Preparation method of optical cable with small cable diameter and large core number and product thereof

Abstract

The invention belongs to the related field of optical communication transmission technology, and discloses a preparation method of a small-cable-diameter large-core-number optical cable and a product thereof, the optical cable is prepared through the processes of coloring, yarn binding, cabling, two sets and a protective layer in sequence, in the process, an optical fiber is firstly colored, and then in the yarn binding process, the optical fiber is subjected to two sets of cabling; coaxially and tightly arranging and twisting a plurality of optical fibers into a first optical fiber bundle and carrying out yarn binding treatment; in the cabling process, the plurality of first optical fiber bundles are coaxially and tightly arranged and twisted into a second optical fiber bundle to form a fiber core; the outer layer of the fiber core is wrapped with a sleeve; and finally, the outer side of the sleeve is provided with an armor and an outer sheath layer. According to the invention, an optical cable product with a small cable diameter, a large core number and qualified overall performance indexes can be obtained, correspondingly, the use of a central reinforcing core can be completely omitted, the material consumption of a sleeve, a sheath, an armor and the like is remarkably reduced, the overall weight of the optical cable product is reduced, the manufacturing process flow is simplified, and the quality controllability and the production efficiency are improved.

Description

Technical Field

[0001] The present invention belongs to the field related to optical communication transmission technology, and more specifically, relates to a preparation method of a small-diameter and large-core optical cable and a product thereof. Background Art

[0002] Optical cable is an optical communication component composed of a cable core made up of several optical fibers and an outer sheath layer. Due to its large transmission capacity, long transmission distance, small size, light weight, and no electromagnetic interference, it is currently the most promising communication transmission media and has been increasingly widely used in many fields such as telecommunications, electricity, and broadcasting.

[0003] In the prior art, such as Figure 3 As shown in the figure, the conventional structure of the optical cable generally includes a central reinforcing core 101 arranged concentrically from the inside to the outside, a plurality of optical fiber units distributed around the central reinforcing core 101, an armor 104 made of, for example, aluminum, and an outermost outer sheath layer 105, wherein each optical fiber unit includes a sleeve 103 and a plurality of optical fibers 102 concentrated therein, and all the optical fiber units are wound around the central reinforcing core 101 in a circular form to form a cylindrical cable core.

[0004] In order to prepare the above conventional structure optical cable products, the current manufacturing process is mainly divided into the following four processes, namely coloring, two sets, cabling, and sheathing. Taking the traditional GYTA-144B1.3 optical cable as an example, each process is briefly introduced as follows: 1) Fiber coloring: The original bare optical fiber is colored. The purpose of coloring is to add a layer of protection mechanism to the optical fiber, and at the same time, the 12 optical fibers in the same sleeve can be distinguished, which is convenient for fiber melting and information transmission; 2) Two sets: The colored optical fibers are grouped into 12 pieces, and the equipment is laid out, and they are closely arranged together and enter the extruder head. Through the extrusion equipment, a layer of sleeve is wrapped around the 12 optical fibers. At the same time, during the extrusion process, fiber paste is added to the sleeve to prevent the optical fiber from contacting with water and causing the optical fiber to fail. The material for the two sets of sheathing is generally used for PBT (polybutylene terephthalate), and the sleeves produced by the two sets will also be distinguished by color; 3) Cabling: The 12 sleeves produced by the two sets are laid out by the equipment and tightly wound on the central reinforcing core to form a cable core. Each cable core has 12 sleeves, each of which stores 12 optical fibers. The 12 sleeves are wound around the reinforcing core in a circular form, and the entire cable core forms a cylindrical form; 4) Sheath: The cable core is extruded through the equipment and mold, and a layer of aluminum tape is wrapped around the outside of the cable core. After wrapping the aluminum tape, it directly enters the extruder head, and a layer of sheath material is coated on the surface of the aluminum tape. After cooling in a cooling water tank, it finally forms an optical cable product.

