Benefits of Loose Tube Cable

Around the tube is a layer of Kevlar which provides tensile strength, and on the outside is an overall sheath made of high density plastic. One or more fibers with 250 micron jackets are installed in the tubes, and the fibers are a little longer than the cable itself, so that strain on the cable which might stretch the cable does not stretch the fibers. In most cases, all the spaces inside the tubes and other places in the cable are filled with a gel which serves to block water and support the fibers in the tubes.

In loose tube construction, the fiber (usually the 250um coated fiber) is contained in a color-coded, flexible plastic tube that has an inner diameter considerably larger than the fiber itself. Up to 12 of these fibers can be put inside a tube, and is usually filled with a gel material that prevents water penetration. These tubes are standed around a dielectric or steel central member to provide more flexibility. Aramid yarn is used as the primary tensile strength member. An outer polyethylene jacket is wrapped over the assembly. Polyethylene is the most common for outdoor cables due to high moisture resistance, abrasion resistance, and stability over a wide temperature range.

The loose tube provides the protection needed for the inner fiber from the exterior mechanical forces acting on a cable by isolating them. Several loose tube cables are often combined with strength members to form a multifiber assembly, and this provides additional protection from stress, and minimizes elongation and contraction. By cutting several fibers slightly longer than the loose tube length and braiding them inside the loose tube, the shrinkage due to temperature variation can be controlled while insulating the fibers from the stresses of installation and environmental loading. This would be a big advantage in outdoor applications, which is why most outdoor fiber optic systems have a loose tube configuration. Loose tube cables are normally used for outside-plant installtion in aerial, duct and direct buried applications.

The loose tube configuration is ideal for modular designs, as each tube can hold up to 12 fibers. With multiple tubes in a cable, this could add up to more than 200 fibers. With a modular design, certain groups of fibers can be routed to intermediate points without interfering with other protected buffer tubes being routed to other locations. The color-coded scheme in loose tube cable assemblies allows for easy identification and administration of fibers in the system.

The loose tube type offers a higher level of isolation from external forces, and when subjected to continuous mechanical stress, it has more stable transmission characteristics. For any given fiber, the effects of micro-bending on cable attenuation are lower. But the main reason the loose tube type is used outdoors is that it exhibits greater stability over temperature variations.

The principle disadvantage of the loose tube cable relates to connectorization. Because of the small fiber jacket size and the use of multiple fibers in a tube, connectors “can not” be installed directly on the fibers. (I have seen it done, but it is not recommended because the very small diameter plastic jacket gives virtually no protection to the fiber, and provides little surface area for the connector to grip.) As a result, the extra step of splicing pre-connectorized pigtails to the cable is commonly used. This makes connectorizing the loose tube cable more expensive than the tight buffer cables. Note that this does not apply to splices joining two cables together, though removing the gel from the fibers and tubes does slow the splicing and connectorization processes. Note also that the majority of loose tube cables are NOT fire rated for indoor use at all, so when a loose tube cable enters a building, it either has to be run in conduit or spliced to a fire rated cable.

We are FiberStore Inc. If you would like to know more about optical fiber cables information and dont know where to buy fiber optic cable, please visit our website and contact us. We also supply fiber jumpers and fiber pigtails. Welcome to contact us.

Fiber Optic Cable Specification

Many structured cabling installations begin with the preparation of a detailed written specification for each system component. Such specifications may be necessary to ensure the correct product is used for the intended application. Specifications also ensure all products offered are equal in a competitive-bidding situation. Consultants and end users often find that they lack the breadth of knowledge or experience necessary to prepare a complete, detailed specification for optical fiber and fiber optic cable. This fact is not surprising because it takes a significant effort to keep abreast of changing product offerings as well as the most recent product evaluation and measurement technology. However, consultants and end users can use industry standards to specify the necessary products without having to delve into excruciating detail.

