A butterfly cable

Abstract

The application discloses a butterfly-shaped optical cable and relates to the technical field of optical fibers. The butterfly-shaped optical cable comprises an optical unit and an outer sheath wrapped outside the optical unit, and a recess is arranged at the middle position of the outer sheath. The outer sheath comprises a first outer protective layer arranged in color and a second outer protective layer arranged in black. The second outer protective layer is arranged on the surface of the first outer protective layer in the recess area. By arranging the second outer protective layer in black in the recess area of the first outer protective layer arranged in color, the anti-ultraviolet radiation performance of the recess area is improved, the weather resistance of the butterfly-shaped optical cable is improved, the service life of the butterfly-shaped optical cable is prolonged, and the failure of the recess area is reduced.

Description

Technical Field

[0001] This application relates to the field of optical fiber technology, and in particular to a butterfly-shaped optical cable. Background Technology

[0002] As the "last mile" connection line for fiber optic networks to cross from outdoors to indoors, the butterfly-shaped optical cable needs to be exposed to harsh outdoor environments such as sun and rain all year round. Among these, ultraviolet rays from sunlight are the "number one killer" of polymer materials.

[0003] Currently, most butterfly-shaped optical cables are black. However, as the number of butterfly-shaped optical cables being laid increases, colored cables are needed to improve visibility and thus increase construction efficiency. However, colored polymer materials generally have poorer weather resistance than black ones, which can easily lead to sheath failure. Summary of the Invention

[0004] This application provides a butterfly-shaped optical cable to improve its service life.

[0005] In a first aspect, this application provides a butterfly-shaped optical cable, including an optical unit and an outer sheath surrounding the optical unit, wherein the outer sheath has a recess in the middle, wherein: The outer sheath includes a first outer sheath that is colored and a second outer sheath that is black; The second outer protective layer is disposed on the surface of the first outer protective layer in the recessed region.

[0006] The V-groove in the conventional butterfly-shaped optical cable structure is a weak point in the cable. Ultraviolet rays and free radicals in sunlight will preferentially attack this area, causing the sheath to fail and reducing the cable's lifespan.

[0007] This application improves the UV resistance of the recessed area by adding a black second outer sheath to the recessed area of ​​the first outer sheath, thereby improving the weather resistance of the butterfly optical cable, increasing its service life, and reducing failures in the recessed area.

[0008] It should be noted that the reason why the black second outer sheath has strong UV resistance and is not prone to aging is that the second outer sheath contains a sufficient amount of carbon black. Carbon black has a very good light shielding effect. The benzoquinone structure and polynuclear aromatic hydrocarbon structure in the carbon black structure can absorb visible light and most ultraviolet rays, converting light energy into heat energy, and preventing ultraviolet rays from directly attacking the molecular bonds in the polymer and causing the molecular chain to break.

[0009] It should be noted that in this application, the recessed area can be the V-groove area in the inherent structure of a conventional butterfly optical cable, or it can be U-shaped or other concave shapes. In some embodiments, it is usually V-shaped for the convenience of stripping the optical fiber.

[0010] In some embodiments, the materials of the first outer sheath include: resin, flame retardant, colorant, antioxidant, ultraviolet absorber, light quencher, and light stabilizer. By adding ultraviolet absorber, light quencher, and light stabilizer to the colored first outer sheath, a three-layer protective barrier can be formed. The ultraviolet absorber forms the first barrier, absorbing ultraviolet light and releasing or consuming the absorbed energy as heat or harmless low-energy radiation, thereby preventing ultraviolet degradation of the polymer molecular chain; the light quencher is the second barrier, which can transfer the excited state energy generated by the polymer molecules after absorbing ultraviolet light, allowing the polymer molecules to return to the ground state, thereby preventing the polymer from generating free radicals; the light stabilizer is the third barrier, which can scavenge the free radicals generated by the polymer and interrupt the auto-oxidation chain reaction.

[0011] In some embodiments, the material of the first outer protective layer, by weight, comprises 90-110 parts resin, 20-35 parts flame retardant, 0.01-3 parts colorant, 0.5-2.5 parts antioxidant, 2-4 parts ultraviolet absorber, 0.1-2 parts light quencher, and 0.5-2.0 parts light stabilizer. Within this proportion range, the above materials can simultaneously possess excellent mechanical properties, weather resistance, and flame retardant properties.

