A discontinuously reinforced optical fiber ribbon, a preparation method thereof, and an optical fiber ribbon cable

Abstract

The present invention discloses an intermittently reinforced optical fiber ribbon, a preparation method thereof, and an optical fiber ribbon cable. The optical fiber ribbon comprises a plurality of optical fibers arranged side by side in a transverse direction, and a ribbon resin that wraps the optical fibers; the ribbon resin is a light-cured elastic acrylic resin material; reinforcing strips are intermittently distributed along the axial direction of the optical fibers in the ribbon resin on the front and back sides of the optical fiber ribbon; the reinforcing strips extend in the transverse direction, and their transverse width is within the transverse width of the ribbon resin; the reinforcing strips have a bending modulus of 9 to 200 GPa and an elongation at break of 1% to 5%. The optical fiber ribbon provided by the present invention, because the ribbon resin is elastic and has a low modulus, greatly weakens the internal stress caused by the curing and bonding of the ribbon resin, and reduces the increase in loss caused by the internal stress on the optical fibers, especially the edge fibers; at the same time, the reinforcing strips are used to maintain the overall flatness of the optical fiber ribbon, solving the problems of optical fiber stringing and surface unevenness that may be caused by the reduction of the ribbon resin modulus.

Description

Technical Field

[0001] The present invention belongs to the field of optical communications, and more particularly, relates to a discontinuously reinforced optical fiber ribbon, a preparation method thereof, and an optical fiber ribbon cable. Background Art

[0002] Optical fiber ribbon is a thin flat ribbon made of 4 to 24 optical fibers arranged in parallel and bonded with UV (ultraviolet) cured resin. It has the advantages of high dissolution efficiency and high fiber density, and has therefore been widely promoted and applied.

[0003] However, fiber optic ribbons have long had significant drawbacks. Due to the high modulus of the resin used in the ribbon, the fibers within the ribbon, particularly the two fibers at the edges, are subject to internal stress from curing. This increases fiber attenuation and compromises transmission performance. Furthermore, fiber optic ribbons fully coated with curing resin exhibit poor bending properties due to the complete bonding of the ribbon and resin, limiting their application in optical cable production and applications. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides an intermittently reinforced optical fiber ribbon, a preparation method thereof, and an optical fiber ribbon cable. Its purpose is to combine elastic resin and reinforcement strips to reduce the internal stress effect of the resin on the edge fibers of the optical fiber ribbon and maintain the surface smoothness of the optical fiber ribbon, thereby solving the technical problem that the existing optical fiber ribbon uses a higher modulus parallel ribbon resin, which causes the edge fibers to be significantly affected by the internal stress and the loss is significantly greater than that of the middle fibers.

[0005] To achieve the above object, according to one aspect of the present invention, there is provided a discontinuously reinforced optical fiber ribbon, comprising a plurality of optical fibers arranged side by side in a transverse direction, and a ribbon resin wrapping the optical fibers;

[0006] The strip resin is a light-cured elastic acrylic resin material;

[0007] The fiber optic ribbon has reinforcing strips intermittently distributed in the ribbon resin on the front and back sides along the axial direction of the optical fiber;

[0008] The reinforcing strip extends in the transverse direction, and its transverse width is within the transverse width of the resin strip;

[0009] The reinforcing strip has a bending modulus of 9 to 200 GPa and an elongation at break of 1% to 5%.

[0010] Preferably, the transverse width of the reinforcement strips of the discontinuously reinforced optical fiber ribbon is within the transverse arrangement width of the optical fibers, preferably covering the transverse width range of the intermediate fibers.

[0011] Preferably, in the discontinuously reinforced optical fiber ribbon, the reinforcement strips are perpendicular to or at an angle to the optical fibers, and the spacing between them is 100 to 500 mm.

[0012] Preferably, in the discontinuously reinforced optical fiber ribbon, the diameter of the reinforcement strip is between 10 and 40 μm, and the diameter of the reinforcement strip is smaller than the thickness of a single resin layer, and preferably the difference between the two is greater than 10 μm.

[0013] Preferably, the reinforcement strips of the discontinuously reinforced optical fiber ribbon are made of short fibers, preferably carbon fibers or glass fibers.

