In the integrated wiring project, we often hear the terms outdoor optical cable and indoor optical cable. But for friends who are not familiar with integrated wiring, they may not even know what an outdoor optical cable is. Let's talk about what outdoor optical cables are and what types of outdoor optical cables are.
What is an outdoor fiber optic cable
Outdoor optical cable, simply used for outdoor optical cable, belongs to a kind of optical cable. It is called outdoor optical cable because it is most suitable for outdoor use. It is durable and can withstand wind, sun, cold and freezing. It has some mechanical and environmental properties such as pressure resistance, corrosion resistance and tensile strength.
What type of outdoor optical cable
Commonly used outdoor optical cables are divided into two structures: central bundle type and layered optical cable:
① Central tube type optical cable: The center of the optical cable is a loose tube, and the strengthening member is located around the loose tube.
GYXTW cable:
Bundle tube: The material of the bundle tube is PBT, which is hard and flexible and resistant to lateral pressure. Some small factories use PP instead of PBT, and the cost can be reduced by half, but the optical fiber inside is easy to break during transportation and construction. The color of PP is translucent.
Colored optical fiber: In order to distinguish each core optical fiber in the communication engineering, the bare fiber is extruded with a layer of colored plastic. The outdoor optical cable is to dye each core bare fiber with different colors of ink. The color of the ink is the same as that of the indoor cable. There are also 12 kinds. The color spectrum of the industry standard of the Ministry of Information Industry is arranged as follows: blue, orange, green, brown, gray, white), red, black, yellow, purple, pink, turquoise. The use of natural colors in place of white is permitted without affecting identification.
Color-locked optical fiber: In order to protect the optical fiber, a layer of 250-micron translucent resin is coated on the surface, and the optical fiber needs to be colored with different colors for each core fiber when it is made into an optical fiber cable. Therefore, some foreign optical fiber manufacturers cover the optical fiber during production. There are 12 different colors of resin on it, so that the fiber optic cable factory does not need to recolor it when it is used. The advantage of this is to save a coloring process, but the disadvantage is that it cannot be used flexibly.
Water-blocking tape: The water-blocking tape is made of water-blocking powder added between two layers of non-woven fabrics. Once the optical cable enters the water, the powder rapidly expands dozens of times after absorbing water, producing a gel like jelly to block the water from going deeper into the optical cable. spread everywhere.
Non-woven fabric: Some manufacturers will replace the water-blocking tape with a non-woven fabric with a much lower cost than the water-blocking tape to reduce the cost. There is no difference in appearance. Once the outer skin of the optical cable is broken, the non-woven fabric cannot block water.
Corrugated steel strip: The water blocking strip is covered with a corrugated steel strip. The main function of the steel strip in the optical cable is to resist lateral pressure, tensile, anti-rat bite, and protect the bundle.
Steel wire: We see two parallel steel wires outside the steel strip. The function of the steel wire is to enhance the tensile force of the optical cable. The gray steel wire is phosphatized, and the silver surface is galvanized to prevent the steel wire from rusting. Galvanized steel wire is more expensive than phosphating steel wire.
Optical cable sheath: Outdoor optical cables generally use medium density polyethylene (MDPE), and some customers specify high density polyethylene (HDPE). The cost of using high-density PE is slightly higher. There are also orders specifying low smoke zero halogen material (LSZH) for the jacket. Many manufacturers also use recycled materials as fiber optic cable jackets to reduce costs. The fiber optic cable made of this material has a rough skin, contains a lot of impurities, and is prone to cracking and water seepage. The source of recycled materials is to smash some wire and cable sheaths, plastic bottles, slippers, etc., and re-granulate them after returning to the furnace.
Because there are only 12 colors of optical fibers, the national standard (also international standard) central bundled tube optical cable can only achieve 12 cores at most. There are also some non-standard central bundle tube optical cables with more than 12 cores, but generally no more than 24 cores. The method is to choose one of the two optical fibers of the same color and use the inkjet printer to spray a bar at a certain distance to distinguish them. Optical cables with more than 12 cores are generally stranded.
Small central bundled fiber optic cable JET
This kind of structure is used a lot abroad, adding glass fiber yarn (or aramid, high-strength yarn) to the bundle tube with optical fiber and then extruding the sheath. The optical cable is relatively soft and has a certain tensile force, which is suitable for indoor and outdoor use. Overhead, wearing pipes are relatively aspects.
② Layer-stranded optical cable: Multiple bundles of optical fibers are stranded on the central core strength member in a twisted manner. Such optical cables, such as GYTS, GYTA, etc., can obtain larger cores by combining loose tubes. number of fiber optic cables. The color separation of the stranded loose tube is usually separated by the red and green color spectrum, which is used to distinguish different loose tubes and different optical fibers. The number of cores of the stranded optical cable can be larger, and it can be produced by optical fiber ribbons, which can achieve more than one thousand cores.
Optical cables with 60 cores and below often use a 5-tube structure. For example, 60-core optical cables use 5 bundled tubes, and each bundled tube contains 12 optical fibers. Generally, the stranded optical cable with less than 12 cores is twisted together with a bundle tube containing 12 optical fibers and 4 solid filler ropes. It can also be twisted with 2 6-core bundles and 3 filling ropes, or can be matched in other ways.
GYTS type optical cable: In the layer stranded optical cable red, this type and GYTA are the most common. Several bundles of tubes are twisted on a thicker phosphating steel wire, the gap of the twisted cable is filled with water-blocking cable paste, and there is a circle of plastic-coated steel tape on the outside, and then the sheath is squeezed.
GYTA type optical cable: The structure of this optical cable is the same as that of GYTS, except that the steel tape is replaced with an aluminum tape. The lateral pressure resistance index of the aluminum belt is not as high as that of the steel belt, but the rust and moisture barrier performance of the aluminum belt is better than that of the steel belt. In some environments where GYTA is used, the optical cable has a longer service life.
GYFTY type optical cable: This type of optical cable is to twist several bundles on a non-metallic reinforcing core, fill the twisted gap with cable paste or protect a circle of water blocking tape, and directly squeeze the sheath without armoring.
This model has various evolutions. It is used in some overhead environments. In order to increase the tensile force of the optical cable, some aramid fibers should be added to the stranded cable core and then extruded. If the central reinforcement is made of steel wire instead of a non-metallic reinforcement core (FRP), the model is GYTY without F (for non-metallic).
FRP reinforced core: This material is generally made of glass fiber, and the strength of the outer diameter is also greater than the tensile force of the steel wire. When training the optical fiber, we know that the optical fiber is made of high-purity glass and is not afraid of lightning, but the optical cable is in an outdoor overhead environment, and the metal parts in the middle are easily damaged by lightning. Seeing the model with F, we should know that it is mainly lightning protection. The cost of FRP reinforcement is slightly higher than that of steel wire reinforcement.
Type 53 optical cable: We see some models such as GYTA53, GYTY53, this model is a layer of steel armor and sheath outside the GYTA, GYTY optical cable. It is used in those occasions where the environment is relatively harsh. When you see 53, you should know that it is an extra layer of armor and an extra layer of sheath.
The above is all about what is an outdoor optical cable and what types of outdoor optical cables are there. I believe that after reading the above, you have a certain understanding of what an outdoor optical cable is, and I hope to give you some help.
