Ribbon fiber optic cable

Abstract

A ribbon fiber optic cable, comprising a cable core, a water blocking layer (4), a steel tape (5) and an outer jacket (6) which are sequentially arranged from inside to outside. The cable core comprises a flexible foamed subunit (1) and tight-buffered subunits. Each tight-buffered subunit comprises a TPU loose tube (2) and optical fiber ribbons (3). A gap is formed between the water blocking layer (4) and the steel tape (5). By using the TPU loose tubes (2), due to a tight-buffered thin-wall structure, the tight-buffered subunits have a small size, thereby increasing the space utilization of optical fibers in the loose tubes and the fiber packing density of optical fibers in the fiber optic cable, and achieving a large core diameter ratio. The cable core uses the flexible foamed subunit (1), and when the tight-buffered subunits and the flexible foamed subunit (1) are stranded, the flexible foamed subunit (1) made of a soft material provides protection for the tight-buffered subunits when the fiber optic cable is in use, thereby ensuring the transmission performance of the fiber optic cable. A gap is formed between the water blocking layer (4) and the steel tape (5), so that there is certain spacing inside the fiber optic cable, and a loose structure is achieved, reducing the impact of outer jacket shrinkage of the fiber optic cable on the TPU loose tube (2) and the optical fiber ribbons (3), and solving the problem of additional fiber attenuation during loose coiling and thermal cycling of the fiber optic cable.

Description

A fiber optic cable Technical Field

[0001] This application relates to the field of optical fiber and cable technology, and in particular to an optical fiber ribbon cable. Background Technology

[0002] With the construction and development of 5G communication networks, the need for new types of optical cables for high-volume data transmission is urgent. However, due to the scarcity of space in ducts, the number of optical cables that can be installed in ducts is limited. To improve this situation, the demand for high-density optical cables with smaller diameters and larger fiber core counts is increasing. Ultra-high density, ultra-large core count fiber ribbon cables can effectively solve the problem of insufficient network traffic transmission capacity in core backbone networks, local area networks, access networks, computer rooms, and big data centers that rely primarily on fiber optic communication. When it enters commercial applications, it will inevitably significantly reduce the manufacturing, installation, and maintenance costs of optical cables.

[0003] With the increasing demand for high-core-count, small-diameter, low-shrinkage optical fiber ribbon cables, traditional stranded ribbon cable products are unable to achieve low shrinkage rates in transmission solutions for central computer rooms.

[0004] Summary of the Invention

[0005] This application provides an optical fiber ribbon cable to solve the problem of increased attenuation caused by the large shrinkage rate of optical fiber ribbon cables in related technologies.

[0006] This application provides an optical fiber ribbon cable, which includes a cable core, a water-blocking layer, a steel strip, and an outer sheath arranged sequentially from the inside to the outside along the radial direction of the cable.

[0007] The cable core includes a flexible foamed sub-unit and a tight-fitting sub-unit stranded on the flexible foamed sub-unit. The tight-fitting sub-unit includes a TPU bundle tube and an optical fiber ribbon located inside the TPU bundle tube.

[0008] A gap is formed between the water-blocking layer and the steel strip.

[0009] This application provides an optical fiber ribbon cable that uses a small-sized TPU bundle tube. Due to its tight-buffered thin-walled structure, the size of the tight-buffered sub-unit is small, thereby increasing the duty cycle of the optical fiber in the loose tube and the fiber density in the cable. This solves the problem of filling large fiber cores under the same size conditions and has a larger core diameter ratio. The center of the cable core uses a flexible foamed sub-unit. After the tight-buffered sub-unit and the flexible foamed sub-unit are twisted together, the latter's flexible foamed sub-unit, being made of a softer material, protects the tight-buffered sub-unit during use, thus ensuring the transmission performance of the cable. At the same time, a gap is formed between the water-blocking layer and the steel strip, creating a certain gap inside the cable. This loose structure reduces the impact of the cable's outer sheath shrinkage on the TPU bundle tube and the optical fiber ribbon, solving the problem of additional fiber attenuation during loose winding temperature cycling.

[0010] In some embodiments, the flexible foamed subunit is made of foamed PE material.

[0011] In some embodiments, the foaming degree of the PE material is 50% to 70%.

[0012] In some embodiments, the filler content within the steel strip is 80% to 90%.

[0013] In some embodiments, the water-blocking layer includes a water-blocking tape wrapped longitudinally on the cable core, and yarn tied on the water-blocking tape.

[0014] In some embodiments, a water-blocking element is also provided outside the flexible foam sub-unit, and the water-blocking element is located between the flexible foam sub-unit and the tight-fitting sub-unit.