[0014] Preferably, the elastic acrylic resin of the discontinuously reinforced optical fiber ribbon has an elastic modulus of 50 to 200 MPa and an elongation at break of 20% to 100%.

[0015] Preferably, the thickness of the resin of the discontinuously reinforced optical fiber ribbon is between 20 and 50 μm.

[0016] Preferably, the intermittently reinforced optical fiber ribbon is filled with ointment, talcum powder or water-blocking powder between the multiple optical fibers.

[0017] According to another aspect of the present invention, a method for preparing the discontinuously reinforced optical fiber ribbon is provided, comprising the following steps:

[0018] Arrange multiple optical fibers side by side horizontally to form a fiber array;

[0019] Periodically place reinforcement strips on the surface of the fiber arrangement and apply elastic acrylic resin to the surface to ensure that the reinforcement strips and the fiber arrangement are relatively fixed.

[0020] The elastic acrylic resin is cured by UV initiation to obtain the discontinuous reinforced optical fiber ribbon.

[0021] According to another aspect of the present invention, an optical fiber ribbon cable is provided, comprising the optical fiber ribbon provided by the present invention.

[0022] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0023] The optical fiber ribbon provided by the present invention greatly weakens the internal stress caused by the curing and bonding of the ribbon resin because the ribbon resin is elastic and has a low modulus, thereby reducing the increase in loss of the optical fibers, especially the edge fibers, due to the influence of internal stress. At the same time, a reinforcing strip is used to maintain the overall flatness of the optical fiber ribbon, solving the problems of optical fiber stringing and surface unevenness that may be caused by the reduction of the ribbon resin modulus. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the structure of the optical fiber ribbon provided in Example 1 of the present invention;

[0025] Figure 21 is a schematic diagram of the cross-sectional projection structure of the optical fiber ribbon provided in Example 1 of the present invention;

[0026] Figure 3 is a schematic diagram of the structure of an optical fiber ribbon provided in Example 2 of the present invention;

[0027] Figure 4 2 is a schematic diagram of the cross-sectional projection structure of the optical fiber ribbon provided in Example 2 of the present invention;

[0028] Figure 5 Schematic diagram of the structure of the optical fiber ribbon cable provided by Example 3 of the present invention;

[0029] Figure 6 This is a schematic diagram of the optical fiber ribbon cable structure provided by Example 4 of the present invention.

[0030] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1 is an optical fiber ribbon, 1.1 is an optical fiber, 1.2 is a ribbon resin, 1.3 is a reinforcing strip, 1.4 is grease, 2 is a ribbon resin, 3 is a reinforcing strip, 4 is a reinforcing member, and 5 is a water-blocking material. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0032] If the modulus of the ribbon resin is lowered to reduce the internal stress generated during the production of the optical fiber ribbon, the restraint on the optical fibers will be reduced, and the fibers may move or separate, causing the optical fiber ribbon to lose its original flat and side-by-side arrangement, thereby losing the advantages of high splicing efficiency and high fiber density brought by the orderly arrangement of the optical fibers. The present invention uses an elastic ribbon resin and rigid reinforcement strips at regular intervals to reduce the internal stress caused by the high modulus of the ribbon resin while maintaining the flatness of the optical fiber ribbon. Because the reinforcement strips do not restrict the lateral movement of the optical fibers, the bending performance and edge fiber loss of the optical fiber ribbon are effectively improved.

[0033] The discontinuously reinforced optical fiber ribbon provided by the present invention comprises a plurality of optical fibers arranged side by side in a transverse direction, and a ribbon resin wrapping the optical fibers;

[0034] The ribbon resin is a light-cured elastic acrylic resin material; the elastic acrylic resin has an elastic modulus of 50 to 200 MPa and an elongation at break of 20% to 100%. The ribbon resin thickness is between 20 and 50 μm. Due to the presence of the reinforcement strip, the modulus of the single-strand resin can be much lower than the typical modulus of the ribbon resin currently used in optical fiber ribbons, which is currently around 600 MPa. Low-modulus single-strand resins produce less stress, which is beneficial to reducing edge fiber loss and improving the overall bending performance of the optical fiber ribbon. In particular, the ribbon resin used in the present invention has a certain elasticity, which reduces the total loss of the optical fiber while improving the overall bending performance of the optical fiber ribbon and is not easy to break. The ribbon resin layer needs to fix the reinforcement strip, so the thickness of the ribbon resin is slightly larger.