[0012] In some embodiments, the resin has a melt index of 0.1~1 g / 10 min at 190°C. A melt index within this range at 190°C improves the extrusion processing performance of the material. Too low a melt index makes extrusion difficult, while too high a melt index reduces melt strength and extrusion moldability. Typically, the VA (vinyl acetate) content in the resin is 20%~30%, which ensures material strength and toughness while giving the material a certain degree of polarity, thus improving compatibility with inorganic flame retardants. Better compatibility reduces the risk of cracking and decreases the probability of cracking in optical cable sheaths.

[0013] In some embodiments, the lightfastness rating of the colorant is Class I. This lightfastness rating ensures that the optical cable is less prone to fading under long-term light exposure, maintaining the product's color for an extended period.

[0014] In some embodiments, the resin includes at least one of polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA); and / or, The flame retardant includes at least one of magnesium hydroxide, aluminum hydroxide, antimony trioxide, and molybdenum trioxide. During combustion, the flame retardant decomposes and dehydrates, absorbs heat from the plastic surface, generates water vapor to reduce the concentration of combustible gases, and the residual oxides form a dense protective layer on the plastic surface, isolating oxygen and promoting carbonization of the plastic surface, thus possessing an oxygen-isolating function. Generally, magnesium hydroxide has better compatibility with plastics than aluminum hydroxide, and at the same addition amount, magnesium hydroxide exhibits better flame retardant performance. A particle size of 2-5 μm can reduce the impact of adding magnesium hydroxide on the mechanical properties of the resin; too small a particle size leads to excessively high costs; and / or, The colorant includes at least one of titanium dioxide, carbon black, pigment orange 34, and pigment green 7, and the colorant can make the outer sheath of the colored butterfly optical cable display different colors; and / or The antioxidants include at least one of antioxidant 1010, antioxidant 300, antioxidant 168, and antioxidant DLTP. Among them, tetrahydric phenol antioxidants (primary antioxidants) have the characteristics of very low volatility, poor migration, high thermal stability, and long-lasting effect in plastics, thus providing long-term protection. Phosphite antioxidants (secondary antioxidants) have small molecular weights and can decompose peroxides generated during polymer processing and use, improving the thermal stability of plastic processing, and can be used as antioxidants in extrusion molding; and / or, The ultraviolet absorber includes at least one of UV-327 and UV-531. The ultraviolet absorber can strongly and selectively absorb high-energy ultraviolet light and release or consume the absorbed energy as heat or harmless low-energy radiation, thereby preventing ultraviolet degradation of the polymer molecular chain. UV-327 can strongly absorb ultraviolet light with wavelengths of 270-300 nm, has good chemical stability, low volatility, low toxicity, good compatibility with polyolefin materials, is not easily precipitated, and can provide long-term protection; and / or, The photoquencher includes at least one of UV-2002 and UV-1084. The photoquencher can transfer the excited-state energy generated by polymer molecules after absorbing ultraviolet light, causing the polymer molecules to return to their ground state, thereby preventing the formation of free radicals in the polymer. UV-2002 has good compatibility with polyolefin materials, is not easily precipitated, and can provide long-term protection; and / or, The light stabilizer includes at least one of GW-540 and LA-57. The light stabilizer can scavenge free radicals generated by the polymer and interrupt the auto-oxidation chain reaction. The light stabilizer has good light stabilizing effect, good compatibility with polyolefin materials, is not easily precipitated, and can provide long-term protection.

[0015] In some embodiments, the thickness of the first outer sheath is 0.3mm to 2.5mm. Within this range, the thickness of the first outer sheath allows for long-term outdoor use without cracking and meets the flame-retardant requirements of butterfly-shaped optical cables; and / or, The thickness of the second outer sheath is 0.2mm to 0.8mm. Within this range, the thickness of the second outer sheath can protect the weak points of the V-groove of the butterfly optical cable, ensuring it will not crack during long-term outdoor use.

[0016] In some embodiments, the mechanical properties retention rate of the butterfly-shaped optical cable is >80%. In some embodiments of this application, the butterfly-shaped optical cable has excellent weather resistance and can meet the requirement of a mechanical properties retention rate of >80% after 2000h xenon lamp accelerated aging test under UL 1581 standard. This ensures that the sheath material still has good mechanical properties after long-term outdoor use and does not crack during long-term outdoor use.

[0017] In some embodiments, the color difference value ΔE*ab of the butterfly-shaped optical cable is ≤6. In some embodiments of this application, the butterfly-shaped optical cable has excellent weather resistance and meets the color difference value ΔE*ab≤6 under the GB / T 7921—2008 standard, which can ensure that the color of the optical cable can be identified during long-term outdoor use.

