OUTDOOR OPTICAL CABLE WITH HIGH FIBER LOOSE MICROTUBE AND ASSOCIATED MANUFACTURING PROCESS

Abstract

The invention relates to a high-fiber-count loose microtube outdoor optical cable and its manufacturing process. The high-fiber-count loose microtube outdoor optical cable comprises a cable core and a sheath layer (5) enclosing the cable core. The cable core comprises several layers of loose microtube optical units (1) arranged in a twisted configuration. The multiple layers of loose microtube optical units (1) are formed by a single twist, and each layer of the loose microtube optical unit (1) is rotationally twisted. Each of the loose microtube optical units (1) comprises a loose microtube and a plurality of optical fibers wrapped within the loose microtube. The optical fibers are coated with a fiber ointment. A reinforcing element (3) is embedded in the sheath layer (5). [Figure 1 accompanies the abstract.]

Description

Title of the invention: OUTDOOR OPTICAL CABLE WITH LOOSE MICROTUBE WITH HIGH FIBER COUNT AND ASSOCIATED MANUFACTURING METHOD Technical field of the invention

[0001] The present invention relates to the technical field of optical cable structure designs and preparation methods and in particular an optical cable with a high fiber count loose microtube and an associated manufacturing method. Prior art

[0002] With the continuous development of modern communication technologies and the increasing popularity of social networks and video services, user demand for a high-capacity, high-speed network is growing. Network capacity expansion, on the one hand, refers to improving the transmission speed of a single optical fiber, which is difficult to improve rapidly due to technical limitations; and on the other hand, refers to increasing the number of data transmission channels, i.e., optical fibers, which is easy to implement in most cases, but is limited by existing infrastructure resources, making it difficult to expand network capacity by laying a plurality of optical cables.Based on this premise, network capacity expansion can only be achieved by increasing the number of optical fibers in a single optical cable, and meanwhile, by using a single optical cable with a high number of fibers instead of a plurality of optical cables with a low number of fibers, the cost of constructing the optical cable can be effectively reduced and the efficiency of the construction can be improved.

[0003] With the increase in hosted computing services, the number of connected optical fibers has increased considerably, and large data centers are attempting to improve their optical transmission infrastructure by installing optical fiber cables with an ultra-high fiber count. Based on the above requirements, the invention of an optical cable with a high fiber count and high density is necessary.

[0004] Existing outdoor optical cable with loose microtube is widely used in short-distance overhead cable laying environments. Such an optical cable can be directly installed and inserted into a cable without the need for any nodes, thus satisfying short-distance overhead laying requirements. but it is difficult to meet the demand for communication technology for optical cable with a high number of fibers at this stage.

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that a loose microtube optical cable of the prior art is difficult to satisfy the demand for a high number of fibers and the present invention proposes an outdoor optical cable with a high number of fibers loose microtube and an associated manufacturing method, and realizes the structural design of the high number of fibers loose microtube and proposes a manufacturing method for the high number of fibers loose microtube. Description of the invention

[0006] In order to solve the above technical problem, the present invention proposes an outdoor optical cable with a high fiber count loose microtube, which comprises a cable core and a sheath layer enveloping the cable core, the cable core comprising several layers of loose microtube optical units arranged in twisted mode, the multiple layers of loose microtube optical units are formed by a single twisting and each layer of the loose microtube optical unit is twisted in rotation in positive and negative directions with a certain pitch and number of rotations; each of the loose microtube optical units comprises a loose microtube made of a low fume halogen-free modified polyolefin material and a plurality of optical fibers wrapped in the loose microtube and the optical fibers are coated with a fiber ointment; and a reinforcing element is embedded in the sheath layer.

[0007] In one embodiment of the present embodiment, a space between the multiple layers of loose microtube optical units is filled with a water-blocking dry wire, and the water-blocking dry wire is twisted and filled with the loose microtube optical units.

[0008] In one embodiment of the present embodiment, a first bonding layer is arranged outside the multiple layers of loose microtube optical units, the first bonding layer comprises a plurality of spirally arranged wires, and the plurality of loose microtube optical units are grouped and bound by the wires.

[0009] In one embodiment of the present embodiment, the cable core is wrapped with a water-blocking dry belt, and the water-blocking dry belt is wrapped around a periphery of the cable core in an enclosed or longitudinal manner.

[0010] In one embodiment of the present embodiment, a second bonding layer is arranged outside the dry water-blocking belt, the second bonding layer comprises a plurality of spirally arranged wires and the dry water-blocking belt is grouped and bound by the wires.

