Abstract: 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.

Abstract: 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.

Abstract: An extrusion method and apparatus for producing a cable including at least one core having at least one transmissive element and at least one pair of coating layers arranged at a radially outer position with respect to the core. At least one coating layer of polymeric material and one coating layer of expanded polymeric material are deposited by co-extrusion simultaneously and residual pressure not greater than the external pressure is maintained in a substantially annular interspace defined between the coating layers. The method avoids the formation of bubbles at the interface between the at least one coating layer of polymeric material and the coating layer of expanded polymeric material, attaining an optimal adhesion between the layers.

Abstract: The present invention relates to a coating for cables which is capable of protecting the cable against accidental impacts. By inserting into the structure of a power transmissioncable a suitable coating of expanded polymer material of adequate thickness, preferably in contact with the sheath of outer polymer coating, it is possible to obtain a cable which has a high impact strength. The Applicant has moreover observed that an expanded polymer material used as a coating for cables makes it possible to obtain a higher impact strength for this cable than using a similar coating based on the same polymer which is not expanded. A cable with a coating of this type has various advantages over a conventional cable with metal armor, such as, for example, easier processing, a reduction in the weight and dimensions of the finished cable and a lower environmental impact as regards recycling of the cable once its working cycle is over.

Abstract: A method for mechanically protecting a connection between at least two components forming part of an electrical and/or telecommunications network. At least one protective coating is provided, the coating being produced from an expanded polymeric material and providing the connection with a mechanical impact strength and ensuring a predetermined heat exchange between the connection and the external environment. This coating is axially and circumferentially continuous with respect to the connection. The present invention also relates to a coating for the mechanical protection of a connection between two components and to a joint thus protected.

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

Abstract: Electric cable (20), in particular for power transmission or distribution at medium or high voltage, comprising a metallic screen (5) and a water swellable layer (21) capable of forming a barrier to the water penetration provided in a position radially external to said metallic screen (5). Said water swellable layer (21) is made of an expanded polymeric material in which a water swellable material preferably in the form of powder, is embedded.

Abstract: A cable for electric power transmission, electric power distribution or telecommunications, having an inner layer including a self-repairing material. The self-repairing material has properties including a predetermined cohesiveness and a controlled flowability. In the event of a discontinuity in at least one of the cable coating layers, these properties assist in reestablishing the continuity of the cable coating layers.

Abstract: The present invention relates to a coating for cables which is capable of protecting the cable against accidental impacts. By inserting into the structure of a power transmissioncable a suitable coating of expanded polymer material of adequate thickness, preferably in contact with the sheath of outer polymer coating, it is possible to obtain a cable which has a high impact strength. The Applicant has moreover observed that an expanded polymer material used as a coating for cables makes it possible to obtain a higher impact strength for this cable than using a similar coating based on the same polymer which is not expanded. A cable with a coating of this type has various advantages over a conventional cable with metal armor, such as, for example, easier processing, a reduction in the weight and dimensions of the finished cable and a lower environmental impact as regards recycling of the cable once its working cycle is over.

Abstract: An electrical cable (1) comprises a conductor (2), a possible inner coating layer (7) put directly into contact with the conductor (2), a self-repairing material layer (4) directly in contact with the inner coating layer (7), and an outer coating sheath (3) externally in engagement with the self-repairing material layer (4). Formed between the outer coating sheath (3) and the conductor (2) are anchoring portions (6) for the purpose of avoiding relative movements between the outer coating sheath (3) and the conductor (2).

Abstract: An electrical cable includes a conductor, an outer sheath, and a self-repairing material layer between the conductor and outer sheath. The self-repairing material layer is distributed around the conductor in a discontinuous manner. An anchor portion is formed between the conductor and the outer sheath.

Abstract: The invention relates to a coating for cable which is capable of protecting the cable against accidental impacts. By inserting into the structure of a power transmission cable a suitable coating of expanded polymer material of adequate thickness, preferably in contact with the sheath of outer polymer coating to obtain a cable which has a high impact strength.

Abstract: Electrical cable, in particular for medium- or high-voltage power transmission or distribution, having a metal shield and a semiconductive water-blocking expanded layer. This layer exerts three main functions, the first one is to elastically and uniformly absorb radial forces of expansion and contraction of the cable coating layers due to thermal cycles of the cable during use, thus preventing deformations or breakages in the metal shield, the second one is to ensure electrical continuity between the cable core and the metal shield, the third one is to effectively avoid penetration and propagation of moisture and/or water along the cable core due, e.g., to possible ruptures in the metal shield. The third function is obtained by including in the expanded layer a water-swellable material.

Abstract: A cable, in particular a cable for electric power transmission or distribution, having an inner layer comprising a self-repairing material with a predetermined cohesiveness and a controlled flowability, so as to re-establish, upon creation of a discontinuity in at least one of the cable coating layers, the continuity in the coating. The discontinuity in the coating can be caused by mechanical abuses of various types, for example accidental impact with cutting tools. Infiltration of moisture and generation of leakage currents, leading to a rapid corrosion of the conductor, are in this way avoided.

Abstract: A cable, in particular a cable for electric power transmission or distribution, having an inner layer comprising a self-repairing material with a predetermined cohesiveness and a controlled flowability, so as to re-establish, upon creation of a discontinuity in at least one of the cable coating layers, the continuity in the coating. The discontinuity in the coating can be caused by mechanical abuses of various types, for example accidental impact with cutting tools. Infiltration of moisture and generation of leakage currents, leading to a rapid corrosion of the conductor, are in this way avoided.

Abstract: A cable, in particular a cable for electric power transmission or distribution, having an inner layer comprising a self-repairing material with a predetermined cohesiveness and a controlled flowability, so as to re-establish, upon creation of a discontinuity in at least one of the cable coating layers, the continuity in the coating. The discontinuity in the coating can be caused by mechanical abuses of various types, for example accidental impact with cutting tools. Infiltration of moisture and generation of leakage currents, leading to a rapid corrosion of the conductor, are in this way avoided.