Specifications for optical fiber and cable can be, and often are, long and arduous; they address a myriad of technical considerations. These considerations include mechanical, environmental, and dimensional characteristics, not to mention the finished product’s compatibility with building codes and transmission equipment. Consultants and end users frequently prepare lengthy specifications, attempting to cover all pertinent details. This effort requires a thorough knowledge of cable design, optical science, and the details of scores of measurement methods. Panels of industry experts have developed national and international standards for fiber and cable; these standards can be the basis for the desired brief, accurate, detailed specifications.

Cables intended for direct burial underground should, in most cases, incorporate a steel tape armor for protection against gnawing rodents. Metallic armor has proven to be an effective rodent 
protection in controlled tests.

For aerial installations, outdoor fiber optic cable require a messenger wire for lashing. However, some cables have an integrated messenger wire in a figure-eight cross section. Also available today are some all dielectric self-supporting aerial cables, which contain no metallic elements but have sufficient tensile strength to support their own weight and a reasonable ice and wind load.

The most popular loose tube cable includes buffer tubes, each of which contains one to 12 color-coded fibers. Some other cables include ribbons of fiber, rather than loose fibers in buffer tubes. Up to 24 fibers, joined together side-by-side, form a fiber ribbon. Stacks of these ribbons are in buffer tubes, creating a cable with a large number of fibers in a small cross-sectional area. Ribbon cables are popular in telephony and other long-haul applications and useful in crowded ducts where dense packing offers an advantage. Mass-fusion-splicing technology allows installers to splice 12 fibers in a ribbon simultaneously, offering labor savings in high-fiber-count applications. Ribbon cables are not common in premises applications but may become more popular as fiber becomes more prevalent in premises networks.

Indoor/Outdoor

Indoor outdoor cable incorporate the characteristics necessary for both applications; they are waterblocked for moisture protection and are sunlight-resistant. Indoor/outdoor cables also meet one or more of the code requirements for flame-spread resistance and smoke generation.

They can be useful in eliminating a splice point for a building-to-building run in a campus environment. They resemble outdoor cables more closely than indoor cables in design and appearance 
and usually require a fanout kit for field termination.

Fiber optic cable specification

A detailed cable specification considers all environmental and regulatory factors that concern the installation environment, including temperature, mechanical loading, moisture, sunlight, 
flammability, rodents, and chemicals. Fully specifying each cable also requires a test or measurement method and criteria. Once again, standards are available to simplify this task.

Two sister documents published by the Insulated Cable Engineers Association (ICEA-South Yarmouth, MA) are useful as detailed product specifications. The ANSI/ICEA S-87-640 Standard for Outside Plant Communications Cable and the ANSI/ICEA S-83-596 Standard for Fiber Optic Premises Distribution Cable cover outside- and inside-plant cables, respectively. A third document, which will be designated S-83-696 and is currently in the works, will address indoor/outdoor cables. In addition to detailed references for test method, loading, and failure criteria for finished cable, these documents also include similar details for the optical fiber. ANSI/ICEA S-83-596 includes a summary of the flammability listing requirements from the NEC. Referencing these documents as appropriate for indoor or outdoor cable ensures you have included a full battery of environmental and mechanical testing and failure criteria in your specification.

In the United States, the federal government is another source for a detailed product specification. The Department of Agriculture’s Rural Utilities Service (RUS) has published a document entitled Specification for Filled Fiber Optic Cables, which provides detailed product specifications for singlemode and multimode fiber, as well as OSP loose-tube cable. The RUS specification even outlines requirements for production and type testing as well as data reporting and manufacturers’ recordkeeping. The RUS conducts technical reviews of cable manufacturers’ products and programs and includes compliant companies’ products on an “accepted list.” By specifying that an OSP cable must be RUS-listed, an end user can take advantage of the RUS’s efforts.

The Difference Between Loose Tube Fiber and Tight Buffer Fiber

Tight-buffered cables oftenn are used for intra-building, risers, general building and plenum applications. Tight buffer fiber contains a thick coating of a plastic-type material which is applied directly to the outside of each individual fiber. Loose tube fiber optic cable is typically used for outside-plant installation in aerial, duct and direct-buried applications. Loose tube fiber contains multiple strands of fiber in a single jacket. Since the fibers are “loose” inside the jacket, outside forces are less likely to reach the fibers. This makes it the more durable option of the two.

