A splitable cable sheath with a wearable sleeve and a preparation method thereof

Abstract

This invention relates to the field of wire and cable technology, specifically disclosing a composite sheath for cable that can be threaded through and split. The composite sheath, from the inside out, consists of a closed-cell foamed buffer layer, a flexible metal shielding layer, and a low-smoke halogen-free outer protective layer. It has an axially pre-compressed easy-tear cutting line (0.5-1mm wide, half the sheath wall thickness). The shielding layer, foaming layer, and outer protective layer are bonded together via heat sealing / co-extrusion, with an interlayer peel strength ≥2.0N / mm, and each layer is indestructible. The composite sheath length is customizable, with a maximum custom length of 3000 meters. The closed-cell foamed buffer layer has a cell density of 50-300 cells / cm³. 3 This invention combines shock absorption, heat insulation, and waterproofing functions. The flexible metal shielding layer (shielding attenuation ≥60dB) is interference-resistant and firmly bonded, while the low-smoke, halogen-free outer protective layer (oxygen index ≥35%) uses materials adapted to different scenarios. This invention solves the problems of existing composite sheaths being non-removable, easily peeling between layers, limited length, and single function. It is suitable for long-distance, multi-scenario cable protection, significantly extending cable lifespan.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, and in particular to a composite sheath for cables that can be threaded through and split open, and its preparation method. Background Technology

[0002] Optical and electrical cables are core carriers for power transmission and information communication. When laid indoors and outdoors in surface, concealed, pre-buried, or directly buried underground environments, as well as in special environments such as high-speed rail, ships, airports, and chemical plants, they are subject to long-term mechanical vibration, sudden temperature changes, moisture erosion, ultraviolet aging, electromagnetic interference, and chemical corrosion. This makes them prone to problems such as sheath cracking, signal attenuation, and conductor oxidation, leading to a decline in cable performance, a significant reduction in service life, and increased maintenance costs.

[0003] In the existing technology, there is no single general-purpose cable sheath. Cable protection mostly uses single-structure sheaths or traditional composite sheaths, which have many technical defects: Limited functionality and poor protection: For example, PVC sheaths only provide basic mechanical protection and lack shielding, shock absorption, and heat insulation functions; although armor layers provide shielding and mechanical protection, they have poor shock absorption and heat insulation, insufficient flexibility, and are heavy and inconvenient to install; ceramicized silicone rubber sheaths only focus on fire resistance and cannot meet the comprehensive protection needs of multiple environments (such as the medium-voltage fire-resistant cable of CN201210084122.4, which only focuses on fire resistance performance and lacks shock absorption and anti-aging design).

[0004] Fixed structure and low adaptability: Existing composite sheaths are mostly integrally formed with the cable body, forming a fixed structure that cannot be disassembled or dissected (such as high-frequency digital communication cables of CN205582567U and floating marine cables of CN218384544U). The size specifications are limited, making it impossible to flexibly adjust according to the on-site laying requirements. Furthermore, it is not possible to perform non-destructive performance upgrades on existing cables, requiring the entire cable to be replaced, resulting in resource waste and increased construction costs.

[0005] Poor interlayer adhesion leads to shortcomings in protection: Existing patented metal shielding layers mostly use wrapping or braiding processes, which only physically adhere to adjacent layers without a dedicated adhesive design. This makes them prone to interlayer peeling (e.g., the gigabit triple-network converged coaxial cable of CN202534435U has an aluminum tube shielding layer without an adhesive structure; the automotive Ethernet cable of CN211555575U has a carbon nanotube shielding layer that is only physically covered). Moisture can easily penetrate through the gaps between layers, affecting the protective effect and service life.

[0006] Limited material selection and insufficient adaptability to different scenarios: Some composite sheaths have shortcomings in environmental protection or performance of their outer protective materials. For example, CN223526914U uses ordinary vinyl chloride sheaths, which release toxic gases when burned; CN205582567U's polyolefin sheaths lack elasticity and do not provide material selection options suitable for multiple scenarios, failing to meet the differentiated needs of different scenarios such as outdoor high and low temperatures, high frequency bending, and conventional indoor environments.

[0007] Limited length specifications pose potential risks for long-distance cabling: Existing sheaths are mostly designed for short sections (within 100 meters), and long-distance cabling requires multiple splicing. The splicing points become weak points in the protection, which are prone to problems such as water ingress and corrosion. Moreover, the construction efficiency is low (for example, patents such as CN202534435U and CN211555575U do not mention customized solutions for long distances).

[0008] Inadequate foam layer design: Existing patents often feature open-cell foam layers or lack clearly defined performance parameters (such as the nitrogen-based physical foam layer in CN202534435U, which does not specify waterproofing and shock absorption parameters), resulting in limited waterproofing, moisture-proofing, shock absorption, and heat insulation effects, and failing to achieve multiple functions in synergy.