[0018] In some embodiments, the tear strength of the butterfly-shaped optical cable is less than 15N. In some embodiments of this application, the butterfly-shaped optical cable has excellent weather resistance and its separability (tear strength) meets the YD / T 1997.1-2022 standard of less than 15N, which can effectively tear the optical cable sheath, facilitate optical fiber splicing construction, and improve construction efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional view of a butterfly-shaped optical cable according to an embodiment of this application.

[0021] Figure 2 This is a cross-sectional view of a butterfly-shaped optical cable according to an embodiment of this application.

[0022] Figure 3 This is a top view of the core of a butterfly-shaped optical cable according to an embodiment of this application.

[0023] Figure 4 This is a cross-sectional view of the core of a butterfly-shaped optical cable according to an embodiment of this application.

[0024] Figure 5 This is a top view of the cover of a butterfly-shaped optical cable according to an embodiment of this application.

[0025] Figure 6This is a cross-sectional view of the mold cover of a butterfly-shaped optical cable according to an embodiment of this application.

[0026] Figure 7 This is a cross-sectional view of the core and cover assembly of a butterfly-shaped optical cable according to an embodiment of this application.

[0027] Explanation of icon numbers: 100 butterfly-shaped optical cable; 1 optical unit; 2 outer sheath; 21 first outer sheath; 22 second outer sheath; 3 reinforcing member; 4 mold core; 41 optical fiber positioning hole; 42 reinforcing member positioning hole; 43 first main feed channel; 44 positioning pin; 45 washer; 5 mold cover; 51 second main feed channel; 52 auxiliary feed channel; 53 forming cavity; 54 positioning hole. Detailed Implementation

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

[0029] As the "last mile" connection line for fiber optic networks to cross from outdoors to indoors, the butterfly-shaped optical cable needs to be exposed to harsh outdoor environments such as sun and rain all year round. Among these, ultraviolet rays from sunlight are the "number one killer" of polymer materials.

[0030] Currently, most butterfly-shaped optical cables are black. However, as the number of butterfly-shaped optical cables being laid increases, colored cables are needed to improve visibility and thus increase construction efficiency. However, colored polymer materials generally have poorer weather resistance than black ones, which can easily lead to sheath failure.

[0031] The V-groove in the conventional butterfly-shaped optical cable structure is a weak point in the cable. Ultraviolet rays and free radicals in sunlight will preferentially attack this area, causing the sheath to fail and reducing the cable's lifespan.

[0032] In view of this, this application provides a butterfly-shaped optical cable to improve the service life of the butterfly-shaped optical cable.

[0033] Firstly, such as Figure 1 and Figure 2 As shown, this application provides a butterfly-shaped optical cable 100, including an optical unit 1 and an outer sheath 2 wrapped around the outside of the optical unit 1. The outer sheath 2 has a recess in the middle, wherein: The outer sheath 2 includes a first outer sheath 21 that is colored and a second outer sheath 22 that is black; The second outer protective layer 22 is disposed on the surface of the first outer protective layer 21 in the recessed region.

[0034] This application improves the UV resistance of the recessed area by adding a black second outer sheath 22 to the recessed area of ​​the first outer sheath 21, which is colored, thereby improving the weather resistance of the butterfly optical cable 100, increasing its service life, and reducing the failure of the recessed area.

[0035] It should be noted that the reason why the black second outer sheath 22 has strong UV resistance and is not easy to age is that the second outer sheath 22 contains a sufficient amount of carbon black. Carbon black has a very good light shielding effect. The benzoquinone structure and polynuclear aromatic hydrocarbon structure in the carbon black structure can absorb visible light and most of the ultraviolet rays, converting light energy into heat energy, and preventing ultraviolet rays from directly attacking the molecular bonds in the polymer and causing the molecular chain to break.

[0036] It should be noted that in this application, the recessed area can be the V-groove area in the inherent structure of a conventional butterfly optical cable 100, or it can be U-shaped or other concave shapes. In some embodiments, it is usually V-shaped for the convenience of stripping the optical fiber.

[0037] In conjunction with the first aspect, in some embodiments provided in this application, the material of the first outer sheath 21 includes: resin, flame retardant, colorant, antioxidant, ultraviolet absorber, light quencher, and light stabilizer. By adding ultraviolet absorber, light quencher, and light stabilizer to the colored first outer sheath 21, a three-layer protective barrier can be formed. The ultraviolet absorber forms the first barrier, absorbing ultraviolet light and releasing or consuming the absorbed energy as heat or harmless low-energy radiation, thereby preventing ultraviolet light from degrading the polymer molecular chain. The light quencher is the second barrier, which can transfer the excited state energy generated by the polymer molecules after absorbing ultraviolet light, causing the polymer molecules to return to the ground state, thereby preventing the polymer from generating free radicals. The light stabilizer is the third barrier, which can scavenge free radicals generated by the polymer and interrupt the auto-oxidation chain reaction.

