A capacity expansion type butterfly cable and preparation method thereof

Abstract

The present invention discloses an expandable butterfly cable and a preparation method thereof, wherein the expandable butterfly cable comprises an outer sheath layer, a zinc coating, a steel belt longitudinal sheath, a heat insulation layer, an inner sheath layer, an aluminum belt longitudinal sheath, a suspension wire sheath layer and a cable core which are sequentially arranged from the outside to the inside, and the cable core comprises a plurality of sub-butterfly cable structures and a central reinforcement member. The present invention evenly arranges a plurality of sub-butterfly cable structures around the central reinforcement member, which is helpful to expand the transmission capacity of the butterfly cable, and by arranging reinforcement members on the periphery of the central reinforcement member and embedding the reinforcement members in the suspension wire sheath layer and making them slightly protrude from the suspension wire sheath layer, not only can the mechanical properties of the butterfly cable be enhanced, but also the separation of the butterfly cable can be made faster; an inner sheath layer and a heat insulation layer are arranged between the aluminum belt longitudinal sheath and the steel belt longitudinal sheath, which is helpful to improve the flame retardant property, anti-aging property and heat resistance function of the butterfly cable, and can prevent the occurrence of electrochemical reaction between the steel belt and the aluminum belt; a zinc coating is applied to the outside of the steel belt longitudinal sheath, which is helpful to enhance the corrosion resistance, mechanical property and environmental property of the butterfly cable.

Description

Technical Field

[0001] The invention belongs to the technical field of optical cables, and in particular relates to an expanded-capacity butterfly cable and a preparation method thereof. Background Art

[0002] At present, traditional communication services have been gradually upgraded, from image, video transmission, and network communication to higher-end services such as VR and smart home, which has put forward higher and faster requirements for network transmission performance. As a type of optical cable for communication, the transmission capacity of butterfly cable (hereinafter referred to as butterfly cable) is extremely important in intelligence and data centers. However, the existing butterfly cable has a single structure, a small number of cores, and a small transmission capacity, which makes the network unable to support existing user needs. In addition, the butterfly cable is easily corroded by acid rain, sunlight, etc., and has poor mechanical properties during laying and use, and is easily damaged, affecting normal use.

[0003] Therefore, developing a high-capacity, corrosion-resistant, enhanced butterfly cable plays a vital role in high-performance network communications. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the object of the present invention is to provide a capacity-expandable butterfly cable and a preparation method thereof.

[0005] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0006] An expandable butterfly cable comprises an outer sheath layer, a zinc coating, a steel belt longitudinal sheath, a heat insulation layer, an inner sheath layer, an aluminum belt longitudinal sheath, a suspension wire sheath layer and a cable core which are arranged in sequence from outside to inside. The cable core comprises a plurality of sub-butterfly cable structures and a central reinforcement member, and the plurality of sub-butterfly cable structures are arranged around the periphery of the central reinforcement member.

[0007] Furthermore, each sub-butterfly cable structure includes an optical unit, a reinforcement member, a sub-butterfly cable sheath, a reinforcement member, a suspension wire sheath and a sling. The optical unit is arranged at a central position of the sub-butterfly cable structure, and reinforcement members are arranged on opposite sides of the optical unit. The sub-butterfly cable sheath is extruded on the outside of the optical unit and the reinforcement member, and reinforcement members are arranged on opposite sides of the outside of the sub-butterfly cable sheath. The reinforcement member is extruded on the outside of the suspension wire sheath and is connected to the sub-butterfly cable sheath through a sling.

[0008] Furthermore, there are two reinforcement members symmetrically arranged on opposite sides of the optical unit, and there are two reinforcement members symmetrically arranged on opposite sides of the sub-butterfly cable sheath. The outside of each reinforcement member is extruded with a suspension wire sheath, and the reinforcement member containing the suspension wire sheath is connected to the sub-butterfly cable sheath through a suspension belt.

[0009] Furthermore, the other two opposite sides of the sub-butterfly cable sheath are symmetrically provided with notches.

