Corrosion-resistant and high-temperature-resistant heat-shrinkable sleeve
By improving the hierarchical structure and port design of heat shrink tubing, the problems of temperature resistance and sealing of traditional heat shrink tubing in high temperature and corrosive environments have been solved, achieving uniform shrinkage and corrosion prevention at high temperatures, making it suitable for high temperature and high corrosion environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XUANCHENG FEIBO INTELLIGENT POWER TECH CO LTD
- Filing Date
- 2025-05-22
- Publication Date
- 2026-04-21
AI Technical Summary
Traditional heat shrink tubing has insufficient temperature resistance and chemical corrosion resistance in high-temperature and corrosive environments, and also suffers from poor interlayer bonding, insufficient shrinkage uniformity, and weak end sealing.
The outer layer is composed of a fluororubber matrix and nano-ceramic particles, the middle layer is an irradiated cross-linked polyolefin material, the inner layer is a polytetrafluoroethylene film with a pre-coated hot melt adhesive layer, and the outer layer is equipped with spiral raised reinforcing ribs. The port is designed with a stepped closing structure to ensure uniform shrinkage and sealing effect.
It achieves uniform shrinkage at high temperatures, prevents local cracking, improves wear resistance and temperature resistance, and also has anti-corrosion and sealing properties, making it suitable for high-temperature and highly corrosive environments.
Smart Images
Figure CN224153199U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat shrink tubing technology, specifically a heat shrink tubing with corrosion resistance and high temperature resistance. Background Technology
[0002] Traditional heat shrink tubing mostly uses single polyolefin materials, which lack sufficient temperature resistance (typically ≤125℃) and chemical corrosion resistance, making it difficult to meet the requirements of high-temperature and corrosive environments (such as chemical, automotive engine, and aerospace). Existing technologies improve performance by adding fillers or coatings, but these methods suffer from problems such as poor interlayer bonding, insufficient shrinkage uniformity, and weak end sealing. Utility Model Content
[0003] The purpose of this invention is to provide a heat shrink tubing with corrosion resistance and high temperature resistance to solve the problems mentioned in the background art.
[0004] The technical solution of this utility model is: a heat shrink tubing with corrosion resistance and high temperature resistance, comprising a heat shrink tubing body, wherein the heat shrink tubing body is composed of an outer layer, a middle layer and an inner layer sequentially from the outside to the inside.
[0005] The outer layer is composed of a fluororubber matrix and nano-ceramic particles dispersed therein, and the outer surface of the outer layer is provided with raised reinforcing ribs that extend spirally along the axial direction.
[0006] The intermediate layer is an irradiated cross-linked polyolefin material;
[0007] The inner layer is a polytetrafluoroethylene film, and the inner wall of the inner layer is pre-coated with a hot melt adhesive layer.
[0008] The effects achieved by the above components are as follows: the synergistic effect of the outer layer (fluororubber matrix + nano-ceramic particles) and the raised reinforcing ribs ensures that the heat shrink tubing shrinks evenly along the spiral angle when shrinking at high temperatures, avoiding local cracking caused by stress concentration. At the same time, the nano-ceramic particles improve the wear resistance and temperature resistance of the outer layer; the middle layer (irradiated cross-linked polyolefin) maintains the shape stability after shrinkage through the cross-linked structure, preventing interlayer peeling caused by mechanical external forces; when the inner layer (PTFE film + hot melt adhesive layer) shrinks under heat, the hot melt adhesive layer melts and adheres to the cable surface, and the PTFE film blocks the penetration of corrosive media, achieving a dual effect of corrosion prevention and sealing.
[0009] Preferably, the heat shrink tubing body has ports with a stepped closing structure at both ends. The ports include at least two steps, with a height difference of 0.5-1mm between adjacent steps, and the interference fit between the inner diameter of the innermost step and the outer diameter of the cable is 0.2-0.5mm.
