Conductors or wires for transmitting electrical or telecommunication currents need to be electrically insulated if they are to be used in our environment. Elastomers or thermoplastics with dielectric properties provide the insulation needed to produce the final cable.
Extrusion, on the other hand, is a process for manufacturing parts with a constant cross-section. In most cases, cable insulation is shaped using a single-screw extruder. The function of the extruder is to plasticize the insulating material in order to push it into the extrusion (or forming) head, where the insulation is deposited on the conductor wire running through it. The reader is referred to files [AM 3 650], [AM 3 651] and [AM 3 655] for further information.
However, the extruder alone cannot guarantee product quality. Other components along the production line have an important role to play. In addition to the extrusion unit (extruder and head), all lines include unwinders, cooling tanks, diameter-measuring elements and winders.
Each line can be specific to each sector of the cable market. These traditionally include power transmission, copper wire telecommunications and fiber optic telecommunications.
In this first dossier [AM 3 640], we present the types of cables and extrusion lines, quality control and line profitability. In a second dossier [AM 3 641], we offer a review of the various elements available on cable lines.