Coaxial HF cable prodn. with air insulation - involves extruding thermoplastic material at constant rate while inner conductor runs at variable speed

摘要

Plastics spacers from a thermoplastic material separate the inner from the outer conductor, and limit the air space between them. They are directly extruded on the inner conductor passed through the extrusion press. The thermoplastic material is extruded at a constant rate from the nozzle, while the speed of the inner conductor (9) varies, so that a plastics layer (12) of variable thickness is applied to the inner conductor. Its thick points (13) serve as spacers for the outer conductor or for a hose (16) on its inside.