KR100633905B1 - Optical fiber unit for air blown installation, method and apparatus for manufacturing the same - Google Patents

Abstract

The optical fiber unit installed by air pressure includes an optical fiber and a protective layer surrounding the optical fiber, and one or more negative bands are formed on the outer circumferential surface of the protective layer along the longitudinal direction of the protective layer, thereby increasing the surface resistance with air pressure. The efficiency of pneumatic laying work can be improved. The negative strip is formed in a spiral, wavy or triangular wave shape on the outer circumferential surface of the protective layer, and the cross section of the negative strip is triangular, semicircular, arc or rectangular. The optical fiber is in the form of a single core, a two core or a ribbon, and the protective layer is composed of a buffer layer or a buffer layer / shell layer or a buffer layer / intermediate layer / shell layer.

Pneumatic laying, fiber optic unit, intaglio, surface resistance

Description

Optical fiber unit for pneumatic laying, manufacturing method and device thereof {OPTICAL FIBER UNIT FOR AIR BLOWN INSTALLATION, METHOD AND APPARATUS FOR MANUFACTURING THE SAME}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a cross-sectional view showing an optical fiber unit according to the prior art.

2 is a cross-sectional view showing another optical fiber unit according to the prior art.

3 is a perspective view showing an optical fiber unit for pneumatic installation according to an embodiment of the present invention.

4 is a perspective view showing an optical fiber unit for pneumatic installation according to another embodiment of the present invention.

5 is a perspective view showing an optical fiber unit for pneumatic laying according to another embodiment of the present invention.

6A to 6F are cross-sectional views illustrating a negative band formed on a surface of an optical fiber unit having various structures.

7A to 7C are cross-sectional views illustrating a negative band formed on a surface of an optical fiber unit having various structures in which an optical fiber ribbon is used.

8 schematically illustrates a facility for manufacturing an optical fiber unit according to an embodiment of the invention.

9 is a schematic illustration of a facility for manufacturing an optical fiber unit in accordance with another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber unit, and more particularly, to an optical fiber unit, a method and a device for manufacturing the same, which are installed by pneumatically laid.

Fiber has been widely used as a long-distance high speed transmission medium due to its low transmission loss and large bandwidth. However, since the optical fiber itself is very vulnerable to external impact or bending, in order to install the optical fiber, the optical fiber has been manufactured to prevent breakage through the coating of the polymer material at the same time.

Conventionally, a method of laying an optical fiber has been used to bundle and twist the optical fiber in several strands, then cable the installation. Fiber optic cables include multiples of 6 or 12 multiples of fiber, and typically deploy much more fiber than necessary at the time of installation, taking into account future demand. However, as communication systems are diversified to suit new communication environments and capacities, and the types of optical fibers are diversified accordingly, existing methods of laying a large amount of specific optical fibers without considering the future environment are not desirable. . In addition, it is difficult to determine in the present time which optical fiber or optical cable will be applied in terms of the user terminal, that is, the access network part or the premise wiring. Therefore, it is economically undesirable to lay a large amount of a particular optical fiber cable at a high cost.

On the other hand, in recent years, the method of laying the optical fiber unit which collected several optical fiber strands using air pressure for the purpose of laying using a narrow space is employ | adopted widely. An attempt to deploy an optical fiber unit using pneumatic pressure was first presented in US Pat. No. 4,961,896, filed by British Telecom, UK, around 1980. Also known as Air Blown Fiber (ABF), this technology uses a diameter of five to five microtubes or ducts with a special composition for lubrication so that the user can additionally embed the optical fiber whenever needed. The tube of about 8mm polymer is buried in the installation area in advance, and the optical fiber unit composed of 1 to 12 cores is blown by air pressure as much as necessary.

The ABF is not only easy to install but also easy to remove, small in size and flexible, which reduces initial installation cost, reduces the burden on additional installation, and is easy to upgrade in the future. In particular, ABF is also suitable for indoor use, such as FTTH (Fiber To The Home), home network.

Since ABF installs only the tubes required for laying, it is hardly restricted even if the installation space such as pipelines is not free. The general process for laying ABF is as follows:

First, a dedicated tube for pneumatic laying is installed in the required section in advance, and the necessary optical fiber unit (ABF) is blown into the tube using a pneumatic laying head (Blowing head) for laying. The ABF has the structure and material that can maximize the fluid towing force on the outer surface of the optical fiber unit because it is the biggest difference from the existing method to install using the fluid drag force of the fluid. In addition, since the installation characteristics such as the installation distance and the minimum installation radius vary depending on the structure and material of the ABF outer surface, the shape and material design of the outer surface are very important.

To date, there are various types of ABF structures for increasing the flow traction of the fluid, and representative patent technologies include US5,042,907, US5,533,164, US5,555,335, US4,440,053, US6,341,188. They mainly disclose the improvement of the ABF outer surface.