[0015] In some embodiments, the water-blocking element is made of water-blocking yarn.

[0016] In some embodiments, a tear rope is provided within the gap.

[0017] In some embodiments, the outer sheath has an embedded reinforcement.

[0018] In some embodiments, the thickness of the water-blocking layer is 0.20 mm or 0.30 mm;

[0019] The steel strip has a thickness of 0.20 mm, 0.23 mm, or 0.25 mm;

[0020] The outer sheath is made of HDPE or MDPE;

[0021] The maximum outer diameter of the optical cable is 24.0±1mm;

[0022] The tight-fitting sub-unit has 144 cores and is available in 6 units.

[0023] The beneficial effects of the technical solution provided in this application include:

[0024] This application provides an optical fiber ribbon cable that uses a small-sized TPU bundle tube. Due to its tight-buffered thin-walled structure, the size of the tight-buffered sub-unit is small, thereby increasing the duty cycle of the optical fiber in the loose tube and the fiber density in the cable. This solves the problem of filling large fiber cores under the same size conditions and has a larger core diameter ratio. The center of the cable core uses a flexible foamed sub-unit. After the tight-buffered sub-unit and the flexible foamed sub-unit are twisted together, the latter's flexible foamed sub-unit, being made of a softer material, protects the tight-buffered sub-unit during use, thus ensuring the transmission performance of the cable. At the same time, a gap is formed between the water-blocking layer and the steel strip, creating a certain gap inside the cable. This loose structure reduces the impact of the cable's outer sheath shrinkage on the TPU bundle tube and the optical fiber ribbon, solving the problem of additional fiber attenuation during loose winding temperature cycling. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 is a schematic diagram of the optical fiber ribbon cable provided in an embodiment of this application.

[0027] In the diagram: 1. Flexible foam sub-unit; 2. TPU bundle tube; 3. Fiber optic ribbon; 4. Water-blocking layer; 5. Steel strip; 6. Outer sheath; 7. Gap; 8. Water-blocking element; 9. Tear rope; 10. Reinforcing element. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Referring to Figure 1, this application embodiment provides an optical fiber ribbon cable, which includes a cable core, a water-blocking layer 4, a steel strip 5, and an outer sheath 6 arranged sequentially from the inside to the outside along the radial direction of the cable; the cable core includes a flexible foaming sub-unit 1, and a plurality of tight-buffered sub-units stranded on the flexible foaming sub-unit 1 in a layer stranding manner, the tight-buffered unit including a TPU bundle tube 2 and an optical fiber ribbon 3 located inside the TPU bundle tube 2; a gap 7 is formed between the water-blocking layer 4 and the steel strip 5.

[0030] The fiber optic cable provided in this embodiment uses a small-sized TPU bundle tube 2. Due to its tight-buffered thin-walled structure, the size of the tight-buffered sub-unit is small, thereby increasing the duty cycle of the optical fiber in the loose tube and the fiber density of the optical fiber in the cable. This solves the problem of filling a large number of optical fiber cores under the same size conditions and has a larger core diameter ratio. The center of the cable core adopts a flexible foamed sub-unit 1. After the tight-buffered sub-unit and the flexible foamed sub-unit 1 are twisted together, the latter flexible foamed sub-unit 1, being made of a softer material, protects the tight-buffered sub-unit during use, thus ensuring the transmission performance of the optical cable. At the same time, a gap 7 is formed between the water-blocking layer 4 and the steel strip 5, creating a certain gap inside the optical cable. This loose structure reduces the impact of the outer sheath shrinkage on the TPU bundle tube 2 and the optical fiber strip 3, solving the problem of additional optical fiber attenuation during loose winding temperature cycling.

[0031] Understandably, the aforementioned flexible foam sub-unit 1 can utilize its relatively soft material to protect the tight-fitting sub-unit. Simultaneously, the flexible foam sub-unit 1 also functions as a central reinforcement, allowing for the layering of various tight-fitting sub-units. Many types of materials can achieve this function; for example, the flexible foam sub-unit 1 is made of foamed PE material. Other existing soft materials can also be used, as long as they can achieve the aforementioned functions.

[0032] Furthermore, in order to serve both as a protective sleeve sub-unit and as a central reinforcement, the foaming degree of the PE material in this embodiment is optimized and limited. As an example, the foaming degree of the PE material used in the flexible foamed sub-unit 1 is 50% to 70%.

[0033] In other words, the foaming degree can be selected from 50% to 70% based on the actual product specifications. For example, as an example, the foaming degree of the PE material used in the flexible foaming sub-unit 1 can be selected as 50%, 52%, 55%, 57%, or even 70%. The foaming degree of the PE material can be selected as 60%. For example, the foaming degree of the PE material used in the flexible foaming sub-unit 1 can be selected as 62%, 64%, 66%, 68%, or 70%.