[0011] In one embodiment of the present embodiment, the sheath layer has a hollow embedded structure, a plurality of non-metallic reinforcing elements are integrated into the sheath layer, the plurality of non-metallic reinforcing elements are arranged symmetrically on two sides along a short axis direction in the sheath layer and the non-metallic reinforcing elements have a flat structure.

[0012] In order to solve the above technical problem, the present invention proposes a method for manufacturing an outdoor optical cable with a high fiber count loose microtube, comprising the following steps: - the unwinding of a plurality of optical fibers respectively by an unwinder and the maintenance of a constant unwinding tension of the optical fibers, the coating of the optical fibers with a fiber ointment then the extrusion of a low fume halogen-free modified polyolefin material to form a loose microtube, and the cooling in a cold water tank to form a loose microtube optical unit; - the introduction of a plurality of loose microtube optical units into a cabling and twisting device, the introduction of a dry wire blocking water in a space between the plurality of loose microtube optical units simultaneously to enter the cabling and twisting device with the loose optical microtube twisting synchronously and rotationally by the cabling and twisting device, the plurality of loose microtube optical units layered in positive and negative directions with a certain pitch and a certain number of rotations, and the grouping and bonding of the multiple twisted layers of loose microtube optical units to obtain a cable core; and - the wrapping of a dry belt blocking water outside the cable core in surrounded or longitudinal mode, the making of a wire bond on the water-blocking belt, the introduction of the cable core wrapped with the dry water-blocking belt into a sheath extruder with non-metallic reinforcing elements in parallel and extrusion to form a sheath layer and cooling to form the outer optical cable with loose microtube.

[0013] In one embodiment of the present embodiment, a fiber ointment microfilling quantity stability technology is used to apply a fiber ointment coating to the outside of the optical fibers, pressurize a fiber ointment storage tank, add a pressure relief channel in a coating mold and heat the fiber ointment storage tank and an ointment filling channel.

[0014] In an embodiment of the present embodiment, when the plurality of loose microtube optical units are twisted into layers, the unwinding tensions of different layers of loose microtube optical units are controlled, so that the lengths of the optical fibers in the loose microtube optical units are consistent.

[0015] In one embodiment of the present embodiment, when the sheath layer is extruded, a vacuum sizing technology is used to control the shape and size of the sheath layer by adjusting the negative pressure and monitoring the water pressure.

[0016] Compared to the prior art, the above technical solutions of the present invention have the following advantages.

[0017] In the outdoor optical cable with a high number of loose microtubes according to the present invention, the plurality of loose microtube optical units is arranged so as to be formed by a unique layered twisting, which improves the density of the optical fibers, reduces the size of the optical cable and solves a problem of limited ducting resources, and the replacement of a single optical cable with a high number of fibers by a plurality of optical cables with a lower number of fibers can effectively reduce the cost of constructing the optical cable and improve construction efficiency; and the loose microtube optical unit is used to bundle and sheath the optical fibers, which achieves high density and small size characteristics and the loose microtube is convenient to tear and peel off by hand, which facilitates the separation of the optical fibers.

[0018] In the process of manufacturing an outdoor optical cable with a high fiber count loose microtube according to the present invention, the single twisting forming technology is used, and compared to the preparation of a stranded loose tube cable, the manufacturing process is simple and the manufacturing cycle and manufacturing cost are reduced; moreover, the conventional twisting process around a central reinforcing element is abandoned and the loose microtube optical units are directly arranged for twisting, so that an outside diameter of the cable core is further reduced and a duty cycle of the optical fibers in the cable core is increased. Brief description of the figures

[0019] To facilitate understanding of the content of the present invention, the present invention is described in more detail below with reference to specific embodiments of the present invention and to the figures:

[0020] Figure 1 illustrates a schematic structural diagram of an outdoor optical cable with a high-fiber-count loose microtube according to the present invention; and

[0021] [Fig.2] shows a flowchart of a method for manufacturing an outdoor optical cable with a high number of fibers loose microtube according to the present invention.

[0022] For clarity, identical or similar elements are identified by identical reference numerals throughout the figures. In particular, 1 refers to the loose microtube optical unit; 2 refers to a water-blocking dry wire; 3 refers to the reinforcing element; 4 refers to the water-blocking dry belt; and 5 refers to the sheath layer. Detailed description of an implementation method

[0023] The present invention is described in more detail below with reference to the drawings and specific embodiments, so that a person skilled in the art may better understand and implement the present invention. However, the embodiments mentioned should not be considered as a limitation of the present invention.