[0038] In conjunction with the first aspect, in some embodiments provided in this application, the material of the first outer protective layer 21, by weight, comprises 90-110 parts resin, 20-35 parts flame retardant, 0.01-3 parts colorant, 0.5-2.5 parts antioxidant, 2-4 parts ultraviolet absorber, 0.1-2 parts light quencher, and 0.5-2.0 parts light stabilizer. Within this proportion range, the above materials can simultaneously possess excellent mechanical properties, weather resistance, and flame retardant properties.

[0039] In conjunction with the first aspect, in some embodiments provided in this application, the melt index of the resin at 190°C is 0.1~1 g / 10 min. A melt index within this range at 190°C improves the extrusion processing performance of the material. Too low a melt index makes extrusion difficult, while too high a melt index reduces melt strength and extrusion moldability. Typically, the VA (vinyl acetate) content in the resin is 20%~30%, which ensures material strength and toughness while giving the material a certain degree of polarity, thus improving compatibility with inorganic flame retardants. Better compatibility reduces the risk of material cracking and decreases the probability of cracking in optical cable sheaths.

[0040] In conjunction with the first aspect, in some embodiments provided in this application, the lightfastness rating of the colorant is Class I. The lightfastness rating of the colorant within this range ensures that the optical cable is less prone to fading under long-term light exposure, and that the color of the product remains unchanged for a long period.

[0041] In conjunction with the first aspect, in some embodiments provided in this application, the resin includes at least one of polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA).

[0042] In conjunction with the first aspect, in some embodiments provided in this application, the flame retardant includes at least one of magnesium hydroxide, aluminum hydroxide, antimony trioxide, and molybdenum trioxide. During combustion, the flame retardant can decompose and dehydrate, absorb heat from the plastic surface, generate water vapor to reduce the concentration of combustible gases, and the residual oxides form a dense protective layer on the plastic surface, isolating oxygen and promoting carbonization of the plastic surface, thus possessing the function of isolating oxygen. Generally, compared to aluminum hydroxide, magnesium hydroxide has better compatibility with plastics, and at the same addition amount, magnesium hydroxide exhibits better flame retardant performance. A particle size of 2~5μm for the flame retardant can reduce the impact of adding magnesium hydroxide on the mechanical properties of the resin; however, a particle size that is too small will lead to excessively high costs.

[0043] In conjunction with the first aspect, in some embodiments provided in this application, the colorant includes at least one of titanium dioxide, carbon black, pigment orange 34 and pigment green 7, and the colorant can make the outer sheath 2 of the colored butterfly optical cable 100 present different colors.

[0044] In conjunction with the first aspect, in some embodiments provided in this application, the antioxidant includes at least one of antioxidant 1010, antioxidant 300, antioxidant 168, and antioxidant DLTP. The tetrahydric phenol antioxidant (primary antioxidant) in plastics exhibits very low volatility, poor migration resistance, high thermal stability, and long-lasting effectiveness, thus providing long-term protection. Phosphite antioxidants (secondary antioxidants) have small molecular weights and can decompose peroxides generated during polymer processing and use, improving the thermal stability of plastic processing and serving as antioxidants for extrusion molding.

[0045] In conjunction with the first aspect, in some embodiments provided in this application, the ultraviolet absorber includes at least one of UV-327 and UV-531. The ultraviolet absorber can strongly and selectively absorb high-energy ultraviolet light and release or consume the absorbed energy as heat or harmless low-energy radiation, thereby preventing ultraviolet degradation of the polymer molecular chain. UV-327, in particular, can strongly absorb ultraviolet light with wavelengths of 270-300 nm, has good chemical stability, low volatility, low toxicity, good compatibility with polyolefin materials, is not easily precipitated, and can provide long-term protection.

[0046] In conjunction with the first aspect, the photoquencher described in some embodiments of this application includes at least one of UV-2002 and UV-1084. The photoquencher can transfer the excited state energy generated by polymer molecules after absorbing ultraviolet light, causing the polymer molecules to return to the ground state, thereby preventing the polymer from generating free radicals. Among them, UV-2002 has good compatibility with polyolefin materials, is not easily precipitated, and can play a long-term protective role.

[0047] In conjunction with the first aspect, the light stabilizer described in some embodiments provided in this application includes at least one of GW-540 and LA-57. The light stabilizer can scavenge free radicals generated by the polymer and interrupt the auto-oxidation chain reaction. The light stabilizer has good light stabilizing effect, good compatibility with polyolefin materials, is not easily precipitated, and can provide long-term protection.