[0005] However, further research shows that the above existing manufacturing process is relatively complex and the material cost is high. For example, the cable core needs a central reinforcing core and the second set of materials is large. At the same time, due to the limitations of the internal structure, the cable diameter is often difficult to reduce, which leads to problems such as low fiber density, large sheath and armor thickness. Accordingly, it is necessary to study and improve it in this field in order to better solve the above technical problems and improve the production efficiency and cost of optical cables. Summary of the invention

[0006] In response to one or more of the above defects or improvement needs in the prior art, the present invention provides a method for preparing a small-diameter and large-core-count optical cable and a product thereof, wherein the preparation process and the main processing parameters of its key process steps are re-studied and designed, and a fiber core structure is used to replace the original cable core structure, so that an optical cable product with a small cable diameter and a large core count and qualified overall performance indicators can be obtained. Accordingly, not only can the use of a central reinforcing core be completely eliminated, the amount of other materials such as casing, sheath, armor, etc. can be significantly reduced, and the overall weight of the optical cable product can be reduced, but the manufacturing process is also simplified, and the quality controllability and production efficiency are improved. Therefore, it can be adapted to the preparation and application of various optical cables, and has good practical value and application prospects.

[0007] To achieve the above object, according to one aspect of the present invention, a method for preparing a small-diameter and large-core optical cable is provided, wherein the optical cable is prepared by coloring, yarn binding, cabling, double-set and sheathing processes in sequence, wherein:

[0008] In the yarn binding process, a plurality of optical fibers are coaxially and closely arranged together, and twisted into a first optical fiber bundle, and then subjected to a yarn binding process;

[0009] In the cabling process, a plurality of the first optical fiber bundles are coaxially and closely arranged together, and further twisted into a second optical fiber bundle, thereby forming a fiber core;

[0010] In the second set of processes, a sleeve is wrapped around the outer layer of the second optical fiber bundle, and fiber paste is added into the sleeve.

[0011] As a further preferred embodiment of the present invention, in the yarn binding process, the plurality of optical fibers are preferably twisted in a forward and reverse spiral twisting manner, and preferably form a first optical fiber bundle that is substantially cylindrical.

[0012] As a further preferred embodiment of the present invention, in the yarn binding process, the number of optical fibers in the first optical fiber bundle is preferably set to 12, and among the 12 optical fibers, preferably 3 optical fibers are placed in the inner layer and then spirally twisted together, and the remaining 9 optical fibers are placed in the outer layer and then spirally twisted together; wherein the above-mentioned optical fibers are all twisted in forward and reverse spirals with a unidirectional twisting pitch of 800 mm.

[0013] As a further preferred embodiment of the present invention, in the cabling process, the plurality of first optical fiber bundles are preferably twisted in a forward and reverse spiral twisting manner, and are preferably formed into a second optical fiber bundle that is substantially cylindrical.

[0014] As a further preferred embodiment of the present invention, in the cabling process, the number of first optical fiber bundles in the second optical fiber bundle is preferably set to 12 bundles, and among the 12 optical fiber bundles, 3 optical fiber bundles are preferably placed in the inner layer and then spirally twisted together, and the remaining 9 optical fiber bundles are placed in the outer layer and then spirally twisted together; wherein, the optical fiber bundles in the inner layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1200mm, and the optical fiber bundles in the outer layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1000mm, and at the same time, the pay-off tension of each optical fiber bundle is controlled to be 10N~20N.

[0015] As a further preferred embodiment of the present invention, in the coloring process, various conventional methods can be used to color the optical fiber; in the sheath process, armor can be formed on the outside of the sleeve where the second optical fiber bundle is placed, and then an outer sheath layer can be formed on the outermost layer.

[0016] According to another aspect of the present invention, a corresponding optical cable is also provided, characterized in that:

[0017] The optical cable includes a fiber core, a sleeve and an outer sheath layer from the inside to the outside, wherein the fiber core is formed by a plurality of optical fiber bundles coaxially closely arranged and twisted together, and each optical fiber bundle is formed by a plurality of optical fibers coaxially closely arranged and twisted together and then bundled.

[0018] As a further preferred embodiment of the present invention, the optical cable product may further include an armor disposed between the fiber core and the outer sheath layer.

[0019] As a further preferred embodiment of the present invention, the above optical cable product does not need to use a central reinforcing core, and does not need to arrange steel wires on the periphery of the armor.

