A flame-retardant insulated cable protection tube with good tensile strength

Abstract

This utility model belongs to the field of protective tube technology, specifically a flame-retardant insulated cable protective tube with good tensile strength. It includes an outer flame-retardant layer protective tube, a reinforcing layer protective tube, an elastomer layer protective tube, and an inner insulation layer protective tube, sequentially composited from the outside to the inside. The outer flame-retardant layer protective tube has a corrugated structure continuously arranged axially on its outer side, with flame-retardant filling layer protective tubes filling the troughs of the corrugations. This utility model, by placing the corrugated structure on the outermost layer and precisely controlling the trough depth, combined with a highly elastic special plastic layer in the middle, can greatly improve the tensile strength of the protective tube, surpassing the tensile strength of traditional protective tubes. The design is more reasonable, and the inner insulation layer and insulating coating provide "double insurance" for the cable. Even when the protective tube is frequently bent and dragged at 150℃, its insulation performance remains good, completely avoiding the safety hazard of the old-style PVC protective tubes experiencing a sharp decline or even failure in insulation performance under similar conditions.

Description

Technical Field

[0001] This utility model relates to the field of protective tube technology, specifically a flame-retardant insulated cable protective tube with good tensile strength. Background Technology

[0002] Cable protection pipes are metal protective tubes with a certain mechanical strength, laid on the outer layer of cables to prevent damage. They are mainly installed at intersections where communication cables and power lines cross to prevent short circuits caused by power line breaks, which could energize communication cables and steel cables. This protects cables, switches, circuit boards, and even the entire device from burning out, and also provides some isolation against magnetic field interference from power lines.

[0003] Traditional PVC protective pipes have poor tensile strength and release toxic halogens when flame-retardant. Although some protective pipes are reinforced with glass fiber, the contradiction between axial tensile deformation and flame-retardant uniformity has not been resolved. Therefore, we propose a flame-retardant insulated cable protective pipe with better tensile strength. Utility Model Content

[0004] This utility model aims to solve one of the technical problems existing in the prior art or related technologies.

[0005] Therefore, the technical solution adopted by this utility model is as follows:

[0006] A flame-retardant insulated cable protection tube with good tensile strength includes an outer flame-retardant layer protection tube, a reinforcing layer protection tube, an elastomer layer protection tube, and an inner insulation layer protection tube, which are sequentially composited from the outside to the inside; a corrugated structure protection tube is continuously arranged along the axial direction on the outer side of the outer flame-retardant layer protection tube, and a flame-retardant filling layer protection tube is filled at the corrugation trough of the corrugated structure protection tube.

[0007] In a preferred embodiment, the present invention can be further configured such that the reinforcing layer protective tube is a glass fiber mesh structure wound at a helical angle of 45°-60°.

[0008] In a preferred embodiment, the present invention can be further configured such that the elastomeric protective tube is a thermoplastic polyurethane with a thickness accounting for 20%-30% of the total tube wall thickness.

[0009] In a preferred embodiment, the present invention can be further configured such that: an insulating coating protective tube with a conductivity of ≤10^-8S / m is provided on the outer surface of the inner insulating layer protective tube, and the insulating coating protective tube is made of fluorinated ethylene propylene copolymer.

[0010] In a preferred embodiment, the present invention can be further configured such that the corrugated protective tube has a peak spacing of 8-12 mm and a trough depth of 1.2-1.5 times the tube wall thickness.

[0011] In a preferred embodiment, this invention can be further configured such that: a mechanical interlocking structure is formed at the interface between the flame-retardant filling layer protective tube and the corrugated structure protective tube groove; the surface of the groove of the corrugated structure protective tube is provided with a laser-processed micro-pit array, the micro-pit depth being 50-80μm and the density being 200-300 pits / mm. 2 .

[0012] The above-mentioned technical solution of this utility model has the following beneficial technical effects:

[0013] 1. This utility model, by setting the corrugated structure on the outermost layer and precisely controlling the depth of the troughs, combined with the middle highly elastic special plastic layer, can greatly improve the tensile strength of the protective tube, which is superior to the tensile strength of traditional protective tubes, and the design is more reasonable.

[0014] 2. This utility model utilizes vacuum injection molding technology to mix high-efficiency flame retardant, magnesium hydroxide, and expanded graphite, and fills the corrugated structure grooves with a tight fit. Then, a laser is used to create numerous tiny pits on the surface of the grooves to firmly "lock" in the flame retardant, ensuring a uniform and stable flame retardant effect. The entire pipe can easily achieve the highest fire resistance rating, thereby greatly reducing the flame spread rate and effectively solving the contradiction that good tensile properties mean poor flame retardancy and good flame retardancy mean short length.

[0015] 3. By setting the corrugated structure on the outer layer and keeping the inner wall smooth, the resistance when the cable is pulled in the tube is very small, thereby avoiding wear on the cable sheath and ensuring safety.

[0016] 4. This utility model provides "double insurance" for the cable through the inner insulation layer and the insulation coating. Even if the protective tube is frequently bent and dragged at a high temperature of 150°C, its insulation performance is still good, completely avoiding the safety hazard of the old-fashioned PVC protective tube's insulation performance dropping sharply or even failing under similar conditions. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the flame-retardant insulated cable protection pipe with good tensile strength according to this utility model.

[0018] Figure 2 An enlarged view of the flame-retardant insulated cable protection pipe A with good tensile strength according to this utility model.