First, US Pat. No. 5,042,907 proposes an optical fiber unit that uses glass beads 5 on its outer surface to receive more air pressure as shown in FIG. In order to form the glass beads 5 on the outer surface of the optical fiber, the glass beads 5 are pre-stirred to the coating resin of the optical fiber 1 and then uniformly applied. However, when using this method, the glass beads 5 contained in the resin 4 on the outer surface of the optical fiber should be relatively larger than the thickness of the coating layer and have a high Young's modulus to give a driving force. As a result, the optical fiber unit has a relatively poor bend characteristic, and a crack occurs between the glass beads 5 and the resin 4, thereby causing a problem of propagating the cracks into the optical fiber.

In order to solve this problem, a technique of inserting an intermediate layer (3) between the inner buffer layer 2 and the resin 4 on the outer surface has been proposed. In this case, however, the coating has to be repeated three or more times, resulting in a complicated process and an increase in cost.

Also, as another conventional example, the technique proposed in US Pat. No. 5,555,335 is shown in FIG. 2. Referring to FIG. 2, the patent does not pre-agitate the glass beads 5 to the resin, but the resin is coated on the optical fiber 1, and then the glass beads are blown before hardening, and electrostatically attached to the outer surface 6 of the optical fiber. Is proposing. However, this method has a problem that it is difficult to apply to the actual process because the adhesion strength of the glass beads and the outer surface of the optical fiber is not evenly distributed. In particular, if some glass beads are dropped, the glass beads may damage the optical fiber unit during the laying operation or be inhaled by the operator, causing a fatal problem for the human body.

As another conventional example, US Pat. No. 5,441,813 proposes a technique of forming a concave dimple on the surface of an optical fiber by using a foamable polymer material so that the optical fiber unit is subjected to a lot of air pressure. However, when the foamable polymer material is used, the friction coefficient of the outer surface of the ABF is increased, thereby shortening the distance that can be laid at once, and the low temperature characteristics and the strength of the optical fiber unit are deteriorated by the polymer material. .

In addition, in the case of ribbon optical fiber, a method of wrapping and wrapping a fiber of a special material has been proposed, but since the ribbon optical fiber has a direction against bending, it is found to be vulnerable such as bending only in one direction when laying. It became.

The present invention was devised to solve the above problems, and does not generate directionality during pneumatic installation, while receiving a lot of fluid traction, pneumatic laying that can be manufactured more safely without using fine particles such as glass and ceramics. It is an object of the present invention to provide an optical fiber unit.

Another object of the present invention is to provide a manufacturing method of the optical fiber unit for pneumatic installation, which can more easily manufacture the above-described air pressure optical fiber unit.

Still another object of the present invention is to provide an apparatus for manufacturing the above-described pneumatic fiber optic unit.

In order to achieve the above object, the optical fiber unit for pneumatic installation according to the present invention comprises at least one optical fiber including a core and a clad; And a protective layer surrounding the optical fiber, wherein one or more intaglio bands are formed on an outer circumferential surface of the protective layer along the longitudinal direction of the protective layer.

In this case, the intaglio band may be formed on the outer circumferential surface of the protective layer in a spiral, wavy or triangular waveform. Furthermore, the intaglio may be formed discontinuously.

In addition, the cross section of the intaglio may be blunt triangle, semi-circular, arc-shaped or square.

In this case, the optical fiber is a plurality, the plurality of optical fibers may be present in the form of a ribbon in the protective layer, a tensile reinforcing member for strengthening the tensile strength with the ribbon-shaped optical fiber may be provided in a ribbon form.

In addition, in the above-described configuration, the protective layer may be formed of only the buffer layer, the buffer layer and the outer layer, or the buffer layer, the intermediate layer and the outer layer. At least the outermost layer of the intaglio banded protective layer is 100 MPa to 1000 MPa at 2.5% strain. It is desirable to have secant modulus.

According to another aspect of the present invention, there is provided a method for manufacturing an optical fiber, comprising: supplying an optical fiber unit having at least one optical fiber and a protective layer surrounding the optical fiber; And forming one or more intaglio bands along the longitudinal direction of the protective layer on the outer circumferential surface of the protective layer of the supplied optical fiber unit.

Preferably, the intaglio strip forming step is performed by a machining apparatus, the machinability is to form the intaglio strip on the outer peripheral surface of the protective layer through the groove cutting process.

In addition, the machinable device may perform a groove cutting while rotating in one direction during the progress of the optical fiber unit to form a spiral engraved band on the outer circumferential surface of the protective layer, or clockwise and Groove cutting may be performed while rotating counterclockwise to form an intaglio strip of wavy or triangular waveform on the outer circumferential surface of the protective layer. Further, the machine factory may be discontinuously performing groove cutting to form a discontinuous intaglio on the outer circumferential surface of the protective layer.

Meanwhile, as described above, the optical fiber unit having a negative band on the outer circumferential surface passes one or more optical fibers having a core and a clad through a coating die having one or more predetermined protrusions formed on the hollow inner circumferential surface, and on the outer circumferential surface of the optical fiber. By supplying the polymer resin, it can also be produced by the manufacturing method of the air pressure optical fiber unit for forming a protective layer formed with one or more intaglio in the longitudinal direction on the outer peripheral surface thereof.

According to another aspect of the present invention, there is provided an apparatus comprising: means for supplying an optical fiber unit having at least one optical fiber and at least one protective layer surrounding the optical fiber; Cutting means for forming one or more intaglio bands along the longitudinal direction of the protective layer through groove cutting on the outer peripheral surface of the protective layer of the supplied optical fiber unit; And a take-up means for winding the optical fiber unit processed by the cutting processing means.

