Preparation method of small-diameter large-core-count optical cable and product thereof

Abstract

The application belongs to the field of optical communication transmission technology, and discloses a preparation method of a small-diameter large-core optical cable and a product thereof, wherein the optical cable is prepared through coloring, yarn binding, cabling, secondary coating and sheath coating processes in sequence, in the process, the optical fiber is first subjected to coloring treatment, then in the yarn binding process, a plurality of optical fibers are coaxially and closely arranged and twisted into a first optical fiber bundle and subjected to yarn binding treatment; then in the cabling process, a plurality of first optical fiber bundles are coaxially and closely arranged and twisted into a second optical fiber bundle to form a fiber core; then a sleeve is wrapped outside the fiber core, and finally an armor and an outer sheath layer are arranged outside the sleeve. Through the application, the optical cable product with small diameter and large core and qualified overall performance index can be obtained, the use of the central reinforcing core can be completely saved, the amount of other materials such as the sleeve, the sheath and the armor is significantly reduced, the overall weight of the optical cable product is reduced, the manufacturing process is simplified, and the quality controllability and the production efficiency are improved.

Description

Technical Field

[0001] This invention belongs to the field of optical communication transmission technology, and more specifically, relates to a method for preparing a small-diameter, high-core-count optical cable and its product. Background Technology

[0002] Optical cables are optical communication components composed of a cable core made of several optical fibers and an outer sheath. Due to their characteristics such as large transmission capacity, long transmission distance, small size, light weight, and no electromagnetic interference, they are currently the most promising communication transmission media and have been increasingly widely used in telecommunications, power, broadcasting and other fields.

[0003] In existing technologies, such as Figure 3 As shown in the example, the conventional structure of an optical cable generally includes a central reinforcing core 101 arranged concentrically from the inside out, multiple optical fiber units distributed around the central reinforcing core 101, such as an armor 104 made of aluminum, and an outermost outer sheath layer 105, etc. Each optical fiber unit includes a sleeve 103 and multiple optical fibers 102 placed therein, and all optical fiber units are wound around the central reinforcing core 101 in a circular form to form a cylindrical cable core.

[0004] To manufacture optical cable products with the aforementioned conventional structure, the current manufacturing process mainly consists of the following four steps: coloring, secondary sheathing, cabling, and sheathing. Taking the traditional GYTA-144B1.3 optical cable as an example, each step is briefly described below: 1) Fiber coloring: The bare optical fiber is colored to add a protective layer and to distinguish the 12 fibers in the same sheath, facilitating fiber splicing and information transmission; 2) Secondary sheathing: The colored fibers are grouped into sets of 12 and fed into an extruder head. The extruder wraps a sheath around the 12 fibers, and fiber paste is added inside the sheath during extrusion to prevent water contact and fiber failure. The secondary sheathing material is generally PBT (polybutylene terephthalate), and the sheaths produced by the secondary sheathing are also color-coded; 3) Cabling: The 12 sheaths produced by the secondary sheathing are fed into a central reinforcing core and tightly wound to form a cable core. Each cable core has 12 sleeves, and each sleeve stores 12 optical fibers. The 12 sleeves are wrapped around the reinforcing core in a circular manner, and the entire cable core forms a cylindrical shape; 4) Sheath: The cable core is fed out by the equipment and extruded by the mold. A layer of aluminum strip is wrapped around the outside of the cable core. After being wrapped with aluminum strip, it directly enters the extruder head. A layer of sheath material is coated on the surface of the aluminum strip. After being cooled by the cooling water tank, the optical cable product is finally formed.

[0005] However, further research shows that the above existing manufacturing process is relatively complex and the material cost is high, such as the cable core will need a central reinforcing core, two sets of material consumption, etc. At the same time, due to the limitation of the internal structure group cost itself, the diameter of the cable diameter is often not easy to reduce, and the optical fiber density of the optical cable is low, the thickness of the sheath and the armor is large, and other problems occur. Accordingly, it is necessary to research and improve it in order to better solve the above technical problems and improve the production efficiency and cost of optical cable. SUMMARY