Loose Tube Cable

Loose-tube fiber generally consists of 12 strand of fiber, but can range anywher as low as 6, all the way up to 244 strands. Loose tube cables can be either dielectric or optionally armored. The modular buffer-tube design permits easy drop-off groups of fibers at intermediate points, without interfering with other protected buffer tubes being routed to other locations. The loose tube design also helps in the identification and administration of fibers in the system.

In a loose tube cable design, color-coded plastic buffer tubes house and protect optical fibers. An optional gel filling compound impedes water penetration. Excess fiber length (relative to buffer tube length) insulates fibers from stresses of installation and environmental loading. Buffer tubes are stranded around a dielectric or steel central member, which serves as an anti-buckling element.

The cable core, typically uses aramid yarn, as the primary tensile strength member. The outer polyethylene jacket is extruded over the core. If armoring is required, a corrugated steel tape is formed around a single jacketed cable with an additional jacket extruded over the armor.

Tight-Buffered Cable

Single fiber tight buffered cables are used as pigtails, optical patch cord or fiber jumpers to terminate loose tube cables directly into opto-electronic transmitters, receivers and other active and passive components. Multi fiber tight buffered cables also are available and are used primarily for alternative routing and handling flexibility and ease within buildings. With tight buffered cable designs, the buffering material is in direct contact with the fiber. This design is suited for “jumper cables” which connect outside plant cables to terminal equipment, and also for linking various devices in a premises network.

The tight-buffered design provides a rugged cable structure to protect individual fibers during handling, routing and connectorization. Yarn strength members keep the tensile load away from the fiber.

As with loose-tube cables, optical specifications for tight-buffered cables also should include the maximum performance of all fibers over the operating temperature range and life of the cable. Averages should not be acceptable.

Outdoor Loose Tube Cables Types

Outdoor Loose Tube Cables are designed for outdoor use. They are prositioned in a loose tube made of high modulus plastic. The loose tube design provides stable performance over a wide temperature range and is compatible with any telecommunication grade optical fiber.

GYXTY Optical Cables Type

Description

In the structure of model GYXTY optical cable, the single mode or multimode optical fibers are jacketed by loose tube and the tube is made of high modulus polyester with waterproof filling compound inside tube. There are two parallel steel wires on the two sides of the loose tube and then they are sheathed by PE to form and optical cable.

Features

. Accurate fiber excess length ensures good mechanical and temperature performance
. Special design with compact structure to prevent tube rebound
. Parallel double FRP as strength member ensures good performance of tensile strength
. PE sheath protects cable from ultraviolet radiation
. Crush-resistance and flexibility
. Small diameter, light weight and installation friendliness
. High strength loose tube with filling compound ensures critical protection of fiber

Application

. Usable for ducts, direct burial, aerial installation
. Long distance communication system
. Subscriber network system
. Local area network system

GYTA(S) Optical Cables Type

Description

GYTA(S) fiber optic cable 250um, is positioned in a loose tube which made of high moudlus plastic. The tube is filled with a water-resistant filling compound, a steel wire. sometimes sheathed with polyethylene(PE) for fiber cable with high fiber count, locates in the center of core as a metallic strenghth member. Tubes are fillers are stranded around the strength member into a compact and circriar cable core, An Aluminum polyethylene Laminate(APL) is applied around the cable core, which is filled with the tilling compound to protect it from water ingress.

