Flexible optical fiber ribbon and optical cable

Abstract

Disclosed are a flexible optical fiber ribbon and an optical cable. The flexible optical fiber ribbon comprises multiple optical fibers. The multiple optical fibers are optical fibers arranged side by side, and multiple bonding portions are arranged between adjacent optical fibers and distributed intermittently in the axial direction, the multiple bonding portions being made of the same material; each optical fiber has a colored layer at the second outermost layer and a transparent layer at the outermost layer; the transparent layers of the multiple optical fibers are made of the same material, and the transparent layers are continuous in the axial direction and continuous in the circumferential direction; the colors and / or shapes of the colored layers of optical fibers are observed through the transparent layers, and there is at least one optical fiber, among the multiple optical fibers, of which the color and / or shape of the colored layer thereof is different from that of another optical fiber among the multiple optical fibers.

Description

Flexible optical fiber ribbons and cables

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202421448566.6, filed on June 24, 2024, entitled “A Flexible Optical Fiber Ribbon and Optical Cable,” which is incorporated herein by reference in its entirety.

[0003] Also, this application claims priority to the Chinese patent application with application number 202311759760.6 filed on December 20, 2023, entitled “A flexible optical fiber ribbon, a method and system for detecting its bonding effect”, which is incorporated herein by reference. Technical Field

[0004] The present application relates to the field of optical fiber communications, and more specifically, to a flexible optical fiber ribbon and optical cable. Background Art

[0005] Intermittent bonding occurs between adjacent fibers in a flexible fiber ribbon. This bonding occurs by applying a bonding material or glue regularly between the fibers. Intermittent bonding means that not all adjacent fibers have a bond. To identify the fibers, individual fibers within the same flexible fiber ribbon are colored with different colors or markings. The coloring layer is a mixture of color masterbatch and resin, applied to or partially coated on the sides of the fibers.

[0006] Because different colored pigments have different effects on the physical and chemical properties of the resin, when the bonding material or glue forms intermittent bonding parts, it is difficult to control the bonding force between different optical fibers and the bonding parts in the same optical fiber ribbon to be consistent, resulting in one optical fiber being more easily debonded or more difficult to separate than other optical fibers, affecting the quality or use of optical cables using flexible optical fiber ribbons.

[0007] Summary of the Invention

[0008] In response to the above-mentioned deficiencies or improvement needs in the related art, the present application provides a flexible optical fiber ribbon and optical cable.

[0009] To achieve the above objectives, according to one aspect of the present application, a flexible optical fiber ribbon is provided, comprising a plurality of optical fibers, wherein the plurality of optical fibers are arranged side by side, and a plurality of bonding portions are intermittently distributed axially between adjacent optical fibers, and the plurality of bonding portions are made of the same material;

[0010] The optical fiber has a colored layer at the second outermost layer and a transparent layer at the outermost layer;

[0011] The transparent layers of different optical fibers are made of the same material, and the transparent layer of the same optical fiber is continuous in the axial direction and circumferential direction;

[0012] The color and / or shape of the colored layer of the optical fiber is observed through the transparent layer, and the color and / or shape of the colored layer of at least one optical fiber among the plurality of optical fibers is different from that of another optical fiber among the plurality of optical fibers.

[0013] Preferably, in the flexible optical fiber ribbon, the color and / or shape of the colored layer of any optical fiber among the multiple optical fibers is different from those of the other optical fibers, so as to serve as a unique mark for the optical fiber.

[0014] Preferably, the flexible optical fiber ribbon has a colored layer with a thickness of 1 to 15 μm, a modulus of a higher than transparent layer, a shape of the colored layer that is circumferentially continuous or discontinuous, and an axially continuous or discontinuous shape; and the colored layer is made of photocurable acrylic ink.

[0015] Preferably, the transparent layer of the flexible optical fiber ribbon has a visible light transmittance of more than 85%, the colored layer has a visible light transmittance of less than 30%, and the bonding portion has a visible light transmittance of less than 50%.

