Difference Between Loose-tube and Tight-buffered Fiber Optic Cable

So let’s discuss the term “Dense buffer”. It describes aramid yarns surrounding a fiber core such as Kevlar wool. The outer acrylic coating consists of two layers, tightly surrounding the quartz fiber core and protecting both the core and the fiber cladding.

• Typically manufactured with 900 m cores, tight buffer cables are often similar in strength to traditional fiber optic patch cords.
• The high-density buffer increases the structural stability of the cable, helps protect the fiber core during installation, and extends the useful life of the cable.
• Tight gauge cable also improves cable attenuation and fiber core protection when the cable is bent, making it ideal for installations requiring tight bend radii. 2 to 144/288 fibers are included in tight buffered cables.

Loose Tube Fibre:

Loose-tube fiber cables have only one protective outer layer, in contrast to tight-tube cables, which contain two layers of aramid yarns (one layer around the fiber core and one outer layer).

• Multiple 250 m strands of fiber form a loose tube fiber cable that can be manufactured dry-laid or gel-filled.
• Both buildings offer some degree of protection against water ingress. An outer jacket and gel, often called a thixatrope, surrounds the fiber core within a gel-filled loose tube. 
• A similar loose tube cable is used for dry applications but contains an additional internal protective coating to keep you dry.
• In more severe conditions, or where there is frequent contact with wires, the outer tube can be made of a more durable or semi-rigid material for even more protection.
• Aramid threads or strength members that provide stiffness are usually present in loose tube fiber cables. Fiber optic loose tube cables have bundles of 2 to 144/288 fibers wrapped around a strength component.

The following table lists the comparison between Tight Buffering and Loose Tube Fiber Optic Cable

Tight Buffering and Loose Tube Fiber Optic Cable:

Parameter	Tight Buffered Fibre	Loose Tube Fibre
Construction	Tight-buffering cables have no gaps between the cladding layers of the fiber core.	Loose tube fiber cables have voids that are either empty or filled with gel.
Applications	Tight fibre cables often have a larger cable diameter than loose tube cables (depending on the outer protective jacket), but are often used indoors in confined spaces. Tight-buffering cables have two layers of protection, so no additional cable protection is required. In addition, it is often easier to handle during installation, such as when connecting pre-terminated fiber optic cables to the back of a patch panel. A well-buffered cable can withstand large bends. This is because the two buffer layers help protect the fiber core from damage when the cable is bent. This makes it suitable not only for short- and medium-range LANs, but also for long-term indoor use.	Loose tube cables are often used when water infiltration is an issue. Loose tube cable is cheaper and more convenient to use in outdoor applications due to its 250m fiber core as opposed to 900m of tight tube cable. For long-distance applications such as campus connections and inter-building communications, loose tube cable is often the best choice. Additionally, gel filling is not suitable for horizontal cabling between building floors. Loose-tube fiber cables are not well suited for short distances due to their high stiffness due to the strength members and materials used for the outer protective jacket. They are often used outdoors and in harsh environments because they are gel-filled loose tube fiber cables or have a durable outer protective coating like corrugated (CST) or steel wire armored (SWA) fiber cables.
Cost	Tight buffered cables often cost more as they require more aramid yarn to manufacture.	Loose Tube Fibres are comparatively less expensive than Tight buffered cables.
Connector options	Tight fibre cables are terminated with non-tensile plugs. A buffer or jacket can also be attached to the connector. This is because it is attached to the fiber and cannot move independently. When the buffer or cladding is pulled, the fiber and ferrule are also pulled, causing the ferrule to move backwards and break the optical link.	For loose-tube cables and semi-loose constructions, use pull-proof connectors. The connector mounts to the jacket or buffer without affecting the fibers and ferrules, so the fibers and ferrules remain unaffected when tension is applied to the jacket or buffer.