On the other hand, as described above, the optical fiber unit having a negative band on the outer peripheral surface, means for supplying one or more optical fibers including a core and a clad; A coating die for passing the supplied optical fiber therein and supplying a polymer resin to an outer circumferential surface of the optical fiber to form a protective layer; And take-up means for winding an optical fiber unit having a protective layer formed by the coating die, wherein the coating die has one or more predetermined protrusions formed on an inner circumferential surface thereof, and at least one intaglio band on an outer circumferential surface of the protective layer. It can also be manufactured by the apparatus for manufacturing an air pressure optical fiber unit for forming a.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be water and variations.

3 is a perspective view showing an optical fiber unit for pneumatic installation according to an embodiment of the present invention. Referring to FIG. 3, the optical fiber unit of the present invention includes one or more optical fibers 10 and a protective layer 20.

The optical fiber 10 is a quartz or plastic optical fiber having a core and a clad. In addition, one or more optical fibers 10 are provided in the form of a single core or a ribbon. Primary and secondary coating layers for protecting the optical fiber may be formed around the optical fiber 10 described above. This coating layer serves to protect the inner layer from dust and moisture and is made of silicon or similar buffer material. In addition, a coloring coating layer for identifying the type of optical fiber may be used as the secondary coating layer. In addition, when easy strippability is required depending on the type of polymer resin applied to the coloring coating layer, an optical cable jelly or silicone oil may be applied to the outer circumferential surface of the coloring coating layer.

The protective layer 20 is formed around the optical fiber 10 described above, and around the coating layer when the primary and secondary coating layers are formed. The protective layer 20 may be formed of only one type, or may be configured by stacking various types of protective layers. As an example, the protective layer 20 is formed in a double structure of the buffer layer 22 and the outer skin layer 24. Here, the buffer layer 22 is a protective layer directly surrounding the optical fiber 10, and the outer skin layer 24 is a protective layer in which the intaglio band 30 to be described later is formed. The protective layer 20 of the present invention, however, is not limited to the examples described above and may include various forms of modification. For example, the protective layer 20 may be composed of only the buffer layer 22, and may further include an intermediate layer between the buffer layer 22 and the outer skin layer 24 described above. Various kinds of such protective layers 20 will be described in detail later. In addition, the protective layer 20 performs various roles such as protecting the optical fiber and securing the rigidity of the optical fiber according to the type of application.

In such an optical fiber unit, an intaglio band 30 is formed to assist the air pressure installation. The intaglio strip 30 is formed on the outer circumferential surface of the protective layer 20 by mechanical processing. In particular, when the protective layer 20 is composed of a plurality of layers, the negative strip 30 is formed on the outer peripheral surface of the outermost protective layer.

The intaglio 30 is formed along the longitudinal direction of the protective layer 20 on the outer circumferential surface of the protective layer 20. In addition, although only one intaglio 30 is formed on the outer circumferential surface of the protective layer 20, it is also possible to simultaneously form a plurality of intaglio 30. In addition, the intaglio strip 30 may be formed in a straight shape on the outer circumferential surface of the protective layer 20, it is more preferable to have a curved shape in order to receive more pressure during air pressure installation. In FIG. 3, the intaglio strip 30 is illustrated as being spirally formed on the outer circumferential surface of the protective layer 20 as an example.

In addition, the intaglio 30 is formed by processing a continuous groove on the outer peripheral surface of the protective layer 20 through mechanical processing. At this time, the cross-sectional shape of the intaglio strip 30 is determined by the shape of the cutting tool used in the machining, the end of the various shapes such as triangles, semicircles, arcs, squares, trapezoids with blunt ends are applied to the intaglio strip 30. Can be.

As such, the intaglio band 30 formed on the outer circumferential surface of the protective layer 20 serves to reduce the contact area with the inner surface of the tube and increase the contact area with air when the optical fiber unit is installed in a narrow space such as a tube. . That is, the contact area between the outer circumferential surface of the protective layer 20 and the inner circumferential surface of the tube is reduced by the intaglio 30 so that the frictional force is reduced, and the area exposed to the air flow during installation is increased due to the compressed air. Make the installation more effective.

The engraved strip 30 formed as described above increases the resistance to the air flow flowing around the protective layer 20 in the air pressure installation process of the optical fiber unit, thereby making it easier to install the optical fiber unit. In particular, when the intaglio strip 30 is formed in a spiral as in this embodiment, the resistance to air pressure becomes larger than when it is straight.

Therefore, the present invention does not need to attach particles such as polymer beads or glass beads to the outer circumferential surface of the protective layer 20, and does not require a process of stirring or attaching the beads to the resin. Do not.

4 illustrates an optical fiber unit according to another embodiment of the present invention. The optical fiber unit of this embodiment is similar to that shown in FIG. 3, except that the concave strip 40 formed on the surface of the protective layer 20 has a form different from the above-described embodiment.

