A rodent and termite resistant composite cable and method of manufacture

Abstract

The present application relates to a kind of rat and termite composite drum cable and its manufacturing method, including cable core unit described cable core unit by multiple power line core, one optical cable, one control cable group and ground wire core is stranded;The cable core unit is covered with spiral self-locking composite armoring layer outside, the spiral self-locking composite armoring layer is made of metal strip with Ω single arch wave cross section and is spirally wrapped, the two side edges of the metal strip are respectively provided with mutually matched ridge and groove structure, gap is left between adjacent wrapping turns;Gradient repelling sheath is extruded outside the spiral self-locking composite armoring layer;At least one FBG sensing optical fiber is contained in the optical cable, and a plurality of fiber bragg gratings are written along the length direction of the cable in the FBG sensing optical fiber.The rat and termite composite drum cable of the present application, by the cooperation of gradient repelling sheath and spiral self-locking composite armoring layer, has flexibility, rat and termite prevention and intelligent early warning function.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and more specifically, to a reel cable with rodent and ant prevention, intelligent early warning and multi-functional composite characteristics suitable for port machinery, mobile equipment and other applications, and a method for manufacturing the same. Background Technology

[0002] In conventional rodent-proof cable design, one approach relies on adding repellents such as capsaicin to the sheath material. However, these repellents are volatile, and their long-term protective effect diminishes significantly. Another approach involves adding a nylon sheath or stainless steel armor layer. However, nylon sheaths reduce cable flexibility, while round steel wire armor or tightly packed steel tape armor, due to their high bending stiffness, are difficult to adapt to frequent winding conditions. Meanwhile, port equipment increasingly demands multi-signal transmission, including power, control, radio frequency, and fiber optic communication. Laying multiple cables independently not only occupies equipment space but also increases system wiring costs and maintenance difficulty. More importantly, existing products generally lack the ability to actively detect rodent gnawing behavior, typically only detecting faults after the sheath has been visibly damaged, failing to provide early warning and precise location. Therefore, developing reel cables that combine high flexibility, strong rodent-proof capabilities, multi-functional integration, and active early warning functions has become a crucial technological bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0003] To address the shortcomings of existing rodent-proof cables, such as poor flexibility, limited functionality, and lack of proactive early warning capabilities, this invention provides a rodent-proof composite reel cable and its manufacturing method.

[0004] The technical solution adopted in this invention is:

[0005] A rodent-proof composite reel cable includes a cable core unit, which is composed of multiple power cores, an optical cable, a control cable group, and a ground core twisted together.

[0006] The cable core unit is covered with a spiral self-locking composite armor layer, which is formed by spirally wrapping a metal strip with an Ω-shaped single-arch wave cross section. The two sides of the metal strip are respectively provided with mutually cooperating protruding ridges and grooves, and a gap is left between adjacent wrapping loops. When the cable is bent, the protruding ridges and grooves on the inner side of the bend engage, and the protruding ridges and grooves on the outer side of the bend separate.

[0007] The spiral self-locking composite armor layer is externally extruded with a gradient repellent sheath; the gradient repellent sheath has a concentration gradient of repellent in the thickness direction, wherein the concentration of the repellent in the outer layer is higher than that in the inner layer.

[0008] The optical cable contains at least one FBG sensing fiber, which has multiple fiber Bragg gratings etched along its length. The FBG sensing fiber is used to sense local strain in the cable caused by external forces. Preferably, the metal strip is a non-magnetic stainless steel strip with a thickness of 0.15-0.25 mm. The Ω-shaped single-arch corrugated cross-section includes a central arch and symmetrical supporting legs on both sides, with an arch height of 1.5-3.0 mm. The pitch of the spiral wrapping is 8-12 times the width of the metal strip, and the gap between adjacent wrapping loops is 0.5-1.0 mm.

[0009] Preferably, the gradient avoidance sheath includes an outer sheath layer and an inner sheath layer formed by double-layer co-extrusion, and an EVOH barrier film located between the outer sheath layer and the inner sheath layer; the thickness of the outer sheath layer accounts for 1 / 3 of the total thickness of the sheath, and the thickness of the inner sheath layer accounts for 2 / 3.

[0010] Preferably, the outer sheath layer contains capsaicin masterbatch and porous molecular sieve uniformly dispersed within it; the capsaicin masterbatch comprises 8-10 parts by weight, and the porous molecular sieve has a pore size of 0.5-1.0 nm; the inner sheath layer contains capsaicin masterbatch and capsaicin-modified bentonite dispersed within it. The capsaicin masterbatch comprises 2-3 parts by weight, and the capsaicin-modified bentonite comprises 5-8 parts by weight.

