Prysmian Cavi E Sistemi Energia S.r.l.

Pirelli Cavi E Sistemi S.p.a.

Prysmian S.p.a.

Pirelli & C. S. P. A.

Sergio Belli

Alberto Bareggi

Luca Balconi

Paolo Veggetti

Gaia Dell'Anna

Gabriele Perego

Giovanni Pozzati

Cristiana Scelza

Gaia Dell'anna

Luigi Caimi

Marco Frigerio

Fabrizio Donazzi

Andrew Maunder

Luca Giorgio De Rai

Walter Castiglioni

Angelo Riella

Alberto Lumachi

Paolo Bossi

Franck O'Neil

Angelo Giuseppe Locatelli

Luca Castellani

Claudio Bosisio

Paolo Maioli

Diego Tirelli

Carlo Marin

Paul Cinquemani

Vincenzo Crisci

Valter Castiglioni

Paolo Marelli

Enrico Borghi

Cesare Bisleri

Gianbattista Grasselli

Ernesto Zaccone

Giuseppe Casanova

Pier Luigi Folcini

Gaia Dell′Anna

Alberto Bianchi

Dario Quaggia

Franck O'neill

A cable includes at least one electrical conductor and at least one electrically insulating layer surrounding the electrical conductor, wherein the at least one electrically insulating layer includes: (a) a thermoplastic polymer material selected from: at least one copolymer (i) of propylene with at least one olefin comonomer selected from ethylene and an V-olefin other than propylene, the copolymer having a melting point greater than or equal to 130&#xb0; C. and a melting enthalpy of from 20 J/g to 90 J/g; a blend of at least one copolymer (i) with at least one copolymer (ii) of ethylene with at least one V-olefin, the copolymer (ii) having a melting enthalpy of from 0 J/g to 70 J/g; a blend of at least one propylene homopolymer with at least one copolymer (i) or copolymer (ii); a blend of at least one propylene homopolymer with at least one copolymer (i) or copolymer (ii); (b) at least one nano-sized filler; wherein at least one of copolymer (i) and copolymer (ii) is a heterophasic copolymer.

Energy cable

A cable includes at least one electrical conductor and at least one electrically insulating layer surrounding the electrical conductor, wherein the at least one electrically insulating layer includes: (a) a thermoplastic polymer material selected from: at least one copolymer (i) of propylene with at least one olefin comonomer selected from ethylene and an a-olefin other than propylene, the copolymer having a melting point greater than or equal to 130&#xb0; C. and a melting enthalpy of 20 J/g to 90 J/g; a blend of at least one copolymer (i) with at least one copolymer (ii) of ethylene with at least one &#x3b1;-olefin, the copolymer (ii) having a melting enthalpy of 0 J/g to 70 J/g; a blend of at least one propylene homopolymer with at least one copolymer (i) or copolymer (ii); at least one of copolymer (i) and copolymer (ii) being a heterophasic copolymer; (b) at least one dielectric fluid intimately admixed with the thermoplastic polymer material; and (c) at least one water tree retardant selected from ethoxylated fatty acids and amide derivatives thereof.

Energy cable having stabilized dielectric resistance

An electric power cable contains a core and a jacket forming the exterior of the cable. The jacket is formed by extruding a first layer and a second layer over a plurality of concentric neutral elements, substantially encapsulating these elements. At least the first layer is an expanded polymeric material, by having its density reduced through the use of a foaming agent during extrusion. The second layer, which may also be expanded, is extruded around the first layer. The expanded polymeric material makes stripping the jacket easier, minimizes indentations in the cable's insulation layers, lightens the cable, and increases the cable's flexibility.

Cable having expanded, strippable jacket

Process for manufacturing a cable comprising the following steps:(a) conveying at least one conductor to an extruder apparatus;(b) extruding an insulating coating layer radially external to said at least one conductor; (c) longitudinally folding a metal tape around said extruded insulating coating layer, said metal tape bearing at least one adhesive coating layer in a radially external position; (e) extruding at least one continuous coating layer comprising at least one polyamide or a copolymer thereof around and in contact with said folded metal tape; wherein the step (e) is carried out at a draw down ratio (DDR) not higher than 2.5, preferably of from 1.2 to 2.0.

