The most important task of optical fiber cable structure design is to protect the optical fiber in it to work safely for a long time in a complex environment. The optical cable products provided by GL Technology realize the protection of optical fibers through careful structural design, advanced process control and strict material control. Let's talk about the structural design of the fiber optic cable.
According to the results of ITU-T survey documents, this traditional structure has formed a leading trend in the world, and it is also the preferred structure for long-distance trunk lines in China. The structure is to insert the optical fiber into the loose tube and fill it with thixotropic waterproof ointment (fiber ointment). The loose tube is twisted around the central reinforcing core in a spiral or SZ shape to form a cable core. According to different applications, different sheaths are extruded outside the cable core, and the gaps in the cable core are filled with ointment (cable paste). feature is:
1. The strengthening core is located in the center of the cable core, and the loose tube is twisted around the strengthening core layer with an appropriate twisting pitch. By controlling the excess length of the optical fiber and adjusting the twisting pitch, the optical cable can have good tensile properties and temperature characteristics .
2. The loose tube material itself has high strength, and the tube is filled with fiber paste, which provides key protection for the optical fiber. Optical fibers move freely in the tube and are protected from external forces
3. The loose tube and the reinforcing core are filled with cable paste and twisted together, so that the integrity of the cable core is protected.
4. The radial and longitudinal waterproofing of the optical cable is guaranteed by the following measures: a single steel wire is used instead of a steel strand to prevent water seepage in the longitudinal direction of the reinforcing core; the filling of the cable paste ensures the longitudinal waterproofing of the triangular area between the steel wire and the casing; The fiber paste can prevent moisture from eroding the optical fiber; the cable paste is filled with pressure to ensure that the cable core is completely filled; the plastic-coated aluminum tape and corrugated steel tape armor are bonded longitudinally with hot-melt adhesive to prevent radial water molecules from intruding; the armor layer Water-blocking yarn is used with the inner sheath to ensure the longitudinal waterproof performance of the cable and improve the structural integrity of the cable.