* What is an air-blown microcable?
Air-blown microcables mainly come in two types: central tube type (GCYFXTY) and loose tube stranded type (GCYFY).
(1) The central tube type air-blown microcable (GCYFXTY) features a 250µm optical fiber placed within a central loose tube made of high-modulus material, filled with fiber jelly, and then extruded with a PE sheath.
(2) The stranded loose tube type air-blown microcable (GCYFY) features a 250µm optical fiber placed within a loose tube made of high-modulus material and filled with fiber jelly. The loose tubes are stranded around a non-metallic FRP core and surrounded by a dry water-blocking material to form the cable core. An extremely thin PE sheath is extruded over the cable core.
1. Principles of Air-blown Optical Cables
Air-blown optical cable installation is a safe and effective method for laying optical cables. During the cable-laying process, the cable is simultaneously acted upon by the pulling force of the tug, the blowing force of the compressed air, and the thrust of the conveyor belt. Therefore, an air compressor is required to assist the cable-blowing machine.
The air compressor generates compressed air, which is delivered to the cable-blowing machine's sealed chamber via an air hose. The outlet end of the silicon-core tube is connected to the sealed chamber of the cable-blowing machine. The tug, used to pull the cable, is placed within the tube along with the optical cable. The rubber surrounding the tug is sealed to the tube's inner wall, forming a sealed chamber that communicates with the cable-blowing machine's sealed chamber. The pressure generated by the compressed air propels the tug, pulling the optical cable forward within the tube. The air compressor continuously supplies air to ensure a relatively constant force on the tug, and thus on the optical cable. Simultaneously, the compressed air flows forward, exerting force on the cable, pushing it forward, while also keeping it suspended within the tube. This reduces friction between the cable and the inner wall of the sub-tube during laying, maximizing cable protection.
High-pressure air generated by the air compressor is rapidly delivered to the cable blowing machine through a connecting hose. This drives the machine's pneumatic motor, which in turn rotates the upper and lower conveyor belts. The optical cable is placed between the upper and lower conveyor belts, thereby propelling the cable forward.
III. Application of Air-Blown Micro-Cable Technology
1. In long-distance networks, microducts with the required number of cores are first laid into a number of silicon-core tubes or other sub-tubes. Micro-cables are then blown in as needed. This ensures that the number of optical fibers can grow with increasing traffic.
2. In access networks, microducts are first simply coupled into a channel. Based on customer requirements, micro-cables with outdoor cable performance are then air-blown into the micro-duct channel. This allows for branching without the need for splicing. This method allows the capacity of the access network to scale with the number and location of required cables, greatly increasing network flexibility.