The application of super absorbent polymer powder in the longitudinal waterproofing of cables. Water blocking powder, and water blocking tape is commonly used for longitudinal water blocking. Their water-blocking mechanism is that these materials contain a water-swellable material. When water enters from the end of the cable or from the defect of the sheath, this material will rapidly expand with water to prevent the water from further spreading in the longitudinal direction of the cable. In this way, the purpose of longitudinal waterproofing of the cable is achieved.

Similarly,when the optical cable is partially damaged, if water enters, the superabsorbent polymer powder in the water blocking tape will quickly expand and compress the gap of the optical fiber cable group, blocking the capillary channel for water migration. If there is no water blocking tape, water will seep into the inside of the optical cable, causing serious or even catastrophic damage to the optical cable.