[0020] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0021] (1) The present invention re-studies and designs the preparation process of the optical cable, adopts a fiber core structure to replace the original cable core structure, and can obtain an optical cable product with a small cable diameter, a large number of cores and qualified overall performance indicators: for example, in terms of cable diameter indicators, based on the average value of the sheath thickness of 1.6 mm, the diameter of the common GYTA-144B1.3 optical cable is 16.8 mm, while the small cable diameter 144-core optical cable of the present application has an equivalent diameter of only 3.5 mm because all 144 core optical fibers are arranged together; in addition, in terms of optical fiber density indicators, the optical fiber density of the common GYTA-144B1.3 optical cable is 0.5187 cores / mm 2 , and the fiber density of the small-diameter 144-core optical cable in this application can be increased to 1.663 cores / mm 2 ;

[0022] (2) The present invention can not only simplify the manufacturing process, improve quality controllability and production efficiency, but also significantly reduce production costs: for example, for sheath material, based on the average sheath thickness of 1.6 mm, the sheath volume required per unit length of a common GYTA-144B1.3 optical cable is 76.40 mm 2 , and the sheath volume required per unit length of the small cable diameter 144-core optical cable of this application is 44.74mm 2 For the second set of materials, the common GYTA-144B1.3 cable sheath diameter is 2.55mm, but 12 pieces are required, so the sheath volume required per unit length is 29.0283mm 2 , and the sheath volume required per unit length of the small cable diameter 144-core optical cable of this application is 8.6394mm 2 ; Regarding the width of the armor, the circumference of the common GYTA-144B1.3 optical cable core is 39.58mm, while the circumference of the small-diameter 144-core optical cable of the present application is only 18.85mm; in addition, the present application can completely omit the use of the central reinforcing core;

[0023] (3) The present invention further optimizes the specific processing method and key parameters of the fiber core. By adopting the processing method of forward and reverse spiral twisting and limiting the parameters such as the unidirectional twisting pitch, it is possible to ensure that the prepared fiber core can provide functions similar to the original cable core under the process conditions of not using a central reinforcing core and using multiple optical fiber sleeves, while ensuring that the optical cable meets the requirements in terms of major indicators such as tensile performance and bending radius; in addition, by evenly twisting the first and second optical fiber bundles into a roughly cylindrical form, the circumference of the optical cable is ensured, and the tensile performance of the optical cable is also improved;

[0024] (4) The optical cable product of the present invention is easy to process and can be manufactured using existing production equipment and materials. It has good quality controllability and significantly reduces costs while reducing the overall weight of the optical cable product. Therefore, it is particularly suitable for the preparation and application of various types of pipeline optical cables, self-supporting optical cables, flame-retardant optical cables, etc., and has good practical value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of a method for preparing a small-diameter and large-core-count optical cable according to the present application;

[0026] Figure 2 is a structural cross-sectional view of a small-diameter and large-core-count optical cable according to a preferred embodiment of the present invention;

[0027] Figure 3 is a structural cross-sectional view of an optical cable used to exemplarily show the prior art;

[0028] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0029] 1-optical fiber; 2-casing; 3-armor; 4-outer sheath layer; 101-central reinforcing core; 102-optical fiber; 103-casing; 104-armor; 105-outer sheath layer. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] Figure 1 This is a process flow chart of the preparation method of the small cable diameter and large core number optical cable according to the present application, which will be referred to below Figure 1 To explain the present invention in more detail.

[0036] In the method for preparing a small-diameter and large-core optical cable of the present application, the optical cable is prepared in sequence through coloring, yarn binding, cabling, double-set and sheathing processes, wherein:

[0037] In the coloring process, various conventional methods can be used to color the optical fibers respectively;

[0038] In the yarn binding process, a plurality of optical fibers are coaxially and closely arranged together, and twisted into a first optical fiber bundle, and then subjected to a yarn binding process;

[0039] In the cabling process, a plurality of the first optical fiber bundles are coaxially and closely arranged together, and further twisted into a second optical fiber bundle, thereby forming a fiber core;

[0040] In the second set of processes, a sleeve is wrapped around the outer layer of the second optical fiber bundle, and fiber paste is added into the sleeve;

[0041] In the sheathing process, various conventional methods can be used to form armor such as aluminum tape on the outer side of the above-mentioned sleeve, and then the outermost layer is processed to form an outer sheath layer.

[0042] In order to better distinguish it from the prior art, the 144-core structure optical cable is still taken as an example to explain it in more detail below.

