Borealis delivers stability advantages with polypropylene in fibre optic cables

Borealis has launched a new polypropylene (PP) compound able to satisfy all the performance criteria for different fibre optic cable constructions such as loose tube and slotted core. An innovative extension of the established Borealis communication cable product family, the new PP1112 grade provides a solution to the dimensional stability issue that had previously prevented PP from entering this application field.

This development, together with the cost savings offered by PP solutions, positions PP1112 as a competitive replacement of polybutadiene-terephthalate (PBT), currently the most widely used material for fibre optic loose tube buffers.

Gel-filled loose tubes represent the most common choice of the cable constructions available to protect optical fibres during manufacturing, storage, transport and installation. Key requirements of the material used include the ability to hold its dimensions, toughness, flexibility, good heat aging properties and good filling-gel compatibility.

“In meeting these requirements polypropylene already offers many advantageous properties such as low density, flexibility at low temperatures, good processability and hydrolytic stability, as well as being insensitive to kinking,” says Hans Mårtensson, Application Marketing Manager, Borealis Wire and Cable. “However, during a manufacturing process in which the tube is extruded around the optical fibres and simultaneously filled with gel, the precise matching of the length of the buffer tube with the fibres is critical and represented a dimensional stability challenge for PP.”

“The development of PP1112 provides the dimensionally stable solution that enables cable producers to achieve a substantially lower cost base using PP materials, without compromising loose tube performance,” confirms Hans.

In the development of the new grade, Borealis co-operated with Nextrom, a leading fibre optical machinery supplier.