[0016] Preferably, the thickness of the transparent layer is greater than or equal to D / 2, where D is a width threshold of the bonding portion.

[0017] Preferably, the transparent layer of the flexible optical fiber ribbon has a thickness of 10 to 100 μm, a modulus greater than 50 MPa, a circular outer contour, and is made of the same resin as the matrix and / or bonding portion of the colored layer.

[0018] Preferably, the transparent layer of the flexible optical fiber ribbon has a thickness of 10 to 50 μm.

[0019] Preferably, the modulus of the transparent layer of the flexible optical fiber ribbon is greater than 500 MPa, and the material is light-curing acrylic resin; the modulus of the colored layer is greater than 600 MPa, and the material is light-curing acrylic ink.

[0020] Preferably, the bonding portion of the flexible optical fiber ribbon is made of a light-curing resin, and the bonding portion is continuous or discontinuous in the optical fiber arrangement direction.

[0021] According to another aspect of the present application, an optical cable is provided, which includes an outer sheath and the flexible optical fiber ribbon provided by the present application, wherein the flexible optical fiber ribbon is housed in the outer sheath.

[0022] In general, the above technical solutions conceived by this application can achieve the following beneficial effects compared with related technologies:

[0023] The flexible optical fiber ribbon provided herein ensures consistent bonding between each optical fiber and the bonding portion within the ribbon by coating the colored layers of multiple optical fibers with a transparent layer of the same material. In a preferred embodiment, the bonding strength of the optical fiber bonding portion is simplified from a combination of bonding resin + a multi-colored resin surface to a combination of bonding resin + a highly transparent resin. This eliminates the need to consider the impact of different optical fiber coloring pigments on the bonding strength between the optical fiber coating and the bonding portion, reducing the difficulty associated with controlling the delicate balance between bonding and tearing forces in material development, manufacturing, and ribbonizing processes. This improves the consistency of bonding between the optical fibers and the bonding portion within the flexible optical fiber ribbon, contributing to stable product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a plan view of a flexible optical fiber ribbon provided in an embodiment of the present application;

[0025] FIG2 is a schematic diagram of the end face of a flexible optical fiber ribbon provided in an embodiment of the present application;

[0026] FIG3 is a schematic diagram of the structure of a flexible optical fiber ribbon cable provided in an embodiment of the present application;

[0027] FIG4 is a plan view of a flexible optical fiber ribbon provided by an embodiment of the present application, wherein the bonding portion is continuous in the optical fiber arrangement direction;

[0028] FIG5 is a schematic diagram of the structure of the color layer of the optical fiber color strip provided in Example 2 of the present application;

[0029] FIG6 is a schematic diagram of the coloring layer structure of the optical fiber color ring provided in Example 2 of the present application;

[0030] FIG7 is a schematic diagram of the structure of the optical fiber spot coloring layer provided in Example 2 of the present application.

[0031] In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein: 1 is an optical fiber, 2 is a bonding portion, 3 is an optical fiber glass portion, 4 is a natural optical fiber resin, 5 is a colored layer, 6 is a transparent layer, 7 is a water-blocking element, 8 is a protective structure, 9 is a tensile element, and 10 is an outer sheath. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application 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 this application and are not intended to limit this application. In addition, the technical features involved in the various embodiments of this application described below may be combined with each other as long as they do not conflict with each other.

[0033] The flexible optical fiber ribbon provided in the present application, as shown in FIG1 , includes a plurality of optical fibers, wherein the plurality of optical fibers are arranged side by side, and a plurality of bonding portions are intermittently distributed axially between adjacent optical fibers, and the plurality of bonding portions are made of the same material;

[0034] The optical fiber has a colored layer at the second outermost layer and a transparent layer at the outermost layer;

[0035] The transparent layers of different optical fibers are made of the same material, and the transparent layer of the same optical fiber is continuous in the axial direction and the circumferential direction, and preferably has a circular outer contour;

[0036] The color and / or shape of the colored layer of the optical fiber is observed through the transparent layer, and the color and / or shape of the colored layer of at least one optical fiber among the plurality of optical fibers is different from that of another optical fiber among the plurality of optical fibers.

