Optical fiber tape core wire
By configuring the optical fiber core wire in parallel and setting multiple connecting parts in the optical fiber tape core wire, we ensure that the tear stress has multiple peaks, and the elastic modulus and tensile fracture strength of the connecting resin are improved, and the bending of the optical fiber tape core wire is solved. The problem of easy tearing of the joint part under force improves the manipulation and crack resistance.
Patent Information
- Application Number
- CN202380039836.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-05-11
- Filing Date
- 2023-05-10
- Publication Date
- 2024-12-20
AI Technical Summary
When bending and other forces are applied to the fiber optic tape core wire, the connecting part is prone to tear, resulting in a decrease in manipulation and dispersion of the fiber optic core wire.
A plurality of optical fiber core wires are arranged in parallel in the length direction of the optical fiber tape core wire, and multiple connecting parts are arranged intermittently therein to form a tear stress distribution with multiple peaks during tearing to ensure tear of the first peak The stress is 0.01 N or more, the tearing stress of the second peak is more than 50% of the first peak, and the elastic modulus of the connecting resin is set to be 1 GPa or more and 5 GPa or less, and the tensile fracture strength is 20 MPa or more.
It effectively suppresses the reduction of the manipulation of the optical fiber core wire, prevents the connection part from being damaged by tiny external forces, reduces transmission losses caused by low-temperature side pressure, and improves the crack resistance of the connection part.
Smart Images
Figure CN119173797A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to optical fiber ribbons.
[0002] This application claims the benefit of priority based on Japanese Application No. 2022-078228 filed on May 11, 2022, and incorporates by reference all the contents described in the aforementioned Japanese Application. Background Art
[0003] Patent Document 1 discloses an optical fiber ribbon having connection portions intermittently provided in the longitudinal direction and the width direction of the ribbon for connecting two adjacent optical fibers. The tear strength of the connection portions is 1.50 to 21.0 gf.
[0004] Patent document 2 discloses an optical fiber ribbon, which comprises: a plurality of optical fiber cores, each having a coloring layer; and a plurality of connecting parts, each connecting two adjacent optical fiber cores. The adhesion between the coloring layer and the connecting part is 0.38 N / mm 2 Above and 4.30N / mm 2 Hereinafter, the tearing force for tearing the connecting portion is 1.0 gf or more and 17.0 gf or less.
[0005] Prior art literature
[0006] Patent Literature
[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-182157
[0008] Patent Document 2: Japanese Patent Application Publication No. 2019-168553 Summary of the invention
[0009] Optical fiber ribbon core wire disclosed herein
[0010] A plurality of optical fiber cores are arranged in parallel in a direction perpendicular to the longitudinal direction.
[0011] In at least a portion of the plurality of optical fiber cores, a plurality of connecting portions for connecting adjacent optical fiber cores are intermittently provided in the length direction.
[0012] One of the plurality of connecting portions is configured so that a tear stress when torn in the longitudinal direction has a plurality of peaks,
[0013] The tear stress has a first peak indicating a maximum tear stress and a second peak indicating a tear stress different from the maximum tear stress,
[0014] The tear stress of the first peak is greater than 0.01N,
[0015] The tear stress of the second peak is 50% or more of the tear stress of the first peak. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a cross-sectional view showing the optical fiber ribbon core wire according to the first embodiment.
[0017] Figure 2 yes Figure 1 A top view of the optical fiber ribbon core is shown.
[0018] Figure 3 It is shown Figure 1 FIG. 4 is a graph showing the relationship between the tear stress and the tear length of the connecting portion when the connecting portion of the optical fiber ribbon core wire is torn.
[0019] Figure 4 This is a graph showing the relationship between the tear stress and the tear length of the connection portion when the optical fiber ribbon core wire according to the comparative example is torn.
[0020] Figure 5 This is a schematic diagram showing a method for measuring the tear stress of a connecting portion.
[0021] Figure 6 It is a cross-sectional view showing an optical fiber ribbon core wire according to the second embodiment.
[0022] Figure 7 yes Figure 6 A top view of the optical fiber ribbon core is shown.
[0023] Figure 8 It is shown Figure 6 FIG. 4 is a graph showing the relationship between the tear stress and the tear length of the connecting portion when the connecting portion of the optical fiber ribbon core wire is torn.