[0048] In conjunction with the first aspect, in some embodiments provided in this application, the thickness of the first outer sheath 21 is 0.3mm to 2.5mm. The thickness of the first outer sheath 21 is within this range, which allows for long-term outdoor use without cracking and meets the flame retardant requirements of the butterfly optical cable 100.

[0049] In conjunction with the first aspect, in some embodiments provided in this application, the thickness of the second outer sheath 22 is 0.2mm to 0.8mm. Within this range, the thickness of the second outer sheath 22 can protect the weak points of the V-groove of the butterfly optical cable 100, ensuring it does not crack during long-term outdoor use.

[0050] In conjunction with the first aspect, in some embodiments provided in this application, the mechanical performance retention rate of the butterfly optical cable 100 is >80%. In some embodiments of this application, the butterfly optical cable 100 has excellent weather resistance, and after undergoing a 2000-hour xenon lamp accelerated aging test under UL 1581 standard, the mechanical performance retention rate is >80%, which can ensure that the sheath material still has good mechanical properties after long-term outdoor use and meets the requirement of not cracking during long-term outdoor use.

[0051] In conjunction with the first aspect, in some embodiments provided in this application, the color difference value ΔE*ab of the butterfly optical cable 100 is ≤6. In some embodiments of this application, the butterfly optical cable 100 has excellent weather resistance and meets the color difference value ΔE*ab≤6 under the GB / T 7921—2008 standard, which can ensure the color identification of the optical cable during long-term outdoor use.

[0052] In conjunction with the first aspect, in some embodiments provided in this application, the tear force of the butterfly optical cable 100 is less than 15N. In some embodiments of this application, the butterfly optical cable 100 has excellent weather resistance and its separability (tear force) meets the YD / T1997.1-2022 standard of less than 15N, which can effectively tear the optical cable sheath, facilitate optical fiber splicing construction, and improve construction efficiency.

[0053] The butterfly-shaped optical cable 100 of this application may include a reinforcing member 3 and may be formed using a double-layer co-extrusion process to simultaneously form the first outer sheath 21 and the second outer sheath 22. The mold used, such as... Figures 3 to 7 As shown, it consists of two parts: the mold core 4 and the mold cover 5. The mold core 4 includes fiber positioning holes 41, reinforcing member positioning holes 42, a first main feed channel 43, positioning pins 44, and washers 45. The mold core 4 is made of S136 mold steel and tungsten carbide alloy composite material. Tungsten carbide inserts are used for the fiber / reinforcing member positioning holes 42 to improve wear resistance and dimensional stability. The S136 substrate ensures overall strength and polishing precision, with a surface polishing grade Ra≤0.025μm, avoiding material flow retention and sheath surface defects. Fiber optic positioning hole 41: Centered, used for stable fiber threading and centering, hole diameter 0.4mm (compatible with single-core fiber). Reinforcing member positioning holes 42: symmetrically distributed on both sides of the fiber positioning holes 41, used for precise guidance of the reinforcing member 3, with a hole diameter of 0.55mm~0.8mm; First main feed channel 43: smooth transition, guides the first outer protective layer 21 slurry flow to evenly cover the light unit 1 and the reinforcing member 3, boss angle 43°~80°, boss height 21mm~32.5mm; Positioning pin 44: Used for connecting and fixing the mold core 4 and the mold cover 5. It consists of two cylinders, each with a diameter of φ5 and a height of 3cm. Washer 45: forms the gap between the mold core 4 and the mold cover 5, and is used as a guide boss for the material flow of the first outer protective layer 21, with a thickness of 2~5mm.

[0054] The mold cover 5 includes a second main feed channel 51, an auxiliary feed channel 52, a molding cavity 53, and positioning holes 54. It is made of S136 mold steel, with a polishing grade Ra≤0.05μm for the inner wall of the flow channels, ensuring smooth material flow, a clear interface between the double-layer sheath, and long-term use without deformation or material sticking. Second main feed channel 51: Connects to the extruder host, conveys the first outer protective material, with a concave angle of 43°~80° and a concave depth of 11.5mm~22.5mm.

[0055] Auxiliary feed channel 52: Connects to the auxiliary extruder, conveys the second outer protective material, and precisely connects to the V-groove area. It is a "Y"-shaped flow channel with a flow channel width of 2mm~4mm.

[0056] Molding cavity 53: Cooperates with mold core 4 to shape the overall shape of the optical cable and the thickness of the double sheath, with a length of 3.0mm~4.0mm, a width of 2.0mm~3.0mm, and a thickness of 2mm~4mm.