Process for manufacturing a cable resistant to external chemical agents

A process for manufacturing a self-extinguishing cable including at least one transmissive element and at least one flame-retardant coating in a position radially external to the at least one transmissive element, wherein the at least one coating includes an expanded flame-retardant polymeric material having (a) at least one expandable polymer; (b) at least one expanding agent; (c) at least one flame-retardant inorganic filler, in an amount of 100 parts by weight of 250 parts by weight with respect to 100 parts by weight of the at least one expandable polymer. The process includes the following steps: (i) feeding the flame-retardant polymeric material to an extruding apparatus, therein melting and mixing it; (ii) passing the flame-retardant polymeric material obtained in step (i) through at least one static mixer; and (iii) depositing by extrusion the flame-retardant polymeric material obtained in step (ii) onto the at least one transmissive element conveyed to the extruding apparatus.

Process for manufacturing a self-extinguishable cable

A method for manufacturing a cable, the cable including at least one transmissive element and at least one coating layer made of a polymeric material and arranged at a radially outer position with respect to the transmissive element. The method includes the steps of: a) feeding the polymeric material to an extrusion apparatus including an extrusion head, the extrusion head including a male die; a female die coaxially arranged with respect to the male die; a conveying channel, at least one portion of which is defined between the male die and the female die; and b) controlling a cross-sectional area of the at least one portion of the conveying channel in response to a detected quantity, the quantity being caused to vary during the manufacturing of the cable as a function of the actual extrusion speed. An extrusion apparatus for carrying out the process.

Cable manufacturing process

An energy cable includes at least one electrical conductor and at least one extruded coating layer including a thermoplastic polymer material in admixture with a dielectric fluid, wherein the dielectric fluid includes a compound of formula (I): X-A-X'; where A is a monocyclic aromatic moiety or an at least partially aromatic condensed polycyclic moiety; and at least one of X and X&#x2032; is methyl or an aliphatic moiety, in both cases optionally substituted with and/or interrupted by one or more of keto, alkoxy, alkylthio, mercapto, hydroxyalkyl, hydroxyl; the other being hydrogen; the compound having a ratio of number of aromatic carbon atoms to total number of carbon atoms greater than or equal to 0.6.

A cable for transporting or distributing electric energy, especially medium or high voltage electric energy, includes at least one electrical conductor, at least one electrically insulating layer surrounding the electrical conductor, and at least one sheath surrounding the electrically insulating layer, wherein the sheath includes 65% to 95% by weight of at least one thermoplastic ethylene polymer; 5% to 35% by weight of at least one plasticizing agent, the percentages being expressed with respect to the total weight of the sheath. The above sheath guarantees improved flexibility without impairing mechanical properties and particularly thermopressure resistance, which is essential to preserve shape and integrity of the screen layer during cable installation and use at high operating temperatures.

An extrusion method and head for depositing by extrusion a polymeric material intended, in particular, for the production of cables includes a core and a coating layer arranged at a radially outer position with respect of the core. The method includes the steps of feeding the polymeric material in a feeding duct of the extrusion head and of conveying a part of the polymeric material towards an undercut extending in the extrusion head in proximity of an end of the feeding duct. The method provides a sealing force between a head body and a conveyor element of the extrusion head exerted by means of the pushing action exerted by the polymeric material in the undercut in a direction substantially perpendicular to the longitudinal axis of the head body.

