Manufacturing method of intermittent connection type optical fiber ribbon core wire and intermittent connection type optical fiber ribbon core wire

Abstract

Provided is a manufacturing method for an intermittent connection type optical fiber ribbon core wire (10) in which a plurality of optical fiber core wires (11A to 11L) are arranged side by side in a direction orthogonal to the length direction of the plurality of optical fiber core wires (11A to 11L), the entirety of the plurality of optical fiber core wires (11A to 11L) is covered with a connection resin (15), a slit (14) is formed by intermittently inserting a cutter (117) into the connection resin (15) between a part of adjacent optical fiber core wires among the plurality of optical fiber core wires (11A to 11L), the outer diameter of each of the optical fiber core wires (11A to 11L) is 220 μm or less, and the distance (g) between the optical fiber core wires into which the cutter (117) is inserted is 10 μm or more and 100 μm or less.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing intermittently connected fiber ribbon cores and the intermittently connected fiber ribbon cores.

[0002] This application claims priority based on Japanese Application No. 2020-128531, filed on July 29, 2020, and incorporates all the contents of that Japanese application. Background Technology

[0003] Conventionally, one example of a method for manufacturing intermittently connected fiber ribbon cores is as follows: multiple fiber cores are arranged side-by-side in a direction orthogonal to their length direction; the entire length of the multiple fiber cores is covered with resin; and slits (non-connected portions) are formed by intermittently inserting cleavers between adjacent fiber cores in the covered portion (e.g., Patent Documents 1 and 4). Furthermore, Patent Documents 2 and 3 describe the inter-fiber core distance (center-to-center distance) of intermittently connected ribbon cores.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2004-206048

[0007] Patent Document 2: Japanese Patent Application Publication No. 2014-157382

[0008] Patent Document 3: Japanese Patent Application Publication No. 2013-088617

[0009] Patent Document 4: Japanese Patent Application Publication No. 2012-208310 Summary of the Invention

[0010] This disclosure discloses a method for manufacturing intermittently connected fiber ribbon cores.

[0011] Multiple optical fiber cores are arranged side-by-side in a direction orthogonal to the length direction of the multiple optical fiber cores.

[0012] The entirety of the multiple optical fiber cores is covered with bonding resin.

[0013] A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores.

[0014] The outer diameter of each optical fiber core is less than 220 μm.

[0015] Between the adjacent fiber cores, the distance between the fiber cores into which the cutter is inserted is more than 10 μm and less than 100 μm.

[0016] The intermittently connected fiber optic ribbon core disclosed herein has the following characteristics:

[0017] Multiple fiber cores are arranged side-by-side in a direction orthogonal to the length direction; and

[0018] The bonding resin covers the entirety of the multiple optical fiber cores.

[0019] A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores.

[0020] The outer diameter of each optical fiber core is less than 220 μm.

[0021] Between the adjacent fiber cores, the distance between the fiber cores into which the cutter is inserted is more than 10 μm and less than 100 μm. Attached Figure Description

[0022] Figure 1 This is a configuration diagram of the manufacturing apparatus for intermittently connected fiber ribbon cores according to the first embodiment of this disclosure.

[0023] Figure 2 It is by Figure 1 A cross-sectional view of the fiber ribbon core manufactured by the manufacturing equipment, perpendicular to the length direction.

[0024] Figure 3 It is a partial unfolded view of the intermittently connected fiber ribbon core along its length.

[0025] Figure 4 This is a schematic diagram of a printing apparatus used in a variant of an intermittently connected fiber ribbon core manufacturing apparatus. Detailed Implementation

[0026] [The technical problem this disclosure aims to solve]

[0027] To install multiple fiber ribbon cores at high density within an optical cable, it is preferable to arrange the fiber ribbon cores with the smallest possible distance between adjacent fiber ribbon cores. However, if the distance is too small, the fiber ribbon cores may sometimes be damaged by the cleaver when forming a slit.

[0028] For example, when using a 200μm outer diameter fiber core as a ribbon fiber core, the coating layer of the thin fiber core is usually thin and the distance between adjacent thin fiber cores is small. Therefore, when forming a slit, even if the insertion position of the cutter is slightly off, the thin fiber core may be damaged.