Features

. Small size, Light weigh, with good bending resistance performance easy for installation
. Reasonable structure design and precise control for over length ensuring excellent characteristics of mechanical tensile strain and environment temperature
. High strength loose tube material with good performance of hydrolysis resistant, special tube. filling compound ensure a critical protection of fiber
. Full section filled ensures moisture-proof and water blocking
. Low dispersion and attenuation
. Proper design, precise control for fiber excess length and distinct stranding process render the cable excellent mechanical and environmental characteristics
. Aluminum-PE sheath makes cable have nice moisture resistance performance
. Small cable diameter, light cable weight, easily to install
. The sheath also can be made by LSZH, which cable type is GYTZA

GYTY Optical Cables Type

Description

GYTY optic fiber cable is with single-mode or multimode structure ,optical fibers are jacketed waterproof compound filled loose tube made of high modulus plastic tube. The center of the cable core is a metal strengthening core for a certain number of cores for the fiber optic cable, metal strengthen squeeze packet layer of polyethylene (PE) in addition to the core. Loose tube (filling cord) around the center to strengthen core twisted into a compact and circular cable core, the core is filled with water blocking compound, PE sheathed cabling.

Features

. Good mechanical and temperature performance
. High strength loose tube that is hydrolysis resistant
. Special tube filling compound ensure a critical protection of fiber
. Crush resistance and flexibility
. PE sheath protects cable from ultraviolet radiation
. Operating temperature:-30~+70℃; storage temperature:-40~+70℃

GYFTA/Y Optical Cables Type

Description

GYFTA/Y-53 fibers, 250μm, are positioned in a loose tube made of a high modulus plastic. The tubes are filled with a water-resistant filling compound. A Fiber Reinforced Plastic (FRP) locates in the center of core as a non-metallic strength member. The tubes (and fillers) are stranded around the strength member into a compact and circular core. An aluminum Polyethylene Laminate (APL) is applied around the strength member into a compact and circular core. Then the cable core is covered with a thin polyethylene (PE) inner sheath, which is filled with jelly to protect it from water ingress. After a corrugated steel tape armor is applied, the cable is completed with a PE outer sheath.

Features

. Good mechanical and temperature performance
. High strength loose tube that is hydrolysis resistant
. Special tube filling compound ensure a critical protection of fiber
. Crush resistance and flexibility
. The following measures are taken to ensure the cable watertight:
. Single Fiber Reinforced Plastics as the central strength member
. Loose tube filling compound
. 100% cable core filling
. APL moisture barrier
. PSP enhancing moisture-proof
. Water-blocking material
. Complies with Standard YD/T 901-2001 as well as IEC 60794-1

GYFTS Optical Cables Type

Description

GYFTS fiber optics cable, Loose tube style, with non-metallic central strength member of FRP and peripheral strength members with moisture barrier inner sheathed. Cable protected by a black PE over sheath, suitable for duct or aerial application.

Features

. Good mechanical and temperature performance
. High strength loose tube that is hydrolysis resistant
. Special tube filling compound ensure a critical protection of fiber
. Specially designed compact structure is good at preventing loose tubes from shrinking
. Crush resistance and flexibility
. PE sheath protects cable from ultraviolet radiation
. The following measures are taken to ensure the cable watertight
. Loose tube filling compound
. 100% cable core filling
. PSP enhancing moisture-proof

We also provides other types of loose tube cable, such as GYHTY, GYDTA, GYFXTY, GYXTS optical fiber cable. What’s more FiberStore provides a range of outdoor cables, breakout fiber optic cable, and optical patch cord. If you would like to know more about our optical cable price, please contact us sales@fiberstore.com.

Something About MPO MTP Fiber Cable

MPO/MTP stands for “Multiple-Fiber Push-On/Pull-off”. The purpose of MPO/MTP technology is that you can pull just one single cable with 8 (for example) fibers. So instead of patching 8 seperate fiber cables, you only need patch one cable with one connector. MPO/MTP Fiber Cable is used in various applications for all networking and device needs like 100 Gigabit modules.