[0010] The effect achieved by the above components is as follows: during the shrinkage process, the outer step shrinks first to form a preliminary seal, and the inner step shrinks subsequently and interferes with the cable to form a step-by-step seal; the interference fit ensures that the hot melt adhesive layer is evenly overflowed under pressure, filling the tiny gaps on the cable surface, solving the problem of easy leakage at the port of traditional flat sleeve, and is suitable for working conditions with frequent vibration (such as automotive wiring harnesses).
[0011] Preferably, the nano-ceramic particles in the outer layer are alumina or silicon carbide, with a particle size of 50-100 nm and a mass percentage of 15%-25%.
[0012] The effects achieved by the above components are as follows: nano-ceramic particles are uniformly dispersed in the fluororubber matrix, filling the micropores inside the material and reducing gas permeability; the high proportion of ceramic particles improves the thermal conductivity of the outer layer, accelerates heat transfer during shrinkage, and at the same time improves creep resistance, enhancing the dimensional stability and chemical corrosion resistance of the sleeve at a high temperature of 200℃.
[0013] Preferably, the height of the raised reinforcing rib is 0.3-0.8mm, and the distance between adjacent raised ribs is 2-5mm.
[0014] The effect achieved by the above components is to balance the mechanical protection and shrinkage uniformity of the sleeve, and reduce surface wrinkles after installation.
[0015] Preferably, the hot melt adhesive layer on the inner layer is an epoxy resin-based hot melt adhesive with a pre-coating thickness of 10-30 μm and a melting point range of 120℃-150℃.
[0016] The effects achieved by the above components are as follows: the adhesive layer thickness of 10-30μm can ensure sealing while avoiding excessive thickness that would delay heat conduction; the melting point of 120℃-150℃ matches the shrinkage temperature of the irradiated cross-linked polyolefin of the intermediate layer (usually ≥110℃), ensuring that the intermediate layer has begun to shrink and set when the adhesive layer melts, preventing interlayer misalignment caused by premature softening of the hot melt adhesive, and improving the sealing and bonding strength.
[0017] Preferably, the irradiated cross-linked polyolefin of the intermediate layer is low-density polyethylene cross-linked by ultraviolet light irradiation.
[0018] The effects achieved by the above components are as follows: compared with electron beam irradiation, ultraviolet light irradiation can precisely control the degree of crosslinking (70%-85%), avoiding embrittlement caused by excessive crosslinking. The LDPE substrate gives the middle layer high flexibility, which complements the rigidity of the outer fluororubber layer. While maintaining insulation performance, it enhances the heat shrink tubing body's resistance to repeated bending, making it suitable for dynamic wiring scenarios.
[0019] This utility model provides a heat shrink tubing with corrosion resistance and high temperature resistance through improvements, which has the following improvements and advantages compared with the prior art:
[0020] Firstly, this utility model, through the synergistic effect of the outer layer and the raised reinforcing ribs, enables the heat shrink tubing body to shrink uniformly along the spiral angle when shrinking at high temperature, avoiding local cracking caused by stress concentration. At the same time, the nano-ceramic particles improve the wear resistance and temperature resistance of the outer layer; the middle layer (irradiated cross-linked polyolefin) maintains the shape stability after shrinkage through the cross-linked structure, preventing interlayer peeling caused by mechanical external force.
[0021] Secondly, this utility model achieves both anti-corrosion and sealing effects by melting the hot melt adhesive layer and bonding it to the cable surface when the inner layer shrinks due to heat, and blocking the penetration of corrosive media by the polytetrafluoroethylene film. Attached Figure Description
[0022] The present invention will be further explained below with reference to the accompanying drawings and embodiments:
[0023] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;
[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of this utility model.
[0025] Explanation of reference numerals in the attached figures:
[0026] 1. Heat shrink tubing body; 2. Raised reinforcing ribs; 3. Port; 4. Outer layer; 5. Middle layer; 6. Inner layer; 7. Hot melt adhesive layer. Detailed Implementation
[0027] The present invention will now be described in detail, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.