[0009] In summary, there is an urgent need for a composite cable sheath that integrates functions, allows for customizable structure, ensures strong interlayer adhesion, adapts to various material scenarios, and offers flexible length adjustment. This sheath should provide multiple protective functions, including shock absorption, heat insulation, waterproofing, anti-aging, electromagnetic shielding, and flame retardancy, without damaging the cable itself. It should also be compatible with the protection needs of both new and old cables, addressing the technical problems of existing technologies such as limited functionality, low adaptability, easy peeling between layers, and limitations on long-distance cabling. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a composite sheath for cables that can be inserted and split open, and a method for preparing the same. This sheath integrates multiple protective functions, has a customizable structure, flexible installation, and strong interlayer bonding, making it suitable for various types of cables, both new and old, as well as long-distance scenarios. The invention also provides a method for preparing the composite sheath and cables using this sheath. The preparation process is highly standardized, and the bonding strength of each layer is controllable, which can significantly improve the environmental adaptability and service life of the cable, meeting the protection needs of multiple scenarios.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A composite sheath for cable that can be threaded and split includes: a cable (10), a closed-cell foam buffer layer (20) fitted on the cable (10), a flexible metal shield layer (30) fitted on the closed-cell foam buffer layer (20), a low-smoke halogen-free outer protective layer (40) fitted on the flexible metal shield layer (30), and a pre-compressed easy-tear cutting line (50) formed on the low-smoke halogen-free outer protective layer (40), the flexible metal shield layer (30), and the closed-cell foam buffer layer (20).

[0012] Preferably, the closed-cell foamed buffer layer (20) is made of ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, and rubber-plastic foam material, with a cell density of 50-300 cells / cm³. 3 Water absorption rate ≤0.5%, compression resilience ≥80%, thermal conductivity ≤0.04W / (m・K), temperature resistance range -40℃~125℃, wall thickness 2-30mm, tightly wrapped around the outer surface of the cable body; the rubber and plastic foam material can be replaced by polyurethane foam material.

[0013] Preferably, the flexible metal shielding layer (30) is a double-sided coated structure of aluminum foil, copper foil or aluminum-plastic composite foil, the coating material is ethylene-acrylic acid copolymer (EAA) or polyethylene (PE), and it is tightly bonded to the closed-cell foamed buffer layer by heat sealing process. The heat sealing temperature is 120-150℃, the heat sealing pressure is 0.3-0.5MPa, the shielding attenuation in the 30MHz-3GHz frequency band is ≥60dB, the metal foil thickness is 0.03-0.08mm, the double-sided coated thickness is 0.02-0.05mm, and the total wall thickness of the shielding layer is 0.1-0.5mm.

[0014] Preferably, the low-smoke halogen-free outer protective layer (40) is made of low-smoke halogen-free modified PE material, POE material or low-smoke halogen-free PVC material, and is bonded to the flexible metal shielding layer by co-extrusion heat sealing process. The interlayer peel strength is ≥2.0N / mm, so that each layer cannot be peeled off. The oxygen index is ≥35%, the UV resistance level is UV400, and the acid and alkali resistance and salt spray corrosion resistance meet the GB / T2423.17 standard. The wall thickness is 0.5-3mm.

[0015] Preferably, the pre-compressed easy-tear cutting line (50) has a width of 0.5-1mm and a depth of 1 / 2 of the composite sheath wall thickness. After cutting, it can be resealed by buckle, self-adhesive tape, glue or heat shrink tape. After resealing, the interlayer peel strength is ≥1.0N / mm.

[0016] A method for preparing a composite sheath for cables that can be inserted and split, including a process for preparing a finished sheath, with the specific steps as follows: Step S1. Preparation of closed-cell foamed buffer layer (20): Extrude ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, rubber-plastic foam material or polyurethane foam material according to the preset inner diameter (5-50mm) and wall thickness (2-30mm), and control the cell density to 50-300 cells / cm. 3 After cooling and setting, cut to the preset length (1-3000 meters) to ensure water absorption rate ≤0.5%; Step S2. Flexible metal shielding layer (30) composite: Aluminum foil, copper foil or aluminum-plastic composite foil is coated on both sides (coating material EAA or PE, thickness 0.02-0.05mm / side), and bonded to the outer surface of closed-cell foam buffer layer by hot air heat sealing or roll heat sealing process. The heat sealing temperature is controlled at 120-150℃, the heat sealing pressure is 0.3-0.5MPa, the heat sealing speed is 2-3m / min, and the shielding attenuation is ≥60dB. Step S3. Low smoke halogen-free outer protective layer (40) co-extrusion: Select low smoke halogen-free modified PE material, POE material or low smoke halogen-free PVC material according to the application scenario, and co-extrude the outer protective layer on the outer surface of the flexible metal shielding layer. Control the extrusion temperature to 140-180℃ (PE material 160-180℃, POE material 150-170℃, PVC material 140-160℃), wall thickness 0.5-3mm, and ensure that the interlayer peel strength after bonding with the shielding layer is ≥2.0N / mm; Step S4. Pre-pressed easy-tear cutting line processing: Process the pre-pressed easy-tear cutting line along the axial direction of the composite sheath, controlling the width to 0.5-1mm and the depth to 1 / 2 of the sheath wall thickness, to ensure easy cutting and structural integrity before processing; Step S5. Finished Product Inspection and Packaging: Test the composite sheath for interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance. Set test marks every 500 meters. The 3000-meter long sheath needs to be continuously tested for jointlessness. After passing the test, package according to the length requirements. Long-distance products are wound into a special large reel (1.5-2.0 meters in diameter).