[0011] Preferably, the optical cable further includes multiple communication optical fibers, which are placed together with the FBG sensing optical fibers in an ETFE loose tube. The loose tube is provided with a stainless steel spiral armor tube and a bidirectional braided aramid fiber reinforcement layer in sequence.

[0012] Preferably, the control cable assembly includes a solid polytetrafluoroethylene (PTFE) insulated coaxial radio frequency (RF) cable and multiple control wire cores stranded around it; a silicone buffer layer with a thickness of 0.5-1.0 mm is provided between the coaxial RF cable and the control wire cores. The conductor of the control wire core is composed of multiple strands of copper foil wires twisted together, wherein the copper foil wires are formed by spirally winding flattened copper foil strips around a fiber core, and the twist pitch ratio is 4.

[0013] Preferably, the power core consists of three wires arranged in a triangle, wherein the outer diameter of the insulation layer of at least one power core is smaller than the outer diameter of the insulation layer of the other two power cores, so that the control cable group and optical cable are located near the bending neutral layer when the cable is bent.

[0014] Preferably, an inner semi-conductive buffer layer is provided between the spiral self-locking composite armor layer and the cable core unit, and the inner semi-conductive buffer layer is made of semi-conductive ethylene propylene rubber material; an outer semi-conductive layer is also provided between the gradient avoidance sheath and the spiral self-locking composite armor layer.

[0015] The fiber Bragg gratings on the FBG sensing fiber are spaced 1-2 meters apart, and each fiber Bragg grating has a different center wavelength.

[0016] Preferably, the gradient avoidance sheath is further provided with an aramid yarn braided reinforcement layer on the outside.

[0017] A method for manufacturing a rodent- and ant-proof composite reel cable includes the following steps:

[0018] S1: Prepare the power core, control core and optical cable; wherein the optical cable contains a pre-embedded FBG sensing fiber with multiple fiber Bragg gratings.

[0019] S2: Twist the control wire cores around the solid polytetrafluoroethylene insulated coaxial radio frequency cable and wrap them sequentially with aluminum-plastic composite tape and braided tinned copper wire shielding layer to form a control cable group;

[0020] S3: The power core, optical cable, control cable group, ground core and rubber core are twisted together to form a cable core unit;

[0021] S4: Extruding an inner semi-conductive buffer layer outside the cable core unit;

[0022] S5: A metal strip with an Ω-shaped single-arch wave cross section and protruding ridges and grooves on both sides is spirally wrapped around the outside of the inner semi-conductive buffer layer. The wrapping pitch is 8-12 times the width of the metal strip, and a gap of 0.5-1.0mm is left between adjacent wrapping loops to form a spiral self-locking composite armor layer.

[0023] S6: Extruding an outer semiconductive layer outside the armor layer;

[0024] S7: The inner sheath, EVOH barrier film, and outer sheath are formed in one step outside the outer semiconductive layer using a double-layer co-extrusion process to form a gradient repellent sheath; wherein the thickness of the inner sheath accounts for 2 / 3 of the total sheath thickness, and the thickness of the outer sheath accounts for 1 / 3; the inner sheath contains 2-3 parts by weight of capsaicin masterbatch and 5-8 parts by weight of capsaicin-modified bentonite; and the outer sheath contains 8-10 parts by weight of capsaicin masterbatch and contains porous molecular sieves.

[0025] S8: An aramid fiber reinforcement layer is woven on the outside of the gradient avoidance sheath.

[0026] The advantages of this invention over the prior art are:

[0027] This invention relates to a rodent- and ant-proof composite reel cable, which uses an Ω-shaped single-arch corrugated stainless steel strip to form an armor layer through a spiral wrapping method. The Ω-shaped cross-section includes a central arched portion and two supporting legs on both sides, resembling an arch bridge. When the cable is subjected to radial puncture force, the arch apex converts the point load into tensile stress along the bandwidth. Because there is only a single arch apex, the arch apex undergoes elastic flattening when the cable bends, resulting in low bending stiffness. Combined with a large-pitch gap wrapping and an edge convex-concave self-locking structure, the convex-concave interlocking on the inner side of the bend prevents excessive compression, while the outer side slides freely, which is far superior to conventional steel strip armored cables.

