Cables dielectric properties

Another example is the influence of the electrical resistance of PVC cable insulation. This is caused not by the organic pigment itself but by ethoxylated surfactants, which are added as auxiliaries in the manufacture of these pigments, especially azo pigments. Contrary to a repeatedly expressed view, a possible electrolyte content, which laked azo pigments for example can have, has no effect on the dielectric properties of PVC [34]. Some pigment manufacturers offer special product ranges with verified dielectric properties for this purpose. 

P.Y.17 may be used for mass coloration and also to print PVC film. For these purposes, P.Y.17 is frequently prepared on a VC/VAc (vinyl chloride/vinyl acetate) mixed polymer basis. Good dispersibility in plastics makes these preparations suitable even for thin films. The dielectrical properties of P.Y.17 allow its application in PVC cable insulations. 

P.R.41 is also known as pyrazolone red. It has lost most of its commercial importance in recent years. P.R.41 production is now limited to the USA, where it is mostly employed to lend color to rubber. To a lesser extent, P.R.41 is found in PVC excellent dielectrical properties make it a suitable candidate for PVC cable insulations. The pigment provides a medium to bluish red of limited brilliance, it is much bluer than P.R.38. P.R.41 is somewhat less fast than P.R.38, which is also true for its stability to a variety of organic solvents. However, it parallels P.R.38 in its alkali and acid resistance. P.R.41 is very lightfast in rubber 1% pigment concentrations equal step 6-7 on the Blue Scale, which meets practically any require-... 

P.R.lll is chemically related to the pyrazolone pigments P.O.34 and P.R.37. Its hue is somewhat bluer than that of its pyrazolone counterparts it equals that of Signal Red (RAL 3000). The lightfastness of P.R.lll is somewhere between that of P.O.34 and of P.R.37. P.R.lll performs similarly as far as other fastness properties are concerned. The pigment lends itself particularly to the coloration of rubber and PVC excellent dielectrical properties also render it suitable for cable insulations. Thermally, P.R.lll is not sufficiently stable to be used in polyolefins, styrene, ABS, and similar plastics. 

P.R.48 4 does not bloom in plasticized PVC and is almost completely fast to bleeding. Its tinctorial strength in this medium is equally good. Desirable dielectric properties make P.R.48 4 a suitable candidate for use in PVC cable insulations. The pigment is also used for mass colored secondary acetate threads, fibers, and films wherever it meets the requirements for application. 

P.R.57 1 is employed in cable insulations because of its good dielectrical properties. It is much more lightfast in rigid PVC transparent colorations (0.1% pigment) equal step 6 on the Blue Scale, while white reductions with TiOz match between step 4 and step 2, depending on the standard depth of shade and on the TiOz content. 

Good dielectrical properties make it a suitable candidate for PVC cable insulations. 

Among the polyesters that are used for PVC, the copolymers of butadiene with ethyl fumarates and ethyl acrylates deserve mention. They have been produced by Badische Anilin-und Sodafabrik (BASF) under the commercial name Palamoll. Palamoll I consists of 75% diethyl fumarate and 25% butadiene Palamoll II contains equal parts of butadiene and ethyl acrylate. In combination with the same amount of liquid plasticizers (such as DOP), films with cold resistance down to — 60°C. can be produced. These products are especially important for cable insulation because of their good dielectric properties. The Palamoll products are produced by emulsion polymerization and can be directly combined with emulsions of PVC. 

Watanabe, T., Watanabe, R., Kondou, T., and Ogasawara, T., Dielectric properties of flame retardants insulation material in the GHz frequency range, in Proceedings of the 53rd IWCS/Focus International Wire Cable Symposium, Philadelphia, PA, 2004, pp. 88-92. 

CSPE have excellent combinations of properties that include total resistance to ozone excellent resistance to abrasion, weather resistance even in light colors, heat, flame, oxidizing chemical, solvents, crack growth, and dielectric properties. Also provide low moisture absorption, resistance to oil similar to neoprene, low temperature flexibility is fair at -40C (-40F), low gas permeability for an elastomer and good adhesion to substrates. Can be made into a wide range of colors. Use includes hoses, roll covers, tank liners, wire and cable covers, footware, and building products (flash, sealing, etc.). 