[0010] Furthermore, a central reinforcement member is provided at the central position of the cable core, and a plurality of sub-butterfly cable structures are evenly arranged around the periphery of the central reinforcement member. One of the reinforcement members containing the suspension wire sheath in each sub-butterfly cable structure is in contact with the central reinforcement member, and another reinforcement member containing the suspension wire sheath is embedded in the suspension wire sheath layer and slightly protrudes from the suspension wire sheath layer.

[0011] Furthermore, the sheath material of the inner sheath layer comprises, by weight: 90 to 98 parts of polyethylene, 1.5 to 5 parts of silanol, 0.05 to 0.12 parts of dicumyl peroxide, and 0.5 to 8 parts of silanol condensation catalyst;

[0012] Under the action of silanol condensation catalyst, diisopropylbenzene peroxide can induce polyethylene to generate unsaturated vinyl groups, and can induce the hydrolysis of unsaturated vinyl groups and silanol to obtain silane containing alkoxy functional groups, which is grafted onto the main chain of polyethylene.

[0013] Furthermore, the thermal insulation layer is made of nano-kaolinite, and the hydroxyl Al-OH connected to aluminum in the nano-kaolinite can undergo condensation reaction with the hydroxyl Si-OH of silanol in the inner sheath layer, thereby generating a silicate with a three-dimensional network structure, thereby preventing electrochemical reaction between the steel strip in the longitudinal cladding of the steel strip and the aluminum strip in the longitudinal cladding of the aluminum strip.

[0014] The present invention also discloses a method for preparing a capacity-expanding butterfly cable, comprising the following steps:

[0015] 1) Prepare the sub-butterfly cable structure;

[0016] 2) Lay out the central reinforcement member and several sub-butterfly cable structures respectively, evenly arrange the several sub-butterfly cable structures around the periphery of the central reinforcement member, enter the extruder and extrude the outer part to form a suspension wire sheath layer;

[0017] 3) Then, an aluminum tape is longitudinally wrapped on the outside of the suspension wire sheath layer to form an aluminum tape longitudinal wrapping layer;

[0018] 4) Then, an inner sheath layer is formed by extruding the outer surface of the longitudinal cladding layer of the aluminum strip through an extruder;

[0019] 5) forming a heat insulation layer outside the inner sheath layer;

[0020] 6) Then, a steel belt longitudinal wrap is used on the outside of the thermal insulation layer to form a steel belt longitudinal wrapping layer;

[0021] 7) Then forming a zinc coating on the outside of the longitudinal cladding of the steel strip;

[0022] 8) Then extrude the zinc coating to form an outer sheath layer.

[0023] Furthermore, in step 1), the step of preparing the sub-butterfly cable structure includes:

[0024] The optical unit, reinforcing member and strengthening member are laid out separately and enter the extrusion die of the extruder at the same time to extrude the sub-butterfly cable sheath, suspension wire sheath and suspension belt, and then cooled through a cold water tank.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The present invention discloses an expandable butterfly cable and a preparation method thereof. The cable core comprises a plurality of sub-butterfly cable structures and a central reinforcement member. The plurality of sub-butterfly cable structures are evenly arranged around the periphery of the central reinforcement member, which is helpful to expand the transmission capacity of the butterfly cable. By arranging a circle of reinforcement members around the periphery of the central reinforcement member, and evenly embedding the reinforcement members in the suspension wire sheath layer and making them slightly protrude from the suspension wire sheath layer, not only the overall mechanical properties of the butterfly cable can be enhanced, but also the separation of the butterfly cable can be simpler and faster, and it is convenient for laying, and the phenomenon of large optical fiber attenuation that may be caused by pulling during the wiring process of the butterfly cable can be solved;

[0027] 2) The present invention discloses an expandable butterfly cable and a preparation method thereof. The aluminum tape longitudinal sheath adopts an aluminum tape, which has good moisture-proof performance and can effectively prevent moisture from penetrating into the optical fiber part, thereby ensuring communication safety. The steel tape longitudinal sheath adopts a steel tape, which has high strength and hardness, can improve the mechanical properties of the butterfly cable, effectively protect the butterfly cable from being squeezed, stretched and impacted by external forces during the laying process, and can prevent rodents such as rats from gnawing. An inner sheath layer and a heat insulation layer are arranged between the aluminum tape longitudinal sheath and the steel tape longitudinal sheath, which helps to improve the flame retardant and heat insulation performance of the butterfly cable. The main raw material of the heat insulation layer is nano-kaolinite, which not only has excellent aging resistance and heat resistance, but also helps to improve the aging resistance and heat resistance of the butterfly cable. In addition, the hydroxyl group (Al-OH) connected to aluminum in its structure can undergo a condensation reaction with the hydroxyl group (Si-OH) of silanol, thereby generating a silicate with a three-dimensional network structure. The silicate can prevent the occurrence of electrochemical reaction between the steel tape and the aluminum tape, thereby extending the service life of the butterfly cable.

