EXTRUSION LINES FOR

OPTICAL FIBER

Considering that fiber optical cables serves as a long-distance high speed medium of transmission, the information transfer shall occur without undergoing any significant attenuation. The insulation and jacketing layers are primarily meant to minimize any leakage of optical transmission, in addition to provide the fiber optical physical strength.

Basically two types of fiber optic cable constructions, Loose tube (jelly filled or dry) and Tight Buffer constructions are used. In case of loose tube the fiber cable is oriented in helical shape within the tube and the empty space is filled up with gel or other suitable material. Such a fiber optic cable construction enables the cable to stretch without causing any damage to the fibers and then it is used mostly outdoor.

The tight buffer insulation is used for indoor application.
The excess of fiber length EFL is a vital parameter which shall be controlled accurately, above all in case of dry-tube solution. Apart from the material of the tube and the line speed, the EFL depends strongly on the cable shrinkage. The shrinkage is controlled by a correct and efficient cooling as well as by the dual wheel capstan position. Additionally the longitudinal compression created by the caterpillar helps to control the cable tension and the to reduce the shrink back of the tube. A well-designed cooling process together with a controlled cable tension are essential to control the shrinkage and then to keep the EFL constant with the line speed.

The EFL and shrinkage are continuously monitored through the line supervision and their values compared in real time to the values of the recipe.

Cerrini’s portfolio includes also the following:

• Secondary coating line
• Flex tube jacketing line
• SZ stranding line line
• Tight buffer extrusion line
• Premises jacketing line
• Drop cables sheathing line