[0035] The fiber optic ribbon has reinforcing strips intermittently distributed along the optical fiber's axis within the ribbon resin on both the front and back sides. These strips are perpendicular to the optical fiber or at an angle, with spacing of 100 to 500 mm. Generally speaking, reinforcing strips perpendicular to the optical fiber have better bending durability. Since the reinforcing strips are virtually unaffected when the entire fiber optic ribbon is bent, they do not separate from the ribbon resin and are easier to strip and weld. Reinforcing strips at an angle to the optical fiber offer more comprehensive axial coverage and, in extreme cases, can even completely cover the axial direction of the fiber optic ribbon. Therefore, they offer a stronger ability to limit optical fiber crosstalk, minimizing the possibility of transmission of optical fibers arranged side by side within the ribbon.

[0036] The reinforcing strip extends in the transverse direction, and its transverse width is within the transverse width of the parallel tape resin, and the transverse width is within the transverse arrangement width of the optical fiber, preferably covering the transverse width range of the middle fiber. The diameter of the reinforcing strip is between 10 and 40 μm. Since the transverse width covered by the reinforcing strip is an important factor affecting the performance of the reinforcing strip, if the reinforcing strip covers a complete circle, stress accumulation will inevitably occur due to the accumulation of resin during bending, especially at the reinforcing strip, resulting in micro-bending and increased optical fiber loss. The reinforcing strip provided by the present invention will not cover the sides of the edge fibers of the optical fiber ribbon. This design changes the situation where the internal stress caused by the deformation of the parallel tape resin is concentrated on the edge fibers, reduces the edge fiber loss, and improves the consistency of optical fiber loss. If the reinforcing strip is as short as possible, it can be better fixed to the parallel tape resin, reducing the probability of the parallel tape resin breaking at the reinforcing strip due to repeated bending, and avoiding the situation where the reinforcing strip is exposed or even damaged in the optical fiber ribbon as much as possible. In order to achieve the function of preventing string movement, the reinforcing strip needs to cover the part of the middle fiber in the transverse direction at the shortest possible length. Similarly, in order to avoid the reinforcement strip from damaging the resin as much as possible, the diameter of the reinforcement strip needs to be smaller than the thickness of the single resin layer, and the difference between the two is preferably more than 10 μm.

[0037] The reinforcing strip has a bending modulus of 9 to 200 GPa and an elongation at break of 1% to 5%.

[0038] The reinforcing strip is made of short fibers, preferably carbon fibers or glass fibers, and provides sufficiently high strength at a sufficiently fine fiber level.

[0039] The spaces between multiple optical fibers are filled with grease, talcum powder, or water-blocking powder. This filler reduces friction between the fibers and between the fibers and the ribbon resin, preventing adhesion between the fibers and the ribbon resin. This further alleviates the problem of internal stress caused by resin curing being transferred to the fibers and affecting transmission. Furthermore, the spaces between adjacent optical fibers are also filled with cured resin, separating them and further preventing fiber tangling, ensuring that the fibers are arranged in parallel.

[0040] The method for preparing an optical fiber ribbon provided by the present invention comprises the following steps:

[0041] Multiple optical fibers are arranged side by side horizontally to form a fiber array; in a preferred embodiment, ointment, talcum powder or water-blocking powder is filled between the multiple optical fibers.

[0042] Periodically place reinforcement strips on the surface of the fiber arrangement and apply elastic acrylic resin to the surface to ensure that the reinforcement strips and the fiber arrangement are relatively fixed.

[0043] The elastic acrylic resin is cured by UV initiation to obtain the discontinuous reinforced optical fiber ribbon.

[0044] The present invention also provides an optical fiber ribbon cable including the optical fiber ribbon.

[0045] The following are examples:

[0046] Example 1

[0047] The discontinuous reinforced optical fiber ribbon provided in this embodiment has a structure such as Figure 1 As shown, the cross-sectional structure is Figure 2 As shown, a 6-core optical fiber ribbon is taken as an example, comprising a plurality of optical fibers 1.1 arranged side by side in a transverse direction, and a ribbon resin 1.2 wrapping the optical fibers;

[0048] The optical fiber cladding roundness (%) is ≤1.0%, the core cladding concentricity error (um) is ≤0.5%, the cladding diameter is about 80-125um, and the coating diameter after coloring is 160-250um.