[0028] 3) The present invention discloses an expandable butterfly cable and a preparation method thereof. A zinc coating is coated on the outside of the longitudinal sheath of the steel belt. The zinc coating has certain corrosion resistance and self-healing properties, which helps to enhance the corrosion resistance, mechanical properties and environmental performance of the butterfly cable. If the zinc coating is accidentally damaged by the environment during installation or use, the zinc element can react with carbon dioxide, water and oxygen in the environment to form an oxide layer again to protect the optical unit from corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the sub-butterfly cable structure of the present invention;

[0031] Figure 3 It is a schematic diagram of the front three-dimensional structure of the extrusion die of the present invention;

[0032] Figure 4 It is a schematic diagram of the back three-dimensional structure of the extrusion die of the present invention;

[0033] Figure 5 It is a schematic diagram of the three-dimensional structure of the male mold of the extrusion mold of the present invention;

[0034] Figure 6 It is a schematic diagram of the three-dimensional structure of the mother mold of the extrusion mold of the present invention;

[0035] Among them, 1. optical unit; 2. reinforcement; 3. sub-butterfly cable sheath; 4. reinforcement; 5. suspension wire sheath; 6. suspension belt; 7-sub-butterfly cable structure; 8. central reinforcement; 9. suspension wire sheath layer; 10. aluminum belt longitudinal sheath; 11. inner sheath layer; 12. thermal insulation layer; 13. steel belt longitudinal sheath; 14. zinc coating; 15. outer sheath layer; 16. extrusion mold; 17. male mold; 17-1. conical part; 17-2 fixing column; 17-3. fixing groove; 18. female mold; 18-1. fixing hole; 18-2. conical cavity; 19-reinforcement mold hole; 20. optical unit mold hole; 21. reinforcement mold hole; 22. sub-butterfly cable mold hole. DETAILED DESCRIPTION

[0036] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0037] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0038] like Figure 1-6 As shown, the present invention discloses an expandable butterfly cable, comprising an outer sheath layer 15, a zinc coating 14, a steel belt longitudinal sheath 13, an insulation layer 12, an inner sheath layer 11, an aluminum belt longitudinal sheath 10, a suspension wire sheath layer 9 and a cable core, which are arranged in sequence from the outside to the inside, wherein the cable core comprises a plurality of sub-butterfly cable structures 7 and a central reinforcement member 8, the central reinforcement member 8 is arranged at the central position of the cable core, and a plurality of sub-butterfly cable structures 7 are evenly arranged around the periphery of the central reinforcement member 8, so as to expand the transmission capacity of the butterfly cable, and the arrangement quantity of the sub-butterfly cable structures 7 can be adjusted according to actual needs.

[0039] Each sub-butterfly cable structure 7 includes an optical unit 1, a reinforcement member 2, a sub-butterfly cable sheath 3, a reinforcement member 4, a suspension wire sheath 5 and a sling 6, wherein the optical unit 1 is arranged at the central position of the sub-butterfly cable structure 7, and the reinforcement members 2 are symmetrically arranged on the opposite sides of the optical unit 1. There are two reinforcement members 2, and the sub-butterfly cable sheath 3 is extruded on the outside of the optical unit 1 and the reinforcement member 2. There are two reinforcement members 4 and they are symmetrically arranged on the opposite sides of the sub-butterfly cable sheath 3. The outside of each reinforcement member 4 is extruded with a suspension wire sheath 5, and the reinforcement member 4 containing the suspension wire sheath 5 is connected to the sub-butterfly cable sheath 3 through the sling 6. The other two opposite sides of the sub-butterfly cable sheath 3 are symmetrically provided with notches to facilitate the separation of the optical unit 1 during the butterfly cable laying process.