[0028] This invention relates to a rodent- and termite-resistant composite reel cable that combines gradient repellency with heat-triggered release, significantly extending its rodent- and termite-resistant lifespan. The invention utilizes a double-layer co-extrusion process to create a high concentration gradient on the outside and a low concentration on the inside, along with an EVOH barrier film to prevent migration. The high concentration in the outer sheath, combined with porous molecular sieves, enables slow release; even after 6 months, the surface release concentration remains above 65% of its initial value. The low concentration in the inner sheath, modified with capsaicin, is stable at room temperature. When the cable is overloaded (temperature > 60℃) or when rodents or termites cause localized high temperatures, the release rate increases, creating secondary protection. This dual-mode repellency mechanism, combining long-term slow release and enhanced heat triggering, extends the cable's effective rodent- and termite-resistant lifespan to over 5 years.

[0029] This invention relates to a rodent- and ant-proof composite reel cable. It incorporates an FBG (Fiber Bragg Grating) sensor fiber optic cable for early warning and precise location of rodent bites. The FBG sensor network is integrated into the communication optical cable, enabling dual-function multiplexing of communication and sensing. The FBG sensors are arranged every 1-2 meters along the cable length, each with a unique center wavelength. When rodents or ants begin to bite, a slight strain occurs locally in the cable, causing a shift in the FBG reflected wavelength. The demodulator can pinpoint the bite location in real time, issuing an early warning before the armor layer is penetrated, providing maintenance personnel with ample time to take repellent or repair measures. Simultaneously, the FBG can also monitor the cable's operating temperature, providing an early warning when overheating occurs due to overload, preventing the sheath from softening and being easily chewed through by rodents or ants.

[0030] This invention integrates five functions—power transmission, signal control, radio frequency communication, fiber optic communication, and intelligent sensing—into a single cable. Compared to laying multiple cables independently, it can save more than 50% of the internal space of the equipment, reduce wiring complexity and maintenance costs, and is particularly suitable for situations where the internal space of port equipment is limited.

[0031] This invention employs an asymmetric power core design, in which one core has a smaller outer diameter, placing the control cable assembly and optical cable in a bending neutral layer to reduce strain; the control core uses copper foil wire conductors; the coaxial RF cable has an external silicone buffer layer to absorb radial pressure; and the center is filled with a spiral elastic rubber core to provide anti-torsional recovery force. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the rodent-proof composite reel cable of the present invention;

[0033] Figure 2 This is a schematic diagram of the end face structure of a stainless steel strip;

[0034] Figure 3 This is a schematic diagram of the connection structure between the inner semi-conductive buffer layer and the spiral self-locking composite armor layer of the rodent-proof composite reel cable of the present invention.

[0035] Figure 4 This is a partial cross-sectional view of the inner semi-conductive buffer layer and the spiral self-locking composite armor layer of the rodent-proof composite reel cable of the present invention.

[0036] Explanation of symbols for key components in the attached diagram:

[0037] In the picture:

[0038] 1. Power conductor core; 2. Conductor shielding layer; 3. Power conductor insulation layer; 4. Semi-conductive outer shielding layer; 5. Optical cable; 6. Control conductor core; 7. Control conductor insulation layer; 8. Coaxial RF cable; 9. Silicone buffer layer; 10. Aluminum-plastic composite tape; 11. Braided tinned copper wire shielding layer; 12. Ground conductor core; 13. Spiral elastic core; 14. Inner semi-conductive buffer layer; 15. Spiral self-locking composite armor layer; 151. Raised ridge; 152. Groove; 16. Outer semi-conductive layer; 17. Gradient avoidance sheath; 17a. Inner sheath layer; 17b. EVOH barrier film; 17c. Outer sheath layer; 18. Aramid braided reinforcement layer. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0040] Appendix Figure 1-4 As can be seen, this embodiment uses three power conductors arranged in a triangle. The conductor 1 of each power conductor is a tin-plated copper conductor to enhance corrosion resistance. Outside the tin-plated copper conductor 1, a conductor shielding layer 2, a power conductor insulation layer 3, and a semi-conductive outer shielding layer 4 are sequentially formed through a three-layer co-extrusion process. The outer diameter of the insulation layer of two power conductors is 15.0 mm, and the outer diameter of the insulation layer of the third power conductor is 13.5 mm, forming an asymmetrical structure. This makes it easier for the control cable group and optical cable 5 to be located near the neutral layer when the cable is bent.

[0041] Optical cable 5 contains four single-mode communication fibers and one FBG sensing fiber. A fiber Bragg grating is etched every 1.5 meters along the length of the FBG sensing fiber, with each grating having a different center wavelength (equally spaced within the range of 1528nm-1568nm). All fibers are housed in a loose tube made of ETFE (ethylene-tetrafluoroethylene copolymer). The loose tube is covered with a 0.2mm thick stainless steel spiral armor, which is then reinforced with bidirectional braided aramid fibers.