[0029] Therefore, this disclosure provides a method for manufacturing intermittently connected fiber ribbon cores that can prevent external damage to the fiber core and can be installed at high density, as well as the intermittently connected fiber ribbon core.

[0030] (A description of one method of this disclosure)

[0031] First, embodiments of this disclosure will be described.

[0032] (1) A method for manufacturing intermittently connected fiber ribbon cores according to one aspect of the present disclosure.

[0033] Multiple optical fiber cores are arranged side-by-side in a direction orthogonal to the length direction of the multiple optical fiber cores.

[0034] The entirety of the multiple optical fiber cores is covered with bonding resin.

[0035] A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores.

[0036] The outer diameter of each optical fiber core is less than 220 μm.

[0037] Between the adjacent fiber cores, the distance between the fiber cores into which the cutter is inserted is more than 10 μm and less than 100 μm.

[0038] According to the intermittently connected fiber ribbon core manufacturing method disclosed herein, since the distance between adjacent fiber ribbon cores to which the cleaver is inserted is 10 μm or more, the fiber ribbon cores will not be damaged even when the cleaver is inserted. Furthermore, since the distance between fiber ribbon cores to which the cleaver is inserted is 100 μm or less, multiple fiber ribbon cores can be arranged at high density on the ribbon core.

[0039] (2) The tensile strength of the connecting resin can be greater than 20 MPa and less than 50 MPa.

[0040] If the tensile strength of the bonding resin is too low, during the manufacturing process, when the intermittently bonded fiber ribbon core is pulled by rollers on the production line, the fiber core may sometimes separate within the ribbon core due to the excessive softness of the bonding resin. However, according to this disclosure, since the tensile strength of the bonding resin is greater than 20 MPa, it is difficult for the fiber core to separate due to weak tensile strength. Furthermore, since the tensile strength of the bonding resin is 50 MPa or less, the bonding resin is not too hard and can be easily broken by a cutter.

[0041] (3) The Young's modulus of the outermost layer of each optical fiber core can be above 800MPa and below 2000MPa.

[0042] According to this disclosure, since the Young's modulus of the outermost covering layer of each optical fiber core is above 800 MPa, it is difficult to damage the optical fiber core with a cleaver. In addition, since the Young's modulus of the outermost covering layer of each optical fiber core is below 2000 MPa, the intermittently connected optical fiber ribbon core will not be difficult to deform due to the rigidity of the resin, and the loss characteristics of the optical cable will not deteriorate.

[0043] (4) The cutter can be inserted after the binding resin has been cured to a gel content of more than 90%.

[0044] If a cleaver is inserted when the bonding resin is not fully cured, the resin is difficult to break due to its high elasticity. Furthermore, its weak strength sometimes leads to separation of the optical fiber cores within the cored wire. According to this disclosure, since the cleaver is inserted after the bonding resin has cured to a gel content of 90% or more, the resin can be easily broken by the cleaver, and separation of the optical fiber cores within the cored wire is prevented.

[0045] (5) The connecting resin covering the multiple optical fiber cores can be cured.

[0046] The binding resin is softened by heating and curing.

[0047] The cutter is inserted into the softened binding resin.

[0048] If a cleaver is inserted into the unsoftened bonding resin, it is not easy to break the bonding resin, and sometimes the bonding resin may peel off from multiple fiber cores when forming a slit. According to this disclosure, since the cleaver is inserted into the softened bonding resin, the bonding resin can be easily broken.

[0049] (6) The connecting resin covering the multiple optical fiber cores can be cured.

[0050] Heating the cutter,

[0051] The heated cutter is inserted into the cured binding resin.

[0052] According to this disclosure, even if the binding resin is cured and in a hard state, the binding resin can be easily broken because the cutter is inserted into the binding resin in a heated state.

[0053] (7) Markings may be made on the surface of each optical fiber core.

[0054] The bonding resin is used to cover the plurality of optical fiber cores marked with the aforementioned markings.

