Screening foil for transposed cable cores - forms channels permitting escape of trapped moisture

摘要

The application is particularly to screened multicore cable for high frequency signal transmission. The screening is applied in the form of a metallic tape wound onto the core (2) with a roughly 20% overlap. One edge of the tape is corrugated so that at the overlap small channels (3) are formed through which moisture inside can escape. This form of manufacture dispenses with the need to punch holes into the tape, and also overcomes the problem of blockages due to the deformation during taping when perforations are employed. Typically the tape is 50mm wide and the channels approximately 15mm long.