[0017] A method for preparing a composite sheath for cable that can be inserted and split, including a co-extrusion integral molding process for preparing the sheath, with the specific steps as follows: Step S01. Cable body (10) extrusion: Extrude the cable body according to the standard process, keep the surface clean and free of oil, and control the gap between the outer diameter and the inner diameter of the composite sheath to be 0.1-0.3mm; Step S02. Extrusion of closed-cell foam buffer layer (20): Extrude the closed-cell foam buffer layer directly onto the outer surface of the cable body, control the extrusion temperature and speed to ensure seamless interlayer bonding, wall thickness 2-30mm, and cell density 50-300 cells / cm². 3 ; Step S03. Simultaneous heat sealing of flexible metal shielding layer (30): While the closed-cell foamed buffer layer is being extruded, the double-sided coated metal foil is laminated onto the outer surface of the foamed layer through a continuous heat sealing process. The heat sealing temperature is controlled at 120-150℃ and the pressure is 0.3-0.5MPa to ensure that the shielding attenuation is ≥60dB. Step S04. Low smoke halogen-free outer protective layer (40) co-extrusion and heat sealing: co-extrude the outer protective layer on the outer surface of the flexible metal shielding layer, and simultaneously achieve tight sealing of each layer with the cable body through the ferrule heat sealing process. Control the heat sealing temperature to 130-160℃, the pressure to 0.4-0.6MPa, and the interlayer peel strength to ≥2.0N / mm. Step S05. Pre-pressed easy-tear cutting line (50) processing: Process the pre-pressed easy-tear cutting line along the axial direction of the sheath, control the width to 0.5-1mm, and the depth to 1 / 2 of the sheath wall thickness, to ensure easy cutting and structural integrity when not processed; Step S06. Finished product cutting and inspection: Cut the cable to the preset length (1-3000 meters) and conduct overall performance testing, including interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance. The finished product is obtained after passing the test.

[0018] Compared with the prior art, this application has the following beneficial effects: 1. This invention integrates multiple protective functions, significantly improving the protective effect. Through a three-layer synergistic structure of "closed-cell foam buffer layer + flexible metal shielding layer + low-smoke halogen-free outer protective layer," this invention simultaneously achieves multiple protective functions, including shock absorption, high-efficiency heat insulation, high shielding effectiveness, waterproofing, moisture resistance, UV aging resistance, flame retardancy, and chemical corrosion resistance. The closed-cell foam buffer layer has a water absorption rate ≤0.5%, effectively blocking moisture; a compression rebound rate ≥80%, absorbing mechanical vibrations of 5-50Hz; and a thermal conductivity ≤0.04W / (m・K), achieving high-efficiency heat insulation. The flexible metal shielding layer exhibits shielding attenuation ≥60dB in the 30MHz-3GHz frequency band, effectively resisting electromagnetic interference. The outer protective layer has an oxygen index ≥35%, meeting Class A flame retardant requirements, and a UV resistance rating of UV400, showing no significant aging after 5 years of outdoor use. The synergistic effect of each layer extends the cable's service life by 3-5 times.

[0019] 2. Flexible structural design with strong adaptability and versatility: This invention innovatively features a pre-compressed easy-tear cutting line, allowing direct cutting and insertion onto existing cables without damaging the cable itself, achieving non-destructive performance upgrades for old cables. After cutting, it can be resealed, with an interlayer peel strength ≥1.0N / mm, without affecting the integrity of the sheath structure. Furthermore, the inner diameter, wall thickness, length, color, and materials of each layer of the composite sheath can be customized according to cable size and usage scenarios, adapting to various types of cables such as power, communication, and data cables with diameters from 5-50mm. It is suitable for various environments including indoor and outdoor use, underground burial, high-speed rail, ships, and airports, solving the technical problems of fixed structures and low adaptability in existing technologies.

