1. Outer cover:
1. The outer jacket of indoor optical cables is generally made of polyvinyl chloride (PVC), polyethylene, or flame-retardant polyurethane (LSZH). This jacket is smooth, glossy, flexible, and easy to strip. The outer jacket of inferior optical cables has a poor finish and is prone to adhering to tight sleeving and aramid fibers.
2. The outer sheath of outdoor optical cables must be made of high-quality black polyethylene (HDPE, MDPE). Once the cable is formed, the outer sheath should be smooth, glossy, of uniform thickness, and free of bubbles. The outer sheath of inferior optical cables is primarily made of recycled materials. The outer sheath of inferior optical cables is rough due to the high levels of impurities (lime dust) in the raw materials, resulting in numerous tiny holes in the cable's outer sheath. If the outer sheath of the optical cable is bent repeatedly, it will be damaged and turn white. After the optical cable is installed for a period of time, the outer sheath will crack and allow water to seep in.
2. Fiber optics:
Standard optical cable manufacturers use Class A fiber cores from leading manufacturers. Low-cost, low-quality optical cables often use Class C, Class D, and contraband fibers of unknown origin. These fibers have complex sources and have been out of the factory for a long time. They are often damp and discolored, and multimode fibers are frequently mixed with single-mode fibers. Smaller factories generally lack the necessary testing equipment and cannot assess the quality of the fibers. These fibers are not identifiable by sight. Common problems encountered during manufacturing include: very narrow bandwidth and short transmission distance; uneven thickness, preventing connection to the pigtail; and lack of flexibility, making the fiber prone to breakage during coiling.
3. Reinforced steel wire:
The steel wires in standard outdoor fiber optic cables are phosphated and have a gray surface. This type of steel wire does not increase hydrogen loss after installation, does not rust, and has high tensile strength. Lower-quality fiber optic cables are primarily made with thin iron or aluminum wires. These can be identified by their white appearance and the fact that they can be bent easily when held in the hand. Fiber optic cables made with these types of steel wires will produce additional hydrogen loss in the future, and over time, the two ends of the fiber optic boxes will oxidize and break.
4. Armored steel belt:
Standard manufacturers use longitudinally wrapped steel strips coated with double-sided, brushed, rust-resistant plastic. Inferior optical cables are made of ordinary iron sheets, and typically only one side has been treated to prevent rust.
5. Fiber optic casing:
The loose tube surrounding the optical fiber in the optical cable must be made of PBT material. This material offers high strength, is resistant to deformation, and is age-resistant. Inferior optical cable housings are typically made of PVC. The outer diameter of these housings is very thin and soft, flattening easily when pinched. They are similar to drinking straws and do not provide adequate protection for the optical fiber.
6. Fiber ointment:
The fiber paste used in outdoor optical cables can prevent silver streaking, hydrogen loss, and even fiber optic breaks caused by moisture. Very little fiber paste is used in inferior optical cables, and some bubbles may be visible to the naked eye. Alternatively, inferior fiber paste is used, which seriously shortens the lifespan of the fiber optic cables.
7. Aramid:
Also known as Kevlar, aramid fiber is a high-strength chemical fiber currently used primarily in the military industry. It is used to manufacture military helmets and bulletproof vests. Currently, the aramid fiber on the market is mainly from the American brand DuPont. Both indoor and overhead power (ADSS) optical cables use aramid yarn as reinforcement. Due to the high cost of aramid (200,000 yuan/ton), lower-quality indoor optical cables typically have a very thin outer diameter, which can save costs by reducing the amount of aramid yarn used. This type of optical cable is easily damaged when passing through conduit.
8. Cable paste:
The fiber optic cable's outer fiber paste is bonded to the outside of the fiber optic sleeve to protect the cable from moisture. High-quality cable paste is evenly mixed and does not separate after prolonged use. In lower-quality optical cables, the cable paste will evaporate or the filler will be insufficient, affecting the cable's moisture-proof performance.
Post time: Nov-17-2023