[0049] The strip resin is a light-cured elastic acrylic resin material with an elastic modulus of 60 MPa and an elongation at break of about 90%. The strip resin is 20 μm thick.

[0050] The elastic acrylic resin comprises the following ingredients: 30-70 wt% acrylic monomer, 20-60 wt% prepolymer, 3-10 wt% thickener, 0.1-1 wt% initiator, and 1-3 wt% auxiliary agent.

[0051] Carbon fiber 1.3 reinforcement strips are intermittently distributed along the optical fiber axis within the ribbon resin on both the front and back sides of the ribbon. These reinforcement strips are arranged at a 45° angle to the optical fibers and spaced 100 mm apart. These reinforcement strips extend transversely, covering the entire width of the intermediate fibers, specifically four intermediate fibers. The diameter of each reinforcement strip is approximately 10 μm. The flexural modulus of these strips is approximately 150 GPa, and the elongation at break is approximately 1.5%.

[0052] Tests show that the edge fiber loss is less than 0.003dB / km and the middle fiber loss is less than 0.001dB / km.

[0053] The preparation method of the discontinuously reinforced optical fiber ribbon provided in this embodiment is as follows:

[0054] Fiber Ribbon: Six optical fibers are laid out from a payout rack and arranged side by side. Short carbon fibers are placed at intervals on the top and bottom surfaces (front and back) to serve as reinforcement strips. A layer of the aforementioned light-curable resin is then applied to the surface and cured under a UV lamp. After cooling, pulling, and winding, the fiber ribbon is produced.

[0055] Example 2

[0056] The discontinuous reinforced optical fiber ribbon provided in this embodiment has a structure such as Figure 3 As shown, the cross-sectional structure is Figure 4 As shown, a 6-core optical fiber ribbon is taken as an example, comprising a plurality of optical fibers 1.1 arranged side by side in a transverse direction, and a ribbon resin 1.2 wrapping the optical fibers;

[0057] The optical fiber cladding roundness (%) is ≤1.0%, the core cladding concentricity error (um) is ≤0.5%, the cladding diameter is about 80-125um, and the coating diameter after coloring is 160-250um.

[0058] The strip resin is a light-cured elastic acrylic resin material, the elastic acrylic resin has an elastic modulus of about 100 MPa and an elongation at break of about 60%, and the strip resin is 50 μm thick.

[0059] Glass fiber reinforcement strips 1.3 are intermittently distributed along the optical fiber axis within the ribbon resin on both the front and back surfaces of the ribbon. These strips are perpendicular to the optical fibers and spaced 500 mm apart. These strips extend transversely, their width covering the entire width of the optical fibers, i.e., six optical fibers. The diameter of each strip is 40 μm. The strips have a flexural modulus of approximately 10 GPa and an elongation at break of approximately 3%.

[0060] The spaces between the optical fibers are filled with grease 1.4.

[0061] Tests show that the edge fiber loss is less than 0.002dB / km and the middle fiber loss is less than 0.001dB / km.

[0062] The preparation method of the discontinuously reinforced optical fiber ribbon provided in this embodiment is as follows:

[0063] Fiber Optic Ribbon: Six optical fibers are laid out from a payout rack, arranged side by side, and coated with grease. Short carbon fibers are placed at intervals on the top and bottom surfaces, serving as reinforcement strips. A layer of the aforementioned light-curable resin is then applied and cured under a UV lamp. After cooling, pulling, and winding, the fiber optic ribbon is produced.

[0064] Example 3

[0065] The optical fiber ribbon of Example 1 or 2 is used to make a central tube optical fiber ribbon cable, the structure of which is as follows: Figure 5 As shown:

[0066] It consists of an optical fiber ribbon 1, a water-blocking tape 5, a plastic tube 2, a sheath 3, and reinforcement 4. The loose tube can be made of materials such as PP and PBT, with a wall thickness of 0.5 to 1.2 mm. The sheath can be made of materials such as HDPE, MDPE, and LDPE. Reinforcements can be made of FRP or steel wire.