[0034] The optical fiber ribbon cable provided in this application embodiment forms a gap 7 between the water-blocking layer 4 and the cable core in the overall structure and the steel strip 5. The existence of this gap 7 makes the cable core, steel strip 5, and outer sheath 6 have a loose structure. The shrinkage of the outer sheath 6 has little impact on the cable core, and avoids the impact of external temperature changes on the optical fiber transmission performance due to the coiling position of the optical cable during use. This solves the problem of additional optical fiber attenuation during the loose winding temperature cycling process of the optical cable.

[0035] If the gap 7 is too small, the loose structure will have limited ability to eliminate the impact of the outer sheath 6 shrinkage on the cable core. If the gap 7 is too large, the overall size of the optical cable will be too large. In order to balance the two, the filling degree of the steel strip 5 is limited in this embodiment. Specifically, the filling degree of the steel strip 5 is 80% to 90%.

[0036] In other words, the fill percentage can be selected from 80% to 90% based on the actual product specifications. For example, as an example, the fill percentage of the overall structure formed by the water-blocking layer 4 and the cable core within the steel strip 5 can be selected as 80%. Another example is 82%, 84%, 86%, 88%, or even 90%.

[0037] To prevent the cable core from twisting, in some preferred embodiments, the water-blocking layer 4 includes a water-blocking tape wrapped longitudinally around the cable core and binding yarn located on the water-blocking tape.

[0038] After several of the tight-buffered sub-units are stranded together on the flexible foamed sub-unit 1, they are longitudinally wrapped with water-blocking tape and then bound with single-strand binding yarn to prevent the cable core from untwisting, so that the optical cable forms an orderly number of turns between the two reversing points, ensuring the stability of the entire cable core structure. Finally, the cable core is placed in the steel tape-outer sheath.

[0039] Referring to Figure 1, in some preferred embodiments, a water-blocking element 8 is further provided outside the flexible foaming sub-unit 1, and the water-blocking element 8 is located between the flexible foaming sub-unit 1 and the tight-fitting sub-unit. The water-blocking element 8 is made of water-blocking yarn.

[0040] The flexible foam subunit 1 is waterproofed by using water-blocking yarn.

[0041] Referring again to Figure 1, the number of water-blocking elements 8 in this embodiment can be determined according to actual water-blocking needs. For example, three water-blocking yarns are provided in Figure 1.

[0042] Furthermore, one of the water-blocking yarns is spirally wound around the outer surface of the flexible foaming sub-unit 1, while the other two water-blocking yarns are laid flat next to the flexible foaming sub-unit 1.

[0043] Similarly, the surface of the TPU bundle tube 2 of the tight-fitting subunit can also be provided with water-blocking yarn for water blocking.

[0044] As shown in Figure 1, a tear rope 9 is provided in the gap 7, which can be used to quickly tear apart the steel strip 5 and the outer sheath 6.

[0045] To make it easier to tear the optical cable, multiple tear ropes 9 can be set, such as two tear ropes 9, which are symmetrically set on both sides of the cable core.

[0046] Manually peeling the fiber optic cable helps save installation and splicing time and improves installation efficiency.

[0047] As shown in Figure 1, a reinforcing member 10 is embedded in the outer sheath 6. The reinforcing member 10 is a non-metallic reinforcing member, made of FRP tape or aramid yarn, which can fit more tightly with the outer sheath. Compared with the reinforcing member set on the inner side of the outer sheath, it will not cause an additional increase in the thickness of the outer sheath.

[0048] Multiple reinforcing members 10 can be provided. For example, two reinforcing members 10 can be arranged in parallel as a group, and two groups can be provided. The two groups of reinforcing members 10 are symmetrically located on both sides of the outer sheath.

[0049] The thickness of the water-blocking layer 4 is 0.20 mm or 0.30 mm.

[0050] The steel strip 5 has a thickness of 0.20 mm, 0.23 mm, or 0.25 mm.

[0051] The outer sheath 6 is made of high-density polyethylene (HDPE) or medium-density polyethylene (MDPE).

[0052] The maximum outer diameter of the optical cable is 24.0±1mm.

[0053] The tight-fitting sub-unit has 144 cores and a quantity of 6 units.

[0054] In the manufacturing of the optical fiber ribbon cable provided in this application, the flexible foamed sub-unit 1 and the tight-sheathed sub-unit are longitudinally wrapped with water-blocking tape after being twisted together, and tied with single strands of yarn to prevent the cable core from untwisting, and the cable core is placed in the steel tape-outer sheath.

