First, the outer skin: indoor optical cable generally uses poly-recorded ethylene or flame-retardant poly-recorded ethylene, the appearance should be smooth, bright, flexible, easy to peel. Inferior optical cable has a poor skin finish and is easy to adhere to tight sleeves and aramid. The PE sheath of the outdoor optical cable should be made of high-quality black polyethylene. After the cable is formed, the outer skin is smooth, bright, uniform and free of bubbles. The outer skin of inferior optical cable is generally produced using recycled materials. The cable has a rough skin. Because there are many impurities in the raw material, it can be found that there are many tiny pits in the outer skin of the cable. After laying for a period of time, it will crack and seep.
Second, optical fiber: optical cable wholesale, regular optical cable production enterprises generally use the A-class core of the big factory, some low-cost inferior optical cable usually use C-class, D-class optical fiber and unidentified smuggled optical fiber, these fibers due to complex sources, factory time Longer, often has been tidal and discolored, and multimode fiber is often mixed with single-mode fiber, and the general small factory lacks the necessary testing equipment, and can not judge the quality of the fiber. Because the naked eye can't distinguish such an optical fiber, the problems encountered during construction are: the bandwidth is narrow, the transmission distance is short, the thickness is not uniform, and it cannot be docked with the pigtail; the fiber lacks flexibility, and the fiber is broken when it is bent.
Third, strengthen the steel wire: the steel wire of the outdoor optical cable of the regular manufacturer is phosphating, the surface is gray, such steel wire does not increase hydrogen loss after cable formation, no rust, high strength. Inferior optical cables are usually replaced by thin iron wire or aluminum wire. The identification method is easy - the appearance is white, and the pinch can be bent freely on the hand. The cable produced by such a steel wire has a large hydrogen loss, and the time is long, and both ends of the hanging fiber optic box will rust and break.
Fourth, steel shovel: the regular production enterprise adopts the longitudinally wrapped steel strip with double-sided brush anti-rust paint. The inferior optical cable is made of ordinary iron, usually only one side is made to prevent the fifth, loose tube: the fiber is loose in the optical cable. The casing should be made of PBT material, which has high strength, no deformation and anti-aging. Inferior optical cables usually use PVC material to produce casings. Such casings have a thin outer diameter and are flattened by hand, which is no different from a beverage straw.
Sixth, the fiber paste: the fiber paste in the outdoor cable can prevent the oxidation of the fiber, because the moisture enters the moisture, etc., the fiber paste used in the inferior fiber is rarely, which seriously affects the life of the fiber.
Seventh, aramid: also known as Kevlar, is a high-strength chemical fiber, currently used in the military industry, military helmets, bulletproof vests are the production of this material. At present, only DuPont and the Dutch Aksu can produce at a price of about 300,000 tons. Both indoor and electric aerial cables (ADSS) use aramid yarn as the reinforcing member. Because of the high cost of aramid, the inferior indoor optical cable generally has a fine outer diameter, which can save costs by reducing a few strands of aramid. The cable is easily broken when it is worn. The ADSS cable is used to determine the number of strands of aramid used in the cable based on the span of the field and the wind speed per second. It must be carefully checked and confirmed before construction.