[0067] The production method is as follows: After being paid out from a payout frame, several optical fiber ribbons 1 are stacked side by side, twisted, and wrapped with water-blocking tape. After entering a forming die, a layer of plastic loose tube 2 is extruded. The loose tube is then wrapped with water-blocking tape 5. After reinforcement members 4 are paid out from the payout frame, the cable core and reinforcement members pass through a forming die, where a layer of jacket 3 is extruded.

[0068] Example 4

[0069] The optical fiber ribbon of Example 1 or 2 is used to make a layer-twisted optical fiber ribbon cable, the structure of which is as follows: Figure 6 As shown:

[0070] It consists of a loose tube 2 containing an optical fiber ribbon 1, a central reinforcement member 2, a water-blocking material 5, a sheath 3, and possibly armoring components. The loose tube can be made of materials such as PP and PBT, with a wall thickness of 0.5 to 1.2 mm. The sheath can be made of materials such as HDPE, MDPE, and LDPE. Reinforcements can be made of materials such as FRP and steel wire. The armor can be made of steel or aluminum tape.

[0071] The production method is as follows: After being unwound from a payout rack, several optical fiber ribbons 1 are stacked side by side, twisted, and wrapped with water-blocking tape 5. After entering the forming mold, a layer of plastic loose tube 2 is extruded. Several loose tubes are twisted around the center of a strength member 4. After twisting, the cable core is wrapped with water-blocking tape 5, then steel tape, and finally a jacket layer 4 is extruded.

[0072] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A discontinuous reinforced optical fiber ribbon, characterized in that: The optical fiber comprises a plurality of optical fibers arranged side by side in a transverse direction, and a ribbon resin wrapping the optical fibers; The strip resin is a light-cured elastic acrylic resin material; the elastic acrylic resin has an elastic modulus of 50 to 200 MPa; The fiber optic ribbon has reinforcing strips intermittently distributed in the ribbon resin on the front and back sides along the axial direction of the optical fiber; The reinforcing strip extends in the transverse direction, and its transverse width is within the transverse width of the resin strip; the reinforcing strip is perpendicular to or at an angle to the optical fiber; The reinforcing strip has a bending modulus of 9 to 200 GPa and an elongation at break of 1% to 5%.

2. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The transverse width of the reinforcement strip is within the transverse arrangement width of the optical fiber.

3. The discontinuously reinforced optical fiber ribbon according to claim 2, wherein: The transverse width of the reinforcing strip covers the transverse width range of the intermediate fiber.

4. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The spacing between the reinforcement strips is 100-500 mm.

5. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The diameter of the reinforcement strip is between 10 and 40 μm, and the diameter of the reinforcement strip is smaller than the thickness of the resin layer.

6. The discontinuously reinforced optical fiber ribbon according to claim 5, wherein: The difference between the diameter of the reinforcing strip and the thickness of the resin layer is greater than 10 μm.

7. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The reinforcing strip is made of short fibers.

8. The discontinuously reinforced optical fiber ribbon according to claim 7, wherein: The short fibers are carbon fibers or glass fibers.

9. The discontinuously reinforced optical fiber ribbon according to any one of claims 1 to 3, characterized in that: The elastic acrylic resin has an elongation at break of 20% to 100%.

10. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The thickness of the tape resin is between 20 and 50 μm.

11. The discontinuously reinforced optical fiber ribbon according to claim 1, wherein: The spaces between the multiple optical fibers are filled with ointment, talcum powder or water-blocking powder.

12. The method for preparing the discontinuously reinforced optical fiber ribbon according to any one of claims 1 to 11, wherein: The following steps are involved: Arrange multiple optical fibers side by side horizontally to form a fiber array; Periodically place reinforcement strips on the surface of the fiber arrangement and apply elastic acrylic resin to the surface to ensure that the reinforcement strips and the fiber arrangement are relatively fixed. The elastic acrylic resin is cured by UV initiation to obtain the discontinuous reinforced optical fiber ribbon.

13. The method for preparing the discontinuously reinforced optical fiber ribbon according to claim 12, wherein: The spaces between the multiple optical fibers are filled with ointment, talcum powder or water-blocking powder.

14. An optical fiber ribbon cable, characterized in that: The optical fiber ribbon comprises the optical fiber ribbon according to any one of claims 1 to 11.

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