[0055] According to this disclosure, the identification of the fiber cores can be improved because the surface of each fiber core is marked.

[0056] (8) The intermittently connected fiber optic ribbon core wire according to one aspect of this disclosure is characterized by having:

[0057] Multiple fiber cores are arranged side-by-side in a direction orthogonal to the length direction; and

[0058] The bonding resin covers all of the multiple optical fiber cores.

[0059] A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores.

[0060] The outer diameter of each optical fiber core is less than 220 μm.

[0061] Between the adjacent fiber cores, the distance between the fiber cores into which the cutter is inserted is more than 10 μm and less than 100 μm.

[0062] According to the intermittently connected fiber ribbon core of this disclosure, since the distance between the fiber ribbon cores into which the cleaver is inserted is 10 μm or more, the fiber ribbon cores will not be damaged even if the cleaver is inserted. Furthermore, since the distance between the fiber ribbon cores into which the cleaver is inserted is 100 μm or less, multiple fiber ribbon cores can be arranged at high density on the ribbon core.

[0063] (9) The tensile strength of the connecting resin can also be greater than 20 MPa and less than 50 MPa.

[0064] If the tensile strength of the bonding resin is too low, during the manufacturing process, when the intermittently bonded fiber ribbon core is pulled by rollers on the production line, the fiber core may sometimes separate within the ribbon core due to the excessive softness of the bonding resin. However, according to this disclosure, since the tensile strength of the bonding resin is greater than 20 MPa, it is difficult for the fiber core to separate due to weak tensile strength. Furthermore, since the tensile strength of the bonding resin is 50 MPa or less, the bonding resin is not too hard and can be easily broken by a cutter.

[0065] (10) The Young's modulus of the outermost layer of each optical fiber core can also be above 800MPa and below 2000MPa.

[0066] According to this disclosure, since the Young's modulus of the outermost covering layer of each optical fiber core is above 800 MPa, it is difficult to damage the optical fiber core with a cleaver. In addition, since the Young's modulus of the outermost covering layer of each optical fiber core is below 2000 MPa, the intermittently connected optical fiber ribbon core will not be difficult to deform due to the rigidity of the resin, and the loss characteristics of the optical cable will not deteriorate.

[0067] [The Effects of This Disclosure]

[0068] According to this disclosure, a method for manufacturing intermittently connected fiber ribbon cores and intermittently connected fiber ribbon cores can be provided, which can prevent external damage to the fiber cores and can be installed at high density.

[0069] (Details of the first embodiment of this disclosure)

[0070] The intermittently connected fiber ribbon core 1 and its manufacturing method are described with reference to the accompanying drawings.

[0071] It should be noted that this disclosure is not limited to these examples, but is represented by the claims and is intended to include all changes within the meaning and scope equivalent to the claims.

[0072] Figure 1 This is a configuration diagram of a manufacturing apparatus 100 for an intermittently connected optical fiber ribbon core 1 according to one aspect of this disclosure. Figure 1 As shown, the manufacturing apparatus 100 includes a feeder 101, a covering device 110, a delivery winch 115, a cutting device 116, a winding tension control regulator 118, and a winding device 119. Furthermore, the manufacturing apparatus 100 includes a gathering roller 105 disposed between the feeder 101 and the covering device 110, and a guide roller 114 disposed between the covering device 110 and the delivery winch 115.

[0073] The feeder 101 includes multiple spools 102, tension rollers 103, and conveyor rollers 104. Optical fiber cores 11 are wound on the multiple spools 102. The outer diameter of each optical fiber core 11 is, for example, 220 μm or less. Multiple optical fiber cores 11 are drawn from the multiple spools 102 and subjected to a predetermined tension by the tension rollers 103. They are then arranged on an alignment surface as they pass through the conveyor rollers 104 and fed to the feed rollers 105.

[0074] Multiple slots (not shown) are arranged at predetermined intervals on the feed roller 105 to allow multiple optical fiber cores 11 to pass through. As a result, the multiple optical fiber cores 11 are gathered and arranged side by side in a direction orthogonal to the length direction of the optical fiber cores 11.