[0006] In view of one or more of the above defects or improvement needs of the prior art, the present application provides a preparation method of a small-diameter large-core-count optical cable and its product, wherein by re-researching and designing the main processing parameters of the preparation process and its key process steps, the original cable core structure is replaced by a fiber core structure, a small-diameter large-core-count optical cable product with qualified overall performance indicators can be obtained, accordingly, the use of central reinforcing core can be completely eliminated, the amount of other materials such as sleeve, sheath, and armor can be significantly reduced, the overall weight of the optical cable product can be reduced, the manufacturing process can be simplified, the quality controllability and production efficiency can be improved, thus it can be applied to various optical cable preparation occasions, and has good practical value and application prospect.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present application, a preparation method of a small-diameter large-core-count optical cable is provided, characterized in that the optical cable is prepared by sequentially passing through coloring, yarn making, cabling, two-sheathing, and sheath layer processes, wherein:

[0008] In the yarn making process, a plurality of optical fibers are arranged coaxially and tightly together, and are twisted into a first optical fiber bundle, and then yarn making treatment is performed;

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

[0010] In the two-sheathing process, a sleeve is wrapped around the outer layer of the second optical fiber bundle, and a fiber paste is added in the sleeve.

[0011] As a further preferred embodiment of the present application, in the yarn making 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 in the form of a substantially cylindrical body.

[0012] As a further preferred embodiment of the present application, in the stranding process, the number of optical fibers in the first optical fiber bundle is preferably set to 12, and 3 of the 12 optical fibers are preferably placed in the inner layer and then twisted together, and the remaining 9 optical fibers are all placed in the outer layer and then twisted together; wherein the optical fibers are all twisted with a one-way twisting pitch of 800 mm in forward and reverse directions.

[0013] As a further preferred embodiment of the present application, in the cabling process, the plurality of first optical fiber bundles are preferably twisted in a forward and reverse direction, and a second optical fiber bundle in the shape of a substantially cylindrical body is formed.

[0014] As a further preferred embodiment of the present application, in the cabling process, the number of first optical fiber bundles in the second optical fiber bundle is preferably set to 12, and 3 of the 12 optical fiber bundles are preferably placed in the inner layer and then twisted together, and the remaining 9 optical fiber bundles are all placed in the outer layer and then twisted together; wherein the optical fiber bundles in the inner layer are twisted with a one-way twisting pitch of 1200 mm in forward and reverse directions, the optical fiber bundles in the outer layer are twisted with a one-way twisting pitch of 1000 mm in forward and reverse directions, and the laying tension of each optical fiber bundle is controlled to be 10N-20N.

[0015] As a further preferred embodiment of the present application, in the coloring process, the optical fibers can be colored by various conventional methods; in the sheath process, an armor can be formed outside the sleeve in which 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 application, a corresponding optical cable is also provided, characterized in that:

[0017] The optical cable comprises, from the inside to the outside, a core, a sleeve, and an outer sheath layer, wherein the core is formed by coaxially and tightly arranging and twisting a plurality of optical fiber bundles, and each optical fiber bundle is formed by coaxially and tightly arranging and twisting a plurality of optical fibers, and then being stranding processed.

[0018] As a further preferred embodiment of the present application, the optical cable product can further comprise an armor disposed between the core and the outer sheath layer.

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

[0020] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

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

[0022] (2) The present application not only can simplify the manufacturing process, improve the quality controllability and production efficiency, but also can significantly reduce the production cost: for example, for the sheath material, calculated by the average value of the sheath thickness of 1.6 mm, the sheath volume required per unit length of the common GYTA-144B1.3 optical cable is 76.40 mm 2 , while the sheath volume required per unit length of the small-diameter 144-core optical cable of the present application is 44.74 mm 2 ; for the two sets of materials, the common GYTA-144B1.3 optical cable has a sleeve diameter of 2.55 mm, but requires 12, so the sheath volume required per unit length is 29.0283 mm 2 , while the sheath volume required per unit length of the small-diameter 144-core optical cable of the present application is 8.6394 mm 2 ; for the width of the armor, the common GYTA-144B1.3 optical cable has a cable core circumference of 39.58 mm, while the circumference of the small-diameter 144-core optical cable of the present application is only 18.85 mm; in addition, the present application can completely omit the use of the central reinforcing core;

[0023] (3) The present application further optimizes the specific processing method of the fiber core and its key parameters, wherein by adopting the forward and reverse spiral twisting method and limiting the parameters such as single twisting pitch, the fiber core prepared under the process conditions of not using the central reinforcing core and using multiple optical fiber sleeves can still provide similar functions to the original cable core, while ensuring that the optical cable meets the requirements in terms of main indicators such as tensile performance and bending radius; in addition, by dividing the first and second optical fiber bundles into layers and twisting them into a substantially cylindrical form, the tensile performance of the optical cable is also improved while ensuring the circularity of the optical cable;