[0024] Fig. 9 : is a cross-sectional view showing an optical fiber ribbon core wire according to a modified example. DETAILED DESCRIPTION
[0025] (Technical Problems to be Solved by the Present Disclosure)
[0026] If the strength of the connection part of the optical fiber ribbon is weak, the connection part may tear if a force such as bending is applied to the optical fiber ribbon or the cable to which the optical fiber ribbon is installed. In this case, the individual optical fibers may be easily separated, and the maneuverability of the optical fiber ribbon may be reduced.
[0027] The present disclosure provides an optical fiber ribbon capable of suppressing a decrease in handling performance.
[0028] (Description of One Mode of the Present Disclosure)
[0029] First, embodiments of the present disclosure will be listed and described.
[0030] (1) Optical fiber ribbon core wire according to one aspect of the present disclosure
[0031] A plurality of optical fiber cores are arranged in parallel in a direction perpendicular to the longitudinal direction.
[0032] In at least a portion of the plurality of optical fiber cores, a plurality of connecting portions for connecting adjacent optical fiber cores are intermittently provided in the length direction.
[0033] One of the plurality of connecting portions is configured so that a tear stress when torn in the longitudinal direction has a plurality of peaks,
[0034] The tear stress has a first peak indicating a maximum tear stress and a second peak indicating a tear stress different from the maximum tear stress,
[0035] The tear stress of the first peak is greater than 0.01N,
[0036] The tear stress of the second peak is 50% or more of the tear stress of the first peak.
[0037] According to the present disclosure, there are multiple peaks of stress generated when tearing in the connecting portion. That is, even if a tearing force acts on the connecting portion, the connecting portion is not easy to tear completely at once, but to tear little by little. Therefore, the optical fiber core wire is not easy to spread out, and the maneuverability of the optical fiber ribbon core wire can be suppressed.
[0038] According to the present disclosure, the tear stress of the first peak, which is the largest tear stress, is greater than or equal to 0.01 N. Therefore, even if a small force less than 0.01 N acts on the connection portion, the connection portion will not tear. Therefore, it is possible to suppress a decrease in the maneuverability of the optical fiber ribbon.
[0039] According to the present disclosure, the tear stress of the second peak is more than 50% of the tear stress of the first peak. Since even if a crack is formed on the connecting portion against the tear stress of the first peak, the crack will not expand unless a relatively strong force of more than 50% of the tear stress of the first peak is applied, the optical fiber core wire is not easy to spread, and the reduction in the maneuverability of the optical fiber ribbon core wire can be suppressed.
[0040] (2) In the above (1), the elastic modulus of the one connecting portion may be greater than or equal to 1 GPa and less than or equal to 5 GPa.
[0041] According to the present disclosure, since the elastic modulus of the connection portion is 1 GPa or more, the connection portion can be prevented from being damaged by a small external force. In addition, since the elastic modulus of the connection portion is 5 GPa or less, the transmission loss caused by the lateral pressure on the optical fiber ribbon core at low temperature can be reduced.
[0042] (3) In the above (1) or (2), the tensile strength of the one connecting portion may be 20 MPa or more.
[0043] According to the present disclosure, since the tensile strength of the connection portion is 20 MPa or more, the optical fiber core wire is less likely to unravel, and the handleability of the optical fiber ribbon core wire is improved.
[0044] (4) In any one of the above (1) to (3), the tear stress of the first peak may be 0.03 N or more.
[0045] According to the present disclosure, since the tear stress of the first peak is 0.03 N or more, the effect of making the connecting portion less likely to tear can be enhanced.
[0046] (5) In any of the above (1) to (3), the first length of the one connecting portion torn in the length direction when a force equivalent to the tear stress of the first peak acts on the one connecting portion may be the same as the second length of the one connecting portion torn in the length direction when a force equivalent to the tear stress of the second peak acts on the one connecting portion.
[0047] According to the present disclosure, the first length of the connecting portion torn in the longitudinal direction when a force equivalent to the tear stress of the first peak acts on the connecting portion is the same as the second length of the connecting portion torn in the longitudinal direction when a force equivalent to the tear stress of the second peak acts on the connecting portion, and the connecting portion is torn at predetermined intervals. That is, since the entire connecting portion is not torn at once, the optical fiber core wire is not easy to be scattered, and the reduction in the maneuverability of the optical fiber ribbon core wire can be suppressed.
