Prysmian Cavi E Sistemi Energia S.r.l.

Pirelli Cavi E Sistemi S.p.a.

Prysmian S.p.a.

Pirelli & C. S. P. A.

Alberto Bareggi

Sergio Belli

Luca Balconi

Paolo Veggetti

Marco Frigerio

Luigi Caimi

Cristiana Scelza

Gaia Dell'Anna

Giovanni Pozzati

Andrew Maunder

Gaia Dell'anna

Paul Cinquemani

Fabrizio Donazzi

Luca Giorgio De Rai

Vincenzo Crisci

Walter Castiglioni

Paolo Bossi

Gianbattista Grasselli

Franck O'Neil

Daniel Cusson

Alberto Lumachi

Luca Castellani

Gabriele Perego

Claudio Bosisio

Paolo Maioli

Stephen H Foulger

Diego Tirelli

Carlo Marin

Flavio Casiraghi

Ivan Troia

Armando Michele Ferrari

Cesare Bisleri

Pier Luigi Folcini

Dario Quaggia

Alberto Bianchi

Gaia Dell′Anna

Chengjun Liu

Jason Carden

Frank L Kuchta

Jean-Louis Pons

Romain Besson

Franck O'neill

An electric cable for high-voltage applications is disclosed which comprises a core surrounded by an electrically insulating layer made of a composition based on a thermoplastic polymeric material charged with boron nitride powder in an amount up to 20 wt % with respect to the weight of the insulating composition, the boron nitride powder having a particle size distribution D50 up 0 to 15 &#x3bc;m. Such a cable has improved thermal conductivity property as well as good dielectric resistance and workability in particular through extrusion processes.

Electric cable with improved thermoplastic insulating layer

Energy cable comprising, from the interior to the exterior, an electrical conductor, an inner semiconductive layer, an electrically insulating layer made from a thermoplastic material in admixture with a dielectric fluid, and an outer semiconductive layer, wherein the outer semiconductive layer comprises: (i) from 55 wt % to 90 wt % of a copolymer of ethylene with at least one ester comonomer having an ethylenic unsaturation; (ii) from 10 wt % to 45 wt % of a propylene copolymer with at least one olefin comonomer selected from ethylene and an &#x3b1;-olefin other than propylene, said copolymer having a melting point of from 145&#xb0; C. to 170&#xb0; C. and a melting enthalpy of from 40 J/g to 80 J/g; (iii) at least one conductive filler; (iv) at least one dielectric fluid; the amounts of (i) and (ii) being expressed with respect to the total weight of the polymeric components of the layer. The outer semiconductive layer is cold-strippable, having an adhesion with the underlying thermoplastic insulating layer which can be tuned so as to obtain a suitable balance between strippability at a temperature ranging from about 0&#xb0; C. to about 40&#xb0; C., without applying heat, and stable adhesion with the insulating layer during the cable lifespan.

Energy cable having a cold-strippable semiconductive layer

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 process for manufacturing an electric cable including at least one core including a conductor and an insulating coating surrounding the conductor includes the steps of: providing a polyolefin material, a silane-based cross-linking system and a foaming system including at least one exothermic foaming agent in an amount of 0.1% to 0.5% by weight with respect to the total weight of the polyolefin material; forming a blend with the polyolefin material, the silane-based cross-linking system and the foaming system; and extruding the blend on the conductor to form the insulating coating. An electric cable includes at least one core consisting of a conductor and an insulating coating surrounding the conductor and in contact therewith, the insulating coating consisting of a layer of expanded, silane-cross-linked polyolefin material having an expansion degree of 3% to 40%.

Electric cable comprising a foamed polyolefine insulation and manufacturing process thereof

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

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.

Energy cable

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.

Method for producing a coating layer made of expandable and cross-linkable material in a cable

A process for producing a cable, such as, for medium-tension or high-tension power transmission or distribution, having at least one coating layer made of a thermoplastic polymer material. The process includes at least the following steps: (a) extruding a thermoplastic material of at least one thermoplastic polymer and at least one dielectric liquid; (b) passing the thermoplastic material through at least one static mixer; and (c) depositing and shaping the thermoplastic material around a conductor belonging to the cable so as to obtain a layer of thermoplastic coating on the conductor.

Process for producing a cable with a recyclable coating comprising a thermoplastic polymer and a dielectric liquid

A process for manufacturing a cable includes the steps of conveying at least one conductor to an extruder apparatus; extruding an insulating coating layer radially external to the at least one conductor; longitudinally folding a metal tape around the extruded insulating coating layer, the metal tape bearing at least one adhesive coating layer in a radially external position; and extruding at least one continuous coating layer of at least one polyamide or a copolymer thereof around and in contact with the folded metal tape. The step of extruding the at least continuous coating layer is carried out at a draw down ratio not higher than 2.5, preferably, 1.2 to 2.0.

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Milan, Italy

Alberto Bareggi