[0024] With reference to [Fig. 1], an outdoor optical cable with a high number of loose microtubes according to the present invention comprises a cable core and a sheath layer 5 surrounding the cable core. The cable core comprises several layers of loose microtube optical units 1 arranged in a twisted configuration. The multiple layers of loose microtube optical units 1 are formed by a single twist, and each layer of the loose microtube optical unit 1 is twisted rotationally in the positive and negative directions with a certain pitch and a certain number of twists.The multiple layers of loose microtube optical units 1 are integrated and twisted together, improving optical fiber density, reducing the size of the optical cable, and addressing the issue of limited conduit resources. Replacing a single optical cable with a high fiber count with multiple optical cables with a lower fiber count can effectively reduce optical cable construction costs and improve construction efficiency. The loose microtube optical unit 1 comprises a loose microtube made of a low-fume, halogen-free modified polyolefin material and a plurality of optical fibers wrapped within the loose microtube. The low-fume, halogen-free modified polyolefin material is easily torn and peeled by hand, facilitating optical fiber separation.The optical fibers are coated with a fiber ointment, which improves the radial capacity blocking water inside the loose microtube optical unit 1. A reinforcing element 3 is embedded in the sheath layer 5, which further improves the overall mechanical properties of the optical cable.

[0025] More specifically, a space between the multiple layers of loose microtube optical units 1 is filled with a water-blocking dry wire 2, the water-blocking dry wire 2 is twisted and filled with the loose microtube optical units 1, which ensures a full cross-section Water-blocking fiber optic cable is used, and a water-blocking yarn with a high expansion rate is selected as the water-blocking dry yarn 2. The cable core is also wrapped with a water-blocking dry yarn 4, which is wrapped around the periphery of the cable core in a wrapped or longitudinal configuration. Through the triple waterproofing technology of filling the loose microtube optical unit 1 with water-blocking fiber ointment, filling the space between the loose microtube optical units 1 with water-blocking dry yarn 2, and coating the outside of the cable core formed by the loose microtube optical units 1 with water-blocking dry yarn 4, the cable core is subjected to complete waterproof protection in both the longitudinal and radial directions, ensuring that its sealing performance meets industry requirements.

[0026] More specifically, a first bonding layer is arranged outside the multiple layers of loose microtube optical units 1. The first bonding layer comprises a plurality of spirally arranged wires, and the plurality of loose microtube optical units 1 are grouped and bound together by the wires. The loose microtube optical units 1 are intended to prevent the loose microtube optical units 1 from loosening to ensure the cable's roundness. A second bonding layer is arranged outside the water-blocking dry belt 4. The second bonding layer comprises a plurality of spirally arranged wires, and the water-blocking dry belt 4 is grouped and bound together by the wires to prevent the water-blocking dry belt 4 from loosening.

[0027] More specifically, the sheath layer 5 has a flat structure, a plurality of non-metallic reinforcing elements 3 are integrated into the sheath layer 5, the plurality of non-metallic reinforcing elements 3 are arranged symmetrically on two sides along a short axis direction in the sheath layer 5, and the non-metallic reinforcing elements 3 have a flat structure. The non-metallic reinforcing elements 3 are glass fiber rods with a light weight, high tensile strength, and a relative density of 1.5 to 2.0, the relative density being only 1 / 4 to 1 / 5 that of carbon steel, but the tensile strength is close to that of carbon steel, and the tensile, flexural, and compressive strengths of the glass fiber rods can all reach more than 400 MPa.Moreover, fiberglass rods are good corrosion-resistant materials with good resistance to atmosphere, water, acids, alkalis, and salts of common concentrations, as well as various oils and solvents. Meanwhile, fiberglass rods are also excellent insulating materials used in the manufacture of insulators and can maintain good dielectric properties at high frequencies. In this embodiment, flat fiberglass rods can not only achieve the tensile strength performance of optical cables, but also... also reduce the external diameter of the optical cable and compared to round glass fiber rods, the cross-sectional area of ​​the optical cable integrated with flat glass fiber rods is reduced by about 10%.