MTP/MPO is usually used in ribbon fiber optic patch cords or ribbon fan out multi fiber assembiles. The ribbon fiber optic cables features multi fiberglass inside each single jacket, MTP/MPO is also multi fiberglass core inside each single connector. That is to say, there are several fiberglass connections in each single MTP/MPO fiber optic patch cord, for example, 4 fibers, 8 fibers, 12 fibers, etc. Typical MTP/MPO fiber optic patch cord assemblies like MTP/MPO to 8 LC, MTP/MPO to 12 MT-RJ, etc. MTP/MPO fiber optic patch cords are also available by single mode and multimode, like PC and APC Polish.

MTP fiber optic patch cable is with MTP fiber optic connectors which are upgrade version of the former MPO. MTP is with better mechanical and optic fiber performance compared with MPO. Both the MTP and MPO series cables are multi fiber connectors. There are many fiber optic channels in each single connector. Because of such multi fiber feature, these connectors need to use with multi fiber cables, especially the ribbon multi fiber optic cables.

MTP and MPO cable is available in female to female or a male to male and male to female configurations. The male version has MTP pins. These can be made with 12 fiber MTP connectors, 24 fibers MTP connectors, 48 fiber MTP connector variations. We use MTP fiber optic connectors for all of our MTP and MPO terminations so that the highest performance is accomplished. Many additional options and combinations are available. All multi fiber optic cables are customizable.

To have a better understanding of MTP, I will introduce you some MTP terminology as following:

About MTP Trunks

The MTP Trunk cable is designs for Data Center Applications. This cable is a round cable with the outer diameter of 3,0 mm or 4,5 mm (with two jackets on both sides).The connectors where this cable is terminated on is the so called MTP connector (female).

About MTP Fiber Optic Cassette
The MTP cassette is nothing more than a basic case which splits out MTP to SC/LC connectors, which is available for 12 SC/LC connectors and 24 connectors.

About MTP fanouts

MTP fanout cables are cables that are multiple cables that are bundeled within the same jacket.This is also often refered as a Breakout cable.

About Direct Splits (MTP to LC or MTP to SC cables)

MTP Direct Split cables are cables with the fanout made directly in the MTP connector. These are designed for high density Data Center applications to plug into MTP casettes and/or MTP patch panels.

FiberStore provides many fiber optic products such as fiber patch cables, hybrid cableloose tube cable, outdoor fiber optic cable and more. MPO/MTP fiber patch cables are available in UPC and APC finishes, and support both multimode and single mode applications. These fiber cables are tested with guaranteed quality, and they can be installed easily, which saves time and money.

How To Buy Bulk Fiber Optic Cable

Optical Fiber Cable Construction

The structure of bulk fiber optic cables have many important characteristics. The fiber optic cable construction needs to provide protection from the external environment in the installation and the fiber optic cable work life time.

They must provide mechanical protection for all the fibers inside the cable, in the meantime, the fiber optic cable has to be pretty easy to handle. Most the time, non-metallic strength members are needed to fully take advantage of fiber’s dielectric property.

Bulk fiber optic cable will experience tensile stress, abrasion, cutting, flexing, bending, crushing during the installation and its operation life. These mechanical stresses introduce macrobending, microbending, light signal loss attenuation.

Due to incomplete production, small surface defects often exist in the optical fibers. So in the real world, fibers tend to break at the cracks that begin from these surface defects under heavy tensile tension.

Bulk Fiber Optic Cable Structural Elements

Optical cables can be divided into several main types. However, the basic elements in a fiber cables are a central strength member, be it metallic or non-metallic, strength members, water barrier (dry water swelling tapes or water blocking gel), a fiber housing (loose tube), and cable sheaths. Armored fiber cables also have aluminum or steel armors for rodent protection for direct burial.

A central strength member sitting in the center of the cable, fiber glass do most of the time. The center provides rigid cable strength members, prevent bulk fiber cable from bending too fast. It also provides the core of the cable.

In addition to the power of the central member, as another layer of fiber strength member is also used. They are made from aramid yarn (most of the time), Nylon yard, fiber glass epoxy rod or even steel. Aramid yarn is also called Kevlar, it has a high breaking strain and about fiber times stronger than steel. They offer low weight and all-dielectric construction.