[0024] (4) The optical cable product of the present application is convenient to process, can be manufactured by using existing production equipment and materials, has good controllability of quality, and significantly reduces the cost while reducing the overall weight of the optical cable product, and thus is particularly suitable for preparation application occasions of various pipeline optical cables, self-supporting optical cables and flame-retardant optical cables, and has good practical value and application prospect. BRIEF DESCRIPTION OF DRAWINGS

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

[0026] Figure 2 is a structure sectional view of the small-diameter large-core-count optical cable according to one preferred embodiment of the present application;

[0027] Figure 3 is a structure sectional view of the optical cable of the prior art for exemplary display;

[0028] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein:

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

[0030] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0031] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an ordered ranking of the indicated technical features. Thus, features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0033] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0035] Figure 1 is the process flow chart of the preparation method of the small-diameter large-core-count optical cable according to the present application, which will be explained more specifically below with reference to Figure 1 .

[0036] In the preparation method of the small-diameter large-core-count optical cable according to the present application, the optical cable is prepared by the processes of coloring, stranding, cabling, secondary coating and sheath coating in sequence, wherein:

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

[0038] In the stranding process, a plurality of optical fibers are arranged coaxially and closely together, and are stranded into a first optical fiber bundle, and then stranding treatment is performed;

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

[0040] In the second process, a sleeve is wrapped around the outer layer of the second fiber bundle, and a fiber paste is added in the sleeve;

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

[0042] In order to better distinguish from the prior art, the following still takes a 144-core structure optical cable as an example for more specific explanation and description.

[0043] First, the optical fiber is colored: as in the above GYTA-144B1.3 optical cable, no more description is given;

[0044] Then, the yarn is tied: using existing equipment, 12 optical fibers are placed on 12 payoff stands, and after the 12 optical fibers are tightly arranged together (preferably in a circular form) through take-up, the yarn is tied in front of and behind the optical fibers, and the 12 optical fibers after being tied form a fiber bundle; in order to distinguish the types of the fiber bundle, the color of the tied yarn can be arranged according to the color of the optical fiber 12;

[0045] Then, the cable is formed: 12 fiber bundles are sequentially placed on 12 payoff stands, and the 12 fiber bundles are twisted into one fiber bundle through the equipment;

[0046] Then, the second process is performed: the fiber bundle designed in the above process is extruded through the second process extrusion equipment, and a sleeve is wrapped around the outer layer of the fiber bundle, and a fiber paste is added in the sleeve during the extrusion process;

[0047] Finally, the sheath is formed: the processing steps of the sheath process are the same as those described above, an aluminum tape is wrapped around the outer side of the sleeve, and finally the required small cable diameter and large core number optical cable is formed.

[0048] According to a preferred embodiment of the present application, in the yarn tying process, the plurality of optical fibers are preferably twisted in a front and rear spiral manner, and a first fiber bundle in the form of a substantially cylindrical body is formed; and in the cable forming process, the plurality of first fiber bundles are preferably twisted in a front and rear spiral manner, and a second fiber bundle in the form of a substantially cylindrical body is formed.

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

[0050] More specifically, when the spiral twisting is performed, the optical fiber or the optical fiber bundle will form a bending radius, so when the twisting pitch of the spiral twisting is small, the bending radius of the optical fiber in the optical cable will be more likely to be smaller than the actual allowed macro-bending radius of the optical fiber, and the optical fiber will be out of standard; but if the twisting pitch of the spiral twisting is large, the tensile property of the optical cable cannot be fully ensured, so how to control the twisting pitch becomes a control difficulty. In the present application, the single-twisting pitch in the stranding process and the cabling process is specifically limited, so that the obtained optical cable product can meet the requirements in bending radius, tensile property and other indexes.