[0048] (Effects of the present disclosure)
[0049] According to the present disclosure, it is possible to provide an optical fiber ribbon capable of suppressing a decrease in handling performance.
[0050] (Details of one aspect of the present disclosure)
[0051] A specific example of the optical fiber ribbon according to one aspect of the present disclosure will be described with reference to the drawings.
[0052] It should be noted that the present disclosure is not limited to these examples but is represented by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.
[0053] (First Embodiment)
[0054] Figure 1 It is a cross-sectional view showing the optical fiber ribbon 1A according to the first embodiment. Figure 2 1A is a top view of the optical fiber ribbon core wire 1A. Figure 1 yes Figure 2 The optical fiber ribbon core wire 1A is shown in an AA cross-sectional view.
[0055] like Figure 1 and Figure 2 As shown, in the optical fiber ribbon 1A, a plurality of (twelve in this example) optical fiber core wires 11 (11A to 11L in this example) are arranged in parallel in a direction perpendicular to the longitudinal direction.
[0056] Each optical fiber core 11 has, for example, a glass fiber 12 composed of a core and a cladding, and two layers of cladding 13 and 14 covering the periphery of the glass fiber 12. It should be noted that the optical fiber core 11 may also have a coloring layer. The inner cladding 13 of the two cladding layers is formed by a cured product of a primary resin. In addition, the outer cladding 14 of the two cladding layers is formed by a cured product of a secondary resin.
[0057] In the primary resin constituting the inner coating layer 13 in contact with the glass fiber 12, a soft resin with a relatively low Young's modulus is used as a buffer layer. In addition, in the secondary resin constituting the outer coating layer 14, a hard resin with a relatively high Young's modulus is used as a protective layer. The Young's modulus of the cured product of the secondary resin is 900 MPa or more, preferably 1000 MPa or more, and more preferably 1500 MPa or more at room temperature (e.g., 23° C.).
[0058] The secondary resin constituting the outer cladding layer 14 is preferably an ultraviolet curable resin composition containing a urethane acrylate oligomer, a monomer, and a photopolymerization initiator.
[0059] The outer diameter R of the optical fiber core wire 11 (11A to 11L) is 180 μm or more and 250 μm or less. In the optical fiber ribbon core wire 1A of this example, the outer diameter R is 200 μm.
[0060] It should be noted that, in this example, the number of cores of the optical fiber ribbon 1A is set to 12, but the present invention is not limited thereto and the number of cores of the optical fiber ribbon 1A may be, for example, 24 or 48.
[0061] In the optical fiber ribbon 1A, 12 optical fiber cores 11A to 11L are alternately arranged in a separated state and a connected state every N cores. The optical fiber cores 11A to 11L of this example are arranged in a state where adjacent optical fiber cores are spaced a certain distance apart from each other and in a connected state every 2 cores. The 12 optical fiber cores 11A to 11L arranged in parallel are connected as a whole by a connecting resin 21.
[0062] like Figure 2As shown in FIG. 1 , a plurality of connecting portions 21a are intermittently provided in the longitudinal direction of the plurality of optical fiber cores 11. Similarly, a plurality of non-connecting portions 23 are intermittently formed in the longitudinal direction of the plurality of optical fiber cores 11. The optical fiber ribbon 1A is an intermittently connected optical fiber ribbon in which the connecting portions 21a and the non-connecting portions 23 are intermittently provided in the longitudinal direction for every two optical fiber cores. It should be noted that Figure 2 The top view of FIG. 1 shows a state where the non-connecting portion 23 is opened in the parallel direction of the optical fiber core wires 11.
[0063] The connecting resin 21 of the optical fiber ribbon 1A is provided so as to cover the outer periphery of each optical fiber core 11. In the connecting resin 21, a plurality of connecting portions 21a for connecting adjacent optical fiber cores 11 are provided on at least a portion of the plurality of optical fiber cores 11. Furthermore, in the connecting resin 21, an outer peripheral coating portion 21b ( Figure 1 ). The connecting portion 21a and the outer peripheral coating portion 21b are formed of the same resin. In addition, the optical fiber ribbon 1A is provided with a plurality of non-connecting portions 23 where adjacent optical fiber cores are not connected.