Types of Bulk Fiber Optic Cable

Bulk fiber optic cables can be categorized into several major types. That includes outdoor cablefiber optic breakout cable, Ribbon Fiber cable, Figure 8 Aerial cable, Loose tube cable and more.

To learn more about the type of fiber cable available on the market, or want to purchase our cable, please visit our website. As one of the best OEM fiber optic cable manufacturers, FiberStore provides a wide range of quality optical fiber cables with detailed specifications displayed for your convenient selecting. Per meter price of each fiber cable is flexible depending on the quantities of your order, making your cost of large order unexpected lower. Customers can also have the flexibility to custom the cable plant to best fit their needs. Only fiber cable that meets or exceeds industry standards is used to ensure quality products with best-in-class performance.

Fiber Optic Cable Construction

In any detailed discussion of how to deal with fiber optic cable, some fibers are discussed briefly and cable design is required. Eliminating confusion of different terms, and to provide an 
understanding of cable construction will make handling the products less complicated.

Fiber

The cable cross section is two fiber cables for interconnect applications. The construction of the glass can be looked at separately from the design of the cable, as the fiber itself is constructed using distinct materials and is shipped by the fiber manufacturer as a finished product. FiberStore takes the coated optical fiber and incorporates it into a multitude of finished cable products.

All of the glass fiber used by FiberStore is manufactured using the same basic construction. Two layers of glass are covered by a protective coating, the fiber’s core and cladding are both made of silica glass. It is these two layers that propagate the light signal and determine the performance of the fiber. A slight difference in optical characteristics between these layers keeps the signal within the core region. The glass is protected by a dual layer of ultra-violet-cured acrylate material.The coating protects the surface of the glass from abrasion during normal routine handling, there by ensuring the glass maintains it’s high tensile strength. The acrylate coating, which also functions optically by stripping out any light which might enter the cladding region, isremoved for termination and splicing.

Buffer Types

All of FiberStore fiber optic cables fall into one of two categories: tight buffered or loose tube buffered. The two cable buffer styles exhibit different optical, mechanical, and costcharacteristics. Originally, loose tube cable constructions were developed for long haul telephony applications which required a rugged, low cost, high fiber count outside plant cable solution. In a premises wiring plan this cable type is often used between buildings, although recent developments in cable design have produced loose tube cable for indoor/outdoor applications (know indoor outdoor cable). The tight buffer cable construction was developed for both indoor and outdoor premises wiring applications. Most of FiberStore’s tight buffer cables are rugged enough for many inter building applications while offering the tight buffer design advantages of ease of terminations, meeting NEC flammability codes, and cable flexibility.

Tight Buffered Fiber

A thermoplastic material is extruded directly over the acrylate coating, increasing the outside diameter of the fiber to 900 micros (0.9 mm), an industry standard. The tight buffer supplies the fiber with added mechanical and environmental protection, increased size for easy handling, and a simple means of adding color coding for fiber identification. During connectorization, the buffer is stripped back to an exact length as required by the connector manufacturer.

Loose Buffered Fiber

In loose tube cable, the coated fiber “floats” within a rugged, abrasion resistant, oversized tube which is filled with optical gel. Since the tube does not have direct contact with the fiber, any cable material expansion or contraction will not cause stress on the fiber. Much of the external stress placed on the tube also will not be transferred to the fiber. The non-hygroscopic gel prevents water from entering the tube.

Strength Members

FiberStore optical fiber cable designs utilize aramid yarn as the primary strength member. Some designs also use a fiberglass central strength member. Both of these materials serve as the load bearing members of an optical fiber cable during installation. In many cables the aramid also acts as a strength member during termination.

Core Wrap and Ripcords

Core wraps and ripcords are designed to make removal of the exterior cable sheath easier, preventing unnecessary stress to the core. The non-hygroscopic core wrap creates a barrier between the core and the jacket, preventing adhesion and facilitating jacket removal. Ripcords provide a means of stripping back the jacket without the use of invasive tools which could harm the cable core and damage fibers.