[0020] 3. Strong interlayer adhesion and high reliability of protection: The flexible metal shielding layer adopts a "double-sided coating + heat sealing process," and the peel strength between the layer and the closed-cell foam buffer layer and the low-smoke halogen-free outer protective layer is ≥2.0N / mm, achieving an integrated effect of "each layer cannot be peeled off." This solves the defects of existing patented shielding layers that are only physically bonded and easily peeled off (such as the aluminum tube shielding layer of CN202534435U and the carbon nanotube shielding layer of CN211555575U). The integrated structure not only improves mechanical strength but also blocks the path of moisture intrusion from the interlayer gaps, further enhancing waterproof and moisture-proof performance and ensuring reliable protection in complex environments.

[0021] 4. Strong material adaptability to meet diverse needs: The low-smoke halogen-free outer protective layer offers three targeted material options, respectively adaptable to different scenarios such as outdoor high and low temperatures, high frequency bending, and conventional indoor use. This solves the problem of existing patents having a single outer layer material that cannot adapt to multiple scenarios (e.g., CN218384544U only uses UV-resistant polyethylene, which has insufficient elasticity; CN223526914U's vinyl chloride sheath has poor environmental performance). Among them, the high elasticity of POE material, combined with the flexible metal shielding layer, allows the sheath bending radius to be as small as 8 times the cable diameter, which is better than the 10-12 times requirement of existing patents, making it suitable for scenarios that require frequent bending, such as high-speed rail tracks and ship cabins.

[0022] 5. Excellent adaptability for long distances and improved construction efficiency: Supports customization from 1 to 3000 meters in length, and can provide continuous, seamless long-distance pre-made sheaths, avoiding weak points in splicing protection during long-distance cabling and improving protection consistency; long-distance sheaths are transported using large reels and unfolded on-site using a cable laying rack, with a sheathing speed of 5-10 meters / minute, and a 3000-meter long sheath can be sheathed in one go. Compared with traditional sheaths of 100 meters / segment, the construction efficiency is improved by 6 times, which is especially suitable for long-distance scenarios such as high-speed rail tracks, underground pipelines, and offshore wind power.

[0023] 6. Two manufacturing processes are available, with a high degree of standardization. This invention provides two manufacturing processes: sheathing and one-piece molding. The sheath prepared by the sheathing process can be quickly installed on site, and the construction steps are simple (cleaning - sheathing - sealing - resealing) without the need for professional equipment. The one-piece molding process is seamlessly integrated with the cable manufacturing process. It adopts co-extrusion ferrule heat sealing and shaping, and the bonding strength of each layer can be controlled to avoid interlayer delamination. The manufacturing process is standardized and can be mass-produced, reducing manufacturing costs.

[0024] Non-destructive protection saves resources and construction costs. The sheathing installation method does not require the replacement of the original cables and can directly upgrade the protection of the existing old cables, greatly reducing the material waste and construction costs of cable replacement. It is especially suitable for cable renovation in large-scale projects such as high-speed rail, airports, and underground pipelines, and has significant economic and environmental benefits. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0026] Figure 1 This is a schematic diagram of the structure of a composite sheath for a cable that can be inserted and cut open, as described in this invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] Unless otherwise defined, the technical or scientific terms used in this patent document shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this patent specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or its equivalents, and do not exclude other elements or objects. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. These terms are only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0030] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0031] like Figure 1 As shown, a composite sheath for a cable that can be threaded and split includes: a cable 10, a closed-cell foamed buffer layer 20 sleeved on the cable 10, a flexible metal shielding layer 30 sleeved on the closed-cell foamed buffer layer 20, a low-smoke halogen-free outer protective layer 40 sleeved on the flexible metal shielding layer 30, and pre-compressed easy-tear slitting lines 50 formed on the low-smoke halogen-free outer protective layer 40, the flexible metal shielding layer 30, and the closed-cell foamed buffer layer 20; the closed-cell foamed buffer layer 20 is made of ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, and rubber-plastic foam material, with a cell density of 50-300 cells / cm². 3The material has a water absorption rate ≤0.5%, compression resilience ≥80%, thermal conductivity ≤0.04W / (m・K), temperature resistance range -40℃~125℃, and wall thickness of 2-30mm, tightly covering the outer surface of the cable body; the rubber-plastic foam material can be replaced by polyurethane foam material; the flexible metal shielding layer 30 is a double-sided coated structure of aluminum foil, copper foil, or aluminum-plastic composite foil, with the coating material being ethylene-acrylic acid copolymer (EAA) or polyethylene (PE), tightly bonded to the closed-cell foam buffer layer through a heat sealing process, with a heat sealing temperature of 120-150℃ and a heat sealing pressure of 0.3-0.5MPa, shielding attenuation ≥60dB in the 30MHz-3GHz frequency band, metal foil thickness of 0.03-0.08mm, double-sided coating thickness of 0.02-0.05mm each, and total shielding layer wall thickness of 0.1-0.5mm; the low-smoke halogen-free outer protective layer 40 is made of low-smoke halogen-free modified PE. Made of PVC, POE, or low-smoke halogen-free PVC, it is bonded to a flexible metal shielding layer through a co-extrusion heat sealing process. The interlayer peel strength is ≥2.0N / mm, making each layer impossible to peel off. The oxygen index is ≥35%, the UV resistance rating is UV400, and the acid, alkali, and salt spray corrosion resistance meets the GB / T 2423.17 standard. The wall thickness is 0.5-3mm. The pre-compressed easy-tear cutting line 50 has a width of 0.5-1mm and a depth of 1 / 2 of the composite sheath wall thickness. After cutting, it can be resealed by buckles, self-adhesive tape, glue, or heat shrink tape. After resealing, the interlayer peel strength is ≥1.0N / mm.