[0075] Multiple optical fiber cores 11, gathered at the gathering roller 105, are fed to the covering device 110. The covering device 110 includes a resin storage tank 111, a coating device 112, and an ultraviolet irradiation device 113.

[0076] All the optical fiber cores 11 are inserted through the coating apparatus 112, and a coating layer 12 is formed by covering them with the connecting resin 15 supplied from the resin storage tank 111 (see reference). Figure 2The bonding resin 15 is preferably an ultraviolet-cured resin, but it can also be a thermoplastic resin, a bonding resin, or other covering resin. The ultraviolet irradiation device 113 cures the bonding resin 15 by irradiating it with ultraviolet light. As a result, multiple optical fiber cores 11 become optical fiber ribbon cores 10.

[0077] The fiber ribbon core 10 is fed to the delivery winch 115 via the guide roller 114. Then, a slit is formed on the fiber ribbon core 10 by the cutting device 116.

[0078] The cutting device 116 includes multiple cutters 117. Each cutter 117 has a tapered shape at its front end, and the thickness of the cutter is, for example, 0.2 mm. A cam mechanism is connected to each cutter 117, and each cutter 117 is linked to the cam mechanism. The cutter 117 is configured to be positioned and oscillate along the length direction of the fiber ribbon core 10. Through the oscillating action of the cutter 117, the cutter 117 intermittently inserts into the bonding resin 15 between a portion of adjacent fiber ribbon cores in the fiber ribbon core 10 to form slits. Here, it is preferable that the cutter 117 is inserted when the bonding resin 15 has cured to a gel fraction of 90% or more. The fiber ribbon core 10 with intermittently formed slits is called an intermittently bonded fiber ribbon core 1.

[0079] The intermittently connected fiber ribbon core 1 is fed to the winding tension control regulator 118, where the tension is controlled. It is then wound onto the winding reel R by the winding device 119.

[0080] Next, the manufacturing process from fiber ribbon core 10 to intermittently connected fiber ribbon core 1 will be described in detail. Figure 2 The diagram shows a cross-sectional view of the fiber ribbon core 10 perpendicular to its length direction. (See diagram for example.) Figure 2 As shown, the multiple fiber cores 11A to 11L (12 cores in this example) arranged side-by-side in a direction orthogonal to the length direction in the fiber ribbon core 10 are covered by a capping layer 12. The bonding resin 15 forming the capping layer 12 has a tensile strength greater than 20 MPa and less than 50 MPa. Each fiber core 11A to 11L has a glass fiber 16 at its center and an outer layer 17 (outermost layer) covering the periphery of the glass fiber 16. The diameter of the glass fiber 16 is, for example, 200 μm, and the thickness of the outer layer 17 is 37.5 μm. The Young's modulus of the outer layer 17 is greater than 800 MPa and less than 2000 MPa.

[0081] In this example, the two fiber optic cores are approximately in contact with each other to form fiber optic core groups, and a distance g is provided between adjacent fiber optic core groups. Figure 2In this example, a distance g is provided between groups of fiber cores 11A and 11B and groups of fiber cores 11C and 11D; between groups of fiber cores 11C and 11D and groups of fiber cores 11E and 11F; between groups of fiber cores 11E and 11F and groups of fiber cores 11G and 11H; between groups of fiber cores 11G and 11H and groups of fiber cores 11I and 11J; and between groups of fiber cores 11I and 11J and groups of fiber cores 11K and 11L. It should be noted that in this example, a distance g is provided for every two fiber cores, but it could also be provided for each individual fiber core.

[0082] Distance g is the distance between the outer layer 17 of the fiber core (11B) located near an adjacent fiber core group (e.g., 11C and 11D) and the outer layer 17 of the adjacent fiber core (11C) on a straight line L passing through the center of the fiber cores 11A to 11L in the parallel direction of the multiple fiber cores 11A to 11L. In this example, distance g is more than 10 μm and less than 100 μm. In this example, a slit is formed by inserting a cutter 117 into the connecting resin 15 portion with a spacing of distance g. As a result, the slit becomes the non-connected portion 14 of the intermittently connected fiber ribbon core 1 (see reference). Figure 3 ).

