Protection against the penetration of water in optical cables is a very important characteristic for the performance and useful life of optical fibers, directly modifying aspects related to their installation.
The effect of water on optical cables
Circumstantial conditions exist where the core of the optical cable and the fibers can be exposed to water – which is a substance that degrades the material that makes up the Fiber optic cable over time.
Said humidity is responsible for the increase of micro cracks, a factor that reduces the mechanical resistance of the fibers and can lead them to the Sheath Loose Tube “Loose Tube” Optical fibers Core of the optical cable Basic structure of an optical cable rupture in a short space of time or impair the adhesion of the fiber’s primary cladding, causing micro bends, which will result in an increase in optical attenuation over time.
Therefore, it is essential that optical fibers be effectively
Protected from contact with water. Consequently, optical cables are produced with materials that protect against these risks/aggressions.
Optical cables
A large part of the optical cables are built using the loose tube technology (Loose Tube), which has the loose optical fibers conditioned inside tubes protected against the penetration of moisture and covered by a sheath of thermoplastic material.
Currently, two types of materials are used for the protection of cables with regard to the penetration and propagation of water: Gel and Hydro- expansible materials (water blocking).
1st Generation – Gelled Optical Cable (G)
The 1st generation of optical cable uses gel throughout its construction (both in the core of the cable and inside the loose tube) with the purpose of providing a physical barrier to protect against water migration, filling the interstitial spaces eliminating places where the water can spread.
Since the mid-1990s, water blocking wire technology began to be introduced in the optical cable industry. This technology uses super absorbent polymers, which expand when they come into contact with water, passing into a gelatinous state, which blocks the spread of water. This innovation allowed the development of the 2nd and 3rd generation described below.
2nd Generation – Dry Optical Cable (S)
It has gel only inside the loose tube, while the gel of the optical core was replaced by tapes and/or threads impregnated with super moisture absorbent powder (water blocking).
3rd Generation – Totally Dry Optical Cable (TS)
It completely eliminates, throughout the cable construction, the presence of petroleum-derived gel compounds, which both in the optical units (loose tube) and in the interstitial spaces of the core, are replaced by water blocking tapes/wires.
As it is a cable for outside plant installations,
It is either filled with a water-blocking gel or made with water-blocking components. Another advantage of the ribbon cable (Some cable designs use an “expansion core” that supports up to 6 of those 144 fiber optic ribbon splices, resulting in 864 fibers in the same cable. As it is a cable for outside plant installations, it is either filled with a water-blocking gel or made with water-blocking components. Another advantage of the ribbon cable (Some cable designs use an “expansion core” that supports up to 6 of those 144 fiber optic ribbon splices, resulting in 864 fibers in the same cable. As it is a cable for outside plant installations, it is either filled with a water-blocking gel or made with water-blocking components. Another advantage of the ribbon cable (is filled with a water-blocking gel or is made with water-blocking components. Another advantage of the ribbon cable (is filled with a water-blocking gel or is made with water-blocking components.