. This fibre, the functional characteristics of which are rather close to silk, has exceptional tenacity, flexibihty and lightness. With the progress of macromolecular chemistry at that time, it was the first of a long series of diverse synthetic fibres. [Pg.32]


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See also in sourсe #XX -- [ Pg.140 ]




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