[0042] The control cable assembly centers on a solid PTFE-insulated coaxial radio frequency cable 8, with solid PTFE insulation and an FEP outer sheath. A 0.8mm thick silicone buffer layer 9 is extruded over the coaxial radio frequency cable 8. Six control cores are stranded outside the silicone buffer layer 9. Each control core conductor 6 is composed of multiple strands of copper foil wire, formed by spirally winding rolled copper foil onto a polyester fiber core. The multiple strands of copper foil wire are stranded at a pitch ratio of 4. An FEP control core insulation layer 7 is extruded over the conductor 6. After the control cores are stranded, an aluminum-plastic composite tape 10 is wrapped around the entire assembly, followed by a tinned copper wire shielding layer 11 with a braiding density of 90%.

[0043] The ground wire core 12 is composed of a tin-plated copper wire bundle with an extruded semi-conductive ethylene propylene rubber layer.

[0044] Connect the three power cores, optical cable 5, control cable group, and ground core 12 according to... Figure 1 The cable is stranded at the indicated position, and the central gap is filled with a spiral elastic core 13 (TPU material, solid spiral strip) to make the cable structure round and improve its torsional recovery ability.

[0045] An inner semi-conductive buffer layer 14 is extruded outside the cable core. The material is semi-conductive ethylene propylene rubber with a thickness of 1.0 mm. It is used to buffer the pressure of the armor layer on the cable core and to uniformize the electric field.

[0046] The spiral self-locking composite armor layer 15 is made of 304 stainless steel strip with a thickness of 0.2mm and a width of 30mm. It is rolled into an Ω-shaped single-arch wave cross-section: the central arch is 2.0mm high, the two side support legs are 10mm long, the radius of curvature of the arch top is about 60mm, and the radius of the edge rounded corner is 0.3mm. The ends of the two side support legs are respectively rolled with a protruding ridge 151 (semi-circular, radius 0.3mm) and a groove 152 (semi-circular, radius 0.35mm). The spiral self-locking composite armor layer 15 is wrapped around the outer side of the inner semi-conductive buffer layer 14 in a spiral wrapping manner, with a wrapping pitch of 300mm and a gap of 0.8mm between two adjacent turns of steel strip. This structure allows the gap of the steel strip on the inner side of the bend to decrease when the cable is bent, and the protruding ridge and groove automatically engage and lock to prevent excessive compression; the gap on the outer side of the bend increases, allowing for compliant bending.

[0047] A semi-conductive neoprene rubber layer 16, 0.5 mm thick, is extruded outside the spiral self-locking composite armor layer 15. A gradient avoidance sheath 17 is extruded around the rubber layer 16. The gradient avoidance sheath 17 is extruded in one pass using a double-layer co-extrusion die head, consisting of an inner sheath layer 17a, an EVOH barrier film 17b, and an outer sheath layer 17c. The inner sheath layer 17a is 3.0 mm thick. The material formulation, by weight, is: 55 parts neoprene rubber, 0.3 parts stearic acid, 30 parts calcined clay, 10 parts low molecular weight polyethylene, 2.0 parts paraffin wax, 1.0 part antioxidant DDA, 2.0 parts magnesium oxide, 10 parts carbon black N550, 2.5 parts zinc oxide, 0.5 parts accelerator DM, and NA-22 accelerator. 0.3 parts, capsaicin masterbatch (50% content) 2.5 parts, capsaicin-modified bentonite 6 parts; the preparation method of the capsaicin-modified bentonite is as follows: sodium-based bentonite is dispersed in deionized water to form a suspension, heated to 60-80℃, capsaicin ethanol solution is added under stirring, the mass ratio of capsaicin to bentonite is 1:10, the pH is adjusted to 4.5-5.5, the reaction is carried out for 4-6 hours, filtered, washed, dried, and ground until the residue on a 200-mesh sieve is ≤0.5%, thus obtaining capsaicin-modified bentonite. EVOH barrier membrane 17b is 0.15mm thick and is formed into a continuous film layer through co-extrusion. Outer sheath layer 17c is 1.5mm thick. The material formulation is based on the inner sheath layer formulation, with capsaicin masterbatch increased to 9 parts and an additional 5 parts of ZSM-5 porous molecular sieve (pore size 0.7nm).

[0048] The aramid yarn braided reinforcement layer 18 is set on the outside of the gradient avoidance sheath 17. It is made of aramid yarn and is bidirectionally braided with a braiding density of 85%, forming the final outer protective layer.