[0064] In the optical fiber ribbon core wire 1A of this example, when observing a cross section perpendicular to the longitudinal direction, the connecting portion 21a is provided between the optical fiber core wires 11D and 11E, and between 11H and 11I. The non-connecting portion 23 is provided between the optical fiber core wires 11B and 11C, between 11F and 11G, and between 11J and 11K. On the other hand, the optical fiber core wires 11A and 11B, 11C and 11D, 11E and 11F, 11G and 11H, 11I and 11J, and 11K and 11L adjacent to each other are arranged so that there is no gap between the optical fiber core wires.
[0065] The elastic modulus of the connecting resin 21 (connecting portion 21a and peripheral covering portion 21b) is greater than 1 GPa and less than 5 GPa at room temperature (for example, 23°C). The elastic modulus of the connecting portion 21a in this example is greater than 2.5 GPa and less than 2.8 GPa. The elastic modulus of the connecting resin 21 can be measured as the elastic modulus in the thickness direction of the cured bonding resin using a nano indenter (HYSITRON TI950 TriboIndenter manufactured by BRUKER) by a test method based on ISO14577. In this example, the indentation depth is 100 nm, and the elastic modulus of the connecting resin 21 is measured using a Berkovich indenter. The Young's modulus of the connecting portion 21a is, for example, 868 MPa at room temperature (for example, 23°C). In addition, the tensile strength of the connecting portion 21a is greater than 20 MPa. The tensile strength at break of the connection portion 21a of this example is, for example, 33 MPa, and the elongation at break is 39%. The connection resin 21 is, for example, an ultraviolet curing resin, a thermosetting resin, or the like.
[0066] It is preferred that the outermost layer of the optical fiber core 11 has a greater adhesion to the bonding resin 21. For example, the bonding resin 21 may contain a ketone-based solvent. As a result, the adhesion to the outermost layer of the optical fiber core 11 becomes greater. As a result, the bonding resin 21 is not easily peeled off from the optical fiber core 11, and the optical fiber core 11 is not easily scattered.
[0067] As an index of the adhesion force, for example, the tear stress required to peel the connecting resin 21 from the outer peripheral surface of the optical fiber core wire 11 can be cited.
[0068] It should be noted that the tear stress of the connection portion 21a is measured as follows. A cut is made with a knife or a razor on the connection portion 21a formed at the center of the width direction (the parallel direction of the optical fiber cores 11) at one end of the optical fiber ribbon core 1A, and the end of the 12-core optical fiber ribbon core 1A is cut into 6 cores each. The ends of the outer peripheral coating portions 21b of the separated 6 cores are grasped, and stretched in a direction orthogonal to the length direction and the width direction at a speed of 200 mm / min, and the tensile force at this time is measured as the tear stress.
[0069] Figure 3 Graph 2 is a graph showing the relationship between the tear stress and the tear length of the connecting portion 21a when one connecting portion 21a of the optical fiber ribbon core wire 1A is torn. Figure 3 As shown, the connection portion 21a of this example is configured so that when it is torn in the longitudinal direction, the tear stress has multiple peaks. In other words, when a force equivalent to the tear stress acts on the connection portion 21a, the connection portion 21a will not be completely torn by a single force, but will be torn little by little through multiple peaks. The tear stress of the connection portion 21a has a first peak PA1 indicating the maximum tear stress, and a second peak PA2 indicating a tear stress different from the maximum tear stress. The tear stress of the first peak PA1, which is the maximum tear stress, is greater than 0.01N. The tear stress of the second peak PA2 is greater than 50% of the tear stress of the first peak PA1.
[0070] The tear stress of the connecting portion 21a has a third peak PA3, a fourth peak PA4, and a fifth peak PA5 which are different from the tear stress of the first peak PA1 and the second peak PA2. The second peak PA2, the third peak PA3, the fourth peak PA4, and the fifth peak PA5 are examples of second peaks which are 50% or more of the tear stress of the first peak.