[0032] ① Manufacturing process of finished sheath: The specific steps are as follows: Step S1. Preparation of closed-cell foamed buffer layer 20: Extrude ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, rubber-plastic foam material or polyurethane foam material according to the preset inner diameter (5-50mm) and wall thickness (2-30mm), and control the cell density to 50-300 cells / cm 3After cooling and shaping, cut to the preset length (1-3000 meters), ensuring water absorption rate ≤0.5%; Step S2. Flexible metal shielding layer 30 composite: Aluminum foil, copper foil, or aluminum-plastic composite foil is double-sided coated (coating material EAA or PE, thickness 0.02-0.05mm / side), and bonded to the outer surface of the closed-cell foamed buffer layer by hot air heat sealing or roller heat sealing process, controlling the heat sealing temperature at 120-150℃, heat sealing pressure at 0.3-0.5MPa, heat sealing speed at 2-3m / min, and shielding attenuation ≥60dB; Step S3. Low smoke halogen-free outer protective layer 40 co-extrusion: Select low smoke halogen-free modified PE material, POE material, or low smoke halogen-free PVC material according to the application scenario, and co-extrude the outer protective layer on the outer surface of the flexible metal shielding layer, controlling the extrusion temperature at 140-180℃ (PE material 160-180℃, POE ... For materials with a temperature of 150-170℃ (PVC material, 140-160℃), and a wall thickness of 0.5-3mm, ensure that the interlayer peel strength after bonding with the shielding layer is ≥2.0N / mm; Step S4. Pre-pressed easy-tear slit line processing: Process the pre-pressed easy-tear slit line along the axial direction of the composite sheath, controlling the width to 0.5-1mm and the depth to 1 / 2 of the sheath wall thickness, ensuring easy slit and structural integrity before processing; Step S5. Finished product inspection and packaging: Test the interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance of the composite sheath, set test marks every 500 meters, and continuously test the 3000-meter long sheath without joints. After passing the test, package according to the length requirements. Long-distance products are wound into a special large reel (diameter 1.5-2.0 meters).

[0033] ② Co-extrusion integrated sheath manufacturing process: The specific steps are as follows: Step S01. Cable body 10 extrusion: Extrude the cable body according to the standard process, keeping the surface clean and free of oil, and controlling the gap between the outer diameter and the inner diameter of the composite sheath to be 0.1-0.3mm; Step S02. Closed-cell foam buffer layer 20 extrusion: Extrude the closed-cell foam buffer layer directly onto the outer surface of the cable body, controlling the extrusion temperature and speed to ensure seamless interlayer bonding, with a wall thickness of 2-30mm and a cell density of 50-300 cells / cm³. 3Step S03. Flexible metal shielding layer 30 synchronous heat sealing: While the closed-cell foamed buffer layer is being extruded, the double-sided coated metal foil is laminated onto the outer surface of the foamed layer through a continuous heat sealing process. The heat sealing temperature is controlled at 120-150℃, and the pressure is 0.3-0.5MPa to ensure that the shielding attenuation is ≥60dB. Step S04. Low smoke halogen-free outer protective layer 40 co-extrusion and heat sealing: The outer protective layer is co-extruded on the outer surface of the flexible metal shielding layer. Simultaneously, the layers are tightly sealed to the cable body through a ferrule heat sealing process. The heat sealing temperature is controlled at 130-160℃, and the pressure is 0.4-0.6MPa. The interlayer peel strength is ≥2.0N / mm. Step S05. Pre-pressed easy-tear slit line 50 processing: The pre-pressed easy-tear slit line is processed along the sheath axis. The width is controlled at 0.5-1mm, and the depth is 1 / 2 of the sheath wall thickness to ensure easy cutting and structural integrity before processing. Step S06. Finished product cutting and inspection: Cut the cable to the preset length (1-3000 meters) and conduct overall performance testing, including interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance. Once the test is passed, it is considered a finished product.