[0040] The preparation method of the sub-butterfly cable structure 7 is based on conventional one-step extrusion molding. First, the reinforcing member 2, the optical unit 1, and the reinforcing member 4 are laid out in sequence, and then simultaneously enter the extrusion die 16 of the extruder. Figure 3-6 As shown, they are formed in an extruder to obtain a sub-butterfly cable sheath 3, a suspension wire sheath 5 and a suspension belt 6, and then cooled in a cold water tank to finally form the desired sub-butterfly cable structure 7.

[0041] The extrusion die 16 comprises a male die 17 and a female die 18 which match each other, and is an improvement made on the existing die.

[0042] A tapered portion 17-1 is provided at the central position of one side of the male mold 17 facing the female mold 18, and a reinforcement mold hole 19, an optical unit mold hole 20 and a reinforcement mold hole 21 are provided at the central position of the tapered portion 17-1, which are respectively matched with the reinforcement 4, the optical unit 1 and the reinforcement 2. During extrusion, the reinforcement mold hole 19, the optical unit mold hole 20 and the reinforcement mold hole 21 are respectively used to pass through the reinforcement 4, the optical unit 1 and the reinforcement 2, and their size, position and quantity are consistent with those of the reinforcement 4, the optical unit 1 and the reinforcement 2.

[0043] The male mold 17 is symmetrically provided with fixing columns 17-2 on two opposite sides of a side facing the female mold 18, and the female mold 18 is symmetrically provided with fixing holes 18-1 on two opposite sides of a side facing the male mold 17. Each fixing column 17-2 is matched with a fixing hole 18-1, and the sizes, positions and quantities of the two are consistent. The connection between the male mold 17 and the female mold 18 is achieved by inserting the fixing columns 17-2 into the matching fixing holes 18-1.

[0044] The male mold 17 is symmetrically provided with fixing grooves 17 - 3 on two opposite sides of the edge thereof for connecting with other equipment.

[0045] The central position of one side of the female mold 18 facing the male mold 17 is recessed toward the female mold 18 to form a conical cavity 18-2 matching the conical portion 17-1 for accommodating the conical portion 17-1. The size of the conical cavity 18-2 is larger than the conical portion 17-1. A sub-butterfly cable mold hole 22 for forming the sub-butterfly cable structure 7 is provided at the central position of the conical cavity 18-2. After the male mold 17 and the female mold 18 are assembled, the conical portion 17-1 is placed in the conical cavity 18-2 with a certain space left therebetween. The sheath material in the space is extruded from the sub-butterfly cable mold hole 22 during extrusion, and becomes the sub-butterfly cable structure 7 after cooling. The shape, size and position of the sub-butterfly cable mold hole 22 are consistent with the sub-butterfly cable structure 7.

[0046] The types of optical unit 1 include G657A2, G652D and other conventional optical fibers that can be used for signal transmission. The structure can be a single or multiple optical fibers, optical fiber ribbons, optical fiber bundles, etc. The quantity can be adjusted at any time according to actual needs and production conditions, and can be purchased on the market.

[0047] The reinforcement member 2 and the reinforcement member 4 are both made of materials with certain tensile properties, including but not limited to steel wire, FRP, copper wire, etc., which can enhance the mechanical properties of the butterfly cable.

[0048] The sheath 3 of the butterfly cable, the sheath 5 of the suspension wire and the suspension belt 6 can be made of conventional sheath materials, such as low-smoke zero-halogen material LSZH.

[0049] The central reinforcement member 8 is a steel wire or FRP material, and is used to enhance the mechanical properties of the butterfly cable.

[0050] A plurality of reinforcing members 4 in the sub-butterfly cable structure 7 are uniformly embedded in the sheath layer 9 of the suspension wire, and the reinforcing members 4 slightly protrude from the sheath layer 9 of the suspension wire, so as to facilitate workers to identify and peel them later.

[0051] The aluminum tape longitudinal cladding 10 is made of aluminum tape, which has good moisture-proof performance and can effectively prevent moisture from penetrating into the optical fiber part, thereby ensuring communication safety.

