tube. Figure 6-7 shows each type of fiber buffer. The
choice of buffering techniques depends on the intended
application. In large fiber count commercial
applications, manufacturers use the loose-tube buffers.
In commercial building and Navy applications,
manufacturers use tight buffers.
CABLE STRENGTH AND SUPPORT
fibers, glass fibers, and glass reinforced plastics.
Fiber-optic cables use strength members to increase
the strength of the cable and protect the fiber from
strain. Fiber-optic cables may use central support
members in cable construction The central support
members generally have buffered fibers or single fiber
subcables stranded over their surface in a structured,
helical manner. The central members may support the
optical fibers as cable strength members or may only
serve as fillers. Strength and support members must be
light and flexible. The materials used for strength and
support include steel wire and textile fibers (such as
nylon and arimid yarn). They also include carbon
CABLE JACKET MATERIAL
The jacket, or sheath, material provides extra
environmental and mechanical protection. Jacket
materials may possess any number of the following
Low smoke generation
Low halogen content
High abrasion resistance
Stable performance over temperature
It is difficult to produce a material compound that
satisfies every requirement without being too costly.
Jacket materials currently used include polyethylene,
polyvinyl chloride, polyurethane, and polyester
elastomers. Most commercial jacket materials are
unsuitable for use in naval applications.
Figure 6-7.Tight-buffered, loose-tube, and gel-filled loose-tube buffer techniques.