[0057] Positioning hole 54: Connects to positioning pin 44, used for connecting and fixing mold core 4 and mold cover 5, with a hole diameter of φ5.

[0058] The technical solution provided in this application will be described in detail below with reference to the embodiments. The specific composition of the material of the second outer protective layer is as follows, by mass parts: 100 parts of resin (EVA (resin matrix, VA content of 20%~30%, melt index (190℃, 2.16kg) between 0.1~1g / 10min)), 30 parts of flame retardant (20 parts magnesium hydroxide (low smoke halogen-free flame retardant, particle size of 2~5um), 10 parts antimony trioxide (synergistic flame retardant)), 2.5 parts of carbon black, and 2.4 parts of antioxidant (2 parts antioxidant 1010 (main antioxidant), 0.4 parts antioxidant 168 (auxiliary antioxidant)).

[0059] Example 1 Embodiment 1 of this application provides a butterfly-shaped optical cable, including one optical fiber, two reinforcing members, and an outer sheath.

[0060] The outer sheath consists of a first outer sheath and a second outer sheath. The first outer sheath is gray and has a thickness of 0.4 mm on the outer side of the optical fiber and 1.0 mm on the outer side of the reinforcing member. The black second outer sheath is located in the V-groove section and has a thickness of 0.2 mm.

[0061] The raw material formula for the first outer sheath is as follows: 100 parts EVA (resin matrix, VA content is 20%~30%, melt index (190℃, 2.16kg) is between 0.1~1g / 10min), 20 parts magnesium hydroxide (low smoke halogen-free flame retardant, particle size is 2~5um), 10 parts antimony trioxide (synergistic flame retardant), 2.95 parts rutile titanium dioxide + 0.05 parts carbon black (light resistance grade I), 0.5 parts antioxidant 1010 (primary antioxidant), 0.1 parts antioxidant 168 (secondary antioxidant), 4 parts ultraviolet absorber (UV-327), 0.2 parts light quencher (UV-2002), and 2.0 parts light stabilizer (GW-540).

[0062] Example 1: The outer sheath is prepared using a double-layer co-extrusion process, with the first and second outer sheaths being extruded and formed simultaneously using a mold.

[0063] The butterfly-shaped optical cable of Example 1, after undergoing a 2000-hour accelerated aging test under UL 1581 standard, exhibited a mechanical property retention rate of 85% for elongation at break and 93% for tensile strength, which is superior to the standard requirement of >80% mechanical property retention after 720 hours of accelerated aging under xenon lamp, demonstrating excellent weather resistance. Under GB / T 7921—2008 standard, the color difference value ΔE*ab was 3.2. Under YD / T 1997.1-2022 standard, the tear strength was 6N. Under GB / T 18380.12 standard, the flame retardant performance was tested, and it passed a single-strand vertical burning test.

[0064] Example 2 Embodiment 2 of this application provides a butterfly-shaped optical cable, including a 4-core optical fiber ribbon, 2 reinforcing members and an outer sheath.

[0065] The outer sheath consists of a first outer sheath and a second outer sheath. The first outer sheath is orange and has a thickness of 0.6 mm on the outer side of the optical fiber and 2.1 mm on the outer side of the reinforcing member. The black second outer sheath is located in the V-groove section and has a thickness of 0.4 mm.

[0066] The raw material formula for the first outer sheath is as follows: 100 parts EVA (resin matrix, VA content 20%~30%, melt index (190℃, 2.16kg) between 0.1~1g / 10min), 30 parts magnesium hydroxide (low smoke halogen-free flame retardant, particle size 2~5um), 5 parts antimony trioxide (synergistic flame retardant), 0.3 parts benzidine orange pigment (pigment orange 34, lightfastness grade I), 1.0 part antioxidant 1010 (main antioxidant). Oxidizing agent), 0.5 parts antioxidant 168 (co-antioxidant), 2 parts ultraviolet absorber (UV-327, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), 1.5 parts light quencher (UV-2002, nickel bis(3,5-di-tert-butyl-4-hydroxybenzyl phosphate), 0.5 parts light stabilizer (GW-540, tris(1,2,2,6,6-pentamethyl-4-piperidinyl) phosphate).

[0067] The outer sheath of the butterfly-shaped optical cable in Example 2 is prepared by a double-layer co-extrusion process, and the first and second outer sheaths are simultaneously extruded and formed with the help of a mold.