[0028] With reference to [Fig.2], a method for manufacturing a high-fiber-count loose microtube outdoor optical cable comprises the following steps:

[0029] the preparation of a loose microtube optical unit 1: unwinding a plurality of optical fibers respectively by an unwinder and maintaining a constant unwinding tension of the optical fibers, coating the optical fibers with a fiber ointment then extruding a low fume halogen-free modified polyolefin material to form a loose microtube and cooling in a cold water tank to form the loose microtube optical unit 1;

[0030] the preparation of a loose microtube multilayer cable core; the introduction of a plurality of loose microtube optical units 1 into a cabling and twisting device, the introduction of a water-blocking dry wire 2 into a space between the plurality of loose microtube optical units 1 simultaneously to enter the cabling and twisting device jointly with the loose microtube optical units 1 synchronously, the rotational twisting, by the cabling and twisting device, of the plurality of loose microtube optical units 1 in layers in the positive and negative directions with a certain pitch and number of rotations, and the grouping and bonding of the multiple twisted layers of loose microtube optical units 1 to obtain the cable core.The single-twist forming technology is used and, compared to the preparation of a stranded loose tube cable, the manufacturing process is simple and the manufacturing cycle and manufacturing cost are reduced; moreover, the conventional process of twisting around a central reinforcing element is abandoned and the loose microtube optical units 1 are directly arranged for twisting, so that an outside diameter of the cable core is further reduced and a duty cycle of the optical fibers in the cable core is increased; and .

[0031] the preparation of a sheath layer 5: wrapping a dry water-blocking belt 4 outside the cable core in surrounded or longitudinal mode, making a wire bond on the water-blocking belt 4, introducing the cable core wrapped with the dry water-blocking belt 4 into a sheath extruder with non-metallic reinforcing elements 3 in parallel and extrusion to form the sheath layer 5 and cooling to form the outer optical cable with a loose microtube.

[0032] More specifically, when the fiber ointment is coated on the outside of the optical fibers, a technology for stabilizing the amount of microfilling of the ointment Fiber is used to pressurize a fiber ointment storage tank, and a pressure relief channel is simultaneously added to a coating mold. A conical drainage pattern and pressure relief channel design are employed. The conical drainage pattern minimizes fiber ointment overflow at the mold inlet due to pressure issues, while the pressure relief channel design addresses local pressure instability during the coating process. This allows the fiber ointment to overflow through a pressure relief hole, ensuring coating uniformity in the microfilling process. The fiber ointment storage tank and filling line are heated in-line to ensure the fiber ointment flows smoothly.

[0033] More specifically, when different loose microtube optical units 1 are twisted into layers, the lengths of the optical fibers arranged in the loose microtube optical units are different due to the different positions of the loose microtube optical units 1. In order to regulate the lengths of the optical fibers in different layers of loose microtube optical units 1 to remain consistent, in the embodiment, when the loose microtube optical units are unwound, the unwinding tensions of the different layers of loose microtube optical units 1 are controlled, so that the lengths of the optical fibers in the loose microtube optical units 1 are consistent, so as to meet the performance requirements of the product.

[0034] In this embodiment, a single spiral twisting process in the positive and negative directions with a certain pitch and number of rotations, without a central reinforcing element, is used in the cabling and twisting. 24 to 112 loose microtube optical units 1 and a certain proportion of water-blocking dry wires 2 are directly distributed and arranged, and then the single twisting technology is implemented. A single loose microtube has 24, 36, or 48 cores, and the number of cores in the single-twisted loose microtube optical cable can reach 576 to 5,376.In the unique cabling and twisting device, a front twisting head is driven by an AC servomotor to rotate in the positive and negative directions with a specific pitch and number of rotations. A rear capstan is connected in series by a fixed steel cable. A twisting bench and the capstan are arranged sequentially by means of a tensioning function of a pneumatic cylinder at the rear of a twisting body. Power is transmitted via a steel wire at the front twisting head to drive the rear capstan to rotate in the positive and negative directions with a specific pitch and number of rotations. The number of rotations is determined according to the manufacturing process of the optical cable. is generally plus or minus 3 to 5, and the performance of the optical cable can be stabilized by means of the SZ twisting process.

[0035] More specifically, when the sheath layer 5 is extruded, a vacuum sizing technology is used to control the shape and size of the sheath layer 5 by negative pressure adjustment and water pressure monitoring.

[0036] Obviously, the above embodiments are merely examples to clearly illustrate the present invention, but are not intended to limit implementations. For those skilled in the art, other forms of modifications or variations may be made based on the above description. It is neither necessary nor possible to exhaust all implementations in the description. Moreover, the obvious modifications or variations that result from this description are always included within the scope of protection of the present invention.