Outer Jacket

The true cable jacket is usually the outermost element in the cable design. It serves to protect the cable against environmental hazards and gives the installer a mean of managing the cable. Without the outer jacket, in many designs the buffered fibers would have only the aramid wrap to cover them. Typical jacket materials include Polyvinylchloride (PVC), Polyethylene (PE) or Polyvinylidene Fluoride (PVDF). Also, without selectively choosing the appropriate jacket material most cables would be entirely incapable of passing a flame test. Outer jackets are always stripped back to expose the fibers at the point of termination or connectorization.

If you would like to buy our optical fiber cables or want to know more about outdoor cables,hybrid cable please visit our website.

Introducing Two Basic Cable Design

There are two basic cable design, loose tube cable and tight buffered cable. Loose-tube cable, used in the majority of outside-plant installations in North America, and tight-buffered cable, primarily used inside buildings.

The modular design of loose-tube cables typically holds up to 12 fibers per buffer tube with a maximum per cable fiber count of more than 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The modular buffer-tube design permits easy drop-off of groups of fibers at intermediate points, without interfering with other protected buffer tubes being routed to other locations. The loose-tube design also helps in the identification and administration of fibers in the system.

Single-fiber tight-buffered cables are used ase pigtails, patch cords and jumpers to terminate loose-tube cables directly into opto-electronic transmitters, receivers and other active and passive components.

Multi-fiber tight-buffered cables also are available and are used primarily for alternative routing and handling flexibility and ease within buildings.

Loose Tube Cable

In a loose-tube cable design, color-coded plastic buffer tubes house and protect optical fibers. A gel filling compound impedes water penetration. Excess fiber length (relative to buffer tube length) insulates fibers from stresses of installation and environmental loading. Buffer tubes are stranded around a dielectric or steel central member, which serves as an anti-buckling element.

The cable core, typically surrounded by aramid yarn, is the primary tensile strength member. The outer polyethylene jacket is extruded over the core. If armoring is required, a corrugated steel tape is formed around a single jacketed cable with an additional jacket extruded over the armor.

Loose-tube cables typically are used for outside-plant installation in aerial, duct and direct-buried applications.

Tight-Buffered Cable

With tight-buffered cable designs, the buffering material is in direct contat with the fiber. This design is suited for “jumper cables” which connect outside plant cables to terminal equipment, and also for linking various devices in a premises network.

Multi-fiber, tight-buffered cables often are used for intra-building, risers, general building and plenum applications.

The tight-buffered design provides a rugged cable structure to protect individual fibers during handling, routing and connectorization. Yarn strength members keep the tensile load away from the fiber.

As with loose-tube cables, optical specifications for tight-buffered cables also should include the maximum performance of all fibers over the operating temperature range and life of the cable. Averages should not be acceptable.

If you’d like to purchase or learn more about our loose tube cable, breakout fiber cable or hybrid cable, simply visit our offical website or call our customer service.

The Different Types of Optical Fiber Cable?

There are many types of fiber optic cable used to supply data to mobile phones, computers and TVs, each handling light in a different way, and each made for a different application. There are two main types of optical fiber cable, multimode and single mode, which use either several beams of light or a single beam at once. Simplex cables use only one or two optical fibers and Kevlar protection. Tightpack cables contain many optical fibers, but the fibers are not individually terminated. Loose tube cables include a water blocking gel and are used outdoor or are buried underground.

Multimode and single mode are the two main types of optical fiber cable, though the terms do not refer so much to the cable design as to how the fibers interact with light. The multimode version sends out many different light beams at once, and each is sent at a different angle so the beams cannot interact with each other, eliminating the chance of interference. These types of optical fiber cable can only be used for short distances; otherwise, the light beams begin to interfere with on another. Single mode optical fibers send only one beam of light at a time, making them ideal for long distances, because there are not multiple light beams to cause interference.