[0037] When two optical fibers have different colored layers in different colors or shapes, directly bonding them through the bonding part will result in inconsistent bonding strength. This problem can be solved by covering the optical fiber with a transparent layer and bonding it to the bonding part through the transparent layer made of the same material.

[0038] Typically, the shape and / or color difference of the optical fiber coloring layer serves as an identification function: the color and / or shape of the coloring layer of any optical fiber among the multiple optical fibers is different from that of the other optical fibers among the multiple optical fibers, serving as a unique mark for the optical fiber.

[0039] The tinting layer has a visible light transmittance of less than 30%, and a thickness of 1 to 15 μm. A tinting layer that is too thin will result in a light color, affecting identification efficiency. A tinting layer that is too thick will squeeze the thickness of the resin inside the tinting layer that is in direct contact with the glass, thereby affecting the fiber's bend loss and long-term durability. The modulus of the tinting layer is higher than that of the transparent layer. When separating the optical fibers, the transparent layer will break before the tinting layer, preventing the tinting layer from tearing and affecting identification after separation. The shape of the tinting layer can be continuous or discontinuous circumferentially; or continuous or discontinuous axially. Typically, the tinting layer is continuous in both the axial and circumferential directions, i.e., full coating. Circumferentially discontinuous tinting layers can be shaped like color stripes; axially discontinuous tinting layers can be shaped like color rings; and both circumferentially and axially discontinuous tinting layers can be shaped like spots. Here, the axial direction refers to the length of the optical fiber or flexible optical fiber ribbon, and the circumferential direction refers to the circumference of the optical fiber. The modulus of the tinting layer is greater than 600 MPa, and it is made of a light-curing acrylic resin.

[0040] The transparent layer has a visible light transmittance of over 85%, making the color and shape of the colored layer easily visible and recognizable. Its thickness ranges from 10 to 100 μm, preferably 10 to 50 μm. The thickness d of the transparent layer should be greater than or equal to D / 2, where D represents the width threshold of the bonding portion. The outermost transparent layer of the optical fiber serves as a detection signal sensor. When the transparent layer transmits the detection light, it indicates poor bonding performance. Therefore, the thickness of the transparent layer determines the detection accuracy. A thicker layer increases the detection standard and the bonding performance requirements, while a thinner layer reduces the bonding performance requirements. The overall strength of the transparent resin coating the colored optical fiber and the bonding resin is the bond strength between the optical fibers. A too thin transparent layer will result in low overall strength, affecting the stability of the optical fiber ribbon structure. An overly thick transparent layer will squeeze the resin thickness within the colored layer, which is in direct contact with the glass, thereby affecting the macrobending loss and long-term durability of the optical fiber. The modulus of the transparent layer is greater than 50 MPa, preferably greater than 500 MPa. The transparent layer is made of the same resin as the matrix and / or adhesive portion of the colored layer, preferably a light-curable acrylic resin. This resin ensures a stable bond between the colored layer and the transparent layer, and the adhesive portion is made of the same resin to ensure a stable bond between the transparent layer and the adhesive portion. The modulus of the transparent layer is lower than that of the colored layer. When separating the optical fibers, the transparent layer will break before the colored layer, preventing the colored layer from tearing and affecting the identification effect after the optical fibers are separated.

[0041] The bonding portion is made of a light-curing resin and may be continuous or discontinuous in the optical fiber arrangement direction. The bonding portion has a visible light transmittance of less than 50%.

[0042] The optical cable provided in this application, as shown in FIG3 , includes an outer sheath and the flexible optical fiber ribbon provided in this application, and, if necessary, also includes:

[0043] Water-blocking components, such as water-blocking ointment, water-blocking yarn, water-blocking tape, and water-blocking powder;

[0044] Protective structures such as loose tubes, skeletons, and steel belt armor layers;

[0045] Tensile elements such as central reinforcement, phosphated steel wire, FRP strips.

