摘要:
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.
摘要:
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.
摘要:
A plug part (1) for an optical plug connection comprises one pin holder (3) in which a plug pin (2) for retaining an optical waveguide which extends over a longitudinal central axis (L) is held. The pin holder (3) can be pushed into a plug housing (4) via a cable-side opening (30) and locked therein in a mounting position, wherein the plug pin (2) is held axially resiliently in the plug housing (4) with the aid of a separate spring element (5). The spring element (5) can here be inserted in a mount in the plug housing (4) before the pin holder (3) is pushed in. The spring element (5) is secured by way of a clamping sleeve (6) which can be inserted into the mount via the plug-side opening (30) in the push-in direction (e). Arranged in the mount is a circlip (7) and the pin holder (3) has a groove (12) which can be brought into engagement with the circlip (7) in a latching manner in order to fix the mounting position.
摘要:
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.
摘要:
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.
摘要:
A multipolar cable for transmitting energy and/or signals, as well as an extrusion method and apparatus for the production thereof, is described. The multipolar cable has at least three transmissive elements and a sheath in which at least three longitudinal housings being intended to house respectively the at least three transmissive elements according to a predetermined configuration and being formed within respective substantially lobe-shaped longitudinal portions of the sheath. The multipolar cable allows the connection of the transmissive elements to one or more consumption points by means of at least one connector provided with at least three perforating elements.
摘要:
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 α-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 α-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° 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.
摘要:
A process for manufacturing an electric cable. In particular, the process includes the steps of: a) feeding a conductor at a predetermined feeding speed; b) extruding a thermoplastic insulating layer in a position radially external to the conductor; c) cooling the extruded insulating layer; and d) forming a circumferentially closed metal shield around the extruded insulating layer. The process may be carried out continuously, i.e., the time occurring between the end of the cooling step and the beginning of the shield forming step is inversely proportional to the feeding speed of the conductor.
摘要:
A process for manufacturing an electric cable. In particular, the process includes the steps of: a) feeding a conductor at a predetermined feeding speed; b) extruding a thermoplastic insulating layer in a position radially external to the conductor; c) cooling the extruded insulating layer; and d) forming a circumferentially closed metal shield around the extruded insulating layer. The process according to the invention is carried out continuously, i.e., the time occurring between the end of the cooling step and the beginning of the shield forming step is inversely proportional to the feeding speed of the conductor.
摘要:
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.