[0034] Example 1: Preparation of finished sheath for through-type cables and its application in the renovation of old cables on high-speed railway tracks 1. Preparation parameters: Closed-cell foamed buffer layer 20: XPE foam material is selected, with a cell density of 200 cells / cm³. 3 5mm wall thickness, 20mm inner diameter, 300m length; Flexible metal shielding layer 30: 0.05mm thick aluminum foil, double-sided EAA material coating, coating thickness 0.03mm / side, heat sealing temperature 135℃, pressure 0.4MPa, shielding attenuation ≥70dB; Low smoke halogen-free outer protective layer 40: POE material, 2mm wall thickness, oxygen index 38%, Shore hardness 55A; Pre-pressed easy-tear cutting line 50: 0.8mm wide, depth is 1 / 2 (3.75mm) of the sheath wall thickness (7.5mm).

[0035] 2. Manufacturing process: Follow the manufacturing process S1-S5 for the finished sheath. For a 300-meter-long sheath, set a test mark every 50 meters. Test the interlayer peel strength ≥2.2N / mm, shielding attenuation ≥70dB, and seal after the waterproof performance meets the standard.

[0036] 3. On-site installation: First, clean the surface of the high-speed rail track signal transmission cable (19.8mm in diameter) to remove oil and impurities; then, cut open the composite sheath along the easy-tear slit line, insert it into the cable at the preset position and calibrate it (as shown in Figure 1); then, use heat shrink tubing to seal and fix both ends of the sheath, and ensure no gaps after heat shrinking; finally, use special clips to reseal the easy-tear slit line, and the peel strength after resealing is ≥1.2N / mm.

[0037] 4. Application Effects: This composite sheath can withstand the mechanical vibration of high-speed rail tracks at 5-50Hz, with significant shock absorption and an 80% reduction in stress damage to the cable itself; the high elasticity of the POE material allows the sheath to bend to a radius of 8 times the cable diameter, making it suitable for complex track wiring paths; it is resistant to outdoor high and low temperatures of -40℃ to 80℃, has low smoke and halogen-free flame retardancy, meets the fire safety requirements of high-speed rail public places, and has strong interlayer adhesion, showing no peeling or water ingress after 6 months of use.

[0038] Example 2: Preparation of Co-extruded Integrated Sheath and its Application in Underground Direct-Buried Communication Optical Cables 1. Manufacturing parameters: Cable 10 body: underground communication optical cable, diameter 12mm; Closed-cell foam buffer layer 20: polyurethane foam material, cell density 180 cells / cm³ 3 8mm thick wall, moisture resistant; Flexible metal shielding layer 30: 0.06mm thick aluminum-plastic composite foil, double-sided PE coating, coating thickness 0.04mm / side, heat sealing temperature 140℃, pressure 0.45MPa, shielding attenuation ≥65dB; Low smoke halogen-free outer protective layer 40: low smoke halogen-free modified PE material, 3mm thick wall, tensile strength ≥12MPa, resistant to soil corrosion; Pre-pressed easy-tear slit line 50: 1.0mm wide, depth is 1 / 2 (5.5mm) of the sheath wall thickness (11mm); Cable length: 3000 meters (continuous without joints).

[0039] 2. Manufacturing process: The manufacturing process of the co-extrusion integral molding sheath is carried out according to S01-S06. The heat sealing temperature and pressure of each layer are controlled to ensure that the interlayer peel strength is ≥2.0N / mm. The shielding attenuation and waterproof performance of the 3000-meter long cable are tested every 500 meters. After the overall test is qualified, it is wound into a large coil.

[0040] 3. Application Effects: The 3000-meter continuous seamless structure avoids water ingress and corrosion problems at the splicing points, improving the consistency of protection by 90%; the polyurethane closed-cell foam layer has a water absorption rate of ≤0.3%, effectively blocking groundwater; the modified PE outer protective layer is resistant to soil corrosion and can withstand minor impacts from mechanical excavation; during construction, it is deployed using a laying frame and completed in one go, increasing construction efficiency by 6 times compared to traditional short-section protective sleeves, meeting the long-term protection needs of underground pipelines for 5-10 years.

[0041] Example 3: Preparation of finished sheath for through-type cable protection and its application in shipboard cabins 1. Preparation parameters: Closed-cell foamed buffer layer 20: Polyurethane foam material is selected, with a cell density of 150 cells / cm³. 34mm thick wall, resistant to seawater moisture; Flexible metal shielding layer 30: 0.05mm thick aluminum foil, double-sided coated with EAA material, coating thickness 0.03mm / side, heat sealing temperature 135℃, pressure 0.4MPa, shielding attenuation ≥65dB; Low smoke halogen-free outer protective layer 40: POE material, 2mm thick wall, resistant to seawater corrosion, tensile strength ≥10MPa; Pre-pressed easy-tear slit line 50: 0.6mm wide, depth is 1 / 2 (3mm) of the sheath wall thickness (6mm); Length: 500 meters.