[0028] This utility model provides an improved heat shrink tubing with corrosion resistance and high temperature resistance. The technical solution of this utility model is as follows:
[0029] In embodiments of this utility model, such as Figures 1-2As shown, a heat shrink tubing with corrosion resistance and high temperature resistance includes a heat shrink tubing body 1. The heat shrink tubing body 1 is composed of an outer layer 4, a middle layer 5, and an inner layer 6, which are sequentially laminated from the outside to the inside. The heat shrink tubing body 1 has ports 3 with a stepped closing structure at both ends. The ports 3 include at least two steps, with a height difference of 0.5-1mm between adjacent steps. The inner diameter of the innermost step has an interference fit of 0.2-0.5mm with the outer diameter of the cable. During shrinkage, the outer step shrinks first to form a preliminary seal, and the inner step shrinks subsequently to form a stepped progressive seal with the cable. The interference fit ensures that the hot melt adhesive layer 7 is evenly overflowed under pressure, filling the tiny gaps on the surface of the cable, solving the problem of easy leakage at the ports of traditional flat-mouth tubing. It is suitable for working conditions with frequent vibration (such as automotive wiring harnesses).
[0030] The outer layer 4 is composed of a fluororubber matrix and dispersed nano-ceramic particles. The outer surface of the outer layer 4 has axially spirally extending raised reinforcing ribs 2, with a height of 0.3-0.8 mm and a spacing of 2-5 mm between adjacent ribs. Higher reinforcing ribs (≥0.5 mm) can resist external mechanical scratches, while lower reinforcing ribs (≤0.5 mm) are preferred for high-flexibility applications. The 2-5 mm spacing ensures that adjacent reinforcing ribs form a continuous guide groove during contraction, preventing axial twisting of the sleeve, balancing the sleeve's mechanical protection and contraction uniformity, and reducing surface wrinkles after installation. The outer layer 4 (fluororubber matrix + nano-ceramic particles) and the raised reinforcing ribs... The synergistic effect of rib 2 ensures that the heat shrink tubing body 1 shrinks uniformly along the spiral angle during high-temperature shrinkage, avoiding local cracking caused by stress concentration. At the same time, the nano-ceramic particles enhance the wear resistance and temperature resistance of the outer layer 4. The nano-ceramic particles in the outer layer 4 are alumina or silicon carbide with a particle size of 50-100nm and a mass ratio of 15%-25%. The nano-ceramic particles are uniformly dispersed in the fluororubber matrix, filling the micropores inside the material and reducing gas permeability. The high proportion of ceramic particles enhances the thermal conductivity of the outer layer 4, accelerates heat transfer during shrinkage, and improves creep resistance, thereby enhancing the dimensional stability and chemical corrosion resistance of the tubing at a high temperature of 200℃.
[0031] The intermediate layer 5 is an irradiated cross-linked polyolefin material. The intermediate layer 5 (irradiated cross-linked polyolefin) maintains the shape stability after shrinkage through the cross-linking structure and prevents interlayer delamination caused by mechanical external force. The irradiated cross-linked polyolefin of the intermediate layer 5 is low-density polyethylene cross-linked by ultraviolet light irradiation. Compared with electron beam irradiation, ultraviolet light irradiation can precisely control the degree of cross-linking (70%-85%) and avoid embrittlement caused by excessive cross-linking. The LDPE substrate gives the intermediate layer 5 high flexibility, which complements the rigidity of the fluororubber of the outer layer 4. While maintaining the insulation performance, it enhances the heat shrink tubing body 1's resistance to repeated bending.