Claims

Demands

1. Outdoor optical cable with a high fiber count loose microtube, comprising a cable core and a sheath layer (5) enclosing the cable core, wherein the cable core comprises multiple layers of loose microtube optical units (1) arranged in a twisted configuration, the multiple layers of loose microtube optical units (1) are formed by a single twist and each layer of the loose microtube optical unit (1) is twisted rotationally in positive and negative directions with a certain pitch and number of twists; each of the loose microtube optical units (1) comprises a loose microtube made of a low fume halogen-free modified polyolefin material, and a plurality of optical fibers wrapped in the loose microtube and the optical fibers are coated with a fiber ointment; and a reinforcing element (3) is embedded in the sheath layer (5);characterized in that in said optical cable the sheath layer (5) has a hollow embedded structure, a plurality of non-metallic reinforcing elements (3) are integrated into the sheath layer (5), the plurality of non-metallic reinforcing elements (3) are arranged symmetrically on two sides along a short axis direction in the sheath layer (5) and the non-metallic reinforcing elements (3) have a flat structure..;

2. Outdoor optical cable with high fiber count loose microtube according to claim 1, wherein a space between the multiple layers of loose microtube optical units (1) is filled with a water-blocking dry wire (2), and the water-blocking dry wire (2) is twisted and filled with the loose microtube optical units (1).

3. Outdoor optical cable with a high fiber count loose microtube according to claim 1, wherein a first bonding layer is arranged outside the multiple layers of loose microtube optical units (1), the first bonding layer comprises a plurality of spirally arranged wires and the plurality of loose microtube optical units (1) are grouped and bonded by the wires.

4. Outdoor optical cable with a high-fiber-count loose microtube according to claim 1, wherein the cable core is wrapped with a water-blocking dry belt (4) and the belt dry water blocking (4) is wrapped around or longitudinally on a periphery of the cable core.

5. Outdoor optical cable with a high fiber count loose microtube according to claim 4, wherein a second bonding layer is arranged outside the water-blocking dry belt (4), the second bonding layer comprises a plurality of spirally arranged wires and the water-blocking dry belt (4) is bundled and bound by the wires.

6. Method of manufacturing an outdoor optical cable with a high number of fibers loose microtube, comprising the following steps: - unwinding a plurality of optical fibers respectively by an unwinder and maintaining a constant optical fiber unwinding tension, coating the optical fibers with a fiber ointment and then extruding a low fume halogen-free modified polyolefin material to form a loose microtube, and cooling in a cold water tank to form a loose microtube optical unit (1);- the introduction of a plurality of loose microtube optical units (1) into a cabling and twisting device, the introduction of a water-blocking dry wire (2) into a space between the plurality of loose microtube optical units (1) simultaneously to enter the cabling and twisting device with the loose optical microtube (1) twisting synchronously and rotationally by the cabling and twisting device, the plurality of loose microtube optical units (1) in layers in positive and negative directions with a certain pitch and a certain number of rotations and the grouping and bonding of the multiple twisted layers of loose microtube optical units (1) to obtain a cable core; - the wrapping of a water-blocking dry belt (4) around or longitudinally outside the cable core, the making of a wire bond on the water-blocking belt (4), introduction of the wrapped cable core; the dry belt blocking water in a sheath extruder with non-metallic reinforcing elements (3) in parallel and extrusion to form a sheath layer (5) and cooling to form the outer optical cable with loose microtube; and - wherein the sheath layer (5) has a hollow embedded structure, a plurality of non-metallic reinforcing elements (3) is integrated into the sheath layer (5), the plurality of non-metallic reinforcing elements (3) is arranged symmetrically on two sides along a short axis direction in the sheath layer (5) and the non-metallic reinforcing elements (3) have a flat structure.

7. A method for manufacturing an outdoor optical cable with a high fiber count loose microtube according to claim 6, wherein a fiber ointment microfill quantity stability technology is used to apply a fiber ointment coating to the outside of the optical fibers, pressurize a fiber ointment storage tank, add a pressure relief channel in a coating mold and heat the fiber ointment storage tank and an ointment filling channel.

8. A method for manufacturing an outdoor optical cable with a high number of fibers loose microtube according to claim 6, wherein, when the plurality of loose microtube optical units (1) is twisted into layers, the unwinding tensions of different layers of loose microtube optical units (1) are controlled, so that the lengths of the optical fibers in the loose microtube optical units (1) are consistent.

9. A method for manufacturing an outdoor optical cable with a high fiber count loose microtube according to claim 6, wherein, when the sheath layer (5) is extruded, a vacuum sizing technology is used to control a shape and size of the sheath layer (5) by adjusting negative pressure and monitoring water pressure.

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