[0068] The butterfly-shaped optical cable of Example 2, after undergoing a 2000-hour accelerated aging test under UL 1581 standard, showed a 91% retention rate of elongation at break and a 95% retention rate of tensile strength, which is superior to the standard requirement of >80% retention rate after 720 hours of accelerated aging under xenon lamp, demonstrating excellent weather resistance. Under GB / T 7921—2008 standard, the color difference value ΔE*ab was 4.6. Under YD / T 1997.1-2022 standard, the tear strength was 10N. Under GB / T 18380.12 standard, the flame retardant performance was tested, and it passed the single-strand vertical burning test.

[0069] Example 3 Embodiment 3 of this application provides a butterfly-shaped optical cable, including two optical fibers, two reinforcing members, and an outer sheath.

[0070] The outer sheath consists of a first outer sheath and a second outer sheath. The first outer sheath is green and has a thickness of 0.3 mm on the outer side of the optical fiber and 2.5 mm on the outer side of the reinforcing member. The black second outer sheath is located in the V-groove section and has a thickness of 0.8 mm.

[0071] The raw material formula for the first outer sheath is as follows: 100 parts EVA (resin matrix, VA content 20%~30%, melt index (190℃, 2.16kg) between 0.1~1g / 10min), 25 parts aluminum hydroxide (low smoke halogen-free flame retardant, particle size 2~5um), 8 parts molybdenum trioxide (synergistic flame retardant), 0.01 parts chlorophthalocyanine (pigment green 7, lightfastness grade I), 0.8 parts antioxidant 300 (main... Antioxidant), 0.3 parts antioxidant DLTP (co-antioxidant), 3 parts ultraviolet absorber (UV-531, 2-hydroxy-4-octyloxybenzophenone), 1.2 parts light quencher (UV-1084, 2,2'-thiobis(p-tert-octylphenol) nickel-n-butylamine complex), 1.4 parts light stabilizer (LA-57, tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylic acid ester).

[0072] The outer sheath of the butterfly-shaped optical cable in Example 3 is prepared by a double-layer co-extrusion process, which, together with a mold, enables the first and second outer sheaths to be extruded and formed simultaneously.

[0073] The butterfly-shaped optical cable of Example 3, after undergoing a 2000-hour accelerated aging test under UL 1581 standard, showed a 93% retention rate of elongation at break and a 96% retention rate of tensile strength, which is superior to the standard requirement of >80% retention rate after 720 hours of accelerated aging under xenon lamp, demonstrating excellent weather resistance. Under GB / T 7921—2008 standard, the color difference value ΔE*ab was 2.2. Under YD / T 1997.1-2022 standard, the tear strength was 14N. Under GB / T 18380.12 standard, the flame retardant performance was tested, and it passed the single-strand vertical burning test.

[0074] Example 4 Embodiment 4 of this application provides a butterfly-shaped optical cable, including two optical fibers, two reinforcing members, and an outer sheath.

[0075] The outer sheath consists of a first outer sheath and a second outer sheath. The first outer sheath is orange and has a thickness of 0.2 mm on the outer side of the optical fiber and 2.7 mm on the outer side of the reinforcing member. The black second outer sheath is located in the V-groove section and has a thickness of 0.1 mm.

[0076] The raw material formula for the first outer sheath is as follows: 100 parts EVA (resin matrix, VA content 20%~30%, melt index (190℃, 2.16kg) between 0.1~1g / 10min), 15 parts magnesium hydroxide (low smoke halogen-free flame retardant, particle size 2~5um), 3 parts antimony trioxide (synergistic flame retardant), 4 parts benzidine orange pigment (pigment orange 34, lightfastness grade I), 0.3 parts antioxidant 1010 (main antioxidant). The ingredients include: 0.05 parts antioxidant 168 (co-antioxidant), 1 part ultraviolet absorber (UV-327, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), 1.7 parts light quencher (UV-2002, bis(3,5-di-tert-butyl-4-hydroxybenzyl phosphate monoethyl ester) nickel), and 0.3 parts light stabilizer (GW-540, tris(1,2,2,6,6-pentamethyl-4-piperidinyl) phosphate).

[0077] The outer sheath of the butterfly-shaped optical cable in Example 4 is prepared by a double-layer co-extrusion process, which, together with a mold, enables the first and second outer sheaths to be extruded and formed simultaneously.

[0078] The butterfly-shaped optical cable of Example 4, after undergoing a 2000-hour accelerated aging test under UL 1581 standard, retained 62% of its elongation at break and 58% of its tensile strength. Under GB / T 7921—2008 standard, the color difference value ΔE*ab was 8.6, indicating that the optical cable faded before and after the accelerated aging test. Under YD / T1997.1-2022 standard, the tear strength was 4N in the separability test.

[0079] Comparative Example 1 Comparative Example 1 of this application provides a butterfly-shaped optical cable, similar to Example 4, except that it does not have a second outer sheath.