[0083] Figure 3 This shows a partial unfolded view of the intermittently connected fiber ribbon core 1 along its length. (See diagram below.) Figure 3 As shown, the fiber ribbon core 10 passing through the cutting device 116 becomes an intermittently connected fiber ribbon core 1, wherein, in a state where it is arranged side by side in a direction orthogonal to the length direction of the multiple fiber ribbon cores 11A to 11L, in part or all of the multiple fiber ribbon cores 11A to 11L, there are intermittently provided, in the length direction, a connecting portion 13 connecting adjacent fiber ribbon cores and a non-connecting portion 14 not connecting adjacent fiber ribbon cores. In this way, the fiber ribbon core 10 sent to the cutting device 116 becomes an intermittently connected fiber ribbon core 1 by intermittently inserting the cutter 117.

[0084] As explained above, in the fiber ribbon core 10 of this example, the fiber cores 11 are arranged with a distance g of 10 μm or more and 100 μm or less, and the bonding resin 15 is cured. Normally, if the distance g is too small, the glass fiber 16 may be damaged by the cleaver 117 when it is inserted. If the distance g is too large, it is impossible to arrange multiple fiber cores 11 at a high density as the fiber ribbon core 10. However, according to this example, since the distance g is 10 μm or more, the possibility of damage to the fiber cores 11 can be reduced even when the cleaver 117 is inserted. Furthermore, since the distance g is 100 μm or less, multiple fiber cores 11 can be arranged at a high density as the fiber ribbon core 10. Therefore, it is possible to suppress external damage to the fiber cores 11, and an intermittently connected fiber ribbon core 1 with a high density of fiber cores 11 is provided.

[0085] Ideally, the tensile strength of the connecting resin 15 should be neither too low nor too high. If the tensile strength is too low, for example, when the fiber ribbon core 10 is pulled by the guide roller 114, the multiple fiber cores 11 within the fiber ribbon core 10 may separate because the connecting resin 15 is too soft. Conversely, if the tensile strength is too high, the connecting resin 15 will be too hard, making it difficult to break with the cutter 117. In the fiber ribbon core 10 of this example, since the tensile strength of the connecting resin 15 is greater than 20 MPa, it is difficult for the fiber cores 11 to separate due to weak tensile strength. Furthermore, since the tensile strength of the connecting resin 15 is less than 50 MPa, the connecting resin 15 is not too hard and can be easily broken with the cutter 117. Therefore, separation of the fiber cores 11 can be prevented, and a slit, i.e., the non-connecting portion 14, can be easily formed.

[0086] If the Young's modulus of the outer layer 17 is too low (outer layer 17 is too soft), the glass fiber 16 may be damaged by the cutter 117 when it is inserted. On the other hand, if the Young's modulus of the outer layer 17 is too high (outer layer 17 is too stiff), the intermittently connected fiber ribbon core is difficult to deform due to the rigidity of the resin, and the optical cable loss characteristics may deteriorate. However, since the Young's modulus of the outer layer 17 of each fiber core 11 in this example is above 800 MPa, it is difficult for the cutter 117 to cause external damage to the outer layer 17. In addition, since the Young's modulus of the outer layer 17 is below 2000 MPa, the intermittently connected fiber ribbon core 1 is not difficult to deform due to the rigidity of the resin, and the possibility of deterioration of the optical cable loss characteristics can be suppressed. Therefore, an intermittently connected fiber ribbon core 1 that prevents damage to the outer layer 17 and has good optical cable loss characteristics can be provided.

[0087] After the connecting resin 15 has cured to a specified value or higher, a cutter 117 is inserted to form a slit. If the cutter 117 is inserted when the connecting resin 15 is not cured, the connecting resin 15 is difficult to break due to its high elasticity. Furthermore, if the connecting resin 15 is not cured, its weak strength may cause the multiple fiber cores 11 within the fiber ribbon core 10 to separate. In this example, because the cutter 117 is inserted into the connecting resin 15 to form a slit after the connecting resin has cured to a gel content of 90% or higher, the connecting resin 15 can be easily broken by the cutter 117, and the separation of the fiber cores 11 within the ribbon core can be prevented.