[0071] When a force equivalent to the tear stress of the fifth peak PA5 acts on the connecting portion 21a, a crack is formed in the connecting portion 21a in the length direction. The length of the connecting portion 21a torn at this time is set to the fifth length LA5. After the connecting portion 21a is torn by the fifth length LA5, when a force equivalent to the tear stress of the fourth peak PA4 acts on the connecting portion 21a, the crack formed at the fifth peak PA5 expands, and the connecting portion 21a is further torn in the length direction. The length of the connecting portion 21a torn at this time is set to the fourth length LA4. Thereafter, when a force equivalent to the tear stress of the third peak PA3 acts, the connecting portion 21a is torn by the third length LA3, when a force equivalent to the tear stress of the second peak PA2 acts, the connecting portion 21a is torn by the second length LA2, and when a force equivalent to the tear stress of the first peak PA1 acts, the connecting portion 21a is torn by the first length LA1.
[0072] In this example, the tear stress of the fifth peak PA5 is, for example, 0.016N, and the fifth length LA5 is, for example, about 13mm of tearing. The tear stress of the fourth peak PA4 is, for example, 0.016N, and the fourth length LA4 is, for example, about 13mm of tearing. The tear stress of the third peak PA3 is, for example, 0.016N, and the third length LA3 is, for example, about 10mm of tearing. The tear stress of the second peak PA2 is, for example, 0.016N, and the second length LA2 is, for example, about 10mm of tearing. The tear stress of the first peak PA1 is, for example, 0.018N, and the first length LA1 is, for example, about 10mm.
[0073] Like this, the tear stress of the second peak PA2 is the same as the tear stress of the first peak PA1 (90% of the tear stress of the first peak PA1). In addition, the first length LA1, the second length LA2, the third length LA3, the fourth length LA4 or the fifth length LA5 are the same. It should be noted that in this example, "the same length" does not mean that the two lengths are completely the same, but that one length is within ±30% of the other length.
[0074] It should be noted that the length of the torn connecting portion 21a may change according to the adhesion between the optical fiber core 11 and the connecting portion 21a (connecting resin 21) in addition to the tearing stress. In other words, when a force equivalent to the tearing stress acts on the connecting portion 21a, the connecting portion 21a is broken, thereby forming a crack between adjacent optical fiber cores. In addition, the connecting resin 21 forming the connecting portion 21a is peeled off from the optical fiber core 11, thereby forming a crack between adjacent optical fiber cores.
[0075] Figure 4Graph showing the relationship between the tear stress and tear length of the connecting portion 21a when the connecting portion 21a of the optical fiber ribbon 1Z as a comparative example is torn. The elastic modulus of the connecting resin 21 (connecting portion 21a and outer cladding portion 21b) of the optical fiber ribbon 1Z is 1.5 GPa at room temperature (e.g., 23°C). In addition, in the optical fiber ribbon 1Z, the Young's modulus of the connecting portion 21a is 115 MPa at room temperature (e.g., 23°C), the tensile strength of the connecting portion 21a is, for example, 16 MPa, and the elongation at break of the connecting portion 21a is 38%. In addition, when the peel strength of the optical fiber ribbon 1A according to the first embodiment is taken as a reference and is set to 1, the peel strength of the optical fiber ribbon 1Z according to the comparative example is 0.2 or more and 0.3 or less. Except for the difference in the physical property values of the connecting resin 21 , the structure of the optical fiber ribbon 1Z is the same as that of the optical fiber ribbon 1A, and thus the description thereof is omitted.
[0076] like Figure 4 As shown, the connection portion 21a of the optical fiber ribbon 1Z involved in the comparative example is configured so that the tear stress has multiple peaks when it is torn in the longitudinal direction. However, it is different from the optical fiber ribbon 1A involved in this example in that the tear stress of the second peak PZ2 is not more than 50% of the tear stress of the first peak PZ1. In the optical fiber ribbon 1Z involved in the comparative example, the tear stress of the first peak PZ1 is, for example, 0.02N, and the tear stress of the second peak PZ2 is, for example, 0.009N. That is, the tear stress of the second peak PZ2 is about 45% of the tear stress of the first peak PZ1. The tear stress of the third peak PZ3 and the tear stress of the fourth peak PZ4 are both about 0.005N, which is about 25% of the tear stress of the first peak PZ1.