[0042] 2. Preparation and installation: Prepared according to the sleeve process of Example 1. When installing cables in the ship's cabin, after passing them through the sleeve along the cut line, seal them with self-adhesive tape and seal both ends with buckles.

[0043] 3. Application effect: The composite sheath is firmly bonded to the cable body. After being tested by ship turbulence and vibration (10-50Hz, continuous for 24 hours), there is no loosening between layers. After being soaked in seawater for 72 hours, no water seeps into the layers and the cable insulation performance remains unchanged. The high elasticity of POE material is adapted to the bending requirements of ship cabin wiring, the low smoke and halogen-free characteristics meet ship fire protection standards, and the shielding layer effectively resists electromagnetic interference from ship equipment.

[0044] Example 4: Preparation of finished sheath for insulated cables and its application in indoor computer room cable protection 1. Preparation parameters: Closed-cell foamed buffer layer 20: EPE foam material is selected, with a cell density of 120 cells / cm³. 3 1. Wall thickness 2mm, shock absorption and collision protection; Flexible metal shielding layer 30: 0.04mm thick aluminum foil, double-sided PE coating, coating thickness 0.02mm / side, heat sealing temperature 125℃, pressure 0.35MPa, shielding attenuation ≥60dB; Low smoke halogen-free outer protective layer 40: low smoke halogen-free PVC material, wall thickness 1mm, oxygen index 38%, smoke density level ≤45; Pre-pressed easy-tear cutting line 50: width 0.5mm, depth is 1 / 2 (1.75mm) of the sheath wall thickness (3.5mm); length: 50 meters, color: light gray.

[0045] 2. Preparation and installation: Prepared according to the sleeve process in Example 1. When wiring in the computer room, it is sleeved on the outside of the data cable, and both ends are sealed with waterproof tape. The cut line is resealed with self-adhesive tape.

[0046] 3. Application effects: Low-smoke halogen-free PVC material is wear-resistant and easy to clean, making it suitable for computer room cabling environments; it releases no toxic gases when burning and has low smoke density, meeting the fire safety requirements of computer rooms; the shielding layer effectively resists electromagnetic interference from computer room equipment, ensuring stable data transmission; the EPE foam layer provides shock absorption and collision protection, protecting cables from mechanical damage during construction or daily maintenance.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A composite sheath for cables that can be threaded through and split open, characterized in that, include: Cable (10), closed-cell foam buffer layer (20) sleeved on cable (10), flexible metal shield layer (30) sleeved on closed-cell foam buffer layer (20), low smoke halogen-free outer protective layer (40) sleeved on flexible metal shield layer (30), and pre-compressed easy-tear cutting line (50) opened on low smoke halogen-free outer protective layer (40), flexible metal shield layer (30) and closed-cell foam buffer layer (20).

2. The composite sheath for a cable that can be threaded through and split open according to claim 1, characterized in that, The closed-cell foamed buffer layer (20) is made of ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, and rubber-plastic foam material, with a cell density of 50-300 cells / cm³. 3 Water absorption rate ≤0.5%, compression resilience ≥80%, thermal conductivity ≤0.04W / (m・K), temperature resistance range -40℃~125℃, wall thickness 2-30mm, tightly wrapped around the outer surface of the cable body; the rubber and plastic foam material can be replaced by polyurethane foam material.

3. The composite sheath for a cable that can be threaded through and split open according to claim 1, characterized in that, The flexible metal shielding layer (30) is a double-sided coated structure of aluminum foil, copper foil or aluminum-plastic composite foil. The coating material is ethylene-acrylic acid copolymer (EAA) or polyethylene (PE). It is tightly bonded to the closed-cell foam buffer layer by heat sealing process. The heat sealing temperature is 120-150℃, the heat sealing pressure is 0.3-0.5MPa, the shielding attenuation in the 30MHz-3GHz frequency band is ≥60dB, the metal foil thickness is 0.03-0.08mm, the double-sided coating thickness is 0.02-0.05mm, and the total wall thickness of the shielding layer is 0.1-0.5mm.

4. The composite sheath for a cable that can be threaded through and split as described in claim 1, characterized in that, The low-smoke halogen-free outer protective layer (40) is made of low-smoke halogen-free modified PE material, POE material or low-smoke halogen-free PVC material, and is bonded to the flexible metal shielding layer by co-extrusion heat sealing process. The interlayer peel strength is ≥2.0N / mm, making each layer impossible to peel off. The oxygen index is ≥35%, the UV resistance level is UV400, and the acid and alkali resistance and salt spray corrosion resistance meet the GB / T 2423.17 standard. The wall thickness is 0.5-3mm.