While a multi-mode optical fiber is cheaper than a single-mode fiber, it is only effective at supplying power to short distances, around 1,968 feet (600 meters). This is because of the different light rays working at once. If the cable is used for longer distances, the light rays begin either to conflict or disperse, meaning that power is inefficiently transferred or will not reach the target destination.

Simplex cables are simplx fiber optic cables that are used for backplanes and patch cord purposes. The outside is reinforced with Kevlar to keep the optical fibers from wearing down as a result of outside stress. Inside, there are only one or two fibers, which make it good for applications for which limited energy is needed.

Tightpack cables are similar to simplex but include many more fibers. The fibers are paired up and jacketed, as with the simplex cables, but there are many pairs, not just one. A major difference, aside from fiber number, is that the fibers are not individually terminated or protected, so there must be a termination unit connected to these types of optical fiber cable. These cables are used mostly for dry conduit runs over short distances.

Loose-tube cable does not use protection or jacketing for their internal fibers, but have another way of keeping the fibers safe. The insulation is filled with a water-blocking gel that is able to keep water from leaking into the cable and also keeps the fibers safe by adding durability to the inside of the cable. These cables are often used outdoor, either in the air or buried underground.

FiberStore is a fiber network solution website, want to know more about outdoor cablefiber optic cable specification please visit our website.

What is Loose Tube Fiber Optic Cable

Loose tube cable: small, thin plastic tubes containing as many as a dozen 250 micron buffered fibers used to protect fibers in cables rated for outside plant use. They allow the fibers to be isolated from high pulling tension and can be filled with water-blocking materials to prevent moisture entry.

Loose tube cables are the most widely used cables for outside plant trunks because it offers the best protection for the fibers under high pulling tensions and can be easily protected from moisture with water-blocking gel or tapes.These cables are composed of several fibers together inside a small plastic tube, which are in turn wound around a central strength member, surrounded by aramid strength members and jacketed, providing a small, high fiber count cable. This type of cable is ideal for outside plant trunking applications, as it can be made with the loose tubes filled with gel or water absorbent powder to prevent harm to the fibers from water. It can be used in conduits, strung overhead or buried directly into the ground. Some outdoor cables may have double jackets with a metallic armor between them to protect from chewing by rodents or kevlar for strength to allow pulling by the jackets. Since the fibers have only a thin buffer coating, they must be carefully handled and protected to prevent damage. Loose tube cables with singlemode fibers are generally terminated by spicing pigtails onto the fibers and protecting them in a splice closure. Multimode loose tube cables can be terminated directly by installing a breakout kit, also called a furcation or fan-out kit, which sleeves each fiber for protection.

Loose tube materials for loose tube cables need to possess a relatively high modulus and good processability. During manufacture, optical fiber is fed into the loose tube at a faster rate than it is being produced so that the optical fiber is laid helically within the tube.

To buffer the fibers from each other and from any perturbations on the tube walls, the loose tube is filled with a gel compound similar in composition to the water blocking gels in conventional telecommunication cables. The loose tube material must therefore be compatible with the gel as in conventional cable insulation.

Structure of a Loose Tube Fiber Optic Cable

Elements in a loose tube fiber optic cable:

1. Multiple 250um coated bare fibers (in loose tube)
2. One or more loose tubes holding 250um bare fibers. Loose tubes strand around the central strength member.
3. Moisture blocking gel in each loose tube for water blocking and protection of 250um fibers
4. Central strength member (in the center of the cable and is stranded around by loose tubes)
5. Aramid Yarn as strength member
6. Ripcord (for easy removal of outer jacket)
7. Outer jacket (Polyethylene is most common for outdoor cables because of its moisture resistant, abrasion resistant and stable over wide temperature range characteristics.)

Futures

. Good mechanical and temperature performance
. High strength loose tube that is hydrolysis resistant
. Special tube filling compound ensure a critical protection of fiber
. Two parallel steel wires ensure tensile strength
. PE sheath protects cable from ultraviolet radiation
. Small diameter, light weight and friendly installation
. Long delivery length

More information about fiber optic cable cost, fibre optic cable specification please visit our website.