1. The expansion water-blocking sand belt enhances moisture resistance.
On the basis of maintaining the structure of the existing fiber optic splice closure, the non-vulcanized rubber belt is replaced by the expanded water-resistant sand belt as a sealing material, which can improve the moisture resistance of the optical fiber joint box. The water blocking function of the expansion water-blocking sand belt is that after the main body of the water-blocking sand belt is in contact with water, it can rapidly expand to form a large-sized gel.
The gel has a large water absorption capacity and a relatively high water retention capacity. It can effectively block the growth of water for a long time, block the water passage space between the fiber optic splice closure and the outside, and prevent the water from continuing to penetrate and spread. Compared with non-vulcanized rubber belts, water-blocking sand belts have the following characteristics: they can be reused, reducing the operation and maintenance costs of optical cables.
2. The cable sleeve improves the structure.
The sealing process of the optical cable entering the joint box is different, and the sealing performance of the different structural joint boxes is different, which brings different moisture-proof effects. The cap type joint box is waterproofed by the thermoplastic sleeve at the introduction part of the cable box of the joint box; the other type of commonly used direct buried fiber optic splice closure of the open type is used in this part to prevent the moisture of the non-liufu rubber belt. From the overall effect, it is clear that the use of a heat-resistant casing is better than that of a non-vulcanized rubber belt. For this purpose, the heat-shrinkable sleeve originally used for sealing the cap fiber optic splice closure should be used for other forms of direct buried fiber optic splice closures. The structure of the improved fiber optic splice closure is unchanged. It only extends the length of the bayonet of the original fiber optic splice closure and is integrated with the upper and lower covers. Thereby further improving the moisture resistance of the direct buried fiber optic splice closure.