5. The composite sheath for a cable that can be threaded through and split as described in claim 1, characterized in that, The pre-compressed easy-tear cutting line (50) is 0.5-1mm wide and 1 / 2 the thickness of the composite sheath wall. After cutting, it can be resealed by buckle, self-adhesive tape, glue or heat shrink tape. After resealing, the interlayer peel strength is ≥1.0N / mm.

6. The method for preparing the composite sheath of the cable with a slub-like and slit-open sleeve according to any one of claims 1-5, characterized in that, The manufacturing process for the sheath-type finished product includes the following steps: Step S1. Preparation of closed-cell foamed buffer layer (20): Extrude ethylene-vinyl acetate copolymer foam, cross-linked polyethylene foam, rubber-plastic foam material or polyurethane foam material according to the preset inner diameter (5-50mm) and wall thickness (2-30mm), and control the cell density to 50-300 cells / cm. 3 After cooling and setting, cut to the preset length (1-3000 meters) to ensure water absorption rate ≤0.5%; Step S2. Flexible metal shielding layer (30) composite: Aluminum foil, copper foil or aluminum-plastic composite foil is coated on both sides (coating material EAA or PE, thickness 0.02-0.05mm / side), and bonded to the outer surface of closed-cell foam buffer layer by hot air heat sealing or roll heat sealing process. The heat sealing temperature is controlled at 120-150℃, the heat sealing pressure is 0.3-0.5MPa, the heat sealing speed is 2-3m / min, and the shielding attenuation is ≥60dB. Step S3. Low smoke halogen-free outer protective layer (40) co-extrusion: Select low smoke halogen-free modified PE material, POE material or low smoke halogen-free PVC material according to the application scenario, and co-extrude the outer protective layer on the outer surface of the flexible metal shielding layer. Control the extrusion temperature to 140-180℃ (PE material 160-180℃, POE material 150-170℃, PVC material 140-160℃), wall thickness 0.5-3mm, and ensure that the interlayer peel strength after bonding with the shielding layer is ≥2.0N / mm; Step S4. Pre-pressed easy-tear cutting line processing: Process the pre-pressed easy-tear cutting line along the axial direction of the composite sheath, controlling the width to 0.5-1mm and the depth to 1 / 2 of the sheath wall thickness, to ensure easy cutting and structural integrity before processing; Step S5. Finished Product Inspection and Packaging: Test the composite sheath for interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance. Set test marks every 500 meters. The 3000-meter long sheath needs to be continuously tested for jointlessness. After passing the test, package according to the length requirements. Long-distance products are wound into a special large reel (1.5-2.0 meters in diameter).

7. The method for preparing the composite sheath of the cable with a slub-like and slit-open sleeve according to any one of claims 1-5, characterized in that, The process for manufacturing a co-extruded integral sheath includes the following steps: Step S01. Cable (10) body extrusion: Extrude the cable body according to the standard process, keep the surface clean and free of oil, and control the gap between the outer diameter and the inner diameter of the composite sheath to be 0.1-0.3mm; Step S02. Extrusion of closed-cell foam buffer layer (20): Extrude the closed-cell foam buffer layer directly onto the outer surface of the cable body, control the extrusion temperature and speed to ensure seamless interlayer bonding, wall thickness 2-30mm, and cell density 50-300 cells / cm². 3 ; Step S03. Simultaneous heat sealing of flexible metal shielding layer (30): While the closed-cell foamed buffer layer is being extruded, the double-sided coated metal foil is laminated onto the outer surface of the foamed layer through a continuous heat sealing process. The heat sealing temperature is controlled at 120-150℃ and the pressure is 0.3-0.5MPa to ensure that the shielding attenuation is ≥60dB. Step S04. Low smoke halogen-free outer protective layer (40) co-extrusion and heat sealing: co-extrude the outer protective layer on the outer surface of the flexible metal shielding layer, and simultaneously achieve tight sealing of each layer with the cable body through the ferrule heat sealing process. Control the heat sealing temperature to 130-160℃, the pressure to 0.4-0.6MPa, and the interlayer peel strength to ≥2.0N / mm. Step S05. Pre-pressed easy-tear cutting line (50) processing: Process the pre-pressed easy-tear cutting line along the axial direction of the sheath, control the width to 0.5-1mm, and the depth to 1 / 2 of the sheath wall thickness, to ensure easy cutting and structural integrity when not processed; Step S06. Finished product cutting and inspection: Cut the cable to the preset length (1-3000 meters) and conduct overall performance testing, including interlayer peel strength, shielding attenuation, waterproof performance, and flame retardant performance. The finished product is obtained after passing the test.

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