[0077] In the optical fiber ribbon 1Z involved in the comparative example, a force equivalent to the tear stress of the first peak PZ1 acts on the connecting portion 21a, forming a crack of the first length LZ1. The first length LZ1 is, for example, 20 mm. In the optical fiber ribbon 1Z, after the crack is formed, if the tear stress of the fourth peak PZ4, the third peak PZ3, and the second peak PZ2, that is, a relatively weak force less than 50% of the tear stress of the first peak PZ1, acts on the connecting portion 21a, the crack expands. If the crack expands due to the relatively weak force, the optical fiber core 11 may be easily scattered, and the maneuverability of the optical fiber ribbon 1Z may be reduced.
[0078] In contrast, in the optical fiber ribbon 1A of this example, since the tear stress of the first peak PA1, which is the largest tear stress, is 0.01N or more, the connecting portion 21a will not tear even if a small force less than 0.01N acts on the connecting portion 21a. In addition, the tear stress of the second peak PA2 is 50% or more of the tear stress of the first peak PA1, so that even if a relatively large tear force is applied to the connecting portion 21a and a crack is formed in a part of the connecting portion 21a, the crack of the connecting portion 21a will not expand unless a relatively large tear force acts again. Therefore, the optical fiber core 11 is not easy to fall apart, and the optical fiber ribbon 1A has good maneuverability, so it is easy to fuse the optical fiber ribbon 1A together.
[0079] The elastic modulus of the connecting portion 21a in this example is 1 GPa or more. Therefore, it is possible to prevent the connecting portion 21a from being damaged by a small external force. In addition, the elastic modulus of the connecting portion 21a is 5 GPa or less. Therefore, it is possible to reduce the transmission loss caused by the lateral pressure on the optical fiber ribbon core wire 1A at low temperatures.
[0080] The tensile strength of the connection portion 21a in this example is 20 MPa or more. Since the connection portion 21a is not broken by a small force, the optical fiber core wire 11 is unlikely to be untied, and the handling property of the optical fiber ribbon core wire 1A is improved.
[0081] In the optical fiber ribbon 1A of this example, the first length LA1 of the connecting portion 21a torn in the longitudinal direction when the force of the tear stress equivalent to the first peak PA1 acts on the connecting portion 21a is the same as the second length LA2 of the connecting portion 21a torn in the longitudinal direction when the force of the tear stress equivalent to the second peak PA2 acts on the connecting portion 21a. In other words, the connecting portion 21a of the optical fiber ribbon 1A is torn at arbitrary lengths. That is, since the entire connecting portion 21a is not torn at once, the optical fiber 11 is not easy to be scattered, and the reduction in the maneuverability of the optical fiber ribbon 1A can be suppressed.
[0082] The tear stress of the connecting portion 21a was measured as follows. Figure 5 21a is a schematic diagram showing a method for measuring the tear stress of the connecting portion 21a. Figure 5 As shown, the outer peripheral coating 21b of the six optical fiber cores 11A to 11F in the optical fiber ribbon core 1A is gripped by the first gripping portion G1, and the outer peripheral coating 21b of the six optical fiber cores 11G to 11L is gripped by the second gripping portion G2. In the up-down direction orthogonal to the length direction and the width direction, the first gripping portion G1 is arranged above the optical fiber ribbon core 1A, and the second gripping portion G2 is arranged below the optical fiber ribbon core 1A.
[0083] A connecting portion 21a is formed between the optical fiber core wire 11F and the optical fiber core wire 11G. The length La of the connecting portion 21a in the longitudinal direction is about 40 mm to 90 mm. In the initial state, the first gripping portion G1 and the second gripping portion G2 are arranged to be separated from each other in the vertical direction, so that the position of one end of the connecting portion 21a becomes a position where the optical fiber core wire 11F starts to bend upward through the first gripping portion G1, and the optical fiber core wire 11G starts to bend downward through the second gripping portion G2. In other words, in the initial state, the connecting portion 21a connects the optical fiber core wire 11F and the optical fiber core wire 11G over the entire length. The initial distance D between the first gripping portion G1 and the second gripping portion G2 in the vertical direction is 70 mm. In addition, the length of the optical fiber ribbon core wire 1A measured in the longitudinal direction is 150 mm.