[0052] The sheath material of the inner sheath layer 11 includes, by weight: 90-98 parts of polyethylene, 1.5-5 parts of silanol, 0.05-0.12 parts of diisopropylbenzene peroxide, and 0.5-8 parts of silanol condensation catalyst. Diisopropylbenzene peroxide has good flame retardant properties, which helps to improve the flame retardant function of the butterfly cable, and can be used as an initiator to initiate the grafting of silane containing alkoxy functional groups obtained by the hydrolysis of unsaturated vinyl (formed by diisopropylbenzene peroxide at high temperature) and silanol onto the main chain of polyethylene, thereby improving the high temperature resistance and corrosion resistance of polyethylene.

[0053] The heat-insulating layer 12 is made of nano-kaolinite, which not only has excellent anti-aging and heat resistance, and helps to improve the anti-aging and heat resistance of the butterfly cable, but also the hydroxyl group (Al-OH) connected to aluminum in its structure can undergo a condensation reaction with the hydroxyl group (Si-OH) of silanol in the inner sheath layer 11, thereby generating a silicate with a three-dimensional network structure, and the silicate can prevent the electrochemical reaction between the steel belt and the aluminum belt.

[0054] The steel belt longitudinal sheath 13 is made of steel belt, which has high strength and hardness, can improve the mechanical properties of the butterfly cable, effectively protect the butterfly cable from external forces such as squeezing, stretching and impact during the laying process, and can prevent rodents such as rats from gnawing.

[0055] The self-repairing function of the zinc coating 14 on the surface of the steel strip originates from the oxidizability of the zinc powder. During installation or use, when the zinc coating 14 is damaged, the zinc element will react again with water, oxygen and carbon dioxide in the atmosphere to form an oxide layer at the damaged location, thus having a certain self-repairing and self-healing function.

[0056] The outer sheath layer 15 is made of conventional flame retardant sheath material, which can be purchased on the market according to actual needs.

[0057] In each sheath of the present invention, appropriate amounts of commonly used functional additives such as plasticizers and ultraviolet absorbers may be added or not added according to actual needs.

[0058] The present invention also discloses a method for preparing a capacity-expanding butterfly cable, comprising the following steps:

[0059] 1) preparing a sub-butterfly cable structure 7;

[0060] 2) The central reinforcement member 8 and a plurality of sub-butterfly cable structures 7 are laid out respectively, and the plurality of sub-butterfly cable structures 7 are evenly arranged around the central reinforcement member 8, and enter the extruder and are extruded externally to form a suspension wire sheath layer 9, and then are cooled in turn through a hot water tank and a cold water tank, the temperature of the hot water tank is 35-65°C, and the temperature of the cold water tank is 10-30°C;

[0061] 3) Aluminum tape is then used to longitudinally wrap the outer portion of the suspension wire sheath layer 9 to form an aluminum tape longitudinal wrapping layer 10;

[0062] 4) Then, the inner sheath layer 11 is formed by extruding the outer surface of the aluminum strip longitudinal cladding layer 10 through a PE extruder, and then cooled in a hot water tank and a cold water tank in sequence. The temperature of the hot water tank is 35-65°C, and the temperature of the cold water tank is 10-30°C.

[0063] 5) forming a heat insulation layer 12 outside the inner sheath layer 11;

[0064] 6) Then, a steel strip longitudinally wraps the outside of the heat insulation layer 12 to form a steel strip longitudinal wrapping layer 13;

[0065] 7) Plasma spraying is then used on the outside of the longitudinal cladding 13 of the steel strip, using a zinc target, and high-energy ions of plasma are used to bombard the surface of the steel strip to achieve immersion, thereby forming a zinc coating 14. The zinc coating 14 can not only enhance the corrosion resistance of the butterfly cable, but also enable the butterfly cable to have a certain self-repair and self-healing function, further protecting the optical unit 1 from environmental erosion and damage;

[0066] 8) Extruding the zinc coating 14 to form an outer sheath layer 15, the zinc coating 14 is then cooled in a hot water tank and a cold water tank in turn. The temperature of the hot water tank is 35-65°C, and the temperature of the cold water tank is 10-30°C.