[0043] First, fiber coloring: As mentioned above, fiber coloring of GYTA-144B1.3 optical cable is omitted;

[0044] Next is the yarn binding: existing equipment can be used to place 12 optical fibers on 12 pay-off racks, and after the 12 optical fibers are closely arranged together (preferably in a circular form) by taking up the wires, yarn binding is performed forward and reversely around the optical fibers, and the 12 optical fibers after yarn binding form a fiber bundle; in order to distinguish the types of fiber bundles, the colors of the yarn binding can be arranged according to the colors of the 12 optical fibers;

[0045] The next step is cabling: 12 optical fiber bundles are placed on 12 pay-off racks in sequence, and the 12 optical fiber bundles are twisted into one optical fiber bundle through the twisting equipment;

[0046] Next is the second set: the optical fiber bundle designed by the above process is passed through the second set of process extrusion equipment, a layer of sleeve is wrapped outside the optical fiber bundle, and fiber paste is added into the sleeve during the extrusion process;

[0047] The last step is the sheath: the processing steps of the sheath process are the same as those mentioned above. The casing can be wrapped with a layer of aluminum tape, extruded through the machine head, and finally the required small cable diameter and large core number optical cable is formed.

[0048] According to a preferred embodiment of the present invention, in the yarn binding process, the plurality of optical fibers are preferably twisted in a forward and reverse spiral twisting manner to form a first optical fiber bundle that is approximately cylindrical; and in the cabling process, the plurality of first optical fiber bundles are preferably twisted in a forward and reverse spiral twisting manner to form a second optical fiber bundle that is approximately cylindrical;

[0049] The reason for the above design is that some actual tests have shown that this processing method of forward and reverse spiral twisting can ensure that the produced fiber core can provide functions similar to the original cable core under the process conditions of not using a central reinforcing core and adopting multiple optical fiber sleeves, while ensuring that the optical cable meets the requirements in terms of major indicators such as tensile performance and bending radius.

[0050] More specifically, after spiral twisting, the optical fiber or optical fiber bundle will form a bending radius. Therefore, when the twisting pitch of the spiral twisting of the optical cable is small, the bending radius of the optical fiber in the optical cable will be easier to be smaller than the macrobending radius actually allowed by the optical fiber, and the optical fiber will exceed the standard; however, if the twisting pitch of the spiral twisting of the optical fiber is relatively large, the tensile performance of the optical cable cannot be fully guaranteed, so how to control the spiral twisting pitch becomes a control difficulty. In the present invention, the unidirectional twisting pitch in the yarn binding process and the cabling process is specifically limited, which can ensure that the obtained optical cable product meets the requirements in terms of bending radius, tensile performance and other indicators.

[0051] According to a preferred embodiment of the present invention, in the yarn binding process, the number of optical fibers in the first optical fiber bundle is preferably set to 12, 3 of the 12 optical fibers are preferably placed in the inner layer and then spirally twisted together, and the remaining 9 optical fibers are evenly distributed in the outer layer and then spirally twisted together. Correspondingly, in the cabling process, the number of first optical fiber bundles in the second optical fiber bundle is preferably set to 12 bundles, 3 of the 12 first optical fiber bundles are preferably placed in the inner layer and then spirally twisted together, and the remaining 9 optical fiber bundles are evenly distributed in the outer layer and then spirally twisted together. Among them, the optical fiber bundles in the inner layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1200mm, and the optical fiber bundles in the outer layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1000mm, and the pay-off tension of each optical fiber bundle is controlled to be 10N~20N.

[0052] The reason for the above design is that after some comparative actual tests, it is shown that the optimal solution of 12 optical fibers or 12 optical fiber bundles is in a circular form, so the distribution of 12 optical fibers or 12 optical fiber bundles can be preferably implemented as above. Accordingly, not only the circularity of the optical cable can be guaranteed, but also the tensile performance of the optical cable can be improved.

[0053] Figure 2 FIG. 1 is a structural cross-sectional view of a small-diameter and large-core optical cable according to a preferred embodiment of the present invention. Figure 2 As shown in the figure, the present invention also provides an optical cable product with a small cable diameter and a large number of cores, the optical cable comprising a fiber core, a sleeve 2 and an outer sheath layer 4 from the inside to the outside, wherein the fiber core is formed by a plurality of optical fiber bundles coaxially and tightly arranged together and twisted, and each optical fiber bundle is formed by a plurality of optical fibers 1 coaxially and tightly arranged together and twisted, and then subjected to yarn binding.