In the present embodiment, the intaglio band 40 is formed in a wavy pattern on the outer circumferential surface of the protective layer 20. The intaglio band 40 may be formed on the outer circumferential surface of the protective layer 20. When the intaglio strip 40 is formed as described above, the air flow flowing to the periphery of the intaglio strip 40 is alternately resisted to both sides according to the shape of the intaglio strip 40. Therefore, while the intaglio band 30 of the previous embodiment receives the air resistance only in one direction, the optical fiber unit can be twisted in one direction during the pneumatic laying, whereas the intaglio band 40 of this embodiment has alternating resistance in both directions. There is an advantage that the optical fiber unit can be installed in a twisted state.

Meanwhile, in the present embodiment, the intaglio 40 is illustrated and described in a wavy pattern, but the present invention is not necessarily limited thereto. For example, intaglio strips of various shapes such as triangular waveform (zigzag) or trapezoidal waveform are possible.

5 shows an optical fiber unit according to another embodiment of the present invention. The optical fiber unit of this embodiment is similar to that shown in Figs. 3 and 4, except that the intaglio band 50 formed on the surface of the protective layer 20 has a different form from the above-described embodiment.

In the present embodiment, the intaglio band 50 is formed in a discontinuous wave pattern on the outer circumferential surface of the protective layer 20. The intaglio band 50 may be formed on the outer circumferential surface of the protective layer 20. When the discontinuous wave-shaped intaglio 50 is formed as described above, the air flow flowing to the periphery of the intaglio 50 is alternately resisted to both sides as in the intaglio 40 of FIG. 4. . Therefore, the intaglio strip 50 of this embodiment also has the advantage that the optical fiber unit can be installed untwisted by alternating resistance in both directions.

On the other hand, in the present embodiment, the discontinuous intaglio 50 is shown and described in a wavy pattern, but the present invention is not necessarily limited thereto. For example, the spiral intaglio 30 as shown in FIG. 3 may be discontinuously formed.

3 to 5, the intaglio strips 30, 40 and 50 of various shapes are determined by the operation method of the processing apparatus used to form the intaglio strips. That is, when the processing device is rotated only in one direction during the formation of the intaglio band, the spiral intaglio band 30 shown in FIG. 3 is formed, and when the processing device is alternately rotated in both directions, the wavy intaglio band shown in FIG. 4 ( 40) is formed. In addition, when the processing apparatus is operated discontinuously, the discontinuous negative strip 50 shown in FIG. 5 is formed. In addition, in addition to the above-described shape, the intaglio may be implemented in various shapes, the operation method of the processing apparatus is determined according to the shape, of course. Such processing apparatus and its operation will be described in detail later.

6A to 6F illustrate an optical fiber unit in which a single-core or two-core optical fiber is surrounded by various kinds of protective layers.

First, the optical fiber unit shown in FIG. 6A has an optical fiber 10 therein, and has only a buffer layer 22 as a protective layer around the optical fiber 10. In addition, the intaglio strip 30 described above is formed on the outer circumferential surface of the buffer layer 22. Of course, the intaglio strip 30 formed on the outer circumferential surface of the buffer layer 22 may have various shapes such as a spiral or a wavy pattern, and the cross-sectional shape may also be implemented in various forms.

The optical fiber unit shown in FIG. 6A is the most basic configuration of the optical fiber unit, in which the buffer layer 22 directly surrounds the optical fiber 10 and serves as a protective layer. Therefore, in the present embodiment, the buffer layer 22 is preferably made of a harder material than the buffer layer generally used for the rigidity of the optical fiber unit and the smooth processing of the intaglio 30. Preferably, the buffer layer 22 used in the present embodiment has a modulus of secant modulus of 2.5 MPa or more and a modulus of elasticity of 20 MPa or more, more preferably 100 MPa or more.

The optical fiber unit shown in FIG. 6B has a form similar to that shown in FIG. 6A, but an outer skin layer 24 is further formed on the outer circumferential surface of the buffer layer 22. Therefore, the intaglio band 30 is formed on the surface of the outer skin layer 24 which is the outermost layer of the optical fiber unit.

In the case of this embodiment, since the outer skin layer 24 is formed outside the buffer layer 22, the thing of the kind generally used is suitable. On the other hand, the material of the outer skin layer 24 located outside the buffer layer 22 should be determined in consideration of the rigidity of the optical fiber unit and the smooth processing of the intaglio 30. If the modulus of the outer skin layer 24 is too low, it is difficult to secure straightness when laying the optical fiber unit by air pressure, and if the modulus is too high, cracking due to bending may occur. Therefore, the modulus of the outer skin layer 24 is suitable for 400 ~ 1000MPa at 2.5% strain, more preferably 500 ~ 800MPa at 2.5% strain.

Next, the optical fiber unit illustrated in FIG. 6C has a form in which an intermediate layer 26 is added to the optical fiber unit illustrated in FIG. 6B. The intermediate layer 26 is located between the buffer layer 22 and the skin layer 24 and is not directly affected by the intaglio 30. The intermediate layer 26 serves to protect the crack from propagating therein when a crack such as a crack occurs in the outer layer 24. In the present embodiment, the modulus of the outer skin layer 24 is preferably 400 to 1000 MPa at 2.5% strain, more preferably 500 to 800 MPa. In addition, in the present embodiment, the intaglio band 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit.