[0067] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0068] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A capacity expansion butterfly cable, characterized in that: It includes an outer sheath layer, a zinc coating, a steel belt longitudinal sheath, a heat insulation layer, an inner sheath layer, an aluminum belt longitudinal sheath, a suspension wire sheath layer and a cable core which are sequentially arranged from the outside to the inside. The cable core includes a plurality of sub-butterfly cable structures and a central reinforcement member. The plurality of sub-butterfly cable structures are arranged around the periphery of the central reinforcement member. The heat-insulating layer is made of nano-kaolinite. The hydroxyl group Al-OH connected to aluminum in the nano-kaolinite can undergo a condensation reaction with the hydroxyl group Si-OH of the silanol in the inner sheath layer, thereby generating a silicate with a three-dimensional network structure, thereby preventing an electrochemical reaction from occurring between the steel strip in the longitudinal cladding of the steel strip and the aluminum strip in the longitudinal cladding of the aluminum strip.

2. The expandable butterfly cable according to claim 1, characterized in that: Each sub-butterfly cable structure includes an optical unit, a reinforcement member, a sub-butterfly cable sheath, a reinforcement member, a suspension wire sheath and a sling. The optical unit is arranged at the central position of the sub-butterfly cable structure, and reinforcement members are arranged on opposite sides of the optical unit. The sub-butterfly cable sheath is extruded on the outside of the optical unit and the reinforcement member, and reinforcement members are arranged on opposite sides of the outside of the sub-butterfly cable sheath. The reinforcement member is extruded on the outside of the suspension wire sheath and is connected to the sub-butterfly cable sheath through a sling.

3. The expandable butterfly cable according to claim 2, characterized in that: There are two reinforcement members symmetrically arranged on the opposite sides of the optical unit, and there are two reinforcement members symmetrically arranged on the opposite sides of the sub-butterfly cable sheath. The outside of each reinforcement member is extruded with a suspension wire sheath, and the reinforcement member containing the suspension wire sheath is connected to the sub-butterfly cable sheath through a suspension belt.

4. The expandable butterfly cable according to claim 3, characterized in that: The other two opposite sides of the sub-butterfly cable sheath are symmetrically provided with notches.

5. The expandable butterfly cable according to claim 3, characterized in that: A central reinforcement member is arranged at the central position of the cable core, and a plurality of sub-butterfly cable structures are evenly arranged around the periphery of the central reinforcement member. One of the reinforcement members containing the suspension wire sheath in each sub-butterfly cable structure is in contact with the central reinforcement member, and another reinforcement member containing the suspension wire sheath is embedded in the suspension wire sheath layer and slightly protrudes from the suspension wire sheath layer.

6. The expandable butterfly cable according to claim 1, characterized in that: In terms of weight, the sheath material of the inner sheath layer includes: 90-98 parts of polyethylene, 1.5-5 parts of silanol, 0.05-0.12 parts of dicumyl peroxide, and 0.5-8 parts of silanol condensation catalyst.

7. A method for preparing a capacity-expandable butterfly cable according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Prepare the sub-butterfly cable structure; 2) Lay out the central reinforcement member and several sub-butterfly cable structures respectively, evenly arrange the several sub-butterfly cable structures around the periphery of the central reinforcement member, enter the extruder and extrude the outer part to form a suspension wire sheath layer; 3) Then, an aluminum tape is longitudinally wrapped on the outside of the suspension wire sheath layer to form an aluminum tape longitudinal wrapping layer; 4) Then, an inner sheath layer is formed by extruding the outer surface of the longitudinal cladding layer of the aluminum strip through an extruder; 5) forming a heat insulation layer outside the inner sheath layer; 6) Then, a steel belt longitudinal wrap is used on the outside of the thermal insulation layer to form a steel belt longitudinal wrapping layer; 7) Then forming a zinc coating on the outside of the longitudinal cladding of the steel strip; 8) Then extrude the zinc coating to form an outer sheath layer.

8. The method for preparing a capacity-expandable butterfly cable according to claim 7, characterized in that: In step 1), the steps of preparing the sub-butterfly cable structure include: The optical unit, reinforcing member and strengthening member are laid out separately and enter the extrusion die of the extruder at the same time to extrude the sub-butterfly cable sheath, suspension wire sheath and suspension belt, and then cooled through a cold water tank.

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