[0088] It should be noted that in this example, the case where the fiber ribbon core 10, which is cured by the covering device 110 with the connecting resin 15, is formed by directly and intermittently inserting the cutter 117 of the cutting device 116 to form an intermittently connected fiber ribbon core 1 has been described, but the manufacturing process is not limited to this. For example, the manufacturing apparatus 100 may also include a first heating section 121 for heating the connecting resin 15 between the covering device 110 and the cutting device 116. Figure 1 In the optical fiber ribbon core 10, where the connecting resin 15 is cured by the ultraviolet irradiation device 113 of the covering device 110, the connecting resin 15 is softened by heating with the first heating part 121. A cutter 117 is inserted into the softened connecting resin 15 to form a slit.

[0089] If the cutter 117 is inserted into the unsoftened state of the connecting resin 15, it is not easy to break the connecting resin 15. Furthermore, when forming the slit, the connecting resin 15 may sometimes peel off from multiple fiber cores 11. In this example, since the cutter 117 is inserted into the connecting resin 15 softened by the first heating section 121, the connecting resin 15 can be easily broken. It should be noted that the heating temperature by the first heating section 121 is preferably around 40°C or higher. If the heating temperature is around 40°C, the effect of softening the connecting resin 15 is confirmed. The heating temperature needs to be below the melting point of the connecting resin 15; specifically, it is preferably around 95°C or lower.

[0090] Alternatively, the cutting device 116 of the manufacturing apparatus 100 may also include a second heating section 122 of the heated cutter 117. Figure 1The optical fiber ribbon core 10, whose connecting resin 15 has been cured by the ultraviolet irradiation device 113 of the covering device 110, is fed to the cutting device 116. A cutter 117, heated by the second heating unit 122, is inserted into the cured connecting resin 15 to form a slit. Therefore, according to this example, even if the connecting resin 15 is cured, the cutter 117 can be inserted into the connecting resin 15 while it is heated, thus making it easy to break the connecting resin 15. In this example, the temperature heated by the second heating unit 122 is preferably between approximately 40°C and 95°C. It should be noted that both the first heating unit 121 and the second heating unit 122 can be provided to heat both the cutter 117 and the connecting resin 15.

[0091] (Modified Example)

[0092] In order to improve the identification of intermittently connected fiber optic cores 1, the manufacturing apparatus 100 in this example can also mark multiple fiber optic cores 11 with a mark M. Figure 4 This is a schematic diagram of a printing device 123 that can be installed on a manufacturing apparatus 100 for intermittently connected fiber ribbon cores 1.

[0093] like Figure 4 As shown, the manufacturing apparatus 100, in addition to Figure 1 In addition to the configuration shown, a printing device 123 for marking the surfaces of multiple fiber optic cores 11 can also be included. The printing device 123 only needs to be positioned between the feeder 101 and the cover device 110, preferably between the feed roller 105 and the cover device 110. The printing device 123 is, for example, an inkjet printer.

[0094] The printing device 123 prints marks on the surface of multiple optical fiber cores 11 fed from the supply 101, forming marks M. The shape of the marks M can be, for example, a strip shape orthogonal to the length direction. Alternatively, ring-shaped marks can be provided on each optical fiber core 11.

[0095] After forming multiple optical fiber cores 11 marked with M, they are sent to a coating apparatus 112. The coating apparatus 112 coats a bonding resin 15 from above the mark M, and an ultraviolet irradiation device 113 cures the bonding resin 15, including the mark M. Subsequent manufacturing processes are similar to... Figure 1 The description is redundant, so the illustrations and descriptions are omitted.

[0096] In this example, the identification of the fiber core 11 can be improved because the marking is made on the surface of the fiber core 11 by the printing device 123.