The optical fiber unit shown in FIG. 6D is similar to that shown in FIG. 6B, but the primary coating layer 12 and the secondary coating layer 14 are further formed between the optical fiber 10 and the buffer layer 22. The primary coating layer 12 serves to protect the optical fiber 10, the coloring coating layer for identifying the optical fiber 10 is used as the secondary coating layer (14). In the present embodiment, the modulus of the outer skin layer 24 is preferably 400 to 1000 MPa at 2.5% strain, more preferably 500 to 800 MPa. In addition, in the present embodiment, the intaglio band 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit.

The optical fiber unit shown in FIG. 6E is similar to that shown in FIG. 6D, but the intermediate layer 26, which serves to protect the crack from propagating therein in case of a crack such as a crack in the outer layer 24, has a coloring coating layer. It is further formed between the 14 and the buffer layer 22. In the present embodiment, the modulus of the outer skin layer 24 is preferably 400 to 1000 MPa at 2.5% strain, more preferably 500 to 800 MPa. In addition, in the present embodiment, the intaglio band 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit.

In the optical fiber unit illustrated in FIGS. 6A to 6E, only one optical fiber 10 is used. This means a single-core optical fiber unit, and the present invention is not necessarily limited to the single-core optical fiber unit. For example, as shown in FIG. 6F, the two-core optical fiber unit can be sufficiently implemented. In FIG. 6F, as an example, the protective layer of the optical fiber has a shape similar to that shown in FIG. 6E, and two optical fibers 10 exist within the protective layer. Each optical fiber 10 is also surrounded by a primary coating layer 12 and a coloring coating layer 14. Also in this embodiment, the modulus of the outer skin layer 24 is preferably 400 to 1000 MPa at 2.5% strain, more preferably 500 to 800 MPa. In addition, in the present embodiment, the intaglio band 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit.

6A through 6F, two to four intaglio bands 30 are formed on the outer circumferential surface of the protective layer of the optical fiber unit illustrated in each drawing. However, it should be understood that the number of the intaglio strips 30 may vary as needed. In addition, in the present embodiment, the intaglio band 30 formed in the protective layer may be formed in various shapes such as spiral or wave pattern, and may be formed discontinuously. In addition, the intaglio band may have various cross-sectional shapes such as a triangle, a semicircle, an arc, and a quadrangle depending on the shape of the processing apparatus.

In addition, although not shown, the buffer layer 22 used for the protective layer may include a plurality of hollow spheres in the form of particulates therein. This hollow sphere is merely to reduce the weight of the buffer layer 22, and is not related to the increase in the fluid pulling force of the optical fiber unit.

7A to 7C show an optical fiber unit in which the optical fiber 10 applies a ribbon optical fiber surrounded by a ribbon 16.

First, the optical fiber unit illustrated in FIG. 7A is formed such that the buffer layer 22 surrounds the ribbon-shaped optical fiber. The ribbon optical fiber is a form in which a plurality of general optical fibers or primary coated optical fibers 10 are bundled by the ribbon 16. The ribbon 16 is made of polyethylene (PE), polyurethane, polyvinyl chloride (PVC), and binds a plurality of optical fibers 10 to protect from the external environment.

In addition, the intaglio strip 30 described above is formed on the outer circumferential surface of the buffer layer 22. Of course, the intaglio strip 30 formed on the outer circumferential surface of the buffer layer 22 may have various shapes such as a spiral or a wavy pattern, and the cross-sectional shape may also be implemented in various forms.

In the optical fiber unit illustrated in FIG. 7A, the buffer layer 22 directly surrounds the optical fiber 10 and serves as a protective layer. Therefore, in the present embodiment, the buffer layer 22 is preferably made of a harder material than the buffer layer generally used for the rigidity of the optical fiber unit and the smooth processing of the intaglio 30. Preferably, the buffer layer 22 used in the present embodiment has a modulus of secant modulus of 2.5 MPa or more and a modulus of elasticity of 20 MPa or more, more preferably 100 MPa or more.

The optical fiber unit shown in FIG. 7B has a form similar to that shown in FIG. 7A, but a coloring coating layer 14 is further formed on the outer peripheral surface of each optical fiber 10 in the ribbon 16, and the outer peripheral surface of the buffer layer 22. An outer skin layer 24 is further formed. Thus, the negative strip 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit.

In the case of this embodiment, since the outer skin layer 24 is formed outside the buffer layer 22, the thing of the kind generally used is suitable. On the other hand, it is preferable that the outer skin layer 24 positioned outside the buffer layer 22 has a modulus of 400 to 1000 MPa at 2.5% strain in consideration of the rigidity of the optical fiber unit and the smooth processing of the negative strip 30. Has a modulus of 500-800 MPa at 2.5% strain.

Next, the optical fiber unit illustrated in FIG. 7C has a form in which an intermediate layer 26 is added to the optical fiber unit illustrated in FIG. 7B. The intermediate layer 26 is located between the buffer layer 22 and the skin layer 24 and is not directly affected by the intaglio 30. Also, in the present embodiment, the negative strip 30 is formed on the surface of the outer skin layer 24 located at the outermost side of the optical fiber unit as in the example of FIG. 7B.

