Nexans, the worldwide leader in the cable industry, has further extended its mastering of advanced technology by launching the new INFITTM technology dedicated to fire resistant cables. Fire-resistant cables ensure the integrity and continued operation of vital safety circuits during the critical evacuation and fire fighting periods required by the highest national and international standards. INFITTM allows a high class fire resistance performance together with an improvement of the installation behaviour of the cables.

INFITTM advanced technology

To insure integrity of flexible cable insulation during a fire, the cable industry mainly used up to now 2 major technologies: fire resistant Mica taping and ceramic forming silicone rubbers.

Each of these technologies presents numbers of advantages. The classical insulation taping based on Mica, and largely used since the 80’s, can for example be easily implemented at industrial scale by giving a hard and good electrical insulation when overcoated with a cross-linked polyethylene. And, the Silicone rubber insulation with its direct extrusion on the conductors gives a good compromise between fire performance and easiness of installation. Nevertheless, considering the new customer requirements regarding resistance, strippability, easiness of connection and of course fire performance, Nexans has developed a technology dedicated to fire-resistant cables insulation.

INFITTM is a unique innovative technology which combines in a polymeric material the advantages of the tough mica tapes layer and the extruded silicone insulation layer. This enables the Nexans cables to combine the hard and easy to handle surface of traditional mica tape/XLPE cables with the strippability and easy installation of flexible silicone rubber insulated cables.

INFITTM technology allows an enhanced integrity of cable insulation during a fire. In the event of a fire, INFIT™ transforms the insulation from a flexible, plastic covering to a tough insulating ceramic layer to assure circuit-integrity (i.e. no breaks or short circuits).

INFIT TM, a fruitful result of an ambitious Research & Development project.

This technology has been developed in the Nexans International Research Center based in Lyon, France, in close partnership with the Australian Nexans R&D Center, during the last ten years. The development of this technology is based on basic studies especially highlighting the synergy between the ceramic science and the latest polymer science.

In case of accidental fire, the temperature ramp up cannot be managed when classically in ceramic science, a well defined curing process must be followed to form a high performance ceramic. The first challenge to manage was to develop a ceramic forming system able to react and form an electrical insulation in a very short time in a large range of temperature increase, and exhibiting a high electrical insulation. The second parallel challenge was to reach this performance from a formulated polymeric extrudable material (and not from a powder), fulfilling with all the very demanding standards of the cable industry.

INFITTM is implemented in respect of many worldwide cable standards and according to the most rigorous product quality and safety criteria. Nexans cables insulated with INFITTM can resist to fires reaching temperatures about 1,000°C, under voltage up to 1kV, exhibiting greater char cohesion and electrical insulation during fire.

INFITTM is a proprietary Nexans technology protected by a dedicated patent portfolio.

INFIT TM, a transversal technology through the cables markets.

INFITTM will be gradually deployed in the coming months thought the whole fire resistant product ranges of Nexans for building as well as industrial application like for example shipboard constructions.

Email: Michel.gedeon@nexans.com