[0080] For the butterfly-shaped optical cable in Comparative Example 1, after 2000 hours of accelerated aging under xenon lamp testing according to UL 1581 standard, the retention rate of mechanical properties showed a 46% retention rate of elongation at break and a 37% retention rate of tensile strength. This did not meet the standard requirement of >80% retention rate of mechanical properties after 720 hours of accelerated aging under xenon lamp testing, indicating poor weather resistance. Color difference testing under GB / T 7921—2008 standard showed a color difference value ΔE*ab of 8.6, indicating significant fading before and after the accelerated aging test. Separability testing under YD / T1997.1-2022 standard showed a tear strength of 3.8N. Flame retardancy testing under GB / T 18380.12 standard failed the single-strand vertical burning test.

[0081] Comparative Example 2 Comparative Example 2 of this application provides a butterfly-shaped optical cable, which is similar to Example 4, except that it does not contain a second outer sheath, and the raw material composition of the first outer sheath does not contain ultraviolet absorbers, light quenchers and light stabilizers.

[0082] Comparative Example 2's butterfly-shaped optical cable, after 2000 hours of accelerated aging under UL 1581 standard, showed a mechanical property retention rate of 18% for elongation at break and 24% for tensile strength. This did not meet the standard requirement of >80% mechanical property retention after 720 hours of accelerated aging under xenon lamp, indicating poor weather resistance. Color difference testing under GB / T 7921—2008 standard showed a value of ΔE*ab of 11, indicating significant fading before and after the accelerated aging test. Separability testing under YD / T 1997.1-2022 standard showed a tear strength of 3.8N. Flame retardancy testing under GB / T 18380.12 standard failed the single-strand vertical burning test.

[0083] In summary, by adding a black second outer sheath to the recessed area of ​​the first outer sheath, which is colored, the UV radiation resistance of the recessed area is improved, the weather resistance of the butterfly optical cable is enhanced, its service life is increased, and the failure rate of the recessed area is reduced.

[0084] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0085] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0086] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A butterfly-shaped optical cable, characterized in that, It includes an optical unit and an outer sheath surrounding the optical unit, wherein the outer sheath has a recess in the middle, wherein: The outer sheath includes a first outer sheath that is colored and a second outer sheath that is black; The second outer protective layer is disposed on the surface of the first outer protective layer in the recessed region.

2. The butterfly-shaped optical cable as described in claim 1, characterized in that, The materials of the first outer protective layer include: resin, flame retardant, colorant, antioxidant, ultraviolet absorber, light quencher and light stabilizer.

3. The butterfly-shaped optical cable as described in claim 2, characterized in that, By weight, the material of the first outer protective layer includes 90-110 parts of resin, 20-35 parts of flame retardant, 0.01-3 parts of colorant, 0.5-2.5 parts of antioxidant, 2-4 parts of ultraviolet absorber, 0.1-2 parts of light quencher and 0.5-2.0 parts of light stabilizer.

4. The butterfly-shaped optical cable as described in claim 2, characterized in that, The resin has a melt index of 0.1~1 g / 10 min at 190°C.

5. The butterfly-shaped optical cable as described in claim 2, characterized in that, The lightfastness rating of the colorant is Class I.

6. The butterfly-shaped optical cable as described in claim 2, characterized in that: The resin includes at least one of polyethylene and ethylene-vinyl acetate copolymer; The flame retardant includes at least one of magnesium hydroxide, aluminum hydroxide, antimony trioxide, and molybdenum trioxide; The colorant includes at least one of titanium dioxide, carbon black, pigment orange 34, and pigment green 7; The antioxidants include at least one of antioxidant 1010, antioxidant 300, antioxidant 168, and antioxidant DLTP; The ultraviolet absorber includes at least one of UV-327 and UV-531; The light quenching agent includes at least one of UV-2002 and UV-1084; The light stabilizer includes at least one of GW-540 and LA-57.

7. The butterfly-shaped optical cable as described in claim 1, characterized in that: The thickness of the first outer sheath is 0.3mm to 2.5mm; and / or, The thickness of the second outer protective layer is 0.2mm to 0.8mm.

8. The butterfly-shaped optical cable as described in claim 1, characterized in that, The mechanical properties of the butterfly-shaped optical cable are retained at a rate greater than 80%.

9. The butterfly-shaped optical cable as described in claim 1, characterized in that, The color difference value ΔE*ab of the butterfly-shaped optical cable is ≤6.

10. The butterfly-shaped optical cable as described in claim 1, characterized in that, The tearing force of the butterfly-shaped optical cable is less than 15N.

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