[0049] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the structure of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A rodent- and ant-proof composite reel cable, characterized in that, include: The cable core unit is composed of multiple power cores, an optical cable, a control cable group, and a ground core twisted together. The cable core unit is covered with a spiral self-locking composite armor layer. The spiral self-locking composite armor layer is formed by spirally wrapping a metal strip with an Ω-shaped single-arch wave cross section. The two sides of the metal strip are respectively provided with mutually cooperating protruding ribs (151) and grooves (152) structures, and a gap is left between adjacent wrapping rings. The spiral self-locking composite armor layer is externally extruded with a gradient drive-avoiding sleeve. The optical cable contains at least one FBG sensing fiber, and the FBG sensing fiber has multiple fiber Bragg gratings inscribed along the length of the cable.

2. The rodent-proof composite reel cable according to claim 1, characterized in that, The metal strip is a non-magnetic stainless steel strip, and the Ω-shaped single-arch wave cross section includes a central arch and two symmetrical support legs.

3. The rodent-proof composite reel cable according to claim 1, characterized in that, The gradient repellent sheath includes an outer sheath layer and an inner sheath layer formed by double-layer co-extrusion, and an EVOH barrier film located between the outer sheath layer and the inner sheath layer.

4. The rodent-proof composite reel cable according to claim 3, characterized in that, The outer sheath layer contains capsaicin masterbatch and porous molecular sieves uniformly dispersed within it; the inner sheath layer contains capsaicin masterbatch and capsaicin-modified bentonite dispersed within it.

5. The rodent-proof composite reel cable according to claim 1, characterized in that, The optical cable also includes multiple communication optical fibers, which are placed together with FBG sensing optical fibers in an ETFE loose tube. The loose tube is provided with a stainless steel spiral armor tube and a bidirectional braided aramid fiber reinforcement layer in sequence.

6. The rodent-proof composite reel cable according to claim 1, characterized in that, The control cable assembly includes a solid polytetrafluoroethylene insulated coaxial radio frequency cable and multiple control wire cores twisted together on its outside; a silicone buffer layer with a thickness of 0.5-1.0 mm is provided between the coaxial radio frequency cable and the control wire cores.

7. The rodent-proof composite reel cable according to claim 1, characterized in that, The power conductor consists of three conductors arranged in a triangle, wherein the outer diameter of the insulation layer of at least one power conductor is smaller than the outer diameter of the insulation layer of the other two power conductors.

8. The rodent-proof composite reel cable according to claim 1, characterized in that, An inner semi-conductive buffer layer is provided between the spiral self-locking composite armor layer and the cable core unit. The inner semi-conductive buffer layer is made of semi-conductive ethylene propylene rubber material. An outer semi-conductive layer is also provided between the gradient avoidance sheath and the spiral self-locking composite armor layer.

9. The rodent-proof composite reel cable according to claim 1, characterized in that, The gradient avoidance sheath is also reinforced with an aramid fiber braided layer.

10. A method for manufacturing a rodent- and ant-proof composite reel cable as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Prepare the power core, control core and optical cable; wherein the optical cable contains a pre-embedded FBG sensing fiber with multiple fiber Bragg gratings. S2: Twist the control wire cores around the solid polytetrafluoroethylene insulated coaxial radio frequency cable and wrap them sequentially with aluminum-plastic composite tape and braided tinned copper wire shielding layer to form a control cable group; S3: The power core, optical cable, control cable group, ground core and rubber core are twisted together to form a cable core unit; S4: Extruding an inner semi-conductive buffer layer outside the cable core unit; S5: A metal strip with an Ω-shaped single-arch wave cross section and protruding ridges and grooves on both sides is spirally wrapped around the outside of the inner semi-conductive buffer layer. The wrapping pitch is 8-12 times the width of the metal strip, and a gap of 0.5-1.0mm is left between adjacent wrapping loops to form a spiral self-locking composite armor layer. S6: Extruding an outer semiconductive layer outside the armor layer; S7: The inner sheath, EVOH barrier film, and outer sheath are formed in one step outside the outer semiconductive layer using a double-layer co-extrusion process to form a gradient repellent sheath; wherein the thickness of the inner sheath accounts for 2 / 3 of the total sheath thickness, and the thickness of the outer sheath accounts for 1 / 3; the inner sheath contains 2-3 parts by weight of capsaicin masterbatch and 5-8 parts by weight of capsaicin-modified bentonite; and the outer sheath contains 8-10 parts by weight of capsaicin masterbatch and contains porous molecular sieves. S8: An aramid fiber reinforcement layer is woven on the outside of the gradient avoidance sheath.

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