Optical fiber cables are generally composed of optical fiber cores, cladding, coatings, reinforcing elements, and outer sheaths. The outer sheaths are used as the protective layer of the cables, which have the functions of fire prevention and moisture resistance. Its primary functions include: While the optical fiber itself remains largely unchanged, the sheath material determines how the cable behaves in fire scenarios, outdoor environments, and long-term service conditions. So the material of the fiber optic cable outer sheath must be able to withstand the sun and rain, and not crack due to ultraviolet radiation. When a fire occurs in the data.