Materiale si tipuri constructive fibra optica

Materials and constructions
Types of secondary coating
The following technologies are available for protecting single fibres:

 • 900µm Tight Buffered Coating (GTC) offering approximately 20mm strippability (stripping down to the fibre's cladding)
 • 900µm Easy Strip Coating (ESTC) with a strippability of approximately 100mm (leaving the fibre's primary coating intact).
 • 900µm oil-filled Semi-tight Coating (SiTC) that provides a strippability of one metre.
Direct connector assembly is possible with all the above technologies. In addition the semi-tight coating offers the possibility of fibre storage inside closures.
Multiple fibres are protected with a loosely fitted gel-filled tube that provides longitudinal water blocking. The dimensions of the tubes depend on the number of fibres and the cable construction.
For miniaturised cable concepts and for fibre units, a new technology was adopted for layer build-up.
By encapsulating the fibres inside a UV-cured resin (much like the resin of the fibre's primary coating), adequate protection is offered together with an "easy peel feature". This concept offers a completely dry solution that saves installation time and costs.
Stress and Strain of fibre-optic cables and fibre units
TKF takes great care in testing and selecting the best materials for Fibre Optic Cables and Fibre Units.
All the optical fibres supplied have been tested for mechanical strength in a manner that ensures a long lifetime of these elements. TKF design and manufacturing policy is directed towards ensuring long-term transmission of information across Fibre Optic Cables and Fibre Units.
In practise the design and manufacture revolve around the permissible fibre strain. Given the excellent mechanical quality of the optical fibres of today, strain levels up to 0.3% are admissible for a period of several hours. This time frame is regarded to be sufficient for the installing of most cables. Next, permissible strain levels of cable composing elements and materials are important as well and are expressed as cable strain. Non-metallic strength members are limited to a strain of 0.8%, steel components are best kept below 0.5% strain. The tensile loads in this brochure are based on these strain levels. For aerial applications such as ADSS, fibre strain levels are best kept at 0% throughout the operational life of the cable.
Indoor, Outdoor or Universal?
All indoor cables are designed to provide a high level of safety to people and equipment.
These cables are equipped with halogen-free and flame-retardant outer sheaths.
TKF outdoor cables are constructed to withstand all kinds of environmental influences including humidity. In addition several solutions with respect to rodent protection are available.
Our universal cables are suitable for both indoor and outdoor applications resulting in a reduction of installation time and costs since there is no need to splice cables when entering or leaving a building.

The range of outdoor and universal cables (not including the aerial cables) are primarily intended for sub-soil ducted installation. Direct burial of these cables can be considered with the use of special backfill but is however not recommended.

Fibre Optic Cables for direct burial are available on request.