Air-blown optical cable principle

The development trend is to make the communication trunk optical cable pipeline.
In the past, the optical cable pipeline used cement pipes (which are basically no longer used due to complex construction and high friction coefficient) or PVC plastic pipes. The optical cable was generally laid by traction. This method has a short cable threading distance and slow speed due to the large friction coefficient of the inner wall of the pipeline, and it is easy to cause mechanical stretching damage to the optical fiber. In order to solve the lubrication problem of the inner wall of the pipeline during the laying of optical cables, before the birth of silicon core tubes, people generally used the method of adding lubricants, that is, applying liquid lubricants to the inner wall of the pipeline. However, due to the effect of gravity, the lubricant cannot be evenly distributed on the inner wall of the pipeline, and it will also be taken away by the dry optical cable in the front section. Therefore, the lubrication problem directly affects the length and speed of cable threading.
At present, silicon core plastic tubes can be mass-produced in China. The silicon core tube is made of high-density polyethylene. Its characteristics are: silica gel is synchronously squeezed into the inner wall of the high-density polyethylene pipe to form a solid permanent lubricating layer. The lubricating layer has the same physical and mechanical properties as the high-density polyethylene pipe. It does not deform even under the pressure of heavy objects. The friction coefficient of the inner wall of the silicon core tube can be ≤0.15, which is 60%-70% smaller than the friction coefficient of ordinary plastic pipes. The friction coefficient between the optical cable and the pipe is greatly reduced, so the length of the cable can be increased at one time, creating favorable conditions for the promotion of the optical cable air-blowing laying process.
The main features of the optical cable air-blowing laying method:
1. Compared with other optical cable laying methods, the tension of the optical cable during the laying process is more uniform and much smaller;
2. The laying process is simplified and the laying speed of the optical cable is fast;
3. The laying distance is long at one time, and the optical cable with a longer coil length can be used, which reduces the number of joints and reduces the attenuation;
4. The number of manholes and handholes on the pipeline line can be greatly reduced;
5. The manpower used for laying operations is longer