In the example of FIGS. 7A to 7C, the intaglio band 30 formed on the outer circumferential surface of the optical fiber unit may be formed in various numbers, and may have various shapes such as a spiral or a wave pattern on the outer circumferential surface of the protective layer, and are discontinuous. It can be formed as. The intaglio bands of various shapes may have various cross-sectional shapes such as triangles, semi-circles, arcs, and quadrangles by the shape of the processing apparatus.

In addition, although not shown, when a plurality of optical fiber 10 is used by the ribbon 16 as shown in Figures 7a to 7c, it is possible to install a tensile reinforcing member with the optical fiber. The tension reinforcing member may be additionally installed with the plurality of optical fibers 10 in the ribbon 16, or alternatively, some of the plurality of optical fibers tied to the ribbon 16 may be replaced with the tensile reinforcing members. . At this time, the tensile reinforcing member serves to reinforce the tensile strength of the optical fiber unit. The number of tensile reinforcing members can be changed in various ways depending on the use environment. In addition, fibers or wires may be used as the tensile reinforcing member, and it is preferable to use Kevlar fibers or Aramid fibers as the fibers.

8 shows a series of devices for manufacturing a fiber optic unit for pneumatic laying according to one embodiment of the invention. An apparatus for manufacturing the optical fiber unit and a manufacturing process thereof according to the present embodiment will be described with reference to FIG. 8 as follows.

In order to manufacture the optical fiber unit of the present invention, it is also possible to add only the equipment for forming the intaglio on the outer circumferential surface of the protective layer of the optical fiber unit in the state of using existing general equipment. Therefore, the existing equipment in the following description will be briefly described, but focuses only on the process of forming the intaglio.

First, to manufacture the optical fiber unit of the present invention includes a payoff (60) for supplying the optical fiber and a take-up (take-up) device for winding it. In other words, the optical fiber is supplied through the payoff 60 to undergo a series of processes to be completed into the optical fiber unit, and then the completed optical fiber unit is wound around the take-up device 100.

The optical fiber supplied from the payoff 60 is first guided to the coating die 70. At this time, the guide roller 62 may be installed near the coating die 70 so that the optical fiber has an appropriate entry direction with respect to the coating die 70. The coating die 70 coats a protective layer such as a buffer layer or an outer shell layer on the surface of the optical fiber to make an optical fiber unit, and supplies the coated optical fiber unit to the ultraviolet curing device 80.

At this time, the protective layer coated on the surface of the optical fiber is in a considerably heated state, in which the operation such as surface processing is not easy. Therefore, the ultraviolet curing device 80 is to cure the coated protective layer by irradiating ultraviolet light to the optical fiber unit. The optical fiber unit of which the protective layer is cured in this way is supplied to a machining device (cutting means) 90.

The machining device 90 forms the above-mentioned intaglio on the outer circumferential surface of the protective layer cured while the optical fiber unit is in progress. At this time, the machining device 90 preferably uses a groove cutting method, for this purpose is provided with a cutting tool (not shown) of a specific shape. In addition, in order to process the intaglio strip in a spiral or wavy pattern as shown in FIGS. 3 and 4, the machining apparatus 90 must be rotated in a predetermined manner, and the machining apparatus 90 includes a motor 92. Is connected. The motor 92 rotates the machining device 90 about the center of the optical fiber unit. In addition, the motor 92 may be connected to the control unit 94 to operate by a command of the control unit 94.

In this case, in order to process the spiral intaglio 30 shown in FIG. 3 on the outer circumferential surface of the optical fiber unit, the machining apparatus 90 only needs to be rotated in one direction. That is, since the optical fiber unit is continuously moving during the formation of the intaglio strip, when the groove cutting is performed while rotating the machining apparatus 90 at an appropriate speed, the spiral intaglio band 30 having the shape shown in FIG. 3 is formed. Will be.

On the other hand, in order to process the wavy intaglio 40 as shown in Figure 4 on the outer peripheral surface of the optical fiber unit, the machining device 90 is rotated alternately clockwise and counterclockwise. Therefore, in this case, the motor 92 should be capable of forward and reverse rotation, and the rotation direction of the motor 92 may be changed by the condition set in the controller 94.

In addition, in order to process the discontinuous intaglio 50 as shown in FIG. 5 on the outer circumferential surface of the optical fiber unit, the protective layer is rotated while rotating the machining device 90 in one direction or in a clockwise and counterclockwise direction. Groove cutting is discontinuously performed while cutting the groove on the outer circumferential surface of 20 to periodically retreat the cutting tool that forms the negative strip 50. At this time, the control unit 94 controls the rotation direction and the speed of the machining device 90 and at the same time controls the advance of the cutting tool.

After the above-described intaglio band forming process is completed, the optical fiber unit of the present invention is completed, and the completed optical fiber unit is supplied to the take-up apparatus 100 and wound up.

9 is a cross-sectional view (a) and exit side front view (b) of a coating die 70 ', which is a device for forming the intaglio 30, according to another embodiment of the present invention. With reference to FIG. 9, the manufacturing method and apparatus of the optical fiber unit of this embodiment are demonstrated in detail.