Method and extrusion head for extruding a polymeric material

A cable includes at least one electrical conductor and at least one extruded covering layer including a thermoplastic polymer material in admixture with a dielectric liquid, wherein the thermoplastic polymer material includes (a) at least 75% by weight, with respect to the total weight of the thermoplastic polymer material, of at least one copolymer of at least two &#x3b1;-olefin co-monomers, the copolymer having a melting enthalpy lower than 25 J/g; and (b) an amount equal to or less than 25% by weight with respect to the total weight of the thermoplastic polymer material of at least one propylene homopolymer or propylene copolymer with at least one &#x3b1;-olefin, the at least one propylene homopolymer or propylene copolymer having a melting enthalpy higher than 25 J/g and a melting point higher than 130&#xb0; C. The covering layer has a melting enthalpy equal to or lower than 40 J/g, and the concentration by weight of the dielectric liquid in the thermoplastic polymer material is lower than the saturation concentration of the dielectric liquid in the thermoplastic polymer material.

Energy cable comprising a dielectric fluid and a mixture of thermoplastic polymers

A process for manufacturing a multipolar cable having at least one pair of cores, each core having at least one conductive element and at least one layer of electrical insulation in a position which is radially external to the at least one conductive element. The process includes the steps of: a) assembling the at least one pair of cores so as to form an assembled element having a plurality of interstitial zones between the cores, and b) depositing by co-extrusion an expandable polymeric material in a position which is radially external to the cores so as to fill the interstitial zone and to form a filling layer of substantially circular transverse cross section, and at least one containment layer of polymeric material in a position radially external to the filling layer. The multipolar cable obtained from the process.

Process for the production of a multipolar cable, and multipolar cable produced therefrom

A process for manufacturing a cable which includes a conductor; an inner semiconductive layer surrounding the conductor and having a thickness lower than or equal to 0.4 mm; and an insulating layer surrounding the inner semiconductive layer. The process includes the step of co-extruding the inner semiconductive layer and the insulating layer and includes: a) providing a first annular flow of inner semiconductive material and a second annular flow of insulating material; b) contacting the outer surface of the first annular flow and the inner surface of the second annular flow at an axial distance from the contacting point where the inner surface of the first annular flow contacts the conductor; c) selecting in combination the predetermined feeding speed and the contacting point as a function of the dynamic viscosity of the inner semiconductive material and of the insulating material, so that a ratio between the shear stress of the inner semiconductive layer at the radially inner wall of the extrusion die and the shear stress of the insulating layer at the radially outer wall of the extrusion die, in proximity of the contacting point, is about 0.5 to 4; and d) compression extruding the insulating layer and the inner semiconductive layer onto the conductor.

A method and plant for the introduction of a liquid into a molten mass under pressure. Such a method and plant are particularly, but not exclusively, suitable for the formation of a coating layer on a cable element having at least one conductor, the layer having an extruded thermoplastic polymer forming a continuous phase incorporating a dielectric liquid, and are useful, for example, in the production of an electric cable for the transportation and/or distribution of electrical power. The method includes the steps of bringing the liquid to a predetermined pressure greater than the pressure of the molten mass; feeding the liquid into a plurality of storage tanks, and injecting the liquid into the molten mass at an injection pressure equal to the above-mentioned predetermined pressure by means of a plurality of injectors in respective fluid communication with the plurality of storage tanks. Advantageously, this allows a substantial continuity of delivery of the liquid in a technologically simple way and at low cost, while ensuring a dispersion as uniform as possible of the liquid within the molten mass.

Method and plant for the introduction of a liquid into a molten mass under pressure

A method for producing a cable including at least one transmissive element, for example, an element transmitting electrical energy or optionally optical signals as well, and an expanded and cross-linked coating layer in a radially outer position with respect to the at least one transmissive element, the coating layer having a composition including an expandable and cross-linkable polymeric material. The method includes a) extruding the composition; b) forming a coating layer made of expandable and cross-linkable polymeric material with the composition thus extruded; c) expanding the coating layer made of expandable and cross-linkable polymeric material; and d) cross-linking the coating layer made of expandable and cross-linkable polymeric material. The expanding and cross-linking steps c) and d) are carried out by heating the coating layer made of expandable and cross-linkable polymeric material at atmospheric pressure by means of a suitable heating fluid. Savings in production time and costs are attained by the method.

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Milan, Italy

Sergio Belli