[0046] The following are examples:

[0047] The flexible optical fiber ribbon provided in this embodiment is a 12-core ribbon with a 250μm spacing between the optical fibers. The structure of the 250μm colored optical fiber used in this embodiment is as shown in Figure 2: a 210μm natural optical fiber with a glass portion having a diameter of 125μm. The glass portion is coated with inner and outer coatings, resulting in a diameter of 210μm. The fiber is then colored with acrylic ink, resulting in an outer diameter of 220μm. A further layer of approximately 15μm thick acrylic light-curable, highly transparent resin with a transmittance exceeding 85% is applied to the outer surface of the colored fiber, reducing the fiber diameter to 250μm. After this coloring, the transparent layer does not affect the ability to distinguish between the fibers through the colored layer. The colored layer has a transmittance of 25%. The modulus of the highly transparent cured resin is 550 MPa, while the modulus of the transparent layer is lower than that of the colored layer, at 650 MPa. When separating the optical fibers, the transparent layer breaks before the colored layer, preventing the colored layer from tearing and affecting identification after separation.

[0048] The coloring layers of the 12 optical fibers are all fully coated, continuous in both the axial and circumferential directions. The colors of the optical fibers are different, namely 12 standard color optical fibers, and the optical fibers are uniquely identified by their colors.

[0049] The bonding resin, i.e., the intermittently distributed bonding parts, are intermittently distributed between the optical fibers. The first arrangement of bonding parts is distributed at the AA position, and the second arrangement of bonding parts is distributed at the BB position. The length L1 of the bonding resin is 5 to 20 mm, and the resin spacing P is 50 to 100 mm, as shown in FIG1 .

[0050] The bonding portion may also be intermittently distributed in the axial direction and continuously distributed along the optical fiber arrangement direction, as shown in FIG4 .

[0051] The light-curing resin used to make the bonding part is preferably a UV-curing resin, which includes oligomers, reactive monomer diluents, photoinitiators and additives to meet the above requirements;

[0052] The composition comprises 25-70 parts by weight of an oligomer, 30-75 parts of a reactive monomer diluent, 1-10 parts of a photoinitiator, and 1-10 parts of an additive. The additive includes a silane coupling agent. The UV-curable resin contains 0.5-5% by weight of the silane coupling agent. The silane structure is preferably added to the resin material via crosslinking. Alternatively, it can be added as an additive, but this may affect the final curing degree and thus the long-term service life of the resin. Additives also include defoamers, leveling agents, and antioxidants.

[0053] The oligomer is a composition containing polyurethane acrylate and epoxy acrylate; wherein the polyurethane acrylate is preferably aliphatic polyurethane acrylate and / or aromatic polyurethane acrylate.

[0054] The reactive monomer diluent is a monofunctional reactive diluent and / or a multifunctional reactive diluent; the functional reactive diluent is preferably β-hydroxyethyl methacrylate; the multifunctional reactive diluent is preferably selected from a combination of one or more of 1,6-hexanediol diacrylate, isobornyl acrylate, trimethylolpropane formal acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and tricyclodecane dimethanol diacrylate. Using a monomer containing more functional groups not only increases reactivity but also imparts a cross-linked structure to the cured film.

[0055] The silane coupling agent is a silane structure organic silicon compound selected from α-[3-(2'-hydroxyethoxy)propyl]-ω-trimethylsiloxypolydimethylsiloxane, α-[3-(2'-hydroxyethoxy)propyl]-ω-trimethylsiloxypolydiphenylsiloxane, α-[3-(2',3'-dihydroxypropoxy)propyl]-ω-trimethylsiloxypolydimethylsiloxane, α-[3-(2',3'-dihydroxypropoxy)propyl]-ω-trimethylsiloxypolydiphenylsiloxane, α-[3-(2',3'-dihydroxypropoxy)propyl]-ω-trimethylsiloxypolydimethylsiloxane, -ethyl-2'-hydroxymethyl-3-hydroxy)propyl]-ω-trimethylsiloxypolydimethylsiloxane, α-[3-(2'-ethyl-2'-hydroxymethyl-3-hydroxy)propyl]-ω-trimethylsiloxypolydiphenylsiloxane, α-[3-(2'-hydroxy-3'-isopropylamino)propyl]-ω-trimethylsiloxypolydimethylsiloxane, and a combination of one or more of α-[3-(2'-hydroxy-3'-isopropylamino)propyl]-ω-trimethylsiloxypolydiphenylsiloxane.