[0054] More specifically, the optical cable may further include an armor 3, which is, for example, an aluminum tape and is disposed between the fiber core and the outer sheath layer.

[0055] It should be noted that the optical cable product of the present invention can completely omit the use of a central reinforcing core. In addition, in existing products, a circle of steel wire is usually wrapped around the outer periphery of the aluminum strip to ensure the tensile performance of the optical cable, but the optical cable of the present application does not need to be wrapped with steel wire on the outer periphery.

[0056] In summary, according to the above technical scheme of the present invention, a fiber core structure is used to replace the original cable core structure, and an optical cable product with a small cable diameter, a large number of cores and qualified overall performance indicators can be obtained. Accordingly, not only can the use of the central reinforcing core be completely eliminated, the amount of other materials such as the casing, sheath, armor, etc. is significantly reduced, and the overall weight of the optical cable product is reduced, but also the manufacturing process is simplified, and the quality controllability and production efficiency are improved. Therefore, it can be applied to various types of optical cables, including but not limited to pipeline optical cables, self-supporting optical cables and flame-retardant optical cables, and has good practical value and application prospects.

[0057] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for preparing a small-diameter and large-core optical cable, characterized in that: The optical cable is prepared by coloring, yarn binding, cabling, double set and sheathing processes, among which: In the yarn binding process, a plurality of optical fibers are coaxially and closely arranged together, and twisted into a first optical fiber bundle, and then subjected to a yarn binding process; In the cabling process, a plurality of the first optical fiber bundles are coaxially and closely arranged together, and further twisted into a second optical fiber bundle, thereby forming a fiber core; In the second set of processes, a sleeve is wrapped around the outer layer of the second optical fiber bundle, and fiber paste is added into the sleeve.

2. The preparation method according to claim 1, characterized in that In the yarn binding process, the plurality of optical fibers are preferably twisted in a forward and reverse helical twisting manner, and are preferably formed into a first optical fiber bundle having a substantially cylindrical shape.

3. The preparation method according to claim 2, characterized in that: In the yarn binding process, the number of optical fibers in the first optical fiber bundle is preferably set to 12, and among the 12 optical fibers, 3 optical fibers are preferably placed in the inner layer and then spirally twisted together, and the remaining 9 optical fibers are placed in the outer layer and then spirally twisted together; wherein the above-mentioned optical fibers are all twisted in forward and reverse spirals with a unidirectional twisting pitch of 800mm.

4. The preparation method according to any one of claims 1 to 3, characterized in that: In the cabling process, the plurality of first optical fiber bundles are preferably twisted in a forward and reverse spiral twisting manner, and are preferably formed into a second optical fiber bundle that is substantially cylindrical.

5. The preparation method according to claim 4, characterized in that: In the cabling process, the number of first optical fiber bundles in the second optical fiber bundle is preferably set to 12 bundles, and among the 12 optical fiber bundles, 3 optical fiber bundles are preferably placed in the inner layer and then spirally twisted together, and the remaining 9 optical fiber bundles are placed in the outer layer and then spirally twisted together; wherein, the optical fiber bundles in the inner layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1200mm, and the optical fiber bundles in the outer layer are twisted in forward and reverse spirals with a unidirectional twisting pitch of 1000mm, and at the same time, the pay-off tension of each optical fiber bundle is controlled to be 10N~20N.

6. An optical cable with a small cable diameter and a large number of cores, characterized in that: The optical cable comprises a fiber core, a sleeve (2) and an outer sheath layer (4) from the inside to the outside, wherein the fiber core is formed by a plurality of optical fiber bundles coaxially closely arranged together and twisted together, and each optical fiber bundle is formed by a plurality of optical fibers (1) coaxially closely arranged together and twisted together and then bundled.

7. The optical cable according to claim 6, characterized in that The optical cable may further include an armor (3) arranged between the fiber core and the outer sheath layer (4).

8. The optical cable according to claim 6 or 7, characterized in that: The optical cable does not need to use a central reinforcing core because the fiber core can ensure the structural circularity of the optical cable, and the optical fiber bundles are twisted without the need to arrange steel wires on the periphery of the armor (3).

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