New Borcell™ cellular compound concept meets the insulation challenge of radio frequency cables

The increasingly higher operating frequency of 3G mobile phone antenna cables places ever greater demands on the performance of insulation materials. To meet this challenge Borealis has launched a new combination of Borcell™ products that provides good insulation together with lower signal attenuation than has been possible with previous cellular materials.

The new insulation concept is based on the recently launched Borcell HE1123 high density polyethylene (HDPE) and Borcell LE1120 low density polyethylene (LDPE). These two compounds give excellent foaming in the gas injection extrusion process and offer a broad operating window enabling use in a variety of radio frequency (RF) cable designs.

"Borcell HE1123/LE1120 has been approved for use in all RF cable constructions at Draka NK Cables, Finland. It is easily processed and gives excellent cell structure and very low attenuation values” according to R&D manager Vesa Tuunanen at Draka Finland.

Offering a wide degree of flexibility, the mix ratio of Borcell HE1123 and LE1120 can be optimised to meet the specific requirements of each insulation thickness in order to give the lowest possible attenuation. Due to the optimisation of processing conditions, the excellent foaming properties mean that expansion above 80% can be achieved. This meets the low permittivity requirements of RF cables.

Importantly, this combination shows very little tendency to dissipate the signal as the frequency increases with the loss factor low across the frequency band. This is important for the provider of mobile telecommunication services to be able to minimise attenuation in the long cables of high mobile phone antennas.

Borcell HE1123/LE1120 PE cellular compounds provide enhanced transmission properties through uniform and evenly distributed cells, which are essential to obtaining good high electrical performance. In addition, their improved flow properties, melt elasticity and purity ensure superior processing, which allows the cable producer to achieve high line speeds and consistent quality.