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:
| Feature | Tight-Buffered Cable | Loose-Tube Cable |
|---|---|---|
| Construction | Fiber core surrounded directly by cladding and a tight buffer coating; no gaps between layers. | Fibers placed inside hollow plastic tubes, either empty or gel-filled for moisture protection. |
| Cable Diameter | Typically larger (≈ 900 µm fibers). | Smaller fiber coating (≈ 250 µm fibers). |
| Applications | - Indoor use, especially in confined spaces.- Easier to install and terminate (e.g., patch panels).- Can withstand tight bends due to buffer layers.- Suitable for LANs, short- and medium-distance runs, and long-term indoor use. | - Designed for outdoor and harsh environments.- Ideal for long-distance runs (e.g., campus networks, inter-building links).- Often reinforced with corrugated steel tape (CST) or steel wire armor (SWA).- Not suitable for short indoor links or horizontal cabling (gel filling is messy and stiff). |
| Water Protection | Not designed for water resistance. | Gel filling or dry-blocking materials protect against water infiltration. |
| Cost | More expensive (requires more aramid yarn). | Less expensive; more cost-effective for large-scale outdoor deployments. |
| Connector Options | Uses standard connectors; buffer is attached to the fiber. Pulling on buffer may stress the fiber and ferrule, risking breakage. | Uses pull-proof (strain-relief) connectors; connector attaches to jacket/buffer without stressing fibers or ferrules. |