[0097] It should be noted that the manufacturing apparatus 100 in this example may also include a plasma treatment apparatus 124 for plasma treatment of the surfaces of multiple optical fiber cores 11. The plasma treatment apparatus 124 can simply be positioned between the feeder 101 and the printing apparatus 123, preferably between the feed roller 105 and the printing apparatus 123. Through the plasma treatment by the plasma treatment apparatus 124, the wettability of the core surface is improved, and the adhesion of the marking material to the core surface is enhanced. Therefore, when marking M is subsequently applied using the printing apparatus 123, it is possible to prevent the marking M from peeling off from the core surface.

[0098] (Evaluation Experiment)

[0099] An evaluation was conducted on the optical fiber cable manufactured according to the manufacturing method of this disclosure. The optical fiber cable used in this evaluation experiment was a 432-core slotless optical fiber cable with 12 intermittently connected fiber ribbon cores 1 installed. The cable outer diameter was 11 mm, and the core density was 4.55 cores / mm². 2 Samples No. 1 to No. 12 were prepared by separately setting the distance g of the intermittently connected fiber core 11 installed in the optical fiber cable, the breaking strength of the connecting resin 15 at 23°C, and the Young's modulus of the outer layer at 23°C. This evaluation experiment assessed whether the fiber core 11 of each sample had external damage, could be cut, whether there was separation during cutting, and the cable loss characteristics. Here, the cable loss characteristics were evaluated to determine whether the attenuation per unit distance was less than 0.3 dB / km when a wavelength of 1.55 μm was incident on the optical cable. The evaluation results are shown in Table 1.

[0100] [Table 1]

[0101] Table 1

[0102]

[0103] In Table 1, samples No. 1 to No. 3 all had a distance g of 0 μm, confirming damage to the fiber core. This is because the distance g was too small, causing damage to the fiber core due to the cleaver 117. Additionally, damage to the fiber core was also confirmed in sample No. 10, which had an outer Young's modulus of 600 MPa. This is because the outer Young's modulus was too soft, resulting in damage to the fiber core due to the cleaver 117. No damage to the fiber core was confirmed in samples No. 4–9 and 11–15. Based on the above, it is confirmed that damage to the fiber core can be prevented when the distance g is 10 μm or more and the outer Young's modulus is 800 MPa or more.

[0104] In Table 1, the tensile strength of the binding resin 15 in samples No. 9 and No. 13 was 70 MPa, confirming that the cutter 117 could not cut through the binding resin 15 (resulting in cutting residue). This is because the binding resin 15 is too hard. On the other hand, in other samples No. 1-8, 10-12, 14, and 15, where the tensile strength of the binding resin 15 was below 50 MPa, it was confirmed that the cutter 117 could cut through the binding resin 15. Based on the above, it is confirmed that the cutter 117 can cut through the binding resin 15 when the tensile strength of the binding resin 15 is below 50 MPa.

[0105] Furthermore, in sample No. 4, where the tensile strength of the connecting resin 15 was 20 MPa, the fiber core separated upon cutting. No separation was observed in other samples. Based on the above, it is confirmed that when the tensile strength of the connecting resin 15 is greater than 20 MPa, fiber core separation upon cutting can be suppressed.

[0106] In Table 1, samples No. 14 and 15 both have a distance g of 150 μm, and an attenuation of over 0.3 dB / km was confirmed as a loss characteristic of the optical cable. If the distance g is too long, it is impossible to install fiber cores with the same core density within the optical cable. That is, due to the increase in the cross-sectional area of ​​each intermittently connected fiber ribbon, the fiber cores within the optical cable are installed without gaps, resulting in mutual lateral pressure. Due to this lateral pressure, the optical cable loss characteristic becomes high. In addition, in sample No. 8 with an outer Young's modulus of 2500 MPa, the intermittently connected fiber ribbon cores are difficult to deform due to the rigidity of the resin, and an attenuation of over 0.3 dB / km was confirmed as a loss characteristic of the optical cable. In other samples No. 1 to 7 and 9 to 13 with a distance g of less than 100 μm, the optical cable loss characteristic is less than 0.3 dB / km. In particular, in sample No. 7, where the distance g is less than 100 μm and the Young's modulus of the outer layer is 2000 MPa, the optical cable loss characteristic is also less than 0.3 dB / km. Based on the above, it is confirmed that it is possible to achieve high-density installation of optical fiber cores within the optical cable and produce an optical cable with low loss characteristics when the distance g is less than 100 μm and the Young's modulus of the outer layer is less than 2000 MPa.