[0056] Example 2

[0057] The structure of this embodiment is similar to that of embodiment 1, with the only difference being that the coloring layer of the 12-core optical fiber uses three primary colors. Each color of optical fiber has four coloring layer shapes, namely:

[0058] Axially and circumferentially continuous full coating;

[0059] Axially continuous and circumferentially discontinuous color stripes, as shown in Figure 5;

[0060] Axially discontinuous and circumferentially continuous color ring, as shown in Figure 6;

[0061] The spots are axially discontinuous and circumferentially discontinuous, as shown in Figure 7.

[0062] The 12-core fiber's coloring layer uniquely identifies the fiber through a combination of shape and color. The limited number of colors used reduces the complexity of material development. The clear layer, using a full-coating process, naturally forms and fills in discontinuities in the coloring layer, maintaining a smooth appearance.

[0063] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A flexible optical fiber ribbon, comprising a plurality of optical fibers, wherein the plurality of optical fibers are arranged side by side, and a plurality of bonding portions are intermittently distributed axially between adjacent optical fibers, and the plurality of bonding portions are made of the same material; The optical fiber has a colored layer in the second outermost layer and a transparent layer in the outermost layer; The transparent layers of different optical fibers are made of the same material, and the transparent layer of the same optical fiber is continuous in the axial direction and in the circumferential direction; The color and / or shape of the colored layer of the optical fiber is observed through the transparent layer, and the color and / or shape of the colored layer of at least one optical fiber among the plurality of optical fibers is different from that of one of the other optical fibers among the plurality of optical fibers.

2. The flexible optical fiber ribbon according to claim 1, wherein: The color and / or shape of the colored layer of any one of the plurality of optical fibers is different from that of the other optical fibers in the plurality of optical fibers, so as to serve as a unique mark for the existence of the optical fiber.

3. The flexible optical fiber ribbon according to claim 1, wherein: The coloring layer has a thickness of 1 to 15 μm, a modulus of the coloring layer higher than that of the transparent layer, a shape of the coloring layer that is circumferentially continuous or discontinuous, and a shape of the coloring layer that is axially continuous or discontinuous; and the coloring layer is made of photocurable acrylic ink.

4. The flexible optical fiber ribbon according to claim 1, wherein: The transparent layer has a visible light transmittance of 85% or more, the colored layer has a visible light transmittance of 30% or less, and the bonding portion has a visible light transmittance of 50% or less.

5. The flexible optical fiber ribbon according to claim 1, wherein: The thickness of the transparent layer is greater than or equal to D / 2, where D is a width threshold of the bonding portion.

6. The flexible optical fiber ribbon according to claim 5, wherein the thickness of the transparent layer is 10 to 100 μm, the modulus of the transparent layer is greater than 50 MPa, the outer contour of the transparent layer is circular, and the material of the transparent layer is the same resin as the matrix and / or bonding part of the colored layer.

7. The flexible optical fiber ribbon according to claim 6, wherein: The thickness of the transparent layer is between 10 and 50 μm.

8. The flexible optical fiber ribbon according to claim 5, wherein: The modulus of the transparent layer is greater than 500 Mpa, and the material is light-curing acrylic resin; the modulus of the coloring layer is greater than 600 Mpa, and the material is light-curing acrylic ink.

9. The flexible optical fiber ribbon according to claim 1, wherein: The bonding portion is made of a light-curing resin, and the bonding portion is continuous or discontinuous in the optical fiber arrangement direction.

10. An optical cable comprising an outer sheath, and the flexible optical fiber ribbon according to any one of claims 1 to 9, wherein the flexible optical fiber ribbon is accommodated in the outer sheath.

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