Aramid water resisting fiber is made by adding a kind of chemical water resisting agent to the surface of aramid fiber through high temperature curing, with high strength, high temperature resistance, low elongation, high water absorption, high expansion rate and other superior properties.

In the process of optical cable production, the water-blocking yarn is covered outside the cable core. When the optical cable encounters moisture or water intrusion, the superabsorbent substance in the water-blocking yarn will rapidly absorb water, expand rapidly, and wrap the water in its network structure, which plays the purpose of water blocking.