In the present embodiment, unlike the embodiment described with reference to FIG. 8, in the coating process of forming the protective layer 20 on the outer circumferential surface of the optical fiber 10, a protective layer in which the intaglio band 30 is formed is formed. That is, according to the present embodiment, the installation in which the coating die 70 'shown in FIG. 9 is used instead of the conventional coating die 70 of FIG. 8, and the machining device 70 of FIG. 8 is omitted. use.

The coating die (mould) 70 ′ shown in FIG. 9 is a protective layer by supplying the polymer resin in the direction of arrow B to the outer circumferential surface thereof while passing the optical fiber 10 in the direction of arrow A into the nipple 71. It is an apparatus which coat | covers 20. The exit shape is basically circular, and as shown in FIG. 9B, one or more projections 72, such as a triangle, a square, a semicircle, an arc, a trapezoid, and an uneven shape, are formed on the inner circumferential surface of the outlet.

Therefore, when the polymer resin is supplied to the outer circumferential surface of the optical fiber 10 while passing the optical fiber 10 into the coating die 70 ′, the protective layer 20 is coated on the outer circumferential surface of the optical fiber 10 and at the same time, according to the shape of the protrusion 72. Is formed.

Meanwhile, the coating die 70 'may include a motor 92 and a control unit 94 as shown in FIG. 8 so that the coating die 70' may rotate to form an intaglio strip such as a spiral or a wavy pattern. Is connected. Therefore, when the coating die 70 'is rotated in a clockwise or counterclockwise direction or the optical fiber 10 is rotated on a plane perpendicular to the advancing direction of the optical fiber in the coating process, various shapes such as spirals and waveforms as described above are provided. An optical fiber unit coated with a protective layer having an engraved band of can be manufactured.

As described above, the optical fiber coated with the protective layer having the intaglio band is wound by the take-up device 100 through the ultraviolet curing device 80 and the guide roller 64 of FIG. 8.

On the other hand, in the present embodiment, the optical fiber 10 passing through the coating die 70 'may be a single optical fiber, a multi-core optical fiber as shown in FIG. 6F, or a ribbon optical fiber as shown in FIGS. 6A to 6C. It may be. Further, the shell layer 24 having the intaglio band may be formed by passing the optical fiber already coated with the buffer layer 22 through the coating die of FIG. 9.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

The optical fiber unit for pneumatic laying according to the present invention as described above can increase the surface resistance with pneumatic by a simple process of forming a negative strip on the outer circumferential surface of the protective layer surrounding the optical fiber, thereby improving the efficiency of pneumatic laying operation. There is an advantage.

In addition, the optical fiber unit of the present invention is very productive because it requires no cumbersome processes such as mixing and coating fine particles used in the conventional polymer resin or attaching the fine particles to the surface of the uncured polymer resin. Problems such as crack generation due to defects between fine particles and crack propagation into the optical fiber unit are greatly reduced.

In addition, the optical fiber unit of the present invention prevents thermal cracking caused by the difference in thermal strain coefficient between the fine particles such as glass beads and the resin, and solves the problem that glass beads are broken in the optical fiber unit.

In the method of manufacturing the optical fiber unit of the present invention, since the process of coating or externally attaching the fine particles can be eliminated, the material cost and manufacturing cost can be reduced, and the deterioration of the working environment by the fine particles can be prevented.

In addition, according to the present invention, the surface morphology suitable for pneumatic laying is made by a mechanical method immediately after the outer protective layer of the polymer is cured, or simultaneously with the coating of the protective layer, thereby simplifying the manufacturing process. In addition, since the optical fiber unit does not cause problems such as breakage or peeling of particles even during the storage and installation process, the optical fiber unit can be safely and conveniently performed compared to the existing product.

Claims (27)