[0051] According to a preferred embodiment of the present application, in the stranding process, the number of optical fibers in the first optical fiber bundle is preferably 12, and 3 of the 12 optical fibers are preferably placed in the inner layer and then twisted together, and the remaining 9 optical fibers are uniformly distributed in the outer layer and then twisted together. Correspondingly, in the cabling process, the number of first optical fiber bundles in the second optical fiber bundle is preferably 12, and 3 of the 12 first optical fiber bundles are preferably placed in the inner layer and then twisted together, and the remaining 9 optical fiber bundles are uniformly distributed in the outer layer and then twisted together. The optical fiber bundles in the inner layer are positively and negatively twisted with a single-twisting pitch of 1200 mm, the optical fiber bundles in the outer layer are positively and negatively twisted with a single-twisting pitch of 1000 mm, and the laying tension of each optical fiber bundle is controlled to be 10N-20N.

[0052] The above design is based on the actual test of some comparative examples, which shows that the optimal solution of 12 optical fibers or 12 optical fiber bundles is in the form of a circle, so the distribution of 12 optical fibers or 12 optical fiber bundles can be preferably performed as above. Accordingly, not only the circularity of the optical cable can be ensured, but also the tensile property of the optical cable can be improved.

[0053] Figure 2 is a sectional view of the structure of the small-diameter large-core-count optical cable according to a preferred embodiment of the present application, as shown in Figure 2 The present application also provides a small-diameter large-core-count optical cable product, which comprises a fiber core, a sleeve 2 and an outer sheath layer 4 from inside to outside, wherein the fiber core is composed of a plurality of optical fiber bundles which are coaxially and closely arranged and twisted together, and each optical fiber bundle is composed of a plurality of optical fibers 1 which are coaxially and closely arranged and twisted together, and then subjected to stranding treatment.

[0054] More specifically, the optical cable can further comprise an armor 3, such as an aluminum tape, which is arranged between the fiber core and the outer sheath layer.

[0055] It should be noted that the optical cable product of the present application can completely eliminate the use of the central reinforcing core. In addition, the existing product usually wraps a layer of steel wire around the outer periphery of the aluminum tape to ensure the tensile properties of the optical cable, but the optical cable of the present application does not need to wrap a layer of steel wire around the outer periphery.

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

[0057] It is easy for those skilled in the art to understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a small-diameter, high-core-count optical cable, characterized in that, Optical cables are manufactured through a series of processes including coloring, yarn binding, cabling, secondary sheathing, and layering. In the yarn binding process, multiple optical fibers are coaxially and tightly arranged together and twisted into a first optical fiber bundle, and then yarn binding is performed; during this process, the multiple optical fibers are arranged in an inner and outer layer in a circumferential form, and then twisted in a forward and reverse spiral using a preset first unidirectional twisting pitch. In the cabling process, several first fiber bundles are coaxially and tightly arranged together, and then further twisted into a second fiber bundle to form a fiber core. During this process, the several first fiber bundles are also arranged in an inner and outer circular pattern without a central reinforcing core. Then, the first fiber bundles in the inner layer are spirally twisted in both directions using a preset second unidirectional twisting pitch, and the first fiber bundles in the outer layer are spirally twisted in both directions using a preset third unidirectional twisting pitch. The first, second, and third unidirectional twisting pitches are different from each other. In the two processes, a tube is wrapped around the outer layer of the second optical fiber bundle, and fiber paste is added into the tube; In the sheathing process, an armor layer and an outer sheath layer are sequentially set on the outside of the sleeve, and steel wire is not required to be wrapped around the armor, thus forming the required small-diameter, large-core-count optical cable.

2. The preparation method according to claim 1, characterized in that, In the yarn binding process, the multiple optical fibers are formed into the first optical fiber bundle, which is approximately cylindrical.

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 set to 12, and 3 of the 12 optical fibers are placed in the inner layer and then spirally twisted together, while the remaining 9 optical fibers are placed in the outer layer and then spirally twisted together; wherein, the optical fibers are all spirally twisted in both directions using a first 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 fiber bundles are formed into a second fiber bundle that is approximately 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 set to 12 bundles, and 3 optical fiber bundles are placed in the inner layer and then spirally twisted together, while the remaining 9 optical fiber bundles are placed in the outer layer and then spirally twisted together. The optical fiber bundles in the inner layer are spirally twisted in both directions using a second unidirectional twisting pitch of 1200mm, and the optical fiber bundles in the outer layer are spirally twisted in both directions using a third unidirectional twisting pitch of 1000mm. At the same time, the tension of each optical fiber bundle is controlled to be between 10N and 20N.

6. A small-diameter, high-core-count optical cable, characterized in that, It is prepared by means of any one of claims 1 to 5.

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