[0084] In the present measuring method, the second holding part G2 is fixed, and the first holding part G1 is moved upward in a manner separated from the second holding part G2. The moving speed of the first holding part G1 is 200 mm / minute. As the first holding part G1 moves upward, the optical fiber core 11F held by the first holding part G1 is separated from the optical fiber core 11G held by the second holding part G2. In this way, the connecting part 21a connecting the optical fiber core 11F and the optical fiber core 11G begins to tear. By a detector (not shown) directly or indirectly provided on the first holding part G1, the force applied to the first holding part G1 when the connecting part 21a is torn is measured as the tear stress of the connecting part 21a. At the same time, the length of the torn connecting part 21a is measured. It should be noted that in the present measuring method, the second holding part G2 is fixed to move the first holding part G1, but the first holding part G1 can also be fixed to move the second holding part G2.
[0085] (Second Embodiment)
[0086] Next, refer to Figures 6 to 8 , an optical fiber ribbon 1B according to a second embodiment will be described. It should be noted that the same components as those of the optical fiber ribbon 1A according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0087] Figure 6 The optical fiber ribbon 1B is different from the optical fiber ribbon 1A according to the first embodiment in that the optical fiber ribbon 1B is arranged alternately with adjacent optical fibers spaced a certain distance apart and connected to each other.
[0088] In the optical fiber ribbon 1B of this example, the connection portion 21a is provided between the optical fiber cores 11A and 11B, between 11C and 11D, between 11E and 11F, between 11G and 11H, between 11I and 11J, and between 11K and 11L. The non-connection portion 23 is provided between the optical fiber cores 11B and 11C, between 11D and 11E, between 11F and 11G, between 11H and 11I, and between 11J and 11K. The elastic modulus of the connection portion 21a of this example is, for example, 2.6 GPa.
[0089] Figure 7 FIG. 1 is a top view of the optical fiber ribbon core line 1B. Figure 7 As shown in FIG. 1 , a plurality of connecting portions 21a are intermittently provided in the longitudinal direction of the plurality of optical fiber cores 11. Similarly, a plurality of non-connecting portions 23 are also intermittently formed in the longitudinal direction of the plurality of optical fiber cores 11. The optical fiber ribbon 1B is an intermittently connected optical fiber ribbon in which the connecting portions 21a and the non-connecting portions 23 are intermittently provided in the longitudinal direction for every other optical fiber core. The other structures are the same as those of the optical fiber ribbon 1A. It should be noted that in Figure 7 The top view of FIG. 1 shows a state where the non-connecting portion 23 is opened in the parallel direction of the optical fiber core wires 11. Figure 6 yes Figure 7 The optical fiber ribbon core wire 1B is shown in cross-sectional view along line BB.
[0090] Figure 8 Graph showing the relationship between the tear stress and the tear length of the connecting portion 21a when the connecting portion 21a of the optical fiber ribbon 1B is torn. Figure 8 As shown, the connection portion 21a of this example is also configured so that when it is torn in the longitudinal direction, the tear stress has multiple peaks. The tear stress of the connection portion 21a has a first peak PB1 indicating the maximum tear stress and a second peak PB2 indicating a tear stress different from the maximum tear stress.
[0091] It should be noted that the first peak PB1 has two peaks PB11 and PB12, which are considered as one peak. More specifically, when the tear stress of the second peak PB12 located close to the first peak PB11 is within ±20% of the tear stress of the first peak PB11, the two peaks PB11 and PB12 are considered as one peak PB1, and the tear stress of the first peak PB11 is set as the tear stress of the first peak PB1.
[0092] The tear stress of the first peak PB1, which is the maximum tear stress, is greater than 0.03 N. The tear stress of the first peak PB1 in this example is, for example, 0.062 N. The tear stress of the second peak PB2 is greater than 50% of the tear stress of the first peak PB1. The tear stress of the second peak PB2 in this example is, for example, 0.051 N, which is 83% of the tear stress of the first peak PB1.
[0093] As described above, in this example, since the tear stress of the first peak PB1 is 0.03 N or more, the effect of making the connecting portion 21 a less likely to tear can be enhanced.
[0094] (Variation Example)
[0095] It should be noted that the optical fiber ribbons 1A and 1B include the connecting resin 21 covering the outer circumference of each optical fiber core wire 11, but they do not necessarily need to include the connecting resin 21 covering the outer circumference. Fig. 9 , an optical fiber ribbon 1C according to a modified example will be described. It should be noted that the same components as those of the optical fiber ribbons 1A and 1B according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0096] Fig. 9 FIG. 1 shows a cross-sectional view of an optical fiber ribbon 1C. The optical fiber ribbon 1C is different from the optical fiber ribbon 1A in that the adjacent optical fiber cores are arranged alternately and repeatedly in a state where a certain distance is between each other and a state where they are connected to each other. Furthermore, the optical fiber ribbon 1C is different from the optical fiber ribbons 1A and 1B in that it does not have an outer peripheral coating 21b covering the outer periphery of each optical fiber core 11. Some adjacent optical fiber cores are connected to each other by a connecting portion 21a.