[0032] The inner layer 6 is a polytetrafluoroethylene (PTFE) film. The inner wall of the inner layer 6 is pre-coated with a hot melt adhesive layer 7. The hot melt adhesive layer 7 on the inner layer 6 is an epoxy resin-based hot melt adhesive with a pre-coating thickness of 10-30 μm and a melting point range of 120℃-150℃. The 10-30 μm thickness of the adhesive layer ensures sealing while avoiding excessive thickness that would delay heat conduction. The melting point of 120℃-150℃ matches the shrinkage temperature of the irradiated cross-linked polyolefin of the intermediate layer 5 (usually ≥110℃), ensuring that the intermediate layer 5 has already begun to shrink and set when the adhesive layer melts, preventing interlayer misalignment caused by premature softening of the hot melt adhesive. When the inner layer 6 (PTFE film + hot melt adhesive layer 7) shrinks due to heat, the hot melt adhesive layer 7 melts and adheres to the cable surface. The PTFE film blocks the penetration of corrosive media, achieving both anti-corrosion and sealing effects.
[0033] The working principle of the corrosion-resistant and high-temperature resistant heat shrink tubing provided by this utility model is as follows: The synergistic effect of the outer layer (fluororubber matrix + nano-ceramic particles) and the raised reinforcing ribs ensures that the heat shrink tubing body shrinks uniformly along the spiral angle when shrinking at high temperature, avoiding local cracking caused by stress concentration. At the same time, the nano-ceramic particles improve the wear resistance and temperature resistance of the outer layer. The middle layer (irradiated cross-linked polyolefin) maintains the shape stability after shrinkage through the cross-linking structure, preventing interlayer peeling caused by mechanical external force. When the inner layer (polytetrafluoroethylene film + hot melt adhesive layer) shrinks under heat, the hot melt adhesive layer melts and adheres to the cable surface. The polytetrafluoroethylene film blocks the penetration of corrosive media, achieving a dual effect of corrosion prevention and sealing. During the shrinkage process of the port 3 with a stepped closing structure, the outer step shrinks first to form a preliminary seal, and the inner step shrinks subsequently and interferes with the cable to form a stepped progressive seal. The interference fit ensures that the hot melt adhesive layer overflows evenly under pressure, filling the tiny gaps on the cable surface and solving the problem of easy leakage at the port of traditional flat-mouth tubing.
[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art 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 appended claims and their equivalents.
Claims
1. A heat shrinkable sleeve with corrosion and high temperature resistance, characterized in that: It includes a heat shrink tubing body (1), which is composed of an outer layer (4), a middle layer (5) and an inner layer (6) sequentially from the outside to the inside; The outer layer (4) is composed of a fluororubber matrix and nano-ceramic particles dispersed therein, and the outer surface of the outer layer (4) is provided with raised reinforcing ribs (2) extending spirally along the axial direction. The intermediate layer (5) is an irradiated cross-linked polyolefin material; The inner layer (6) is a polytetrafluoroethylene film, and the inner wall of the inner layer (6) is pre-coated with a hot melt adhesive layer (7).
2. A heat-shrinkable sleeve with corrosion and high temperature resistance according to claim 1, characterized in that: The heat shrink tubing body (1) has ports (3) with a stepped closing structure at both ends. The ports (3) include at least two steps with a height difference of 0.5-1mm between adjacent steps, and the interference fit between the inner diameter of the innermost step and the outer diameter of the cable is 0.2-0.5mm.
3. A heat-shrinkable sleeve with corrosion and high temperature resistance according to claim 1, characterized in that: The outer layer (4) contains nano-ceramic particles made of alumina or silicon carbide with a particle size of 50-100 nm and a mass percentage of 15%-25%.
4. A heat-shrinkable sleeve with corrosion and high temperature resistance according to claim 1, characterized in that: The height of the raised reinforcing rib (2) is 0.3-0.8mm, and the distance between adjacent raised ribs is 2-5mm.
5. A heat-shrinkable sleeve with corrosion and high temperature resistance according to claim 1, characterized in that: The hot melt adhesive layer (7) on the inner layer (6) is an epoxy resin-based hot melt adhesive with a pre-coating thickness of 10-30 μm and a melting point range of 120℃-150℃.
6. A heat-shrinkable sleeve with corrosion and high temperature resistance according to claim 1, characterized in that: The irradiated cross-linked polyolefin of the intermediate layer (5) is low-density polyethylene cross-linked by ultraviolet light irradiation.