In the optical fiber unit that is installed using the air pressure inside the tube, At least one optical fiber comprising a core and a clad; And A protective layer surrounding the optical fiber; At least one intaglio band is formed on the outer circumferential surface of the protective layer in the longitudinal direction of the protective layer. The method of claim 1, The intaglio band is a pneumatically laid optical fiber unit, characterized in that formed on the outer circumferential surface of the protective layer in a spiral, wavy or triangular waveform. The method of claim 1, The intaglio band is an optical fiber unit for pneumatic laying, characterized in that formed discontinuously. The method of claim 1, Cross section of the intaglio band is a pneumatic fiber installation unit, characterized in that the triangular, semi-circular, arc-shaped or square. The method of claim 1, And the plurality of optical fibers, and the plurality of optical fibers are present in a ribbon form in the protective layer. The method of claim 5, And a tensile reinforcing member for reinforcing tensile strength in the protective layer. The method of claim 6, The tensile reinforcing member is any one of Kevlar fiber, Aramid fiber and wire, the optical fiber unit for pneumatic installation. The method of claim 1, And a plurality of hollow spheres in the form of particulates for reducing weight in the protective layer. The method of claim 1, And the protective layer includes a buffer layer surrounding the optical fiber, and an outer skin layer surrounding the buffer layer and having the engraved band formed on a surface thereof. The method of claim 1, When the protective layer is formed of a single buffer layer surrounding the optical fiber, the buffer layer having the engraved band on the surface has a secant modulus of 100 MPa to 1000 MPa at 2.5% strain, When the protective layer includes a buffer layer surrounding the optical fiber and an outer skin layer surrounding the buffer layer and the negative band is formed on the surface, the outer skin layer has a secant modulus of 400 MPa to 1000 MPa at 2.5% strain Fiber optic unit for installation. The method of claim 10, When the protective layer includes the buffer layer and the outer layer, the outer layer has a secant modulus of 500 MPa to 800 MPa at 2.5% strain. The method of claim 9, The protective layer further comprises an intermediate layer between the buffer layer and the shell layer, the intermediate layer for preventing the cracks generated in the shell layer from propagating to the inside. In the method for manufacturing an optical fiber unit that is installed using the air pressure inside the tube, Supplying an optical fiber unit having at least one optical fiber and a protective layer surrounding the optical fiber; And And forming one or more intaglio bands along the longitudinal direction of the protective layer on an outer circumferential surface of the protective layer of the supplied optical fiber unit. The method of claim 13, The intaglio strip forming step is performed by a machining apparatus, and the machine part factory manufacturing the pneumatic fiber unit for pneumatic installation, characterized in that for forming the intaglio strip on the outer peripheral surface of the protective layer through the groove cutting process. The method of claim 14, Wherein the machine factory is a manufacturing method of the optical fiber unit for pneumatic laying, characterized in that to form a spiral engraved band on the outer circumferential surface of the protective layer by performing a groove cutting while rotating in one direction while the optical fiber unit is in progress. The method of claim 14, Wherein the machine factory is to perform groove cutting while rotating in the clockwise and counterclockwise direction while the optical fiber unit is in progress to form an intaglio strip of wavy or triangular waveform on the outer peripheral surface of the protective layer Manufacturing method of optical fiber unit for pneumatic laying. The method of claim 14, And said machine prefabricated groove cutting process discontinuously while said optical fiber unit is in progress to form a discontinuous spiral negative band on the outer circumferential surface of said protective layer. In the method for manufacturing an optical fiber unit that is installed using the air pressure inside the tube, One or more optical fibers having a core and a clad are passed through a coating die having one or more predetermined protrusions formed on the hollow inner circumferential surface, and a polymer resin is supplied to the outer circumferential surface of the optical fiber, thereby providing at least one intaglio along the longitudinal direction thereof. A method of manufacturing an optical fiber unit for pneumatic laying, characterized by forming a protective layer having a band formed thereon. The method of claim 18, The coating die rotates in one direction while the optical fiber is passed to form a spiral engraved band on the outer circumferential surface of the protective layer. The method of claim 18, The coating die is rotated in a clockwise and counterclockwise direction while the optical fiber is passed, thereby forming an intaglio band of wavy or triangular waveform on the outer circumferential surface of the protective layer. . In the apparatus for manufacturing an optical fiber unit that is installed using the air pressure inside the tube, Means for supplying an optical fiber unit having at least one optical fiber and at least one protective layer surrounding the optical fiber; Cutting means for forming one or more intaglio bands along the longitudinal direction of the protective layer through groove cutting on the outer peripheral surface of the protective layer of the supplied optical fiber unit; And And a take-up means for winding the optical fiber unit processed by the cutting processing means. The method of claim 21, A motor providing a one-way rotational force is connected to the cutting means, and the cutting means rotates in one direction by the motor while the optical fiber unit is in progress to form a spiral intaglio on an outer circumferential surface of the protective layer. The manufacturing apparatus of the optical fiber unit for pneumatic laying. The method of claim 21, The cutting means is connected to a motor providing a bidirectional rotational force, the cutting means is rotated in the clockwise and counterclockwise direction by the motor while the optical fiber unit is in progress, the wave pattern on the outer peripheral surface of the protective layer Or an apparatus for manufacturing a pneumatic optical fiber unit, characterized in that for forming a triangular waveform intaglio. The method of claim 21, The cutting means is a device for manufacturing a pneumatically laid optical fiber unit, characterized in that for performing the groove cutting process discontinuously while the optical fiber unit is supplied to form a discontinuous spiral negative band on the outer peripheral surface of the protective layer. In the apparatus for manufacturing an optical fiber unit that is installed using the air pressure inside the tube, Means for supplying at least one optical fiber comprising a core and a clad; A coating die for passing the supplied optical fiber therein and supplying a polymer resin to an outer circumferential surface of the optical fiber to form a protective layer; And And take-up means for winding an optical fiber unit having a protective layer formed by the coating die, The coating die has at least one protrusion having a predetermined shape formed on its inner circumferential surface, thereby forming at least one intaglio band on the outer circumferential surface of the protective layer. The method of claim 25, A motor providing a one-way rotational force is connected to the coating die, and the coating die is rotated in one direction by the motor while the optical fiber is in progress to form a spiral negative band on the outer circumferential surface of the protective layer. Apparatus for manufacturing optical fiber unit for use. The method of claim 25, The coating die is connected to a motor providing bidirectional rotational force, and the coating die rotates alternately in a clockwise and counterclockwise direction by the motor while the optical fiber is running, and is wavy or triangular on the outer circumferential surface of the protective layer. Apparatus for manufacturing an optical fiber unit for pneumatic laying, characterized in that forming an intaglio band.

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