[0107] The present disclosure has been described in detail above with reference to specific embodiments, but various changes and modifications can be made without departing from the spirit and scope of the present disclosure, which will be apparent to those skilled in the art. Furthermore, the number, position, shape, etc., of the constituent components described above are not limited to the above embodiments, and can be changed to appropriate numbers, positions, shapes, etc., when implementing the present disclosure.

[0108] Symbol Explanation

[0109] 1: Intermittently connected fiber optic ribbon core; 10: Fiber optic ribbon core; 11, 11A~11L: Fiber optic core; 12: Covering layer; 13: Connecting part; 14: Non-connecting part; 15: Connecting resin; 16: Glass fiber; 17: Outer layer (outermost layer); 100: Manufacturing device; 101: Supplier; 102: Reel; 103: Tension roller; 104: Conveyor roller; 105: Hub roller; 110: Covering device 111: Resin storage tank; 112: Coating device; 113: Ultraviolet irradiation device; 114: Guide roller; 115: Delivery winch; 116: Cutting device; 117: Cutter; 118: Winding tension control regulator; 119: Winding device; 121: First heating section; 122: Second heating section; 123: Printing device; 124: Plasma treatment device; R: Winding reel; M: Marker.

Claims

1. A method for manufacturing intermittently connected fiber ribbon cores, Multiple optical fiber cores are arranged side-by-side in a direction orthogonal to the length direction of the multiple optical fiber cores. The entirety of the multiple optical fiber cores is covered with bonding resin. A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores. The outer diameter of each optical fiber core is less than 220 μm. Between adjacent fiber cores, the distance between the fiber cores into which the cleaver is inserted is greater than 10 μm and less than 100 μm. The bonding resin is an ultraviolet-cured resin. After the binding resin has cured to a gel content of 90% or more, the cutter is inserted.

2. The method for manufacturing intermittently connected fiber ribbon cores according to claim 1, wherein, The tensile strength of the bonding resin is greater than 20 MPa and less than 50 MPa.

3. The method for manufacturing intermittently connected fiber ribbon cores according to claim 1 or 2, wherein, The Young's modulus of the outermost layer of each optical fiber core is above 800 MPa and below 2000 MPa.

4. The method for manufacturing intermittently connected fiber ribbon cores according to claim 1 or 2, wherein, The bonding resin covering the multiple optical fiber cores is cured. The binding resin is softened by heating and curing. The cutter is inserted into the softened binding resin.

5. The method for manufacturing intermittently connected fiber ribbon cores according to claim 1 or 2, wherein, The bonding resin covering the multiple optical fiber cores is cured. Heating the cutter, The heated cutter is inserted into the cured binding resin.

6. The method for manufacturing intermittently connected fiber ribbon cores according to claim 1 or 2, wherein, Markings are made on the surface of each optical fiber core. The bonding resin is used to cover the plurality of optical fiber cores marked with the aforementioned markings.

7. An intermittently connected fiber optic ribbon core, comprising: Multiple fiber cores are arranged side-by-side in a direction orthogonal to the length direction; and The bonding resin covers the entirety of the multiple optical fiber cores. A slit is formed by intermittently inserting a cleaver into the bonding resin between a portion of adjacent optical fiber cores among the plurality of optical fiber cores. The outer diameter of each optical fiber core is less than 220 μm. Between adjacent fiber cores, the distance between the fiber cores into which the cleaver is inserted is greater than 10 μm and less than 100 μm. The bonding resin is an ultraviolet-cured resin. The bonding resin is cured to a gel fraction of over 90%.

8. The intermittently connected fiber ribbon core according to claim 7, wherein, The tensile strength of the bonding resin is greater than 20 MPa and less than 50 MPa.

9. The intermittently connected fiber ribbon core according to claim 7 or 8, wherein, The Young's modulus of the outermost layer of each optical fiber core is above 800 MPa and below 2000 MPa.

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