The Key Elements : Insulation/Dielectric

The simplest way of describing how a dielectric influences the performance of a cable is to think of a cable that has a good dielectric as being like a clear pipe that you can pour water straight though. The water quickly propagates though the pipe and comes out the other end. A cable with a high dielectric (not so good) is like a pipe filled with sponge, so the water has to saturate the sponge before passing through the pipe and its propagation through the pipe is slowed down.

cell-detail[1]The insulation material, known as the dielectric, is one of the most influential elements on analogue or digital signals in cable. The best dielectric known to man is nitrogen. On its own, it is impractical for use in flexible cable. One of the best solid insulator materials is polyethylene. Our recent ES designs use polyethylene foamed with nitrogen giving exceptionally good results.

This image shows a magnified cross section of a polyethylene dielectric that has been highly foamed with nitrogen. The gas cells are clearly seen. This amount of foaming is very hard to manufacture but its performance is outstanding and is illustrated on the Results page.