[0019] Figure label:

[0020] 1. Outer flame retardant layer; 2. Reinforcing layer; 3. Elastomer layer; 4. Inner insulation layer; 5. Corrugated structure; 6. Flame retardant filler layer; 7. Insulating coating. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features of the present utility model can be combined with each other.

[0022] It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this invention.

[0023] The following describes, with reference to the accompanying drawings, some embodiments of the present invention, providing a flame-retardant insulated cable protection tube with good tensile strength.

[0024] Combination Figures 1-2 As shown, the present invention provides a flame-retardant insulated cable protection pipe with good tensile strength, comprising an outer flame-retardant layer 1, a reinforcing layer 2, an elastomer layer 3, and an inner insulation layer 4, which are sequentially composited from the outside to the inside. The outer flame-retardant layer 1 has a corrugated structure 5 continuously arranged along the axial direction on its outer side, and the corrugated valleys of the corrugated structure 5 are filled with a flame-retardant filling layer 6. Through the four-layer composite structure + outer surface corrugation + valley filling layer, an axial tensile deformation basic structure is established, and the three functional layers have clear division of labor: inner insulation / middle elasticity / outer flame retardancy, which is a relatively reasonable design.

[0025] Furthermore, the reinforcing layer 2 is a glass fiber mesh or aramid fiber tape wound at a helical angle of 45°-60°, with a mesh count of 60-100 mesh. Preferably, the 45° angle balances the axial / circumferential strength, and the high mesh count ensures the permeability of the flame retardant.

[0026] Furthermore, the elastomer layer 3 is a thermoplastic polyurethane or a styrene-based elastomer SEBS, with a thickness accounting for 20%-30% of the total pipe wall thickness. It can provide elastic recovery force, while the buffer layer protects the inner insulation layer from cracking.

[0027] On the other hand, the outer surface of the inner insulation layer 4 is provided with an insulating coating 7 with a conductivity of ≤10^-8S / m. The coating material is fluorinated ethylene propylene copolymer. Together with the inner insulation layer 4, it provides "double insurance" for the cable. Even if the protective tube is frequently bent and dragged at a high temperature of 150℃, its insulation performance is still good, completely avoiding the safety hazard of the old-fashioned PVC protective tube's insulation performance dropping sharply or even failing under similar conditions.

[0028] Furthermore, the corrugated structure 5 has a peak spacing of 8-12 mm and a trough depth of 1.2-1.5 times the pipe wall thickness, which can optimize the tensile deformation rate and prevent excessive stretching from causing the reinforcing layer to break.

[0029] It should be noted that a mechanical interlocking structure is formed at the interface between the flame-retardant filler layer 6 and the groove of the corrugated structure 5. The surface of the groove of the corrugated structure 5 is provided with a micro-pit array generated by laser processing, with a depth of 50-80μm and a density of 200-300 pits / mm. 2 Mechanical interlocking is used to enhance the interfacial bonding force, while micro-pit storage delays the thermal decomposition of flame retardant, thereby strengthening the interface and improving the overall strength of the protective tube.

[0030] In this application, the terms "located at", "set at", "composite at", and "located in" in the protective tube stack system specifically refer to molecular / interface level bonding. The specific implementation methods include vapor deposition bonding, hot pressing bonding, solution coating-drying, plasma treatment coupling, co-extrusion casting, dip coating, and adhesive bonding. Such descriptions explicitly exclude mechanical connection forms such as welding, riveting, or screw fixing.

[0031] The above explanation of layered structures refers to the configuration relationship that can be understood and implemented by those skilled in the art based on the function of the relevant components, the context, and common knowledge. Its purpose is to clearly describe the relative positions, cooperation methods, and functional implementation paths between structures. To ensure smooth and concise reading of the manual and to facilitate understanding, no separate explanation is provided after the corresponding terms.

[0032] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A flame retardant, insulating, electrically conductive cable protection tube having improved stretchability, characterized in that, It includes an outer flame-retardant layer (1), a reinforcing layer (2), an elastomer layer (3), and an inner insulating layer (4) that are sequentially composited from the outside to the inside; The outer flame-retardant layer (1) has a continuous corrugated structure (5) along the axial direction on the outer side, and the troughs of the corrugated structure (5) are filled with a flame-retardant filling layer (6).

2. The flame-retardant insulated cable protection pipe with good tensile strength according to claim 1, characterized in that, The reinforcing layer (2) is a glass fiber mesh structure wound with a helical angle of 45°-60°.

3. The flame-retardant insulated cable protection pipe with good tensile strength according to claim 1, characterized in that, The elastomer layer (3) is thermoplastic polyurethane, and its thickness accounts for 20%-30% of the total thickness of the pipe wall.

4. The flame-retardant insulated cable protection pipe with good tensile strength according to claim 1, characterized in that, The outer surface of the inner insulation layer (4) is provided with an insulating coating (7) with a conductivity ≤10^-8S / m, and the insulating coating (7) is made of fluorinated ethylene propylene copolymer.

5. The flame-retardant insulated cable protection pipe with good tensile strength according to claim 1, characterized in that, The corrugated structure (5) has a peak spacing of 8-12 mm and a trough depth of 1.2-1.5 times the pipe wall thickness.

6. The flame-retardant insulated cable protection pipe with good tensile strength according to claim 1, characterized in that, The fire-retardant filling layer (6) forms a mechanical interlocking structure at the interface with the corrugated structure (5) groove, the groove surface of the corrugated structure (5) is provided with a laser-processed micro-pit array, the micro-pit depth is 50-80 μm, and the density is 200-300 pieces / mm 2 .

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