Electro-insulation materials. The retention of dielectric properties in a high-temperature environment, coupled with good corrosion resistance in contact with certain reactive chemicals, suggests excellent possibilities of polybenzimidazole use in electrical insulation and other dielectric applications at high operating temperatures and/or in aggressive chemical environments. Typical applications, hence, can be foimd in special cable and wire insulation, in the manufacture of circuit boards and radomes for supersonic aircraft, as battery and electrolytic cell separators, and as fuel cell frame structural materials. Some recent publications in the patent and technical report literature may serve to illustrate such applications. 

Polyethylene has become one of the most widely used materials for electrical insulation due to its excellent dielectric properties and low cost. Original estimates of its probable lifetime using Arrhenius type extrapolation led to lifetime predictions of the order of forty years or more and yet a substantial number of failures in transmission and distribution cables have been observed at times under ten years. For 1977 failures on HMW URD cable totalled 1697 a failure rate of 3,08 per 100 miles while XLP cables were 0.53 per 100 miles and increasing (5). This work was undertaken to find out the role played by the polymer molecule under separate thermal and electrical stress. 

Electrical properties of fluoropolymers are highly valuable in electronic and electrical applications. In data communications, for example, FEP is used to insulate cables installed in air-handling spaces (plenums) in office buildings. FEP provides the excellent dielectric properties these cables require to perform well at high data-transmission rates as well as... 

The determination of clustered water and water molecule clusters trapped in polyethylene have been described by Baker (209). This water has been related lo a loss in the dielectric properties of polyethylene used in a submarine cable core. When DSC is employed, as shown by the curve in Figure... 

The influence of moisture on the dielectric properties of three experimental resin casting systems and an epoxy based laminate is investigated in this chapter to see if the mechanisms described above, can be recognised. Besides, the resistivity of an epoxy based tank coating and that of plasticised PVC cable insulation material in contact with water is described. 

Fluoriuated Ethylene Propylene Copolymer Thermoplastic copolymer of tetrafluoroethylene and hexafiuoro-propylene. Has deereased tensile strength and wear and creep resistanee, but good weatherability, dielectric properties, fire and ehemical resistance, and friction. Decomposes above 204°C (400°F), releasing toxic products. Processed by molding, extrusion, and powder coating. Used in chemieal apparatus liners, pipes, containers, bearings, films, eoatings, and cables. Also called FEP. 

Low Density Polyethylene A branched-chain thermoplastic with density 0.91-0.94 g/cm. Has good impact strength, flexibility, transparency, chemical resistance, dielectric properties, and low water permeability and brittleness temperature, but poor heat, stress cracking, fire resistance, and weatherability properties. Processed by extrusion coating, injection and blow-molding, and film extrusion. Can be cross-linked. Used in packaging and shrink films, toys, bottle caps, cable insulation, and coatings. Also called LDPE. 

Vinyl Thermoplastic Elastomers Vinyl resin alloys having good fire and aging resistance, flexibility, dielectric properties, and toughness. Processed by extrusion. Used in cable jackets and wire insulation. 

It has good dielectric properties, electrical resistivity and chemical resistance, and is particularly favoured in polymers for electrical cable insulation. Grades for wire and cable are normally first calcined, i.e., strongly heated to remove most of the surface hydroxyl groups. Between 450 and 700 °C kaolin is converted to metakaolin, and at temperatures around 1000 °C it imdergoes further changes to form defect spinel. 

Telecommimication cables establish a wired connection between users to allow data transmission and audiovisual commimication. The main characteristics required from the polymer insulation are a low dielectric constant and low dissipation factor. As the best dielectric properties are given by air, the dielectric losses can be reduced drastically by expanding the insulation (30-50% vol.% inert gas) this is called cellular insulation, as opposed to solid insulation. 

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