[0055] Example 1

[0056] A tight-fitting subunit has a large core diameter ratio for a single TPU bundle tube 2. The outer diameter of the TPU bundle tube 2 is 5.4±0.2mm, the wall thickness of the TPU bundle tube 2 is 0.2mm, and the total number of fiber ribbons inside the TPU bundle tube 2 is 144 cores. The fiber ribbons include 12 12-core ribbons, each composed of 12 colored fibers of 245μm±10μm. The fiber ribbon bandwidth is 2580±30μm, and the ribbon height is 250±20μm. The fiber ribbons are stacked in a square shape and are tightly connected to the TPU bundle tube 2 without gaps. The TPU bundle tube 2 is close to square in shape.

[0057] During manufacturing, the flexible foaming sub-unit 1 and the tight sleeve sub-unit are wound together in a 1+6 structure and an SZ twisting method. The surfaces of the flexible foaming sub-unit 1 and the tight sleeve unit are covered with water-blocking yarn. After exiting the twisting head, the cable is bound by first wrapping the water-blocking tape longitudinally and then binding the yarn to prevent the sleeve from deforming and the cable core from twisting. A twisting number of 3-5 turns is formed between the two reversing points. Finally, the cable is wound onto the reel with low tension by using a swing rod.

[0058] There is a gap between the cable core and the steel strip, and the filling degree inside the steel strip is 80-90%. Four 1.6mm circular FRPs are embedded in the outer sheath. The FRPs are placed in pairs, parallel to each other. Finally, the finished cable is taken up by extrusion, water cooling and crawler traction.

[0059] This fiber optic ribbon cable structure can have up to 864 cores, with an outer diameter of 24.0±1mm. The tight-buffered subunit features close contact between the fiber ribbon and the TPU bundle tube 2, resulting in a compact structure and high fiber density per unit cross-section. Furthermore, the tight-buffered subunit can be manually peeled, saving installation and splicing time and improving installation efficiency. Simultaneously, the cable forms an orderly number of turns between the two reversal points, ensuring the stability of the entire cable core structure. The loose structure between the cable core and the steel tape-outer sheath minimizes the impact of outer sheath contraction on the fiber ribbon, preventing the cable's coiling position from affecting fiber transmission performance due to external temperature changes.

[0060] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0061] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An optical fiber ribbon cable, characterized in that: The optical cable includes a cable core, a water-blocking layer (4), a steel strip (5), and an outer sheath (6) arranged sequentially from the inside to the outside along the radial direction of the optical cable; The cable core includes a flexible foam sub-unit (1) and a tight-fitting sub-unit stranded on the flexible foam sub-unit (1). The tight-fitting sub-unit includes a TPU bundle tube (2) and an optical fiber ribbon (3) located inside the TPU bundle tube (2). A gap (7) is formed between the water-blocking layer (4) and the steel strip (5).

2. The optical fiber ribbon cable as described in claim 1, characterized in that: The flexible foamed subunit (1) is made of foamed PE material.

3. The optical fiber ribbon cable as described in claim 2, characterized in that: The foaming degree of PE material is 50% to 70%.

4. The optical fiber ribbon cable as described in claim 1, characterized in that: The filling degree of the steel strip (5) is 80% to 90%.

5. The optical fiber ribbon cable as described in claim 1, characterized in that: The water-blocking layer (4) includes a water-blocking tape wrapped longitudinally on the cable core and a binding yarn located on the water-blocking tape.

6. The optical fiber ribbon cable as described in claim 1, characterized in that: A water-blocking element (8) is also provided outside the flexible foaming subunit (1), and the water-blocking element (8) is located between the flexible foaming subunit (1) and the tight-fitting subunit.

7. The optical fiber ribbon cable as described in claim 6, characterized in that: The water-blocking element (8) is made of water-blocking yarn.

8. The optical fiber ribbon cable as described in claim 1, characterized in that: A tear rope (9) is provided in the gap (7).

9. The optical fiber ribbon cable as described in claim 1, characterized in that: The outer sheath (6) has a reinforcing member (10) embedded inside.

10. The optical fiber ribbon cable as described in claim 1, characterized in that: The thickness of the water-blocking layer (4) is 0.20 mm or 0.30 mm; The steel strip (5) has a thickness of 0.20 mm, 0.23 mm, or 0.25 mm; The outer sheath (6) is made of HDPE or MDPE; The maximum outer diameter of the optical cable is 24.0±1mm; The tight-fitting sub-unit has 144 cores and is available in 6 units.

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