[0097] In the optical fiber ribbon core wire 1C of this example, the connection part 21a is provided between the optical fiber core wires 11A and 11B, between 11C and 11D, between 11E and 11F, between 11G and 11H, between 11I and 11J, and between 11K and 11L. The connection part 21a is formed so that there is no gap between these two adjacent optical fiber core wires. In addition, the non-connection part 23 is provided between the optical fiber core wires 11B and 11C, between 11D and 11E, between 11F and 11G, between 11H and 11I, and between 11J and 11K.
[0098] The optical fiber ribbon 1C has the same effects as the optical fiber ribbons 1A and 1B. In particular, the connection portion 21a of the optical fiber ribbon 1C is also configured so that when torn in the longitudinal direction, the tear stress has multiple peaks, and the optical fiber ribbon 1C can suppress a decrease in its handling properties.
[0099] The present disclosure has been described in detail with reference to specific embodiments, but it is obvious to those skilled in the art that various changes or modifications can be made without departing from the spirit and scope of the present disclosure. In addition, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the preferred number, position, shape, etc. when implementing the present disclosure.
[0100] In the optical fiber ribbon core wire of this example, the connecting portion 21a and the non-connecting portion 23 are formed by providing the connecting resin 21 in a portion in the length direction, but the forming method is not limited to this. It is also possible to provide a ribbon coating that integrally covers each optical fiber core wire 11, and form the non-connecting portion 23 by cutting a portion in the length direction between the optical fiber core wires 11.
[0101] Description of Reference Numerals
[0102] 1A, 1B, 1C, 1Z: Optical fiber ribbon core wire
[0103] 11, 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H, 11I, 11J, 11K, 11L: Optical fiber core
[0104] 12: Fiberglass
[0105] 13: Inner coating
[0106] 14: Outer covering layer
[0107] 21: Bonding resin
[0108] 21a: Connection part
[0109] 21b: Peripheral coating
[0110] 23: Non-connected part
[0111] D: Initial distance
[0112] LA1, LZ1: first length
[0113] LA2: Second length
[0114] LA3: Third length
[0115] LA4: Fourth Length
[0116] LA5: Fifth Length
[0117] PA1, PB1, PZ1: First peak
[0118] PA2, PB2, PZ2: Second peak
[0119] PA3: The third peak
[0120] PA4: Fourth Peak
[0121] PA5: Fifth Peak
[0122] PB11, PB12: Peak
[0123] R: outer diameter.
Claims
1. An optical fiber ribbon core wire, A plurality of optical fiber cores are arranged in parallel in a direction perpendicular to the longitudinal direction. In at least a portion of the plurality of optical fiber cores, a plurality of connecting portions for connecting adjacent optical fiber cores are intermittently provided in the length direction. One of the plurality of connecting portions is configured so that a tear stress when torn in the longitudinal direction has a plurality of peaks, The tear stress has a first peak indicating a maximum tear stress and a second peak indicating a tear stress different from the maximum tear stress, The tear stress of the first peak is greater than 0.01N, The tear stress of the second peak is 50% or more of the tear stress of the first peak.
2. The optical fiber ribbon according to claim 1, The elastic modulus of the one connecting portion is greater than or equal to 1 GPa and less than or equal to 5 GPa.
3. The optical fiber ribbon according to claim 1 or 2, The tensile strength of the one connecting portion is 20 MPa or more.
4. The optical fiber ribbon according to any one of claims 1 to 3, The tear stress of the first peak is 0.03N or more.
5. The optical fiber ribbon according to any one of claims 1 to 3, The first length of the one connecting portion torn in the length direction when a force equivalent to the tear stress of the first peak acts on the one connecting portion is the same as the second length of the one connecting portion torn in the length direction when a force equivalent to the tear stress of the second peak acts on the one connecting portion.